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Feeding by the western flower thrips, Frankliniella occidentalis (Pergande), causes damage to the fruits of vegetables, and the species is the key vector of Tomato spotted wilt virus. Frankliniella tritici (Fitch) and Frankliniella bispinosa (Morgan) are not pests of fruiting vegetables. Both species compete with F. occidentalis. Effective management of F. occidentalis in pepper integrates conservation of natural populations of the predator, Orius insidiosus (Say), with the use of reduced-risk insecticides such as spinetoram for the control of western flower thrips and other pests. Naturally occurring O. insidiosus are very effective predators and their effectiveness is predictable based on the number of the predator relative to the number of thrips prey. Populations of F. occidentalis resurge when natural enemies and competing thrips are killed. Some insecticides especially pyrethroids have beneficial effects on the development and reproduction of F. occidentalis. The predator O. insidiosus does not prefer tomato, and numbers remain too low in fields to suppress thrips. Tomato growers primarily rely on the use of ultra-violet reflective mulch combined, if needed, with the use of effective insecticides. Additional management efforts are needed in the future to manage F. occidentalis and other difficult pests in space and time. Management of the pepper weevil (Anthonomus eugenii Cano) is proving a challenge to pepper growers in central and southern Florida trying at the same time to manage F. occidentalis. Growers need to emphasize sanitation and other cultural tactics over the use of broad-spectrum insecticides that kill O. insidiosus and induce F. occidentalis in other ways. The identification of thrips in scouting programs also is critical as the use of broad-spectrum insecticides against populations of the non-pest flower thrips is inducing F. occidentalis to pest status.
In the past 30 years, western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), has become one of the most important agricultural pests worldwide. Certain biological attributes of this insect predispose it to be a direct pest across a wide range of crops. In addition to the direct damage it can cause, this species is an efficient vector of Tomato spotted wilt virus and other Tospoviruses. This review addresses questions regarding the biological and ecological attributes of western flower thrips that have enabled it to become a significant pest and make it so difficult to manage. These important life history traits include western flower thrips polyphagy and a tendency to reside and feed in concealed areas of flowers and fruits. Consequently, large populations can develop and disperse into a wide range of crops. The larvae and adults feed in a similar manner and can share the same host plant resources. The relatively short generation time and haplodiploid sex determination also contribute to the pest status of this species. These life history traits interact in complex ways to make western flower thrips one of the most significant and difficult to manage pests in the world.
Flower thrips are considered key pests in southern highbush (Vaccinium corymbosum L. × V. darrowi Camp) and rabbiteye (Vaccinium ashei Reade) blueberry fields in Florida. During 2005 and 2006, we evaluated the effectiveness of selected natural enemies (preventative and curative releases) for control of flower thrips in blueberries. Experimental designs were randomized complete blocks with 4 treatments and 4 replicates in 2005 and 3 treatments and 4 replicates in 2006. In 2005, treatments were evaluated as a preventative tactic and included the following biological control agents: (1) Thripor-I [Orius insidiosus Say (Hemiptera: Anthocoridae)], (2) Thripex-plus [Amblyseius cucumeris (Oudemans) (Acari: Phytoseiidae)], (3) combination of both O. insidiosus and A. cucumeris in 50% of standard dosages, and (4) untreated control (no natural enemies). Orius. insidiosus (Thripor-I) was released at 0.5 insects per m2 and A. cucumeris (Thripex-Plus) at 0.5 sachets of 1000 mites per m2. For the combination treatment, 50% of each standard dosage was released. In 2006, treatments were evaluated as a curative technique and included (1) Thripor-I (O. insidiosus) released at 10 insects per m2, (2) Thripex-Plus, and (3) control [no natural enemies were released]. In 2005, the results indicated that thrips populations in the control were on average significantly lower than in treatments of O. insidiosus and A. cucumeris alone, implicating the potential for intraguild predation among natural enemies. In 2006, there were no significant differences among the treatments evaluated probably due to the short duration of time during which flower thrips are present in blueberry fields.
