Fourteen cations were tested at a 1% concentration (wt:wt), as chlorides, for their effects on the biological activity of the gypsy moth, Lymantria dispar (L.), nuclear polyhedrosis virus (LdMNPV). Cupric chloride was toxic to gypsy moth larvae. Ferrous and ferric chloride were inhibitory to larval growth and development as well as to virus activity. Strontium chloride was inhibitory to virus activity but had no apparent effects on gypsy moth larvae. Six cations had little or no effect on virus activity (i.e., calcium, lanthanum, magnesium, nickel, potassium, sodium), whereas four cations (i.e., cobalt, manganese, ruthenium, zinc) acted as viral enhancers, as indicated by reductions in LC₅₀s.

The pecan weevil, Curculio caryae (Horn), is a key pest of pecans in the Southeast. Entomopathogenic nematodes have been shown to be pathogenic toward the larval stage of this pest. Before this research, only three species of nematodes had been tested against pecan weevil larvae. In this study, the virulence of the following nine species and 15 strains of nematodes toward fourth-instar pecan weevil was tested: Heterorhabditis bacteriophora Poinar (Baine, HP88, Oswego, NJ1, and Tf strains), H. indica Poinar, Karunakar & David (original and Hom1 strains), H. marelatus Liu & Berry (IN and Point Reyes strains), H. megidis Poinar, Jackson & Klein (UK211 strain), H. zealandica Poinar (NZH3 strain), Steinernema riobrave Cabanillas, Poinar & Raulston (355 strain), S. carpocapsae (Weiser) (All strain), S. feltiae (Filipjev) (SN strain), and S. glaseri (Steiner) (NJ43 strain). No significant difference in virulence was detected among nematode species or strains. Nematode-induced mortality was not significantly greater than control mortality (in any of the experiments conducted) for the following nematodes: H. bacteriophora (Baine), H. zealandica (NZH3), S. carpocapsae (All), S. feltiae (SN), S. glaseri (NJ43), and S. riobrave (355). All other nematodes caused greater mortality than the control in at least one experiment. Heterorhabditis megidis (UK211) but not H. indica (original) displayed a positive linear relationship between nematode concentration and larval mortality. Results suggested that, as pecan weevil larvae age, they may have become more resistant to infection with entomopathogenic nematodes.

Parasitism of Plutella xylostella (L.) third and fourth instars was evaluated in a cabbage field in Geneva, NY, in 1999. Over the entire season, average parasitism was 33.6% for third instars and 53.6% for fourth instars, and the main parasitoids were Diadegma insulare (Cresson) and Microplitis plutellae Muesbeck. In the early season, total parasitism was low, and mainly caused by D. insulare. However, later in the season, parasitism reached >80% for the fouth instars and 50% for the third instars. Our survey indicated that M. plutellae heavily parasitized P. xylostella, and provided higher parasitism rates than D. insulare in the late season. Comparison of these two species in laboratory bioassays indicated there were no significant differences in susceptibility to four insecticides commonly used in crucifer fields. For both parasitoids, an experience with P. xylostella on a damaged leaf increased their host-searching efficacy. Compared with M. plutellae, D. insulare was a better host-searcher both for the naive and the experienced adults. Although both parasitoids can cause high mortality rates of P. xylostella, D. insulare may be more suitable to be released in fields to enhance natural control against P. xylostella.

Effects of novobiocin, nalidixic, and oxolinic acids on the survival and development of the hymenopterous endoparasitoid Pimpla turionellae L. were investigated alone and in various combinations by rearing larvae aseptically on chemically defined synthetic diets. Effects varied with the levels and kinds of the antibiotics in the tested combinations. Among the tested antibiotics alone, only the lowest level of novobiocin enhanced the postlarval survival. Most of the combinations significantly increased the number of survivors in the postlarval developmental stages. Novobiocin in combination with nalidixic acid (6.0:2.0 mg) in the artificial diet produced a yield of 80.8% pupae and 69.4% adults, respectively. This combination also shortened the developmental time to adult emergence. Similarly, on most of the diets with combinations of the antibiotics, the development of the larvae up to adult stage was noticeably faster than those on the control diets. An ≈50% reduction in the percentages of pupae and adults was recorded by 6.0 mg of novobiocin in combination with 0.75 mg of oxolinic acid compared with the control diet. Although this combination prolonged the complete development of the insect according to other novobiocin and oxolinic acid combinations, developmental time was significantly shorter than that with control diet.

The effect of nitrogen fertilization on Aphis gossypii Glover color and size, fertility, and intrinsic rate of increase (r_m) was studied on cotton plants. Nitrogen fertilization treatments consisted of 0, 50, 100, and 150% of the agronomic recommended level. Adult and nymph densities, as well as r_m, were positively correlated with nitrogen fertilization. Aphid body length, head width, and darkness of color were recorded in populations on cotton plants fertilized with 100% nitrogen or with no nitrogen fertilization. Aphids on nitrogen-fertilized plants were significantly bigger and darker. All body size and darkness of color measurements were positively correlated with aphid fecundity. It was also found that the nutritional quality of the host plant on which the parent generation feeds has a stronger effect on the aphids than that of the quality of their own food plants. This phenomenon may dampen the effect short-term fluctuations in host plant quality have on aphid performance. Results are discussed in the context of aphid population biology, aphid–plant interactions and aphid population management.

Campylomma verbasci Meyer is a zoophytophagous mirid that feeds on small arthropods as well as apple (Malus domestica Borkhausen) fruits, causing economic damage to some cultivars. The influence of timing and prey availability on the amount of fruit damage was studied to determine whether either factor could be used to refine a management program. C. verbasci nymphs were caged on branches of fruiting ‘Golden Delicious’ apple trees during the period from bloom through early fruit set. The greatest amount of fruit damage occurred during the bloom period; little or no damage occurred after fruit reached ≈13 mm in diameter. The availability of prey did not reduce the incidence of fruit damage by C. verbasci, nor did it influence the survival of nymphs. Nymphal survival was higher, however, in cages where a blossom or fruitlet was present versus a vegetative spur. These data support the hypothesis that post petal fall insecticide applications (those made after the fruit is greater than ≈10–13 mm in diameter) are not useful in preventing economic levels of fruit damage in Washington State, and that petal fall applications would only prevent a fraction of the total amount of damage by this pest. The data from this study do not support the hypothesis that manipulating arthropod prey species of C. verbasci will prevent fruit damage. There was evidence to support the hypothesis that nymphs can survive a relatively short period (7 d) without arthropod prey.

