Diapause in the boll weevil, Anthonomus grandis Boheman, has been extensively studied, but remains poorly understood. In particular, results of diapause induction studies have been inconsistent, and the body of published literature does not clearly indicate the factors or cues responsible for induction. A likely contributor to this variability may be the differences among studies in the criteria used to distinguish diapause. We present illustrated descriptions of the stages of male and female reproductive development, and of the fat body types and conditions associated with reproductive and diapausing weevils. These descriptions provide clearer and more extensive guidelines for the classification of reproductive and diapausing boll weevils than were previously available. We also propose criteria for distinguishing diapause based on specific characters of the fat body and male and female reproductive organs. These criteria provide a means of standardizing diapause assessments in future studies, or at least a baseline for comparison when describing alternate criteria, and should serve to clarify these descriptions in future reports.

The Drosophila mimica subgroup is revised, including descriptions of 10 new species (D. acanthos Kam & Perreira, D. antecedens Kam & Perreira, D. chimera Kam & Perreira, D. echinostoma Kam & Perreira, D. gagné Kam & Perreira, D. inebria Kam & Perreira, D. lobatopalpus Kam & Perreira, D. ma’ema’e Kam & Perreira, D. odontostoma Kam & Perreira, D. xenophaga Kam & Perrierra) and a needed lectotype designation for Drosophila kauluai Bryan. We erect seven species complexes; conjectura, flavibasis, infuscata, involuta, kauluai, mimica, and soonae, based on a variety of morphological characters, most specifically the chaetotaxy of the labellae and the forelegs of males. A key to all taxa in the mimica subgroup is provided. The ecological associations of this species subgroup are also reviewed. We report host use from 13 of the 20 mimica subgroup species.

Rileya doganlari sp.n., in the subgenus Rileya Doganlar, is described and illustrated based upon specimens from galls of Asphondylia anatolica Skuhrava and Cam 1998 (Diptera: Cecidomyiidae) on the terminal stem of Astragalus lagurus Willdenow, 1794 (Fabaceae) in northern Turkey. The larva and pupa of the new species are illustrated and briefly described. Notes on the mating behavior of the adults and biology of R. doganlari are also provided.

A new molecular marker has been developed to clarify the status and systematic relationships of forms within the Bactrocera tau (Walker) taxon. The B. tau taxon, previously described as a widely distributed species, has recently been subdivided into forms A, B, C, D, E, F, G, and I based on host-plant preferences, cytological differences and external morphologies. This new molecular marker is derived from the sequence of the heat shock protein 70 cognate gene Bthsc1. Fragments of this gene were analyzed from B. tau individuals representing each of the different forms. Patterns of sequence variation revealed that the average genetic distance measurement within the B. tau form A is significantly smaller compared with the other B. tau forms. Unweighted pair-group method with arithmetic average and neighbor joining analyses both indicated that B. tau form A individuals derived from various geographical populations may be reliably separated from other forms B, C, D, E, F, G, and I. Our results also show that the Bthsc1 marker may successfully resolve other relationships among these forms. For example the B. tau forms B, F, and G, which are monophagous on related host plants, also cluster together as a closely related group.

We studied the phenologies of phorid flies from the genus Pseudacteon; their host, the native tropical fire ant (TFA), Solenopsis geminata (F.); a second native ant, Monomorium minimum (Buckley); and the non-native red imported fire ant (RIFA), Solenopsis invicta Buren, at a site in Austin, TX. We took a census on an hourly basis from dawn until dusk once a month for a year (July 1998–June 1999). Previous studies have focused largely on the RIFA’s escape from natural enemies (e.g., phorid parasitoids) as an explanation for the ant’s competitive success. Here, we show that the RIFA has additional advantages over its native congener. We found the RIFA had a significantly greater association than the TFA with extremes in ambient temperature, relative humidity, and light levels. However, M. minimum was found at temperatures that were significantly higher than for the RIFA. Native TFA-specific phorids had activity patterns that were similar to their host’s. In addition, we documented the expansion of RIFA foraging territory in relationship to that of the TFA. This occurred throughout the year, so expansion was due to actual competitive takeover by mature RIFA colonies, rather than by establishment of new colonies. Predictions about the activities of South American phorids introduced to control the RIFA in North America are discussed.

The strepsipteran Xenos peckii Kirby, the ichneumonid Pachysomoides fulvus Cresson, the pyralid Chalcoela pegasalis Walker, and the eulophid Elasmus polistis Burks were recorded from 303 Polistes metricus Say early season colonies collected from northeast Georgia during 1997–2000. Colonies of P. metricus were significantly more likely to be infested by X. peckii than by P. fulvus, C. pegasalis, or E. polistis. Both X. peckii and C. pegasalis infested colonies more frequently when either eggs, larvae, and pupae or only larvae and pupae were present in the nest.