The University of Florida, IFAS, IPM Florida and Southern Plant Diagnostic Network (SPDN) are cooperatively developing education and training to increase integrated pest management (IPM) of western flower thrips (WFT), Frankliniella occidentalis (Pergande). Management of WFT is exacerbated by difficulty in identifying thrips species and by their development of insecticide resistance. Education and training will emphasize workshops on identification of thrips; insecticide resistance management protocols; description of the effects of insecticides on natural enemies, i.e., Orius spp., and use of the “Grower's IPM Guide for Florida Tomato and Pepper Production”. Thrips identification aids, such as a national field-based identification deck currently under development by the SPDN and the North Central IPM Center (NCIPMC), will be useful to Florida growers. This kind of information will be delivered through Extension programs, including workshops, in-service training, field days, and classroom education. A section of the IPM Florida website is devoted to thrips in several Florida crops (blueberry, cotton, greenhouse and nursery grown ornamentals, pepper, strawberry, tomato) and contains general information, such as (1) F. occidentalis biology and ecology, (2) management tactics incorporated into an IPM program that is crop and location specific, (3) identification of thrips and natural enemies, (4) practices that reduce damaging pest populations in space and time, (5) problems with managing F. occidentalis and other pests, (6) updated, crop and location specific information on population levels, and (7) resistance monitoring. Future needs for specific in-service or other educational programs, including advanced diagnostic training sessions, will be determined by clientele groups. Adoption of IPM for WFT will benefit growers by minimizing insecticide resistance and maximizing benefits of cultural practices and biological controls.
All parties involved in growing the world's food, including growers, crop consultants, university researchers, extension personnel, national and regional regulatory agencies, and the agrochemical and seed industry, spend significant time, money, and effort to solve the problems associated with growing food. The needs of these parties are varied and sometimes in conflict, which is not always conducive to developing and implementing integrated pest management (IPM) systems that are both sustainable and economical. IPM encompasses simultaneous management of multiple pests, regular monitoring of pests and their natural enemies and antagonists, use of economic or treatment thresholds when applying pesticides, and integrated use of multiple, suppressive tactics. IPM components with the greatest impact on resistance management are rotating classes of chemistry, use of recommended rates, not exceeding label restrictions, and avoiding sequential treatments of products with the same mode of action. The best way to insure that these components are followed is to have pesticide record keeping and reporting. However, pesticide use record keeping and reporting are not currently required in all areas. Other activities that can be integrated include educational workshops on IPM, resistance monitoring of pests to pesticides, proper identification of pests and natural enemies, real time scouting reports on the pests that are being found, maintenance of a data base on the effects of various products on natural enemies, and field validation of IPM use.
Since the first report of Florida establishment in 1982, the western flower thrips (WFT), Frankliniella occidentalis (Pergande), has caused economic damage to vegetable crops, notably peppers, Capsicum annuum L. A survey of thrips infesting peppers in Palm Beach County, FL in 2006–07 showed that WFT populations were more prevalent than in a survey conducted in 1995–96, and exceeded economic thresholds for much of the growing season. The possible contribution of pyrethroid insecticide use to damaging populations of WFT is discussed.
Three natural enemies naturally present in southern California avocado groves were evaluated against different stages of the avocado lace bug, Pseudacysta perseae (Heidemann), in the laboratory. The natural enemies tested were adult females of a predatory thrips, Franklinothrips orizabensis, second instar green lacewing larvae, Chrysoperla rufilabris, and a predaceous mite, Neoseiulus californiens. The most promising natural enemy from laboratory and subsequent greenhouse evaluations was C. rufilabris. In addition to natural enemies, insecticides were evaluated for P. perseae control. The contact impact of less persistent materials on nymphs in the laboratory was assessed. The most effective insecticides based on residual impact studies were carbaryl, imidacloprid, and fenpropathrin, and 2 materials commonly used on avocados in California, abamectin and spinosad, which were ineffective. Among the insecticides evaluated based on contact activity, a pyrethrin mixture was the best treatment followed by petroleum oil and potash soap. The contact insecticides were evaluated for their impact on second instars of C. rufilabris. The pyrethrin mixture was less toxic to C. rufilabris, and because of its low mammalian toxicity this insecticide may be suitable for use with natural enemy releases for homeowners to manage P. perseae populations on backyard avocados.