Male lures are known for many tephritid fruit fly species and are often preferred over food bait based traps for detection trapping because of their high specificity and ability to attract flies over a wide area. Alpha-ionol has been identified as a male lure for the tephritid fruit fly Bactrocera latifrons (Hendel). The attraction of this compound to male B. latifrons individuals, however, is not as strong as is the attraction of other tephritid fruit fly species to their respective male lures. Cade oil, an essential oil produced by destructive distillation of juniper (Juniperus oxycedrus L.) twigs, synergizes the attraction of α-ionol to male B. latifrons. Catches of male B. latifrons at traps baited with a mixture of α-ionol and cade oil were more than three times greater than at traps baited with α-ionol alone. Substitution of α-ionol cade oil for α-ionol alone in detection programs could considerably improve the chance of detecting invading or incipient populations of B. latifrons. However, detection programs should not rely solely on this lure but also make use of protein baited traps as well as fruit collections. Further work with fractions of cade oil may help to identify the active ingredient(s), which could help to further improve this male lure for B. latifrons.

Adult whitefly Bemisia argentifolii Bellows & Perring trap (CC trap) catches were compared with suction type trap catches. CC trap catches were significantly correlated to the suction trap catches. Higher numbers of B. argentifolii adults were caught in CC traps oriented toward an untreated, B. argentifolii-infested, cotton field as compared with traps oriented toward Bermuda grass fields, farm roads, or fallow areas. CC trap catches at five heights above ground (from 0 to 120 cm) were significantly related to each other in choice and no-choice studies. CC trap catches were low in the Imperial and Palo Verde Valleys from late October to early June each of 1996, 1997, and 1998. Trap catches increased with increasing seasonal air temperatures and host availability. Trap catches were adversely affected by wind and rain. Abrupt trap catch increases of 40- to 50-fold for 1–2 d in late June to early July followed by abrupt decreases in adult catches suggest migrating activity of adults from other nearby crop sources.

Laboratory-reared predators, the insidious flower bug, Orius insidiosus (Say), and big-eyed bug Geocoris punctipes (Say), were exposed to 10 insecticides, including three newer insecticides with novel modes of action, using a residual insecticide bioassay. These species are important predators of several economic pests of cotton. Insecticides tested were: azinphos-methyl, imidacloprid, spinosad, tebufenozide, fipronil, endosulfan, chlorfenapyr, cyfluthrin, profenofos, and malathion. There was considerable variation in response between both species tested to the insecticides. Tebufenozide and cyfluthrin were significantly less toxic to male O. insidiosus than malathion. Tebufenozide was also significantly less toxic to female O. insidiosus than malathion. Imidacloprid, tebufenozide, and spinosad were significantly less toxic to male G. punctipes than chlorfenapyr, endosulfan, and fipronil. Spinosad, tebufenozide, and azinphos-methyl were significantly less toxic to female G. punctipes than fipronil and endosulfan. Fecundity of O. insidiosus was significantly greater in the spinosad treatment compared with other treatments including the control. Consumption of bollworm, Helicoverpa zea (Boddie), eggs by O. insidiosus was significantly lower in the fipronil, profenofos, and cyfluthrin treatments compared with other treatments including the control. Consumption of H. zea eggs by G. punctipes was significantly lower in the malathion, profenofos, endosulfan, fipronil, azinphos-methyl, and imidacloprid treatments compared with the control. Egg consumption by G. punctipes was not significantly different in the tebufenozide treatment compared with the control. The lower toxicity of spinosad to G. punctipes is consistent with other reports. Based on these results, the following insecticides are not compatible with integrated pest management of cotton pests: malathion, endosulfan, profenofos, fipronil, and cyfluthrin; while imidacloprid, tebufenozide, azinphos-methyl, and spinosad should provide pest control while sparing beneficial species.

Routes by which nontarget predatory insects can be exposed to turfgrass pesticides include topical, residual, and dietary exposure. We used each of these routes to evaluate potential lethal or sublethal effects of two novel turfgrass insecticides, imidacloprid and halofenozide, and a carbamate, bendiocarb, on survival, behavior, and fecundity of the ground beetle Harpalus pennsylvanicus DeGeer. Field-collected carabids were exposed to direct spray applications in turf plots, fed food contaminated by such applications, or exposed to irrigated or nonirrigated residues on turf cores. Halofenozide caused no apparent acute, adverse effects through topical, residual, or dietary exposure. Moreover, the viability of eggs laid by females fed halofenozide-treated food once, or continuously for 30 d, was not reduced. In contrast, topical or dietary exposure of carabids to bendiocarb inevitably was lethal. Exposure to imidacloprid by those routes caused high incidence of sublethal, neurotoxic effects including paralysis, impaired walking, and excessive grooming. Intoxicated beetles usually recovered within a few days in the laboratory, but in the field, they were shown to be highly vulnerable to predation by ants. One-time intoxication by imidacloprid did not reduce females’ fecundity or viability of eggs. There was no apparent behavioral avoidance of insecticide residues, or of insecticide-treated food. Carabids exposed to dry residues on turfgrass cores suffered high mortality from bendiocarb, and some intoxication from imidacloprid, but these effects were greatly reduced by posttreatment irrigation. Implications for predicting hazards of insecticides to beneficial invertebrates in turfgrass are discussed.

Twelve families, 26 genera, and 30 identifiable spider species were found in surveys conducted in apple orchards of western Oregon. The Salticidae, Linyphiidae, Clubionidae, Philodromidae, and Theridiidae comprised 85.56% of the total spiders collected. The most common species in order of abundance were Metaphidippus aeneolus Curtis, Spirembolus mundus Chamberlin & Ivie, Cheiracanthium inclusum (Hentz), Philodromus spectabilis Keyserling, Eris marginata (Walckenaer), and Theridion lawrencei Gertsch & Archer. Individuals of these species were collected in 50–60% of the samples and were most abundant in the month of August. The Bacillus thuringiensis-based insecticides, DiPel (100 Million International Units/100 liters) and MVP (250 ml/100 liters), summer oil (0.5–1.0 liter/100 liters), the insect growth regulator (IGR) diflubenzuron (3–12 g/100 liters), and organophosphate Phosmet (6–60 g/100 liters) were generally harmless (P > 0.05) to these spider species. Full field rates of organophosphate azinphosmethyl (25 g/100 liters) and carbamate carbaryl (60 g/100 liters) were slightly to moderately harmful (25–75% mortality). These insecticides at reduced rates (azinphosmethyl 2.5–5.0 g and carbaryl 12 g/100 liters) applied alone or in combination with DiPel and MVP, had a negligible effect. Full rates of pyrethroids esfenvalerate (2.5 g/100 liters) and permethrin (4.0 g/100 liters) were moderately to highly harmful (50–75% mortality) and their reduced rates (esfenvalerate 0.25–0.50 g and permethrin 0.4–0.8 g/100 liters) were selective to the spiders.

