Larvae of Chlosyne poecile (Felder) (Lepidoptera: Nymphalidae: Melitaeini) on Razisea sp. (Acanthaceae) feed in large aggregations as early instars but disperse and feed in small groups or as solitary caterpillars in later instars. The effect of group size on per capita feeding rate was tested by manipulating the number of larvae on a leaf and measuring the leaf area eaten in short-term feeding trials. Feeding rate increased significantly with group size for first instars but decreased with group size for all larger instars. Although feeding rate decreased significantly with group size for second instars, second instars in the field were usually found in large groups and did not begin to disperse until the third instar. Variance-to-mean ratios indicate that larval aggregation was lower in later instars, slowly approaching a random distribution. The distributions of larger instars may therefore be the result of random dispersal to food and not the active avoidance of other larvae. If the observed lag between the predicted optimal time to disperse and the observed pattern is adaptive, then it may be due to unmeasured benefits of aggregation, such as lower predation rates and unmeasured costs of dispersal. Egg clustering and aggregation of larvae may be more common for butterflies in the Neotropics than in other areas.

The insidious flower bug, Orius insidiosus (Say), can be maintained on a minimal artificial diet composed of brewers yeast, soy protein hydrolysate and chicken yolk. However, egg production is poor even though the level of protein in the diet exceeds the amount consumed by adults that are fed insect eggs and have higher levels of egg production. We therefore fractionated eggs of the almond moth, Ephestia kuehniella Zeller by preparative isoelectric focusing and bioassayed the resultant fractions in test diets. Ovipositional rates were evaluated using a short 1-week bioassay. Adult predators were placed on the diets the third day after eclosion, allowed to feed for six days, and then provided with an oviposition substrate for 24 h on day seven. Egg production significantly increased only in a fraction with an isoelectric point of pH 5. SDS-PAGE revealed the presence of several Commassie blue-stained bands; however, the nature of the factor is unknown. These results point to a fecundity factor required by females of O. insidiosus for egg laying that potentially may be used to supplement artificial diets for Orius species by commercial producers of beneficial insects.

Courtship of sib-mating Melittobia digitata Dahms, a parasitoid of solitary wasps and bees, is reviewed, described, and quantified for 125 virgins of the non-dispersing brachypterous female (BF) morph paired with 24 experienced males, and for 158 virgins of the dispersing macropterous female (MF) morph paired with 21 males. Males performed 1-5 courtship bouts with both morphs; about half of all successful matings in both morphs occurred after a single bout. Depending on number of bouts performed, mean courtship durations ranged from 47-268 sec for MFs and 59-277 sec for BFs. Courtship success rates were greater for BF couples (80%) than for MF couples (57%). Compared to BF couples, MF couples were more apt to undergo multiple bouts. Results are interpreted in the context of the morphs" life history and the costs/benefits of alternatives. Failure to initiate any courtship during the 15-min observation period (22% for MF pairs, 21% for BF pairs) appeared to be due to apparent lack of interest or to occasional male violence toward females. Possible explanations for the latter, including mistaken identity, odor contamination, and nutritional stress are discussed.

Laboratory feeding trials evaluated fly survivorship on six insecticides (acetamiprid, clothianidin, deltamethrin, fipronil, imidacloprid, and spinosad) incorporated at 4, 40, and 400 ppm in protein baits. Higher concentrations of insecticides resulted in increased fly mortality. At all concentrations of insecticides in baits, except those on deltamethrin, there was a significantly higher mortality 4 d after the initial feeding, compared with flies that fed on a control bait. The presence of clothianidin or imidacloprid in baits led to significantly less feeding compared with a control bait without insecticide. There were no feeding deterrent effects of bait containing either fipronil or spinosad compared with a control bait without insecticide. Exposure of flies to fresh bait containing 40 ppm of acetamiprid, clothianidin, or imidacloprid, resulted in significantly more flies becoming knocked down than the control. Baits containing 40 ppm of fipronil or spinosad resulted in higher levels of fly mortality than baits containing either neonicotinoids (acetamiprid, clothianidin, or imidacloprid) or no insecticide for trials with fresh and 1-d-old bait with unlimited exposure. At the rates tested baits containing deltamethrin resulted in no fly knockdown and always had the lowest mortality of any insecticide treatment. The tradeoffs between insecticides capable of knockdown and mortality are discussed as they relate to management of R. mendax.

We report data obtained concerning the occupation of trap nests by xylicolous Crabronidae (sensu Melo 1999) in a study carried out in central Spain between 1992 and 1995. In particular, we analyze the data on the occupation of the nests for Psenulus concolor (Dahlbom), Trypoxylon attenuatum F. Smith, and Trypoxylon beaumonti Antropov. All three species use pre-existing cavities of 2-4 mm to establish their nests. The mortality rates varied between 33% and 55%, and of special interest was the variation between the two species of Trypoxylon L. and the absence of mortality due to natural enemies in P. concolor. In the three species, mortality was similar along the nests, with no increase in the innermost or outermost cells. Trichrysis cyanea (L.) was the most abundant natural enemy in the nests analyzed. Sex distribution was not random in any of the species studied: in P. concolor and T. attenuatum, the males developed in the outermost cells, while in T. beaumonti they appeared in the innermost ones. The sex ratio did not deviate from 0.5 in P. concolor and T. attenuaum, although in T. beaumonti, the number of females was significantly higher than that of males.

