James H. Lashomb

Assimilation of carbon and nitrogen from pollen and nectar by a predaceous larva and its effects on growth and development

Abstract.  1. Predaceous insects may benefit from feeding on non‐prey foods, such as pollen, nectar, and honeydew, because they can provide nutrients that help maintain metabolism and enhance overall nutrient intake. Yet, the extent to which predaceous insects can assimilate non‐prey food and the importance of diet mixing during particular life history stages is poorly understood. In this study the relative contribution of an omnivorous diet to the growth and survivorship of a predaceous larva was tested in a hypothetical situation in which nutritionally optimal prey was not available. The study system comprised a predaceous larva (second‐ and third‐instar larvae of the green lacewing Chrysoperla carnea), nutritionally poor prey (larvae of Drosophila melanogaster), and non‐prey food (pollen suspension, a mixture of bee pollen and artificial nectar (1 M sucrose solution)). Chrysoperla carnea larvae in the mixed diet treatment were provided with both Drosophila larvae and pollen suspension, while those reared on the prey and non‐prey diet treatments received only Drosophila larvae or pollen suspension respectively.

Responses of two parasitoid wasps to nectar odors as a function of experience

Adult parasitoid wasps can learn to recognize specific resource‐based cues, making them adept at locating essential resources within their native habitats. However, relatively little is known about their ability to recognize the odors emitted by flowers and extra‐floral nectar glands. A novel test arena mimicking the distribution of nectaries within an umbelliferous inflorescence was developed to measure and compare the responses of two eulophid wasps, Edovum puttleri and Pediobius foveolatus, to nectar‐based odors. Although both parasitoid species were able to associate nectar location with the odors emitted by both real nectaries (dill flowers and snap bean stipules) and artificial nectars (1 M sucrose solution scented with banana or lemon food flavoring), the responses of inexperienced wasps to nectary odors differed. While inexperienced E. puttleri displayed little attraction to the odor of either dill flowers or snap bean stipules, inexperienced P. foveolatus displayed a strong attraction to odors of both types of nectaries. However, once it had experienced foraging on either dill or snap bean nectar, E. puttleri responded to those nectary odors as strongly as did P. foveolatus. The responsiveness of both wasp species to the odor of artificial nectar greatly increased after they foraged on sugar solution scented with either banana or lemon odor. That parasitoid wasp species can differ in their ability to recognize food‐based cues is of fundamental and applied importance.

Distribution and new host records of a race of Chrysomelobia labidomerae Eickwort (Acari: Tarsonemina; podapolipidae) attacking the Colorado potato beetle in Mexico

ABSTRACT Distribution and host data are given for a race of Chrysomelobia labidomerae Eickwort, an ectoparasite of the Colorado potato beetle, Leptinotarsa decemlineata (Say), and some closely related species.

Effect of Temperature on Development, Fecundity, and Life Table Parameters of Encarsia citrina Craw (Hymenoptera: Aphelinidae), a Parasitoid of Euonymus Scale, Unaspis euonymi (Comstock), and Quadraspidiotus perniciosus (Comstock) (Homoptera: Diaspididae)

Abstract The development, reproduction, and life history of Encarsia citrina Craw were studied in the laboratory on San Jose scale, Quadraspidiotus perniciosus (Comstock), at constant temperatures of 15, 17.5, 20, 25, 27.5, and 30°C at 60–70% RH, and a photoperiod of 16:8 (L:D) h. Larval development did not occur at 15 and 30°C. Total developmental time varied from 22.7 d at 27.5°C to 47.4 d at 17.5°C. The lower development thresholds for larval, pupal, and egg to adult periods were 10.4, 6.3, and 9.0°C, respectively. The number of degree-days required to complete development was 434.8. The average longevity of adults ranged from 34.3 d at 15°C to 8.0 d at 30°C. The average fecundity of females ranged from 96.3 eggs at 20°C to 40 eggs at 17.5°C. Life table parameters were also determined at four constant temperatures (17.5–27.5°C). The intrinsic rate of increase, rm, values for E. citrina ranged from 0.074 at 17.5°C to 0.176 at 27.5°C. The highest net reproductive rate, R0, of 93.7 female offspring/female was estimated at 20°C. The mean generation time, T, ranged from 49.3 d at 17.5°C to 23.4 d at 27.5°C. The results of this study emphasize E. citrina survival and population growth under varied temperature conditions.

Distribution of Natural Enemies of Euonymus Scale, Unaspis euonymi (Comstock) (Homoptera: Diaspididae), in New Jersey

Abstract A statewide survey of New Jersey was carried out during 2001 to determine the current establishment and distribution of introduced natural enemies of euonymus scale. One hundred twenty-two sites were surveyed, and their location was recorded. Euonymus scale infestations were recorded at 89% of the sites surveyed. The most commonly encountered natural enemies were Cybocephalus sp.nr. nipponicus Enrody-Younga, Chilocorus kuwanae Silvestri, and the endoparasitoid, Encarsia citrina Craw. Neither of the introduced aphelinid parasitoid species, Encarsia sp.nr. diaspidicola (Silvestri) and Aphytis proclia (Walker), were recovered from the collection sites. The geographic distributions of the most commonly encountered natural enemies of euonymus scale are discussed.

