Dung-baited pitfall traps were used to conduct a survey of dung beetles (Coleoptera: Scarabaeidae) in alpaca pastures located at Virginia State University, Petersburg, VA, from May to September in 2010 and 2011. Beetles were collected weekly and identified to species. Of the 3,136 beetles collected, 11 species were represented: Onthophagus taurus Schreber, O. pennsylvanicus Harold, O. hecate hecate Panzer, Copris minutus Drury, Phanaeus vindex MacLeay, Dichotomius carolinus L., Sphaeridium scarabaeoides L., Aphodius erraticus L., A. fimetarius L., A. (Nialaphodius) nigrita F., and A. (Labarrus) lividus Olivier. The most common species found in both years was O. taurus, which accounted for 43% and 59% of the populations in 2010 and 2011, respectively. Paracoprid tunneler beetles dominated the collection in both years. Both native and exotic species were abundant, indicating that the introduction of exotic dung beetle species has not been detrimental to native populations. The species abundance and diversity fluctuated throughout the summer, likely related to weather patterns.

Methyl salicylate is an organic compound produced by potato and other plants in response to insect herbivory. In other studies the compound has been shown to be attractive to numerous predatory arthropods. Experiments were conducted in Virginia to evaluate methyl salicylate lures for attracting natural enemies in potato plots to manage populations of Leptinotarsa decemlineata (Say). Abundance of predatory arthropods and L. decemlineata life stages were measured in plots treated with and without 90 day, 5 g slow-release packets of methyl salicylate (95% methyl salicylate [Predalure™]). Mortality of L. decemlineata eggs and small larvae was estimated by calculating the difference in numbers of individuals recruited to subsequent stages using a stage-specific life table approach. Methyl salicylate treatment had no impact on predator recruitment or mortality of L. decemlineata eggs and small larvae, compared with nontreated plots. Cumulative mortality of L. decemlineata ranged from 87.9 - 89.2% in 2010 and from 81.9 - 94.8% in 2011. The dominant arthropod predators observed on potatoes included Hippodamia convergens Guerin-Meneville, Coccinella septempunctata L., and Perillus bioculatus (F.).

Warm season turf taxa of centipedegrass [Eremochloa ophiuroides (Munro) Hack], bermudagrass [Cynodon L.C. Rich, spp.], St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze], and zoysiagrass [Zoysia Willd. spp.] were evaluated for tolerance to adult twolined spittlebug (Prosapia bicincta Say) feeding in choice and no-choice experiments, and for their ability to support nymphal development (antibiosis potential). Among 133 selections evaluated, few showed evidence of potential antibiosis and/or improved tolerance over commercially available cultivars. Most of the centipedegrass taxa evaluated were susceptible to the spittlebug. However, some potential antibiosis among Chinese centipedegrass taxa was identified, and there was a gradient in the ability to tolerate spittlebug feeding. Among centipedegrasses, TC 358 and TC 362 showed moderate tolerance and recovery in no-choice and choice trials. The most tolerant bermudagrasses in no-choice trials were 00 - 23, 03 - 14, and 03 - 15. Centipedegrasses overall were the best hosts for nymph development, but TC 379, TC 422 and E. ciliaris did not support nymph development, and TC 341 and TC 399 showed very low numbers of nymphs. The bermudagrasses 00 - 23 and 00 - 28 and the St. Augustinegrasses T638 and Mercedes failed to support nymph development.

Insecticide rotations for the management of the diamondback moth, Plutella xylostella (L), and other lepidopteran pests of cabbage and collard crops were evaluated in 2010, 2011, and 2012 at Tifton, GA, with the intent of identifying mode of action rotations equal in efficacy to single insecticide mode of action treatments. This was to demonstrate how insecticide rotations, which are purported to aid in the prevention of insecticide resistance, can be an economically-viable insect control option in Brassica crops. The insecticides and mode of actions tested included: chlorantraniliprole and flubendiamide (ryanodine receptor modulators), spinetoram (nicotinic acetylcholine receptor allosteric activator), indoxacarb (voltage-dependent sodium channel blocker), Bacillus thuringiensis subsp. aizawai (microbial disrupter of insect midgut membranes), novaluron (inhibitor of chitin biosynthesis) and zeta-cypermethrin (sodium channel modulator). The results demonstrated that all rotations were equally effective in the control lepidoteran pests in Brassica crops to the use of single insecticide treatments and that at least one rotation treatment provided the highest marketable yield each year.

