A chicken feather hydrolysate prepared by heating feathers with 6N hydrochloric acid was highly attractive to the West Indian fruit fly, Anastrepha obliqua (Macquart), and the Mexican fruit fly, Anastrepha ludens (Loew). In cage-top laboratory tests to determine the influence of pH on attraction, chicken feather hydrolysate, adjusted to pH 8.0, elicited the greatest response from adult A. obliqua; the attraction response was more than twice that observed for a 10% NuLure® (Miller Chemical and Fertilizer Corp., Hanover, PA) standard. Neutral or slightly acidic preparations of chicken feather hydrolysate were less effective. While A. ludens was less attractive in the laboratory tests to a 25% chicken feather hydrolysate than a 10% NuLure standard, A. obliqua appeared slightly more attracted to the hydrolysate than NuLure, but not significantly. In a 5-day field test using sterile released A. ludens, 4.5% chicken feather hydrolysate, adjusted to pH 8.0, caught almost 2.5 times more flies than 10% NuLure. Twenty-three volatile compounds that emanated from chicken feather hydrolysate were identified by headspace analysis using GC-MS and GC retention index comparison techniques. Among the volatiles were 7 ketones, 6 alcohols, 2 aldehydes, 2 chlorocarbons and 2 furans. At pH 8.0, the five most abundant compounds in decreasing order were 4-methyl-2-pentanone (76.3%), 4-methyl-2-pentanol (16.5%), 1-hexanol (3.1%), 1-heptanol (0.81%) and 2-butoxyethanol (0.64%).

Sweep-nets and pitfall traps were used to examine the distribution and dynamics of predominant predators and pests in turfgrass foliage in parks, golf courses and suburban/rural landscapes in 1991 and 1992. Araneae, Formicidae, and Coccinellidae were the most abundant predators in the sweeps, while Araneae, Formicidae, and) Carabidae were the most abundant predators in the pitfall traps. In both years, Araneae comprised over 60% of the total predators in the sweep samples. Formicidae (>70%) and Araneae (13–19%) were the most abundant arthropod predators in the pitfall samples. Cicadellidae, Chrysomelidae, and Orthoptera accounted for over 96% of the prey in the sweep samples, while Cicadellidae, Orthoptera (grasshoppers and crickets), and Aphididae comprised over 90% of the prey in the pitfall samples. Abundance of predators and prey, and prey / predator ratios fluctuated with site, date, and distance from the trees. During the season, high prey / predator ratios usually preceded peak prey abundance in the sweep samples. Predators usually were more prevalent in sweep samples closer to tree borders, while prey populations tended to be higher at distances further from the tree borders. These results suggest that tree borders provide food, shelter, and refuge for predators during periods of environmental stress.

Predation rates for the anthocorid predator Lyctocoris campestris (F.) against varying densities of late-instar Plodia interpunctella (Hübner) were compared in whole corn, whole wheat, or rolled oat stored commodities. More prey were attacked in corn and wheat than in oats, and female predators generally fed on more larvae than did male predators. Predation increased with an increase in prey density. This relationship was best described by a Type II functional response equation. Our results suggest that commodity type affects the number of prey attacked by this predator.

Information on the risk of western corn rootworm, Diabrotica virgifera virgifera LeConte, damage to continuously-grown corn previously was lacking in Virginia, as well as other mid-Atlantic states. A field study was conducted in 1993 and 1994 comparing root damage, whole-plant yields, and silage quality in insecticide-treated and untreated sections of 32 continuous corn fields in Virginia. Approximately 28% of the fields had serious root damage exceeding a rating of 3.5 (1–6 scale) in sections not treated with a soil insecticide. Also, 19% of the fields had an economic loss in whole-plant yield due to corn rootworm feeding damage. Silage quality, as evidenced by percent crude protein and acid detergent fiber, was not significantly affected by corn rootworm feeding. Because much of the continuous corn acreage in Virginia is treated preventively with soil insecticides for corn rootworms, the results of this study suggest that a large percentage of this insecticide use is unnecessary.