Cicadomorpha insects associated with bacterial leaf scorch infected oak in central New Jersey.

ABSTRACT Potential insect vectors for transmission of oak leaf scorch caused by Xylella fastidiosa Wells et al., in pin and red oaks in New Jersey were surveyed by placing yellow sticky card traps in tree canopies and fogging with Pyrethrin insecticide during 2002–2006. Thirty-seven Cicadomorpha species were collected from 20 genera in Membracidae, Cicadellidae, Aphrophoridae, and Clastopteridae. Of the 12,880 potential vectors collected, 91.4% were Membracidae, 6.9% were Cicadellidae, and 1.7% were Aphrophoridae and Clastopteridae. Fogging collected more insect species and individuals than sticky card collections. Sticky card sampling, done more frequently and at a larger number of locations provided similar community structure information as fogging. Sticky card collections of the dominant treehopper species, Ophiderma definita Woodruff were male biased when females were gravid. O. definita populations peaked in early June, comprised 68.2% of the total collection, and were more abundant in pin oaks than red oaks. Graphocephala versuta (Say) peaked in mid-July, comprising 6.2% of the total collection. Higher Cicadomorpha populations were observed in asymptomatic oak canopies than in neighboring X. fastidiosa infected oaks. Individual insect specimens collected from oaks were subjected to a X. fastidiosa DNA assay by polymerase chain reaction amplification. The average X. fastidiosa positive rate was 13.89% for all specimens tested. Eleven treehopper species, six leafhopper species, and four spittlebug species tested DNA positive for X. fastidiosa.

Effect of Insecticides on Two Predators of the Colorado Potato Beetle (Coleoptera: Chrysomelidae)

The effect of insecticides currently used in commercial eggplant fields to control the Colorado potato beetle, Leptinotarsa decemlineata (Say) on two egg predators, Coleomegilla maculata DeGeer and Chysoperla carnea (Stephens) was evaluated. Mortality from contact exposure to leaf residues, topical applications, and ingestion of contaminated eggmasses was compared for the following insecticides: esfenvalerate alone and in combination with piperonyl butoxide (PBO); oxamyl; PBO; and rotenone alone and in combination with PBO. Topical exposure and feeding studies were conducted using concentrations 1.00, 0.90, 0.80, 0.70, 0.60, 0.50, 0.40, 0.30, 0.20, and 0.10X the maximum labeled dose; leaf exposure studies were conducted using concentrations 1.00, 0.75, 0.50, and 0.25X the maximum labeled dose. Mortality of C. maculata adults and larvae from topical exposure was high after 48 h of exposure for all chemicals and doses. Mortality from topical exposure was low for C. carnea larvae in all cases when compared to PBO alone. Mortality from exposure to leaf residues was low in all cases for C. maculata adults but varied, depending on dose and chemical, for both C. maculata and C. carnea larvae. For all treatments, ingestion of treated eggs negatively affected the feeding and survival of C. maculata adults and larvae and C. carnea larvae. Esfenvalerate combined with PBO had the greatest effect on C. maculata adults; rotenone combined with PBO had the greatest effect on C. maculata larvae; esfenvalerate combined with PBO affected C. carnea larvae the most.

Comparison of conventional and biological control intensive pest management programs on eggplant in New Jersey

Adoption of biological control and Integrated Pest Management programs by growers depends on adequate control of pests while remaining cost effective. Some New Jersey eggplant growers follow a biological control intensive pest management (BCIPM) program, utilizing the egg parasitoid Edovum puttleri Grissell for the control of Colorado potato beetle. This study evaluates the profitability of the BCIPM program based on comparisons of planting and insecticide application costs, and yield information from conventional and BCIPM growers during the 1993 and 1994 growing seasons. On average, BCIPM growers utilized less insecticide and made fewer applications than conventional growers to control Colorado potato beetles. Differences for the control of aphids, eggplant flea beetles, and two-spotted spider mites were less evident. Each year, BCIPM growers harvested increased levels of higher quality fruit when compared with conventional growers, while incurring similar production costs. These differences resulted in higher per hectare crop values, increased monetary returns, and a more environmentally friendly production system for BCIPM growers.

Impact of Selected Insecticides Used in Eggplant Production on Edovum puttleri Grissell (Hymenoptera: Eulophidae)

The impact of insecticides currently used in commercial eggplant fields to control the Colorado potato beetle, Leptinotarsa decemlineata (Say), on the egg parasitoid Edovum puttleri Grissell was ev...

Consumption of Eggplant Foliage by Colorado Potato Beetle (Coleoptera: Chrysomelidae)

Feeding of second- to fourth-instar Colorado potato beetle, Leptinotarsa decemlineata Say, on eggplant was monitored at constant temperatures of 20, 26, 29, 32 and 35° C, and at 16, 20, 27, 29, and...