Validation of a feeding disruption bioassay for the detection of resistance to Bacillus thuringiensis toxin and species identification is reported using field strains of Heliothis virescens and Helicoverpa zea collected from the southern United States in 1998. Feeding disruption is measured by a lack of fecal production from larvae exposed to a diagnostic concentration of CryIAc in a blue indicator diet. The bioassay provided rapid (24 h) diagnosis of the species composition of larvae tested and also monitored for the presence of resistance in H. virescens. An additional diagnostic concentration was established for monitoring resistance in H. zea. A probit model was used to compare the fecal production responses of insect strains over a range of CryIAc doses. Probability calculations, derived from our assay results, are also presented to aid in the interpretation of future results from field trials. Integration of the feeding disruption bioassay into integrated pest management programs is discussed.

Six insecticides of different chemistries were evaluated against the cotton bollworm, Helicoverpa zea (Boddie), in non-B.t. (Deltapine ‘DP 5415’, Deltapine ‘DP 5415RR’) and transgenic Bacillus thuringiensis (Berliner) (B.t.) (Deltapine ‘NuCOTN 33B’, Deltapine ‘DP 458 B/RR’) cotton. In 1998, treatments consisted of three rates each of a pyrethroid (lambda-cyhalothrin), spinosyn (spinosad), carbamate (thiodicarb), pyrrole (chlorfenapyr), oxadiazine (indoxacarb), and avermectin (emamectin benzoate) in a nonirrigated field. In 1999, treatments consisted of three rates each of lambda-cyhalothrin, spinosad, thiodicarb, and indoxacarb in an irrigated and a nonirrigated (dryland) field. The highest rate of each insecticide corresponded to normal grower-use rates. Spinosad and thiodicarb controlled H. zea in non-B.t. cotton, whereas other materials were less effective. Even though H. zea is becoming increasingly resistant to pyrethroid insecticides, lambda-cyhalothrin was highly effective in dryland B. thuringiensis cotton. Spinosad and thiodicarb were equally effective. Data indicated that reduced rates of lambda-cyhalothrin, spinosad, and thiodicarb could be used for control of H. zea in dryland B.t. cotton systems. However, reduced rates of these insecticides in a heavily irrigated B.t. cotton system did not provide adequate control.

The potato leafhopper, Empoasca fabae (Harris), is a key pest of alfalfa, Medicago sativa L., in part because of the leafhopper’s ability to disrupt upward translocation within phloem tissues. To determine if leafhopper injury also disrupts basal translocation necessary for regrowth and perenniality of alfalfa, we used radiolabeled ¹⁴CO₂ to measure the basal transport of photoassimilates in injured and healthy plants. In one experiment, less ¹⁴C was transported to lower stem tissue of leafhopper-injured plants in comparison to the same tissue of healthy plants in early vegetative and early reproductive stages of alfalfa development. In a second experiment, less ¹⁴C was transported to lower stem, crown, and root tissues of injured plants in comparison to the same tissues of healthy, early reproductive plants. The disruption of basal transport caused by potato leafhopper may impact carbon storage and mobilization subsequent to defoliation, winter survival, and nitrogen fixation.

Crop rotation for portions of east central Illinois and northern Indiana no longer adequately protects corn (Zea mays L.) roots from western corn rootworm, Diabrotica virgifera virgifera LeConte. Seventeen growers in east central Illinois monitored western corn rootworm adults in soybean (Glycine max L.) fields with unbaited Pherocon AM traps during 1996 and 1997. In the following years (1997 and 1998), growers left untreated strips (no insecticide applied) when these fields were planted with corn. Damage to rotated corn by rootworms was more severe in untreated than in treated strips of rotated corn, ranging from minor root scarring to a full node of roots pruned. Densities of western corn rootworms in soybean fields from 1996 were significantly correlated with root injury to rotated corn the following season. Adult densities from 1997 were not significantly correlated with root injury in 1998, due to heavy precipitation throughout the spring of 1998 and extensive larval mortality. Twenty-eight additional growers volunteered in 1998 to monitor rootworm adults in soybean fields with Pherocon AM traps based on recommendations that resulted from our research efforts in 1996 and 1997. In 1999, these 28 fields were rotated to corn, and rootworm larval injury was measured in untreated strips. Based on 1996–1997 and 1998–1999 data, a regression analysis revealed that 27% of the variation in root injury to rotated corn could be explained by adult density in soybeans the previous season. We propose a sampling plan for soybean fields and a threshold for predicting western corn rootworm larval injury to rotated corn.

Two field experiments were conducted in 1995–1996 to determine if there are common yield responses among maize hybrids to larval western corn rootworm, Diabrotica virgifera virgifera LeConte injury. Three yellow dent hybrids, five white food grade dent hybrids, and a popcorn hybrid were included in the study. The minimum level of rootworm injury as measured by root damage ratings (3.2–4.2) that significantly reduced yield was similar across the hybrids included in the study. However, the pattern of yield response to different rootworm injury levels varied among hybrids. This suggests that maize hybrids may inherently differ in their ability to tolerate rootworm injury and partition biomass in response to injury and other stresses. The complex interaction among hybrid, level of injury, and other stresses suggests that a common western corn rootworm injury–yield relationship may not exist within maize.

We examined effects of aerial application of acephate (Orthene), Bacillus thuringiensis variety kurstaki Berliner (Foray), and tebufenozide (Mimic) on larval/pupal parasitoids of the Nantucket pine tip moth, Rhyacionia frustrana (Comstock), in the southwestern Georgia coastal plain. Parasitism of tip moths in acephate-treated plots was significantly lower than in untreated plots. Bacillus thuringiensis and tebufenozide showed no significant effects on parasitism. A tachinid, Lixophaga mediocris Aldrich, comprised a significantly greater proportion of emerging parasitoids in acephate-treated than in untreated control plots, whereas a chalcidid, Haltichella rhyacioniae Gahan, was less abundant in the acephate-treated plots. Acephate has a negative, but somewhat species-specific, impact on tip moth parasitism.