Movement and feeding of newly-hatched imported cabbageworms, Pieris rapae (L.), on the upper and lower leaf surfaces of collard plants with glossy and normal waxes were monitored using a videocamera. During the 50-min observation period, more of the larvae fed when placed on the lower surface of leaves with normal wax (50 to 68%) than on the upper surface (23 to 32%), or on either upper (27%) or lower (16%) surfaces of leaves with glossy wax. A larger portion of the larvae moved at least 1 mm on glossy leaves than on normal leaves, and they moved farther during the observation period on glossy than on normal leaves, and on the upper leaf surface compared to the lower leaf surface. The failure of a large proportion of the larvae to begin feeding on either surface of leaves with glossy wax is likely to be an important factor in the resistance to imported cabbageworms observed in the field.

Soybean lines isogenic for glabrous, normal, and dense pubescence developed from the genotypes ‘Davis’, ‘Tracy-M’, and D75-10169 were used in studies of the impact of pubescence on twospotted spider mite, Tetranychus urticae Koch, development and feeding damage under controlled environmental conditions and a known infestation rate. Significant differences in progeny and feeding damage of the twospotted spider mite between genotypes were observed. There were no significant differences between isolines within genotypes for number of progeny. Glabrous isolines had significantly more adult mites leave the excised plant leaf and significantly less feeding damage than the normal or dense isolines. Results suggest that leaf pubescence, or in this case lack of, could be a potential factor in the control of the twospotted spider mite on soybean. This study also demonstrates a reliable and uniform laboratory procedure, under controlled conditions, for rearing the twospotted spider mite, screening soybean germplasm, and determining resistance mechanisms.

The parasitoid Cotesia marginiventris (Cresson) was treated topically with minimum recommended field rates of formulated insecticides commonly used in cotton insect control. The 14 insecticides were acephate, azinphosmethyl, bifenthrin, cyhalothrin, cypermethrin, endosulfan, esfenvalerate, fipronil, methomyl, methyl parathion, oxamyl, profenofos, thiodicarb, and AC 303,630. Eleven of the 14 insecticides were extremely toxic to C. marginiventris, causing 80 to 100% mortality of adult wasps, whereas treatment with thiodicarb, oxamyl, and acephate resulted in lower mortality of C. marginiventris males and females. For both male and female C. marginiventris, thiodicarb and oxamyl were less toxic than acephate. Esfenvalerate was the least toxic pyrethroid for C. marginiventris females. Of the three insecticides used in boll weevil control (oxamyl, azinphosmethyl, and methyl parathion), oxamyl was the least toxic to C. marginiventris. Selective use of the insecticides which result in higher survival could facilitate conservation of C. marginiventris.

Seasonal abundance and spatial distribution of wireworm feeding damage were determined for sweet potato by examining storage roots. Spatial distribution of wireworms was determined by sampling corn-wheat seed baits. Wireworm feeding damage (deep, shallow and healed holes) increased as the season progressed. The distribution of wireworms in sweet potato fields was clumped as was feeding damage distribution. The spatial distribution of wireworm damage on sweet potato roots fits the negative binomial distribution. Values for the negative binomial parameter k for two fields indicated a clustered distribution of wireworm feeding damage. Greater k-values for healed feeding damage and total feeding damage than for deep and shallow feeding damage indicate that sample size could be adjusted, depending on seasons, to achieve optimal sampling efficiency. As feeding damage can predict wireworm populations, a sampling strategy based on early-season wireworm damage data is particularly timely, efficient and economical for evaluating wireworm damage data.

Sperm transfer and fertility of the gypsy moth, Lymantria dispar (L.), held as pupae under constant temperature and 24-h light, 24-h darkness, or a photoperiod of 16:8 (L:D) h were compared with males held in cyclic temperature and 24-h light, 24-h darkness, or a photoperiod of 16:8 (L:D) h. Constant temperature and constant light or darkness severely reduced its ability to transfer sperm. Males held under constant light were more severely affected than males held in darkness, but sperm transfer was not correlated with light intensity (between 80 and 3960 lux). Nearly all males held under constant light and most held under constant darkness were sterile or partially sterile. In either case, sterility was caused by poor sperm transfer. Females with a full complement of sperm were fertile regardless of holding condition of male pupae. The sterilizing effect of constant light or darkness was overridden by cyclic temperature of 28°C for 16 h and 22°C for 8 h. At a photoperiod of 16:8 h, pupae held in constant 28°C transferred less sperm than those held at 25°C. Pupae held at constant 30°C were sterile, but those held at 30°C for 16 h and 25°C for 8 h transferred similar quantities of sperm as males held at constant 28°C.