Eicosandoids, or icosanoids, are signaling compounds created by the oxidation of 20-carbon fatty acids. They control many complex physiological and immunological functions in vertebrate and invertebrate animals. This study tested the hypothesis that eicosanoids act in insect antioxidant defense. The effects of 3 eicosanoid biosynthesis inhibitors (EBIs) – dexamethasone, esculetin, and phenidone – on the oxidative stress indicator, malondialdehyde (MDA), and the detoxification enzyme, glutathione S-transferase (GST), was examined in the midgut of larvae of the greater wax moth, Galleria mellonella (L.). The larvae were reared on artificial diets supplemented with 0.001, 0.01, 0.1 or 1.0% of the EBIs. Esculetin, which is a lipoxygenase inhibitor, significantly increased MDA content; whereas, GST activity was significantly increased at only the highest concentration tested. Dexamethasone, a phospholipase A₂ inhibitor, significantly increased MDA content and GST activity at concentrations of 0.01, 0.1, and 1.0%. Phenidone, a dual inhibitor of cyclooxygenase and lipoxygenase, increased MDA content, whereas the 0.01 and 0.1% concentrations of phenidone significantly increased GST activity. Our results indicate that antioxidative responses are, at least in part, controlled by a physiological system that includes eicosanoid biosynthesis.

The symbiosis of plants with arbuscular mycorrhizal fungi can improve crop growth by enhancing nutrient uptake and by increasing plant tolerance to certain pests. Pest populations also can be affected, but the effects of mycorrhizal colonization of plant hosts on species of thrips are unknown. We inoculated 2-week-old bell pepper seedling roots with a commercial mycorrhizal mixture of Glomus species (Glomales: Zygomycotina) and evaluated the effects 8 wks later on the bell pepper pest, western flower thrips (Frankliniella occidentalis (Pergande)). Females that were 10-days-old after adult emergence significantly preferred plants inoculated with arbuscular mycorrhizae compared with noninoculated plants in a laboratory choice experiment. Their numbers were greater on inoculated plants 48 h after release into cages containing inoculated and noninoculated plants. A no-choice laboratory experiment compared performance of F. occidentalis on noninoculated and inoculated bell pepper plants. Females that were 10-days-old after adult emergence were released into cages containing individual plants, and there were significantly greater total thrips (larvae, pupae, and adults) on treated plants. Further testing over a range of plant host fertility levels is needed to evaluate the potential for increased pest damage from F. occidentalis on crops growing in mutualistic symbiosis with arbuscular mycorrhizal fungi. Additional interactions with other microorganisms and natural enemies are possible under field conditions.

Field collections of early nymphs of Nezara viridula (L.) revealed that normal change in coloration pattern occurring between the fourth and fifth stadia do not occur in some individuals producing abnormally-colored fifth instars. To determine if abnormal coloration is an indicator of poor health, field-collected fifth instars were grouped in 4 coloration pattern groups: (1) Green, normal coloration pattern; (2) faded, displaying similar patterns as “green” but with paler colors; (3) intermediate black-green; and (4) black, retaining fourth-instar coloration pattern. The fitness of nymphs within coloration pattern groups was measured by recording survival to adulthood and assessment of adult weight, fecundity, and egg viability. Adults originating from each nymphal coloration pattern were grouped to determine if the variability in nymphal coloration was hereditary. Survival from fifth instar to adult was significantly lower in nymphs displaying abnormal coloration patterns showing 21 and 12.5% survival in the black and faded groups, respectively, as compared with 76.2% in the normal green coloration group. Adults originating from nymphs of black coloration did not produce progeny, whereas adults originating from the faded coloration produced significantly less eggs with lower viability than adults originating from nymphs with normal coloration. However, adults originating from normally-colored nymphs produced progeny of abnormal coloration in similar frequency as adults originating from black and intermediate colored nymphs. Abnormal nymphal coloration can be used as an indicator of health and can aid in the selection of healthy individuals for culture.

Mainstem girdling of soybean seedlings by threecornered alfalfa hoppers, Spissistilus festinus (Say), can result in several plant responses: (1) death of the plant, usually within 2 - 3 wks of injury,(2) mainstem breakage at the girdle soon after girdling through maturity, (3) partial breakage at the girdle with continued plant growth, (4) or the injured area (girdle) may heal over and the plant remain upright. Studies were conducted to simulate plant loss occurring during the reproductive growth stages which would result from threecornered alfalfa hopper injury during the early vegetative growth stages and examine the impact of this plant loss on yield of full-season indeterminate, late-planted/double-crop indeterminate, and full-season determinate soybeans, Glycine max (L.) Merr., at specific reproductive growth stages. Yield of full-season indeterminate soybeans was reduced by 6.4 - 15% when plant loss exceeded 20% at the R1–R2 growth stage. At R3 and R5, yields were reduced 7.4 - 30% and 7.2% to 32.1%, respectively, when plant density was reduced by ≥ 10%. For late-planted / double-crop indeterminate soybeans, yield losses of 10.6% to 19.3% occurred when plant loss exceeded 30% at the R1–R2 growth stage. Yields were reduced 6.9% to 20.6% at R3 when plant loss was ≥ 20. At the R5 growth stage, yields were reduced 22.4 - 40% when plant density was reduced by ≥ 30%.