Usage patterns of entomological research websites were examined to assess their current roles as information resources. A 5-year review of logfiles at three Florida entomological research websites indicated that usage has increased since 1999 and that visitors increasingly have taken advantage of Internet search engines to find pages with high information content. Websites provide opportunities for dissemination of information (for example, in sound files or databases) that is difficult to include in traditional refereed publications. Given the rapid growth of website usage, research organizations may wish to consider formal procedures for vetting such information.

During spring to autumn, Gryllotalpa africana males stridulate and produce phonotactic calling songs from specially constructed acoustical burrows. Songs start just after dusk and continue for several hours. The characteristics of the trilling song and sound pressure levels produced were investigated by near field digital recordings made during autumn 2002 and spring 2002 with soil temperatures noted by measuring sound pressures beyond the near field with a sound level meter in spring 2002, respectively. The carrier frequency (2.161-2.477 kHz) and syllable duration (7.340-12.078 ms) of calls showed no significant relationship with soil temperature and no significant differences between autumn and spring with soil temperature constant. Syllable period (10.455-17.221 ms) and inter syllable interval (1.912-9.607 ms) were significantly negatively correlated with soil temperature, and with the latter constant, significantly longer in spring than in autumn. The syllable repetition rate (0.058-0.096 syllables/ms) and duty cycle (43.31-81.72%) showed a significant positive relationship with soil temperature and significant decrease in values with soil temperature constant in spring relative to autumn. Sound pressure levels (re. 20 μPa) at 200 mm from the burrow varied from 77.6 to 89.8 dB.

Various trap specifications were evaluated to identify the most effective trap for capturing wild male Cactoblastis cactorum (Berg). All traps were baited with virgin female C. cactorum and, except for the first comparison of trap type, a standard wing trap was used in all experiments. Although wing traps captured more males than did the other trap types (delta or bucket), the differences were not significant. However, significantly higher numbers of males were captured in wing traps placed 2 m above ground than traps at 1 m or 0.5 m, and wing traps baited with four virgin females caught significantly more males than wing traps baited with a single female. Differences in number of males captured by young and old females were not significant, but more than twice as many males were captured in traps baited with one-day-old females than traps baited with four day old females. In addition, there were no significant differences in number of males caught in unpainted, white, wing traps and wing traps painted one of eight different colors (flat white, black, dark green, fluorescent green, yellow, fluorescent yellow, orange, or blue), although, more males were captured in the unpainted wing traps. The results presented here suggest that the best trap currently available to monitor C. cactorum is a standard (unpainted) wing trap, placed at a height of 2.0 m aboveground, and baited with four newly emerged females.

The chief objective of this study was to determine whether the inclusion of protein in the adult diet influences male mating success in the oriental fruit fly, Bactrocera dorsalis (Hendel). Previous studies on this species have shown that ingestion of methyl eugenol (ME) greatly enhances male mating performance. Accordingly, we also examined the interaction between adult diet and ME and investigated whether this chemical boosts the male mating success independent of diet. In trials conducted in field tents, we compared the mating frequency of control, protein-fed males (no ME) versus males (1) deprived of protein during the entire adult life, the pre-maturation period, or the post-maturation period and (2) not provided ME or provided ME 1 day before testing. Males deprived of protein completely or when immature (1-12 days old) obtained very few matings (<5% total matings) with or without ME feeding. Males provided protein as immature adults but deprived of protein as mature adults (>12 days old; no ME) also were competitively inferior to control males but achieved a significantly higher proportion (37%) of total matings than males in the preceding treatments. ME exposure boosted the mating success of these males slightly (40% of total matings) such that their mating frequency was not significantly different from control males. Additional tests showed that for treated males fed protein their entire adult life short-term (30 h) food deprivation resulted in a significant decrease in mating success, and feeding on ME did not boost the mating frequency of the food-deprived males. The implications of our findings for controlling B. dorsalis via sterile male releases are discussed.

The almond moth, Cadra cautella (Walker), is a common storage pest known to infest a wide range of dried plant materials, and it has been recorded from a warehouse in Florida during storage of dried passion-flower (Passiflora incarnata L.) and dried saw palmetto berries Serenoa repens (Bartram) Small. Its status as a pest of stored saw palmetto was confirmed by trapping in a second warehouse used solely for storage of this commodity. The moth occurred in high numbers, captures were closely associated with stacks of bagged berries, and trap catch was very low after the stacks were consolidated under a tarp and fumigated. Yet the results of laboratory rearing on saw palmetto suggested that C. cautella has little ability to infest this commodity--development was protracted and highly variable in duration, mortality was high, and pupal weight was low. This sort of contradiction in host suitability, which we refer to as the “host paradox,” may be widespread among stored-product insects but has seldom been reported and almost never studied. Published reports suggest that the solution lies partly in dietary supplementation through fungivorous, saprophagous, or carnivorous feeding, although more subtle factors also are suggested. Even cursory observations of the host paradox should be reported to document frequency of occurrence and perhaps stimulate studies directed toward solutions. Such studies would inevitably provide better understanding of population dynamics, which would, in turn, lend support to better management of insects in commercial storage situations.

The patterned wings of tephritid fruit flies often are moved in complex manners during sexual encounters. However, there are few cases of sexual dimorphism, and wing movements also may occur in non-sexual contexts. There was no evidence that enhancing or obliterating the patterns on the wings of male Caribbean fruit flies, Anastrepha suspensa (Loew), had any effect on their sexual success. There is convergence in wing patterns with another Dipteran family, the distantly related Bombyliidae. Additional studies of mating systems with this family might illuminate the significance of similar wing patterns in tephritids.