Anoplophora glabripennis Motschulsky, a wood borer native to Asia, was recently found in New York City and Chicago. In an attempt to eradicate these beetle populations, thousands of infested city trees have been removed. Field data from nine U.S. cities and national tree cover data were used to estimate the potential effects of A. glabripennis on urban resources through time. For the cities analyzed, the potential tree resources at risk to A. glabripennis attack based on host preferences, ranges from 12 to 61% of the city tree population, with an estimated value of $72 million–$2.3 billion per city. The corresponding canopy cover loss that would occur if all preferred host trees were killed ranges from 13–68%. The estimated maximum potential national urban impact of A. glabripennis is a loss of 34.9% of total canopy cover, 30.3% tree mortality (1.2 billion trees) and value loss of $669 billion.

We evaluated the effects of a single application of granular carbaryl made against nymphal Ixodes scapularis Say on the diversity and abundance of forest arthropods taken in pitfall traps in oak and mixed oak–pine forest sites for 12 wk after treatment in central New Jersey. Significant short-term changes in arthropod assemblages were detected immediately posttreatment. Effects were not distributed equally across taxa. Seasonal changes in numbers and diversity of forest arthropods in the study areas may have affected the impact of the acaricide in the treatment area. Comparison with control areas indicated that reductions in abundance of some arthropod taxa in the treatment area were detectable 12 wk after treatment.

The effects of azalea lace bug, Stephanitis pyrioides (Scott), feeding injury on azalea growth and development were investigated using ‘Girard’s Rose’ azaleas during a 2-yr field study in Georgia. Low, medium, and high injury treatments, which corresponded to 6, 8, and 14% maximum canopy area injury, were compared with control azaleas that received no lace bug infestation. Flower number, whole-shrub leaf and stem dry mass, and dry mass and size of new growth tissues were unaffected by treatments. In contrast, growth index measurements, a general measure of variability frequently used for horticultural differentiation, showed significant reductions for all treatments in comparison to control azaleas after 20 wk. Though not directly quantified, this apparent discrepancy may be explained as an artifact of lace bug feeding-induced leaf abscission. Growth index measurements had considerable variability and may not be the most reliable measurement of size. In July 1998, plant canopy densities among azaleas maintained in the high injury treatments were ≈15% less full than the canopies of control shrubs. Predaceous insects had a significant negative association with azalea lace bug number during the 2-yr study. Flower and new tissue production, measured destructively during two growing seasons, revealed azalea tolerance to 14% of maximum canopy area lace bug feeding-injury levels.

Field experiments were conducted to evaluate population densities and survival, developmental rate, and fecundity of grape phylloxera, Daktulosphaira vitifoliae (Fitch), as influenced by root attachment or detachment from mature, field-grown, Vitis vinifera L. grapevines through the growing season. Experiments were performed using artificial infestations of California biotype A grape phylloxera. Thirty-day bioassays on attached- and detached-roots were repeated monthly from May to September in 1997 (cultivar ‘Carignane’) and April to September in 1998 (cultivar ′Thompson Seedless′). The bioassays showed that attached roots had lower population densities than detached roots in all months of both years. Densities varied by month, tending to be higher in spring than in summer. Of the population parameters studied, survival was most influenced by attachment condition, being higher on detached than on attached roots by up to 25-fold. These results imply the importance of vine-related mortality factors to grape phylloxera population density. Influence of root attachment condition on developmental rate and fecundity was not uniform across bioassay months for either year; however, in the four out of 21 assays where there was a significant difference it favored detached roots by twofold. Fruit harvest resulted in higher survival in the July assay but not for assays in August and September; however, neither developmental rate nor fecundity was affected by harvest in any of the assays. We conclude that mortality rather than nutritional factors are most limiting for field populations on susceptible vines. This work suggests that detachment of roots as occurs with root girdling by root pathogens may increase grape phylloxera populations on infested, susceptible vines. These results imply that excised root bioassays over-estimate grape phylloxera virulence and underestimate rootstock resistance.

Field experiments were conducted to measure the effects of four commonly used turfgrass insecticides (isofenphos, diazinon, imidacloprid, halofenozide) on white grubs (Coleoptera: Scarabaeidae) and ant predators of white grub eggs. Ant populations were measured over time with canned tuna, whereas predation by the ants was measured with artificially placed Japanese beetle, Popillia japonica Newman, eggs. The effectiveness of each insecticide at controlling Japanese beetle grubs, when applied at different times during the growing season, also was measured. Isofenphos and diazinon significantly reduced both ant numbers and white grub egg predation, whereas imidacloprid and one halofenozide treatment did not significantly impact either measurement. A second halofenozide treatment significantly reduced white grub egg predation. Isofenphos and diazinon were ineffective at controlling Japanese beetle grubs when applied in June but were highly efficacious when applied in August. Evidence of enhanced biodegradation was found in plots that received both June and August applications of diazinon. Both June and August applications of imidacloprid and halofenozide provided good control of white grubs.

The efficacy of photo active dyes as insecticides depends on the ingestion of the dye by the target insect and the activity of the dye at sensitive sites or on essential chemical functions. The site of this activity in insects is not understood, but we have found that certain chemical additives enhance the toxicity of phloxine B in the Mexican fruit fly. A series of tests with commercial adjuvants was performed under laboratory conditions that demonstrated a multifold decrease in the LD₅₀ of phloxine B concentration and a decrease in the time required for photodynamic action to kill the flies. A total of 22 commercial adjuvants was tested. Of these, six were selected for evaluation under field cage conditions in comparison with a non-insecticide control bait (no treatment) and a phloxine B check bait with no adjuvant. Mortality was estimated by counting dead flies, feeding was estimated by fly counts at feeding stations, survival was estimated by trapping flies after the treatment period. In all cases the adjuvants increased the rate of mortality and decreased numbers surviving the treatment. Significant differences between adjuvants and both check and control were observed for mortality rates and the three best adjuvants, SM-9, Kinetic, and Tween60, induced significantly more mortality than the other adjuvants, the control, or the check. Feeding rates and survival rates indicated that the adjuvants increase the effectiveness of phloxine B in a predictable manner. The adjuvants appear to be active inside the insect rather than increasing the solubility of the dye in the bait medium. We propose that the addition of 1% vol:vol of the best adjuvant, Tween60 to the proteinaceous bait with 0.5% phloxine B will enhance toxicity as well as improve mixing and other characteristics of the bait.

