Jay F. Brunner

Effect of Pesticides on Colpoclypeus florus (Hymenoptera: Eulophidae) and Trichogramma platneri (Hymenoptera: Trichogrammatidae). Parasitoids of Leafrollers in Washington

Abstract Pesticides were evaluated for their effect on two parasitoid species, Colpoclypeus florus and Trichogramma platneri, that are potential biological control agents of leafrollers in apple orchards. Organophosphate and carbamate insecticides were highly toxic to both parasitoids in topical applications, but foliar residues of some products were nontoxic after 7 d. At reduced rates, topically applied pyrethroids were low in toxicity to C. florus were highly toxic to T. platneri, and foliar residues were nontoxic after about 7 d. Imidacloprid and abamectin were highly toxic when applied topically to both parasitoids but were not toxic as 1-d-old residues. Insect growth regulators did not cause mortality either as topical applications or residues; however, diflubenzuron caused severe sublethal effects, completely blocking the production of C. florus offspring. Biorational pesticides, such as soap, oil, and B. thuringiensis products, caused no toxicity to C. florus but had a direct impact on T. platneri as topical applications through physical immobilization. The potential to integrate different pesticides with biological control of leafrollers and the need for a step-wise approach to evaluate the impact of pesticides against natural enemies is discussed.

Effects of Broad-Spectrum Insecticides on Epigeal Arthropod Biodiversity in Pacific Northwest Apple Orchards

Abstract Analyses of pitfall traps in Washington and Oregon apple orchards revealed that highly mobile invertebrates were strongly susceptible to applications of broad-spectrum, neural-active insecticides. When compared with orchard blocks managed without broad-spectrum insecticides, orchard blocks under conventionally managed regimes had significantly lower populations of ground beetles (Coleoptera: Carabidae), centipedes (Chilopoda), earwigs (Dermaptera: Forficulidae), harvestmen (Opiliones), and spiders (Aranae). The carabid species Pterostichus adstrictus Eschscholtz and P. melanarius Illiger constituted 89% of all ground beetles collected over 2 growing seasons. Three times as many free-hunting spiders were found in the no broad-spectrum blocks than in the conventional blocks. Less mobile invertebrates such as mites, slugs, and snails appeared to be less affected by the different management strategies. Ground beetles, spiders, harvestmen, earwigs, and centipedes are all probable predators of lepidopteran and homopteran pests of apple.

An Inexpensive Immunomarking Technique for Studying Movement Patterns of Naturally Occurring Insect Populations

Abstract An immunomarking system useful for determining insect movement patterns was developed that allows the marking of naturally occurring populations of insects within large areas with inexpensive and readily available proteins that can be applied using standard spray equipment. Enzyme-linked immunosorbent assay (ELISA) protocols were developed to detect chicken egg albumin (as egg whites), bovine casein (as cows’ milk), and soy protein (as soy milk) at levels ≤30 ppb. Field applications showed that all of the proteins were stable and detectable at high levels on apple leaves at least 19 d after application. When adult pear psylla (Cacopsylla pyricola Foerster, Homoptera: Psyllidae) walked across apple leaves with field-aged residues of the marker proteins plus either Sylgard 309, EDTA, or both, they acquired the mark over the 19-d test period an average of 78.9, 19.4, and 2.1% of the time for egg whites, milk, and soy milk, respectively. Two field applications of the three markers were applied to an apple orchard during the first generation flight of codling moth (Cydia pomonella L., Lepidoptera: Tortricidae). We found that 46.5% of moths captured within a 2.8-ha area (including 1.6-ha surrounding the treated areas) tested positive for at least one of the three proteins. The marker systems developed cost between

Tree fruit IPM programs in the western United States: the challenge of enhancing biological control through intensive management.

0.12 and

Susceptibility of Choristoneura rosaceana (Lepidoptera: Tortricidae) to Two New Reduced-Risk Insecticides

0.26liter versus older immunomarkers (using purified vertebrate IgG) that cost roughly

A web-based decision support system to enhance IPM programs in Washington tree fruit.