The mature larvae of Bembix bidentata and one of its chrysidid and mutillid parasitoids are described and illustrated, and structures of phylogenetic value are discussed. The mature larva of B. bidentata is characterized by an integument with short setae (< 40 µm) and scanty microspinules. The ratio between the length of the antennal papilla and the width of the antennal orbit is a character state that can be used in the separation of the final instar of European Bembix species. The mature larva of Chrysidea disclusa is characterized by a combination of two character states: (1) an atrium without asperities or weak lines on the circumference, and (2) antennal papillae longer than broad; the larval morphology of Chrysidea previously was unknown. The mature larva of Chrysura hybrida is characterized, within the genus Chrysura, by the autapomorphy “maxillary palpus with 4 sensilla at apex.” The range of hosts of Chrysura spp. is broadened to the Crabronidae. The mature larva of Smicromyrme rufipes is characterized, within the Mutillinae, by having more than 8 apical setae and no apical papillae on the labium.
The Asian plant bug Stethoconus praefectus (Distant) (Heteroptera: Miridae) was recently discovered in Florida preying on the avocado lace bug, Pseudacysta perseae (Heidemann) (Heteroptera: Tingidae). Its life cycle and effectiveness as a predator of P. perseae were investigated at 26 ±I°C, 60 ± 5 RH, and 12: 12 (L: D) under laboratory conditions. Stethoconus praefectus developed from egg to adult in 16.5 ± 0.2 d. On average, the first 4 instars consumed 2 to 4 prey per day, whereas the last 2 instars consumed 2 to 7 lace bugs per day. Stethoconus praefectus was observed in the field from Aug through Dec 2007.
Larra bicolor F. (Hymenoptera: Crabronidae) is a specialist parasitoid of Scapteriscus (Orthoptera: Gryllotalpidae) mole crickets, attacking adults and medium to large nymphs. Reproductive systems were dissected from 10 female wasps collected in northern Florida. Each had 2 ovaries, each with 3 ovarioles. The maximal number of mature eggs (10) plus developing oocytes (83) was 93. Female wasps deposit an egg on the venter of the host's thorax, and the wasp larva develops as an ectoparasitoid. Twenty newly-emerged female wasps housed in small cages with at least 1 male and with 7 potential hosts replaced daily deposited a mean 2.44 eggs (range 0–10) per day for a total lifetime production averaging 56 eggs (range 17–91) during a lifespan averaging 23.5 d (range 8–40). Assuming 3 wasp generations with fecundity as shown to 1 host generation, per year, the wasp should easily be able to outreproduce its host mole crickets. A few of the hosts became superparasitized with 2 or even 3 eggs, but at most 1 larva of L. bicolor developed successfully on each host, so superparasitism is a disadvantage; its incidence in the laboratory (<2%) and field (3%) was low.
Two new species of the genus Aulacorthum, Aulacorthum asteriphagumsp. nov. and Aulacorthum corydalicolasp. nov., are recognized from Korea on Aster scaber Thunb. and Corydalis spp. (C. pallida Pers. and C. speciosa Maxim.), respectively. They are described and illustrated in comparison with the closely related species Aulacorthum solaniKaltenbach 1843. Aulacorthum asteriphagum is mainly characterized by many secondary rhinaria (4–12) on Antenna III, and A. corydalicola is distinguished by short antennae (2.30–2.75 mm) including dark Antenna III. A revised key to the identification of the Korean species of Aulacorthum is presented.
Experiments were conducted at 3 sites in Florida to determine whether landscape fabric, used as soil mulch, can reduce damage to citrus trees by Diaprepes abbreviates. The mulches were intended to prevent newly hatched weevil larvae from entering the soil to feed on roots and to prevent teneral adult weevils from exiting the soil to initiate egg-laying. The weight of aboveground parts of trees at a site heavily infested by D. abbreviatus on the east coast was 70% larger (P ≤ 0.05) for trees grown for 3 years on mulched compared to unmulched soil. Mulching did not affect the amount of feeding damage to roots at the east coast site, suggesting that mulched trees tolerated the damage better than trees in bare soil. Small plot size and relatively narrow fabric dimensions at the east coast site may have facilitated the entry of neonate larvae into soil. At a site on the Central Ridge with low weevil population density, average trunk cross-sectional area of 5-year-old mulched trees was 31% greater (P < 0.02) than trees in bare soil. At both this site and a central flatwoods site, the number of adult weevils captured in ground traps that catch weevils emerging from soil was reduced by up to 99% when traps were installed next to trees on mulch compared to bare soil. Adult weevils did not appear to migrate beneath fabric to emerge at the edges because mean numbers of weevils trapped at the edges of the fabric (2.75 ± 1.01) did not differ (P > 0.05) from those trapped at the same position on unmulched trees (4.38 ± 1.95). Additional work is needed to demonstrate the effect of fabric mulches on weevil population density. Nevertheless, fabric mulches were shown to consistently increase tree growth in weevil-infested orchards. Fabric mulches also eliminate the need for herbicides and potentially insecticides or other IPM tactics to manage root weevil pests.
