Comparing Host Plant Resistance, Engineered Resistance, and Insecticide Treatment for Control of Colorado Potato Beetle and Potato Leafhopper in Potatoes

Gerald M Ghidiu,Joseph J Coombs,Kimberly J Felcher,David S Douches

doi:10.1155/2011/390409

Abstract

The Colorado potato beetle,Leptinotarsa decemlineata(Say) Order Coleoptera and the potato leafhopper,Empoasca fabae(Harris) Order Homoptera, are the major insect pests of potato in eastern North America. In two years of field trials, we compared the effectiveness of three pest management options for the control of Colorado potato beetle and potato leafhopper: natural host plant resistance (glandular trichomes), engineered resistance (Bacillus thuringiensis[Bt] Berlinercry3Agene) and a susceptible potato cultivar (Superior) with an at-planting application of the insecticide thiamethoxam. Similar and acceptable control of the Colorado potato beetle larvae was obtained with theBt-cry3Alines and the thiamethoxam treated “Superior” variety. The glandular trichome cultivar had significantly less Colorado potato beetle damage than did the untreated “Superior” in 2004, although damage was significantly greater than in theBt-cry3Alines and the insecticide-treated potatoes for both years, and was the only treatment that consistently had very little potato leafhopper damage. These data demonstrate that although each type of host plant resistance mechanism (Bt-cry3Aor glandular trichomes) was as effective as the chemical control against one of the insects, neither provides adequate resistance to both Colorado potato beetle and potato leaf hopper.

Highlights

The Colorado potato beetle, Leptinotarsa decemlineata (Say) Order Coleoptera, is considered the most important pest of potatoes throughout the northeastern and mid-Atlantic regions of the United States [1]
There were no significant differences between “Yukon Gold + Btcry3A,” “Norwis + Btcry3A,” and “Superior” + thiamethoxam for Colorado potato beetle larval counts in both years (Table 1)
The same three treatments (“Yukon Gold + Btcry3A,” “Norwis + Btcry3A,” and “Superior” + thiamethoxam) resulted in significantly less plant defoliation caused by Colorado potato beetle as compared with “Prince Hairy” and the untreated control in both years (Table 2)

Summary

Introduction

The Colorado potato beetle, Leptinotarsa decemlineata (Say) Order Coleoptera, is considered the most important pest of potatoes throughout the northeastern and mid-Atlantic regions of the United States [1]. Growers rely on pesticides to control Colorado potato beetle in the field but it has developed field resistance to nearly every insecticide used against it and is resistant to more than 40 chemical insecticides [2]. Another important insect pest of potatoes, the potato leafhopper (Empoasca fabae (Harris) Order Homoptera), is a sap-feeding insect pest that causes damage known as “hopper burn” [1, 3]. The length of effective protection can vary and additional foliar insecticide sprays may be needed to control midsummer populations of potato leafhopper, adding to the cost of production

Methods

Results

Conclusion