A study was undertaken to establish the diversity within the Bemisia tabaci (Gennadius) species complex in Argentina using the mitochondria cytochrome oxidase I gene (mt COI) as a molecular marker. For one haplotype, common to cotton in the Santiago Province, biotic characters were evaluated, and included host range and life history traits: fecundity, generation time, intrinsic rate of increase, longevity, and rate of reproduction. To investigate genetic diversity, B. tabaci were collected from representative geographical locations and host plants in six provinces of Argentina. Also, B. tabaci found colonizing tomato plants in nearby Bolivia, which exhibited viruslike symptoms, were included in the study. We report, for the first time, the presence of the introduced ‘B’ biotype in Argentina, and present evidence for indigenous or ‘local’ B. tabaci haplotypes in both Argentina (ARG) and Bolivia (BOL), which collectively formed a distinctive, South American phylogeographic grouping of New World B. tabaci. Two closely related ARG haplotypes, ARG2/3 from Salta and Tucamán, and ARG1 from Santiago, shared 98.7% identity, whereas the Bolivian haplotype (BOL), their closet relative, shared 99.4% and 99.9% identity with ARG1 and ARG2/3, respectively. Mt COI sequences for collections identified as the ‘B’ biotype from Argentina (ARG4/5) shared 99.5–100% nt identity with the five ‘B’ biotype reference sequences and colonies established for ARG4 and ARG5 were capable of inducing silvering in Cucurbita spp., confirming their identity as the B bioytpe. The closest relatives to the ARG/BOL haplotypes were members of the North/Central American clade of B. tabaci with which they shared 4.6 to 8.6% identity, indicating that the ARG and BOL B. tabaci are of New World origin. The latter range of divergence is similar to that estimated for the Old World B biotype and its closest relatives from the Mediterranean region, at 5.4 to 6.4%. Divergence estimates for Old World X Old World and New World X Old World phylogeographical clades were 14.6 to 16.2% and 14.4 to 17.4%, respectively, indicating that haplotypes in both eastern and western hemispheres exhibit substantial diversity from one another. Despite the somewhat more moderate interclade divergence for New World compared with Old World clades, the South American B. tabaci formed a distinctive New World clade, suggesting a common ancestry with other previously studied New World taxa, from which they are separated by geographical barriers. Life history traits for the cotton-associated B. tabaci haplotype (ARG1) were most similar to those previously reported for the polyphagous A biotype, AZA, from Arizona, and differed substantially with respect to the B biotype.

Papilio zelicaon Lucas has become a common study system, and has been the subject of numerous investigations into ecological variation among populations and regions. Morphological variation has been less intensively studied, with the exception of a dark form occurring on the eastern edge of the animal’s range. In 1968, Remington described populations from the Rocky Mountains and adjacent areas as a distinct species, Papilio gothica. Gothica was not widely adopted, and was subsequently reduced to a junior synonym of P. zelicaon. Using a new wing character not previously considered, we reexamine the evidence for P. gothica, and investigate patterns of morphological variation within the California range of P. zelicaon. Evidence is found supporting significant phenotypic differences within and among three areas: lowland California, montane California, and Colorado. These results are discussed in terms of seasonal and geographic variation, and their bearing on the status of gothica. We conclude that there is significant and patterned phenotypic variation in P. zelicaon, but any taxonomic conclusions at this time would be premature.

Information on feeding by subterranean termites is important because of their status as major pests in urban areas and their roles in forest nutrient cycles, in which they degrade wood litter and fix nitrogen. We examined the response of the subterranean termites Reticulitermes flavipes (Kollar) and Reticulitermes virginicus (Banks) (Isoptera: Rhinotermitidae) to sugar solutions of glucose, xylose, and sucrose in laboratory experiments. Termites consumed more filter paper treated with 1 or 3% (wt:vol) sugar solutions than water-treated paper in choice tests. No-choice diets of sugar-treated filter paper had little effect on termite survivorship, live or dry biomass, or rates of nitrogen fixation.

The polygyne form of the red imported fire ant, Solenopsis invicta Buren, is thought to occur primarily in discrete populations embedded within areas composed of monogyne colonies. This distribution implies that polygyne colonies compete with monogyne colonies and subsequently create a population homogenous in social form. Because polygyne colonies produce mostly sterile males, opportunities for insemination of female alates might be minimal at the centers of large polygyne areas. To test for homogeneity in social form, a large polygyne population described in northcentral Florida was examined for the presence of single queen colonies. Forty-six to 51 colonies were sampled from each of six sites located along an east-west transect through the middle of the polygyne area in Marion County and a site at the northernmost limit of the polygyne area, Gainesville, FL. Several hundred workers from each nest were collected along with nest material. The social form of each sample was determined by an aggression test of workers to the introduction of non-nestmates and by the dissection of males for sterility. Both social forms of S. invicta were present at all collection sites and 103 of 333 (30.93%) colonies sampled were determined to be monogyne colonies. Among the collection sites, the percentage of colonies that were monogyne ranged from 3.9 to 57.4%. The polygyne region in northcentral Florida is more accurately described as an area where relatively high frequencies of polygyne colonies are interdispersed with single queen colonies.