The unique genetic phenomena responsible for inherited F1 sterility in Lepidoptera and some other arthropods provide advantages for the use of inherited sterility in a sterile insect technique (SIT) program. Lepidopteran females generally can be completely sterilized at a dose of radiation that only partially sterilizes males of the same species. When these partially sterile males mate with fertile females, many of the radiation-induced deleterious effects are inherited by the F1 generation. At the appropriate dose of radiation, egg hatch of females mated with irradiated males is reduced and the resulting (F1) offspring are both highly sterile and predominantly male. Lower doses of radiation used to induce F1 sterility increase the quality and competitiveness of the released insects. However, during a SIT program it is possible that traps used to monitor wild moth populations and over-flooding ratios (marked released males vs unmarked wild males) may capture unmarked F1 sterile males that cannot be distinguished from wild fertile males. In this study we developed a cytological technique with orcein and Giemsa stains to distinguish adult F1 progeny of irradiated males and fertile males. Our observations on 6 pest species in 5 families of Lepidoptera indicate that F1 males (sterile) from irradiated fathers can be distinguished from fertile males by the nuclei cluster in the eupyrene sperm bundles. The nuclei cluster in the fertile males exhibited a regular and organized arrangement of the sperm and was homogeneously stained, whereas in F1 males the nuclei cluster of sperm was disorganized, irregular and unevenly stained.
A new cicada species, Dilobopyga aprina Lee, sp. nov. from Sulawesi is described. This new species is distinguishable from its congeners by the presence of 2 pairs of transverse black spots on the abdominal tergite 3 and the absence of such spots on other tergites and by the unique shape of the upper lobes of pygofer and the long and pointed claspers in the male genitalia.
Increased threat of mosquito-vectored diseases necessitates the development for new management tactics and programs. We tested a pyrethroid barrier treatment by using a power sprayer to target upper tree canopies against orniphilic and other resting mosquitoes. Mosquito populations were monitored weekly with CO2-baited Centers for Disease Control (CDC) miniature light traps (without a light) (1) d level and within the vegetation. Traps were operated weekly for 10 weeks; 2 weeks pre- and 8 weeks post-treatment. Culex spp. were collected predominantly in tree canopy CO2-baited traps (81%) compared with CO2-baited traps at ground level (11%) and gravid traps (7%). Over 96% of the mosquitoes collected were Culex spp. Pretreatment canopy catches averaged 489.7 and 618.6 adults per trap-night prior to insecticide treatment in the control and treatment plots, respectively. Tree canopy treatments significantly reduced populations of Aedes spp. and Culex spp. At 4 weeks post-treatment, mosquito numbers collected in CO2-baited traps were reduced by 86% at ground level and 76% in tree canopies. No reduction in mosquito numbers was noted in gravid traps. These data demonstrated that pyrethroid barrier sprays applied to upper canopy vegetation might be effective in reducing adult mosquito populations.
The leaf beetle, Gratiana boliviana Spaeth, is a biological control agent of tropical soda apple (Solanum viarum Dunal), a noxious weed invading the rangeland and agricultural fields of Florida and other southeastern states. In caged experiments, we examined the influence of beetle density and the time of day on the dispersal of the leaf beetle. Increasing beetle density from 2 to 100 beetles per plant did not increase G. boliviana dispersal, as long as the host plants were not severely defoliated. An increase in beetle density from 10 to 100 beetles per plant significantly reduced the per capita fecundity from 0.3 to 0.02 eggs over a 24-h period. Thus, a mass rearing method for G. boliviana should consider the potential detrimental effect of increasing density on the fecundity of the leaf beetle. When the dispersal activity of the leaf beetle was observed between 8:00 and 18:00 h, the proportion of beetles dispersing from a given plant increased throughout the morning hours and peaked at noon. A monitoring or sampling program of G. boliviana should be conducted in the early morning or late afternoon when the beetles' tendency to disperse is the lowest in order to more accurately sample for the population density in a certain area. Beetle density and the time of day interacted to influence the proportion of G. boliviana dispersing from a given plant. The proportions of beetles that dispersed were not different among the different time periods at densities of less than 40 beetles per plant. At or above 40 beetles per plant, the proportion of beetles that dispersed peaked at noon. This study suggests that a myriad of factors, including density, feeding damage, photoperiod and host plant quality, interact to determine the dispersal pattern of G. boliviana.