The toxicities of the herbicide glufosinate-ammonium to three predatory insect and two predatory mite species of Tetranychus urticae Koch were determined in the laboratory by the direct contact application. At a concentration of 540 ppm (a field application rate for weed control in apple orchards), glufosinate-ammonium was almost nontoxic to eggs of Amblyseius womersleyi Schicha, Phytoseiulus persimilis Athias-Henriot, and T. urticae but highly toxic to nymphs and adults of these three mite species, indicating that a common mode of action between predatory and phytophagous mites might be involved. In tests with predatory insects using 540 ppm, glufosinate-ammonium revealed little or no harm to larvae and pupae of Chrysopa pallens Rambur but was slightly harmful to eggs (71.2% mortality), nymphs (65.0% mortality), and adults (57.7% mortality) of Orius strigicollis Poppius. The herbicide showed no direct effect on eggs and adults of Harmonia axyridis (Pallas) but was harmful, slightly harmful, and harmless to first instars (100% mortality), fourth instars (51.1% mortality), and pupae (24.5% mortality), respectively. The larvae and nymphs of predators died within 12 h after treatment, suggesting that the larvicidal and nymphicidal action may be attributable to a direct effect rather than an inhibitory action of chitin synthesis. On the basis of our data, glufosinate-ammonium caused smaller effects on test predators than on T. urticae with the exception of P. persimilis, although the mechanism or cause of selectivity remains unknown. Glufosinate-ammonium merits further study as a key component of integrated pest management.

Newly acquired Ulmus species from the temperate regions of China growing at The Morton Arboretum, Lisle, IL, were evaluated in laboratory bioassays for feeding preference and suitability for larvae and adults of the elm leaf beetle, Pyrrhalta luteola (Müller). Larval and adult no-choice and adult multiple-choice feeding studies revealed that U. changii, U. lanceaefolia, U. prunifolia, U. pseudopropinqua, and U. taihangshanensis were the least suitable for feeding and reproduction by the elm leaf beetle. Ulmus wallichiana and the highly preferred U. pumila were more suitable for feeding and reproduction. Suitability had no significant effect on male and female longevity. The least suitable species of U. changii, U. lanceaefolia, U. prunifolia, U. pseudopropinqua, and U. taihangshanensis show promise for future elm breeding programs.

Essential oils of Artemisia absinthium L. and Tanacetum vulgare L. were extracted by three methods, a microwave assisted process (MAP), distillation in water (DW) and direct steam distillation (DSD), and tested for their relative toxicity as contact acaricides to the twospotted spider mite, Tetranychus urticae Koch. All three extracts of A. absinthium and of T. vulgare were lethal to the spider mite but to variable degrees. The LC₅₀ obtained from the DSD oil of A. absinthium was significantly lower (0.04 mg/cm²) than that of the MAP (0.13 mg/cm²) and DW (0.13 mg/cm²) oil of this plant species. DSD and DW extracts of T. vulgare were more toxic (75.6 and 60.4% mite mortality, respectively, at 4% concentration) to the spider mite than the MAP extract (16.7% mite mortality at 4% concentration). Chromatographic analysis indicated differences in composition between the more toxic DSD oil of A. absinthium and the other two extracts of this plant, indicating that a sesquiterpene (C₁₅H₂₄) compound present in the DSD oil and absent in the other two may enhance the toxicity of the DSD oil. Chemical analysis of the T. vulgare extracts indicated that β-thujone is by far the major compound of the oil (>87.6%) and probably contributes significantly to the acaricidal activity of the oil.

Laboratory studies were conducted to assess tomato, Lycopersicon esculentum Mill. (Solanaceae), quality in relation to the level of buzz-pollination by bumble bees. Studies were conducted in commercial tomato greenhouses in the Leamington, Ontario, area to categorize bruising of tomato anther cones by bumble bees into five levels of bruising. The number of pollen grains per stigma was determined for each bruising level, and the bruising level was found to be a good predictor of stigmatic pollen load. Experimental flowers were pollinated by bumble bees and assigned to bruising levels based on the degree of anther cone discoloration. Fruit set, tomato weight, minimum diameter, the number of days until ripe, roundness, weight, percentage sugars, and number of seeds were assessed and compared among bruising level. Fruit set in flowers receiving no pollination visits was 30.2%, whereas, 83.3, 84.4, 81.2, and 100% of the flowers set fruit in bruising levels 1, 2, 3, and 4, respectively. Minimum diameter, number of seeds, and tomato weight all increased from no bruising to different levels of bruising. There was no increase in weight or diameter above a bruising level of 1, and no increase in the number of seeds per fruit after a bruising level of 2. We found that pollination of tomato flowers greater than a bruising level of 2 (corresponding to approximately one to two bee visits) did not result in a significant increase in quality.

A range of infestation levels of the whitefly Bemisia argentifolii Bellows & Perring were established across experimental field plots of cantaloupe by varying insecticide treatments to evaluate the relationships between whitefly density and crop yield and quality. High levels of whitefly adults and immatures were associated with significant reductions in fruit yield, a decrease in fruit size, and an increase in the percentage of fruits with sooty mold. Yield loss rates (kg/ha/adult or nymph) decreased in a nonlinear fashion with increasing whitefly numbers. Estimated economic injury levels varied as a function of whitefly density, whitefly stage, control cost, crop cultivar, and crop season. Estimates of economic injury levels for one ($31.2/ha), five ($156/ha), and 10 ($312/ha) insecticide treatments ranged from 0.02 to 0.39, from 0.12 to 1.96, and from 0.24 to 3.92 adults/leaf, and from 0.20 to 5.43, from 0.98 to 27.17, and from 1.97 to 54.35 nymphs/6.45 cm², respectively.

