Articles
TEXAS RESULTS: IMIDACLOPRID RESISTANCE IN BLACKMARGINED PECAN APHIDS
Article number
1070_19
Pages
167 – 169
Language
English
Abstract
During the 2011 and 2012 growing seasons, 46 separate laboratory tests of blackmargined pecan aphid (BMA) populations from 11 Texas counties were tested against imidacloprid.
All testing was conducted in a laboratory setting by placing BMA alataes on treated foliage and recoding mortality and first instar production after 24, 48 and 72 h of continuous exposure.
Results after 72 h of continuous exposure to imidacloprid treated foliage ranged from 85% survival and 165 first instars to 0% survival and no reproduction.
This range of control indicated that there are areas of resistance in Texas.
When difficult to control populations were detected, populations were retested against products with different modes of action (IRAC Groups 4C, sulfoxaflor; Group 9B, pymetrozine and Group 9C, flonicamid) effective control was achieved.
Where imidacloprid was effective against blackmargined aphid populations, effective control was also achieved by another IRAC Group 4A insecticide clothianidin.
Based on two years of test results, recommendations to producers for management actions to reduce or prevent resistance to imidacloprid in BMA populations include: 1) rotate IRAC group numbered products; 2) do not use more than two consecutive applications of the same IRAC group numbered product per season; 3) where possible, treat only problem varieties or areas; and 4) do not base your treatment decision just on the presence of honeydew.
All testing was conducted in a laboratory setting by placing BMA alataes on treated foliage and recoding mortality and first instar production after 24, 48 and 72 h of continuous exposure.
Results after 72 h of continuous exposure to imidacloprid treated foliage ranged from 85% survival and 165 first instars to 0% survival and no reproduction.
This range of control indicated that there are areas of resistance in Texas.
When difficult to control populations were detected, populations were retested against products with different modes of action (IRAC Groups 4C, sulfoxaflor; Group 9B, pymetrozine and Group 9C, flonicamid) effective control was achieved.
Where imidacloprid was effective against blackmargined aphid populations, effective control was also achieved by another IRAC Group 4A insecticide clothianidin.
Based on two years of test results, recommendations to producers for management actions to reduce or prevent resistance to imidacloprid in BMA populations include: 1) rotate IRAC group numbered products; 2) do not use more than two consecutive applications of the same IRAC group numbered product per season; 3) where possible, treat only problem varieties or areas; and 4) do not base your treatment decision just on the presence of honeydew.
Authors
W.O. Ree Jr., J. Lopez
Keywords
imidacloprid, blackmargined pecan aphid, Monellia caryella (Fitch), pecan, Carya illinoinensis, IRAC
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