Erin M. Hitchner

Host plant choice experiments of Colorado potato beetle (Coleoptera: Chrysomelidae) in Virginia.

Abstract Field and laboratory-choice experiments were conducted to understand aspects of host plant orientation by the Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), in Virginia. In laboratory bioassays, L. decemlineata oriented to volatiles emitted by potato, Solanum tuberosum L., foliage over both tomato, Lycopersicon esculentum L., and eggplant, Solanum melongena L., foliage, and eggplant over tomato foliage, all of which had been mechanically damaged. Field choice tests revealed more L. decemlineata adults, larvae, and egg masses on eggplant than on tomato. In other experiments, counts of live L. decemlineata on untreated paired plants and counts of dead beetles on imidacloprid-treated plants did not differ between potato and eggplant. L. decemlineata was significantly attracted to eggplant over both tomato and pepper. To determine whether feeding adults affected orientation to host plants, an imidacloprid-treated eggplant or potato plant was paired with an untreated eggplant or potato plant covered in a mesh bag containing two adult male beetles. Significantly more adults were attracted to eggplant with feeding male beetles paired with another eggplant than any other treatment combination. These results indicate that the presence of male L. decemlineata on plants affects host plant orientation and suggests that the male-produced aggregation pheromone may be involved.

Baseline toxicity and field efficacy of metaflumizone on colorado potato beetle (Coleoptera: Chrysomelidae)

ABSTRACT Baseline toxicity levels to a novel semicarbazone insecticide, metaflumizone were established for 25 field populations of Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), from North America. Excluding the susceptible laboratory strain, 50% lethal concentrations of metaflumizone ranged from 0.57 to 1.31 ppm, while response slopes ranged from 1.92 to 4.24 (average = 2.93), and were unrelated to the 50% lethal concentration (r = 0.06; P = 0.76). Beetle populations with known resistance to the neonicotinoid imidacloprid also exhibited the highest LC50 levels to metaflumizone suggesting at least the possibility of cross-resistance. Additional experiments using a potato leaf-dip bioassay as well as field efficacy evaluations confirmed the high level of toxicity of metaflumizone to L. decemlineata and demonstrated a potential benefit of tank mixing a low rate of the pyrethroid esfenvalerate with metaflumizone at one-tenth the recommended field rate. These research findings confirm that metaflumizone is highly active against L. decemlineata larvae and adults and could provide an effective alternative insecticide for potato pest management.

Fruit size and infestation by european corn borer, Ostrinia nubilalis hubner, in bell pepper

Abstract Growers initiate application of sprays when 4 corn borer moths were trapped in black light traps, regardless of fruit size, resulting in a potential of damaged fruit. Greenhouse trials with bell peppers demonstrated that European corn borer, Ostrinia nubilalis Hubner, larvae did not attack pepper fruit that were 1.3 cm dia, but did attack pepper fruit when they were 3.8 cm dia or larger. If fruit were 1.3 cm dia, or if there were no fruit on the plant, borers readily entered the plant stems instead. These data are important to an effective pest management program for growers to initiate the first pesticide spray in bell peppers in the mid-Atlantic region to protect the fruit from infestation by European corn borers. Growers can continue to use blacklight traps and pheromone traps to monitor moth activity and determine their weekly spray schedule (days between sprays), if necessary, for the remainder of the season. Pepper fruit size can be used to determine when to initiate sprays for control of the European corn borer in bell peppers.

Effect of Simulated Rainfall on the Control of Colorado Potato Beetle (Coleoptera: Chrysomelidae) and Potato Leafhopper (Homoptera: Cicadellidae) with At-Plant Applications of Imidacloprid, Thiamethoxam or Dinotefuran on Potatoes in Laboratory and Field T

© 2013 Ghidiu et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Effect of Simulated Rainfall on the Control of Colorado Potato Beetle (Coleoptera: Chrysomelidae) and Potato Leafhopper (Homoptera: Cicadellidae) with At-Plant Applications of Imidacloprid, Thiamethoxam or Dinotefuran on Potatoes in Laboratory and Field Trials