Action thresholds, based on the percentage of plants infested, for the lepidopteran pest complex in fresh-market cabbage Brassica oleracea variety capitata were evaluated in 1996 and 1997 in southern Minnesota. Three lepidopteran pests are common in Minnesota, including the imported cabbageworm, Pieris (=Artogeia) rapae (L.), diamondback moth, Plutella xylostella (L.), and the cabbage looper, Trichoplusia ni (Hübner). Most of the thresholds tested included all three pests. However, because T. ni is often the most consistent and damaging pest in Minnesota, two thresholds were based solely on the percentage of plants infested with T. ni eggs and larvae. Action thresholds were also evaluated for their compatibility with a recently labeled biologically based insecticide, spinosad, and a conventional pyrethroid, permethrin. Although all three lepidopteran pests were present in both years of the study, P. rapae provided most of the pest pressure in 1996, and T. ni was most abundant in 1997. Compared with the 0% larval infestation treatment (approximately weekly sprays from early heading to harvest), all action thresholds resulted in less insecticide use (17–80%), while maintaining high levels of marketability. Despite variable pest pressure between years, one of the thresholds based solely on T. ni (10% of plants infested with eggs or larvae) performed as well as each of the thresholds based on all three species combined. For both years, and compared with a weekly spray schedule from early heading to harvest (average of 5.5 sprays per year), use of the 10% T. ni egg or larval threshold resulted in an average of 36.5% (3.5 sprays) and 65% (2.0 sprays) fewer applications of spinosad and permethrin, respectively, with no significant loss in marketability. The results indicate that a variety of incidence-based action thresholds can be used to ensure the production of high-quality cabbage in the midwestern United States with only minimal applications of spinosad or permethrin.

Field studies were done in 1995–1996 to assess the efficacy of three sweet corn hybrids that express the Bacillus thuringiensis (Bt) toxin, Cry1Ab, against two lepidopteran pests, Ostrinia nubilalis (Hübner) and Helicoverpa zea (Boddie). The Bt hybrids tested were developed by Novartis Seeds, using the event BT-11, which expresses Bt toxin in green tissue as well as reproductive tissues including the tassel, silk, and kernel. Bt hybrids were compared with a standard non-Bt control or the non-Bt isoline for each hybrid; none of the hybrids were treated with insecticides during the study. Hybrid efficacy was based on larval control of each pest, as well as plant or ear damage associated with each pest. In both years, control of O. nubilalis larvae in primary ears of all Bt hybrids was 99–100% compared with the appropriate non-Bt check. Plant damage was also significantly reduced in all Bt hybrids. In 1996, control of H. zea in Bt hybrids ranged from 85 to 88% when compared with the appropriate non-Bt control. In 1996, a University of Minnesota experimental non-Bt hybrid (MN2 × MN3) performed as well as the Bt hybrids for control of O. nubilalis. Also, in 1996, two additional University of Minnesota experimental non-Bt hybrids (A684su X MN94 and MN2 × MN3) performed as well as Bt hybrids for percent marketable ears (ears with no damage or larvae). In addition, compared with the non-Bt hybrids, percent marketable ears were significantly higher for all Bt hybrids and in most cases ranged from 98 to 100%. By comparison, percent marketable ears for the non-Bt hybrids averaged 45.5 and 37.4% in 1995 and 1996, respectively. Results from the 2-yr study strongly suggest that Bt sweet corn hybrids will provide high levels of larval control for growers in both fresh and processing markets. Specifically, Bt sweet corn hybrids, in the absence of conventional insecticide use, provided excellent control of O. nubilalis, and very good control of H. zea. However, depending on location of specific production regions, and the associated insect pests of sweet corn in each area, some insecticide applications may still be necessary.

Experiments were conducted to test a portable trench barrier composed of an extruded, UV-retarded, PVC plastic trough, designed to allow Colorado potato beetles, Leptinotarsa decemlineata (Say), to enter and become trapped and killed inside. Tests demonstrated that the portable plastic trenches were effective as barriers to Colorado potato beetles as they walked into tomato, Lycopersicon esculentum Mill., fields from overwintering sites in the spring. In field tests, plots that were protected by portable trench barriers had significantly fewer beetles per tomato plant, and lower levels of defoliation. Tomato yields in plots that were protected by portable trench barriers were similar to yields in plots that were protected by insecticide sprays, and significantly higher than plots where beetles were not controlled.

Lures that are used to attract German cockroaches, Blattella germanica (L.), to traps were compared in olfactometer assays in the laboratory and in trapping experiments in cockroach-infested homes and a swine farm. In olfactometer assays, AgriSense GP-2 was the most attractive lure, followed by peanut butter, and distiller’s grain. Other lures, including Trapper tablet; Victor pheromone, a crude fecal extract that ostensibly contains B. germanica aggregation pheromone; and Victor food lure elicited upwind orientation from <50% of the test insects. Peanut butter and distiller’s grain were equally attractive in trapping experiments in swine production barns and they captured significantly more cockroaches than the GP-2 tablet or the Victor pheromone lure; the commercial lures failed to attract significantly more cockroaches than the unbaited control traps. When tested against blank controls, cockroaches preferred to rest in shelters that contained the aggregation pheromone-based lure (Victor), but this lure was the least attractive to cockroaches in olfactometer assays. These results do not support claims that commercial crude fecal extracts attract cockroaches to traps, and they highlight a need for developing more attractive lures for detection of cockroaches and for monitoring populations.

Two formulations of spinosad (NAF-85 and NAF-371) were evaluated to determine the effect of concentration, deposit condition (dried, wet, or topical), and exposure time (0.1–10 h) for toxicant transfer among nestmates in the drywood termite Incisitermes snyderi (Light). Spinosad treatments were compared with two formulations of disodium octaborate tetrahydrate (DOT) (10% aqueous dilution, 98% dust) and with 35% calcium arsenate dust. Termites were dyed and individually exposed to different treatments for 0.1, 1.5, 1.0, 5.0, 10.0 h, or 0.1 and 1.0 h (DOT and calcium arsenate dust) and then placed with 10 unmarked, untreated nestmates in a petri dish. Spinosad formulations also were evaluated by topical application to dyed termites. Transfer of lethal doses of toxicants between termites was indicated by significant mortality of untreated termites in 25 of 28 treatments by 28 d after introduction of dyed, treated termites. Only three treatments, one spinosad treatment (NAF-371, wet, 1 h) and both DOT 10% solution treatments, resulted in mortality of untreated termites that was not significantly different than that of water-treated controls. Two spinosad treatments and both calcium arsenate dust treatments resulted in >90% (94–98%) mortality of untreated termites by 28 d after introduction. Mortality of untreated termites was significantly different from controls for the two spinosad formulations, depending on condition of deposit and duration of dyed termite exposure to treatments.