The invasive red imported fire ant, Solenopsis invicta Buren, has successfully dispersed across many countries from its South American homeland and now has reached the US-Mexico border (e.g., Matamoros, state of Tamaulipas, México), where it now coexists with native fire ants, Solenopsis geminata, Solenopsis xyloni, and others. The morphological identification of Solenopsis spp. workers is difficult, particularly small ones. We examined the sequence of the cytochrome oxidase I (COI) mitochondrial gene (mtDNA) as a marker for fire ants collected at several Mexican localities. PCR products from this locus yielded unique sequences and restriction patterns that allowed distinguishing between S. invicta, S. geminata, and specimens harboring S. xyloni sequences. The S. invicta sequences obtained were 99% identical to sequences reported from Florida and New Mexico specimens. The S. xyloni sequences obtained were 96% identical to New Mexico sequences. The S. geminata sequences were similar (93% identity) to those from Florida, and shared a Hinf I restriction site with some but not all Florida sequences. The S. xyloni sequences were detected in S. geminata/S. xyloni hybrids identified by morphology; along with other characters, the marker allows their characterization.
The feeding of Homalodisca vitripennis, also known as the glassy-winged sharpshooter (GWSS), on Citrus sinensis cv. Navel and Vitis vinifera cv. Chardonnay was monitored in relation to free and protein bound amino acids in xylem fluid. Mean consumption rate of GWSS confined to feeding assemblies was significantly higher on Chardonnay (2.0 cm3/d) than on Navel (0.4 cm3/d). The concentration of free amino acids in xylem fluid was substantially higher than amino acids in protein form for both host species. For Navel, the major amino acids were asparagine/aspartic acid and proline, which represented 75% of the free amino acids. Glutamine/glutamic acid accounted for 75% of the free amino acids in Chardonnay. To test whether GWSS feeding induced changes in xylem fluid chemistry, GWSS were caged on shoots of Navel and Chardonnay for 10 d, at which time feeding rate was determined and amino acids in xylem fluid and in insect excreta were quantified. There was no significant effect of prior feeding on GWSS feeding rate. For Navel, GWSS feeding induced a significant increase in serine, arginine, alanine, methionine, isoleucine, leucine and lysine in protein form; however, the concentrations of most protein amino acids in xylem fluid of Chardonnay were not significantly increased. The assimilation efficiency (AE) of total free amino acids exceeded 99%, whereas total amino acids in protein form were assimilated with 90 to 98% efficiency. The AE was significantly increased for GWSS feeding on GWSS-caged shoots compared to that of control shoots.
Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae: Dynastinae) causes economically important damage to ornamental and commercial coconut palm trees in the western Pacific region that could be mitigated significantly by early detection and treatment. Adults are difficult to detect visually because they attack the crowns of the trees and feed internally before mating and dispersing to new hosts. Visual inspection is nevertheless the most widely used detection method, augmented with pheromone traps. This species is an ideal candidate for acoustic detection because the adults are large, active borers that produce stridulations during courtship and mating. The stridulations have distinct, easily recognized temporal patterns. Larvae and pupae also produce stridulations. To assist in development of new detection methods, acoustic characteristics of the adult and larval stridulations have been quantified and compared with stridulations produced by larvae of other dynastids recorded in the western Pacific region.
A new species of the genus Merocoris subgenus Merocoris belonging to the coreid monobasic tribe Merocorini is described from Brazil under the name M. (M.) tumulus. Keys to the known subgenera and species of Merocorini are provided, along with dorsal view illustration of adult and drawings of parameres.
Chaenusa glabra Kula, new species from India and Pakistan is described, and sexual dimorphism is reported and discussed. A diagnosis is provided to differentiate it from all other species of Chaenusa Haliday sensu lato. It was reared from Hydrellia pakistanae Deonier and Hydrellia sarahae laticapsula Deonier infesting Hydrilla verticillata (L. f.) Royale during foreign exploration for natural enemies of H. verticillata, and is in quarantine at the Florida Biological Control Laboratory in Gainesville. It is the first species of Chaenusa described from the Oriental Region and the only species of Chaenusa known to attack species of Hydrellia Robineau-Desvoidy infesting plants from a genus other than Potamogeton L.
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