The effect of continuous, intensive grazing by cattle on aphid populations was examined in the first growth cycle of ‘Alfagraze’ and ‘Apollo’ alfalfa which are tolerant and not tolerant to grazing, respectively. Populations were almost entirely pea aphid, Acyrthosiphon pisum (Harris). The effect of grazing on aphid populations was examined in small plot exclusion studies in 1991 and 1992, and the effects of grazing and use of an early insecticide application with ≤7 day grazing restriction were examined in large plot exclusion trials in 1993 and 1994. Grazing reduced aphid populations by 66% to 90% when numbers exceeded ~1 aphid per stem. Populations were not significantly reduced by grazing when numbers did not exceed 1 per stem. Permethrin reduced aphid numbers for up to 7 wks and was more effective than carbofuran. Effects of grazing were similar regardless of insecticide usage. Coccinellid beetle populations in 1993 and 1994 were composed of Coccinella septempunctata L., Harmonia axyridis (Pallas), and Coleomegilla maculata DeGeer. Coccinellid numbers were much lower in grazed than ungrazed plots when aphid numbers were reduced by grazing in 1993, but were not greatly affected by grazing in 1994 when aphid numbers were low. Coccinellid numbers paralleled trends in aphid numbers. Continuous, intensive grazing or the early application of an insecticide at a low rate followed by grazing were effective approaches for suppressing pea aphid in alfalfa.

European corn borer (Ostrinia nubilalis Hübner) can severely affect commercial sweet corn quality during years of heavy infestation. The isolation and identification of allelochemicals in sweet corn which detrimentally affect O. nubilalis may enhance breeder selection for greater ear feeding resistance, thus reducing the need for insecticide application. Field selection techniques for improving plant resistance to O. nubilalis cannot easily distinguish between plant tolerance or antibiosis. A laboratory bioassay incorporating ear tissues from field resistant and susceptible sweet corn genotypes into a nutritionally complete O. nubilalis larval diet was developed as an initial step to facilitate the isolation and identification of potential chemical resistance factors in sweet corn. Neonates reared for 7 d on a meridic diet with limited fungal and bacterial contaminant control agents weighed more than larvae grown on a comparable diet with high levels of contaminant control (5.96 and 2.46 mg, respectively). Silk tissue from several sweet corn genotypes significantly reduced larval weight and increased total larval development time compared with kernel tissue. Silk tissues incorporated on a weight basis had volumes about 3 × that of an equal weight of kernel tissues. However, tissues incorporated into a specific diet volume on a weight or volume basis usually did not alter larval weight or time to pupation within a genotype. Incorporation on a weight basis was most time efficient. Future bioassays screening for antibiotic effects of sweet corn tissue on O. nubilalis development should utilize a diet with limited contaminant control agents, incorporate tissue on a weight basis, and focus on silk tissue.

Yellow cards coated with adhesive were used to survey for the presence, relative abundance and seasonal patterns of lady beetles in research and commercial fields of processing sweet corn in central and western New York in 1992 and 1993. The lady beetles species recorded, in order of abundance were: Coleomegilla maculata lengi Timberlake, Coccinella septempunctata L., Psyllobora vigintimaculata (Say), Hippodamia parenthesis (Say), Propylea quatuordecimpunctata (L.), Cycloneda munda (Say), Hippodamia glacialis glacialis (F.), Adalia bipunctata (L.), Coccinella trifasciata perplexa Mulsant, and Coccinella transversoguttata richardsoni Brown. Coleomegilla maculata lengi was in sufficient number to reflect seasonal patterns. Coleomegilla maculata lengi populations rapidly increased in early July, peaked in late July or early August and then rapidly declined. The timing of C. maculata lengi peak abundance was more closely related to day-of-year than to stage of crop development based on accumulated degree days from planting. The pattern of capture of C. maculata lengi at incremental distances into the field did not indicate colonization from the field edge.