To investigate the genetic basis of cross-resistance to insecticides, natural populations of Drosophila melanogaster (Meigen) were first collected from four different locations in Japan. After 10–80 isofemale lines of each population had been established in a laboratory, the susceptibility of each line to each of the insecticides permethrin, malathion, fenitrothion, prothiophos, and DDT was examined. Broad ranges of continuous variation in susceptibility to all the chemicals were observed within each natural population as a whole. In addition, highly significant correlations among responses to organophosphates were observed. However, based on the coefficients of determination, about less than half of variation in responses to one insecticide could be explained by variation in responses to another insecticide, suggesting that not only a common resistance factor but also other factors could be involved in a natural population. Genetic analyses by using resistant and susceptible inbred lines from the same natural population demonstrated that resistance to organophosphates in some resistant lines could be due to a single or tightly linked factors, and that resistance in the other line may be due to more than one major factor. These observations could suggest that several resistance factors may be involved within each natural population, and that some of major factors could contribute to correlations among responses to organophosphates. These major factors could then contribute to the broad ranges of continuous variation observed at the level of the populations.

Toxicological responses to azinphosmethyl of male Oriental fruit moth, Grapholita molesta (Busck), from five commercial orchards in which control failures had occurred were examined for azinphosmethyl resistance and for potential resistance mechanisms by using topical pheromone trap bioassay and compared with a reference population that had no history of control failure and had received little selection pressure. The 1998 field survey indicated moderate level of resistance to azinphosmethyl (2.7–4.1-fold); slopes of regressions lines (2.47–2.76) indicate genetically heterogeneous populations. An approximate twofold decline was observed between the fourth flight of 1998 and the first flight of 1999, suggesting the presence of unstable resistance in moths collected from these study sites. The 1999 field surveys indicated lower levels of tolerance to azinphosmethyl. The resistance ratios ranged from 1.17 to 1.86 during the first flight of 1999 and 1.24–2.64 during the fourth flight of 1999. Steep slopes of the concentration–response lines during 1999 season indicated the presence of genetically homogeneous populations with some exceptions. A 1.5–2.0-fold increase was observed between the first and fourth flights of 1999, indicating that resistance can build up during the growing season. S,S,S,-tri-n-butyl phosphorotrithioate (DEF), but not piperonyl butoxide, significantly enhanced the toxicity of azinphosmethyl, suggesting that enhanced metabolism by esterases is involved in the tolerance of azinphosmethyl in moths collected from these study sties.

Experimental evaluation of the effectiveness of resistance management tactics is vital to help provide guidelines for the deployment of transgenic insecticidal crops. Transgenic broccoli expressing a Cry1Ac gene of Bacillus thuringiensis (Bt) and the diamondback moth, Plutella xylostella (L.), were used in greenhouse tests to evaluate the influence of size and placement of nontransgenic refuge plants on changes in resistance allele frequency and pest population growth. In the first test with an initial Cry1Ac-resistance (R) allele frequency of 0.007, P. xylostella were introduced into cages with the following treatments: 0, 3.3, 10, 20, and 100% refuge plants. Results after four generations showed that resistance could be delayed by increasing the proportion of refuge plants in the cage. Population growth was also influenced by refuge size with the highest populations occurring in treatments that had either no refuge plants or all refuge plants. In the second test, we evaluated the effect of refuge placement by comparing 20% separate and 20% mixed refuges. P. xylostella with an initial frequency of resistant alleles at 0.0125 were introduced into cages and allowed to cycle; later generations were evaluated for resistance and population growth. Separating the refuge had a pronounced effect on delaying resistance and slowing establishment of resistant larvae on Bt plants. Combining information from both trials, we found a strong negative correlation between the number of larvae on Bt plants and the mortality of the population in leaf dip bioassays. Results from larval movement studies showed that separate refuges delayed resistance better than mixed refuges because they conserved relatively more susceptible alleles than R alleles and did not increase the effective dominance of resistance.

Laboratory selection increased resistance of pink bollworm (Pectinophora gossypiella) to the Bacillus thuringiensis toxin Cry1Ac. Three selections with Cry1Ac in artificial diet increased resistance from a low level to >100-fold relative to a susceptible strain. We used artificial diet bioassays to test F₁ hybrid progeny from reciprocal crosses between resistant and susceptible strains. The similarity between F₁ progeny from the two reciprocal crosses indicates autosomal inheritance of resistance. The dominance of resistance to Cry1Ac depended on the concentration. Resistance was codominant at a low concentration of Cry1Ac, partially recessive at an intermediate concentration, and completely recessive at a high concentration. Comparison of the artificial diet results with previously reported results from greenhouse bioassays shows that the high concentration of Cry1Ac in bolls of transgenic cotton is essential for achieving functionally recessive inheritance of resistance.

Pyrethroid resistance was found in 54 field strains of Helicoverpa armigera collected between 1995 and 1999 from 23 districts in seven states of India. LD₅₀ values of the field strains ranged from 0.06 to 72.2 μg/larva with slopes of 0.5–3.1. Resistance was highest in regions where pyrethroid use was frequent (four to eight applications per season). Resistance to deltamethrin was exceptionally high with resistance ratios of 13,570 and 27,160 in two strains collected during February 1998 in central India. Resistance to cypermethrin, fenvalerate and cyhalothrin also was high with resistance ratios of >1,000 in four strains collected from central and southern India. Resistance ratios were below 100 in >50% of the strains tested. Pyrethroid resistance was high in strains collected from the districts in Andhra Pradesh where a majority of the cotton farmer suicide cases in India were reported. Resistance to pyrethroids appeared to have increased over 1995–1998 in most of the areas surveyed. Studies carried out through estimation of detoxification enzyme activity and synergists indicated that enhanced cytochrome p450 and esterase activities were probably important mechanisms for pyrethroid resistance in field strains. Pyrethroid nerve insensitivity also was found to be a major mechanism in some parts of the country where the use of pyrethroids was high. The information presented illustrates the importance of proper insect management programs to avoid the consequences associated with improper insecticide use.

A diet-incorporation larval bioassay was developed to measure the response of codling moth, Cydia pomonella (L.), to the benzoylhydrazine insecticides tebufenozide and methoxyfenozide. The bioassay tested neonates and third, fourth, and fifth instars from a laboratory colony and neonates and fourth instars from a pooled population collected from five certified-organic apple orchards. Bioassays were scored after 6 and 14 d. No differences between the laboratory and field population were found for either insecticide. Significant differences were found in the response of third and fifth instars between the 6 and 14 d bioassays, primarily due to a high proportion of moribund larvae in the shorter assay. Larval age had a significant effect in bioassays and was more pronounced in 6- versus 14-d tests. Fifth instars were significantly less susceptible to both insecticides than other stages, while responses of third and fourth instars were similar. The response of neonates was significantly different from third and fourth instars to tebufenozide but not with methoxyfenozide in the 14-d test. Field bioassays excluded the use of fifth instars and were scored after 14 d. LC₅₀s estimated for 18 field-collected populations varied five- and ninefold for tebufenozide and methoxyfenozide, respectively. The responses of all but six field-collected populations were significantly different from the laboratory strain. Five of these six populations were collected from orchards with no history of organophosphate insecticide use. The LC₅₀ for methoxyfenozide of one field-collected population reared in the laboratory for three generations declined fourfold, but was still significantly different from the laboratory population. These data suggest that transforming current codling moth management programs in Washington from a reliance on organophosphate insecticides to benzoylhydrazines may be difficult.