500/liter.

Field Attraction of the Stink Bug Euschistus conspersus (Hemiptera: Pentatomidae) to Synthetic Pheromone-Baited Host Plants

The seminal work of Stern and his coauthors on integrated control has had a profound and long-lasting effect on the development of IPM programs in western orchard systems. Management systems based solely on pesticides have proven to be unstable, and the success of IPM systems in western orchards has been driven by conservation of natural enemies to control secondary pests, combined with pesticides and mating disruption to suppress the key lepidopteran pests. However, the legislatively mandated changes in pesticide use patterns prompted by the Food Quality Protection Act of 1996 have resulted in an increased instability of pest populations in orchards because of natural enemy destruction. The management system changes have made it necessary to focus efforts on enhancing biological control not only of secondary pests but also of primary lepidopteran pests to help augment new pesticides and mating disruption tactics. The new management programs envisioned will be information extensive as well as time sensitive and will require redesign of educational and outreach programs to be successful. The developing programs will continue to use the core principles of Stern and his co-authors, but go beyond them to incorporate changes in society, technology and information transfer, as needed.

Dispersal of Epiphyas postvittana (Walker) and Planotortrix octo Dugdale (Lepidoptera: Tortricidae) at a Canterbury, New Zealand orchard.

ABSTRACT The response of field-collected populations of the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), to chlorantraniliprole, spinetoram, spinosad, and azinphosmethyl was assessed using a diet incorporation bioassay. Populations of obliquebanded leafroller were collected from nine orchards in Chelan, Douglas, Grant, and Okanogan counties of Washington. The neonates of the F1 or F2 generation were used in all assays. The parameters of probit regression lines were estimated and lethal concentration ratios were calculated for all populations compared with a susceptible laboratory population. Significant variation was detected in response to all four insecticides including chlorantraniliprole and spinetoram, which had never been used in the field, lethal concentration ratios were 3.9–39.7 for azinphosmethyl, 0.5–3.6 for spinosad, 1.2–5.3 for chlorantraniliprole, and 0.5–4.1 for spinetoram. Correlation analysis indicated possibility of cross-resistance between spinosad and spinetoram, which are both members of spinosyn class. The occurrence of low but significant levels of resistance against chlorantraniliprole and spinetoram in field-collected populations of C. rosaceana before their first field application indicates that the risk of resistance evolution against these two new reduced-risk insecticides exists. However, it is likely that these low levels of resistance can be managed if the insecticides are used judiciously in conjunction with sound resistance management programs. Implications of these results for developing and implementing resistance management strategies are discussed.

Lethal and Sublethal Effects of an Insect Growth Regulator, Pyriproxyfen, on Obliquebanded Leafroller (Lepidoptera: Tortricidae)

BACKGROUND Integrated pest management (IPM) decision-making has become more information intensive in Washington State tree crops in response to changes in pesticide availability, the development of new control tactics (such as mating disruption) and the development of new information on pest and natural enemy biology. The time-sensitive nature of the information means that growers must have constant access to a single source of verified information to guide management decisions. RESULTS The authors developed a decision support system for Washington tree fruit growers that integrates environmental data [140 Washington State University (WSU) stations plus weather forecasts from NOAA], model predictions (ten insects, four diseases and a horticultural model), management recommendations triggered by model status and a pesticide database that provides information on non-target impacts on other pests and natural enemies. A user survey in 2008 found that the user base was providing recommendations for most of the orchards and acreage in the state, and that users estimated the value at

Resistance and cross-resistance in populations of the leafrollers, Choristoneura rosaceana and Pandemis pyrusana, in Washington apples

16 million per year. CONCLUSIONS The design of the system facilitates education on a range of time-sensitive topics and will make it possible easily to incorporate other models, new management recommendations or information from new sensors as they are developed.