Two transgenic rice (Oryza sativa L.) lines, KMD1 and KMD2 at the R₄ generation, transformed with a synthetic cry1Ab gene from Bacillus thuringiensis Berliner, were first evaluated for stem borer resistance in the field during the rice growing season of 1998 in two areas of Zhejiang Province, China. Both KMD1 and KMD2 were highly resistant to the stem borers Chilo suppressalis (Walker) and Scirpophaga incertulas (Walker), and were completely undamaged during the whole rice growing season. In contrast, damage to the plants of the untransformed parental control (Xiushui 11) was in the form of deadhearts or whiteheads. Under natural infestation by the C. suppressalis, the damage to control plants reached a peak of 88.7% of plants and 20.1% of tillers encountered with deadhearts. Under artificial and natural infestation of neonate striped stem borers at the vegetative stage and booting stage, 100% of plants and 25.6% of tillers, 78.9% of plants and 15.6% of productive tillers among artificially infested control plants were observed with the symptom of deadhearts and whiteheads, respectively. Damage to the control plants from artificial infestation by the S. incertulas reached a peak of 97.0% of plants and 22.9% of tillers damaged. The field research indicated that both KMD1 and KMD2 show great potential for protecting rice from attack by these two stem borers.

Sesamia nonagrioides Lefebvre is a major insect pest of maize (Zea mays L.) in northwestern Spain. The inheritance of ear resistance in field corn to this pest has not been studied. This work aims to determine the importance of genetic (additive, dominance, and epistatic effects) and environmental effects in the inheritance of ear resistance to S. nonagrioides. Three field corn inbreds (CM109, EP31, and EP42) were used as parents and two crosses (CM109 × EP31 and CM109 × EP42) were made. These inbreds show different ear resistance levels to S. nonagrioides, with CM109 more resistant than EP31 and EP42. For each cross, parents (P₁, P₂), F₁, F₂, and backcrosses to each parent (BC₁ and BC₂) were evaluated. Correlations among ear damage traits showed that general appearance of the ear should be useful indicator of ear resistance. Ear resistance was dominant to susceptibility and was transmitted from inbreds to their hybrids. The additive-dominance model fit the generation mean analysis for both crosses and the degree of genetic control varied depending on the cross and trait. For both crosses, additive and dominance effects were significant for most ear damage traits. Epistatic gene effects were significant for husk and shank damage, and gene effects for number and length of tunnels were not significant. Because ear resistance involved additive and dominance effects for this set of inbreds, breeding procedures based on both types of gene action should be effective.

Differences in larval survival and development of bollworm, Helicoverpa zea (Boddie), and fall armyworm, Spodoptera frugiperda (J. E. Smith), respectively, were found to exist among commercially available Cry1A(c) transgenic Bacillus thuringiensis Berliner (Bt) varieties. Using a quantification assay (ELISA) to measure the levels of δ-endotoxin in two of these varieties (‘DP 451B/RR’ and ‘NuCOTN 33B’), differences in the amount of δ-endotoxin present in various plant parts was correlated with larval survival of bollworms and larval development of fall armyworms throughout the growing season. Larvae that were fed on DP 451B/RR completed development faster and exhibited better survivorship than those larvae fed NuCOTN 33B, whereas lower levels of δ-endotoxin were generally detected in plant parts from DP 451B/RR compared with NuCOTN 33B. These differences may impact population dynamics of these pests which may be a critical factor in managing resistance to Bt. Furthermore, the utility of using this system for providing information to the grower concerning varietal choices may be more common in the future.

The grape mealybug, Pseudococcus maritimus (Ehrhorn), is an important pest of table grapes in California’s San Joaquin Valley. The mealybug causes direct damage by infesting grape bunches, resulting in very low economic injury levels. To develop a sampling program to help growers predict damage and make control decisions, we destructively sampled six entire grapevines each month to determine mealybug abundance and within-vine distribution. These absolute counts were then used to evaluate several relative sampling methods: sticky tape barriers on canes, excised spur samples, standard-sized pieces of bark, timed counts, and nondestructive counts on spurs. At midseason we sampled additional vines to correlate mealybug numbers with economic damage at harvest. Finally, mealybug life stages and natural enemies were recorded throughout the study. Timed 5-min counts show the strongest correlation with total mealybug numbers, and a simple count of mealybugs on three spurs per vine at midseason is the best predictor of economic damage. Mealybugs completed ≈2.5 generations in 1998. Comparison to data on mealybug development suggests that exceptionally long growing seasons could exacerbate infestations by allowing the completion of a third generation. No mealybugs were found on bunches before early August, when second-generation crawlers moved out of the bark. Grape bunches that touched old wood had significantly higher damage and mealybug densities. The majority of mealybugs were always found in protected locations (under the bark of the trunk, spurs or canes), indicating the need for chemical or biological controls that can penetrate these refugia.

Culled bananas (dwarf ‘Brazilian’, ‘Grand Nain’, ‘Valery’, and ‘Williams’) sampled from packing houses on the islands of Hawaii, Kauai, Maui, Molokai, and Oahu identified specific “faults” that were at risk from oriental fruit fly, Bactrocera dorsalis (Hendel), infestation. Faults at risk included bunches with precociously ripened bananas, or bananas with tip rot, fused fingers, or damage that compromised skin integrity to permit fruit fly oviposition into fruit flesh. No Mediterranean fruit fly, Ceratitis capitata (Wiedemann), or melon fly, B. cucurbitae (Coquillett), infestations were found in culled banana samples. Field infestation tests indicated that mature green bananas were not susceptible to fruit fly infestation for up to 1 wk past the scheduled harvest date when attached to the plant or within 24 h after harvest. Recommendations for exporting mature green bananas from Hawaii without risk of fruit fly infestation are provided. The research reported herein resulted in a USDA-APHIS protocol for exporting mature green bananas from Hawaii.