Please note this concern for resistanct to
two organically allowed pesticides (pyrethroid as a natural botanical
pesticide) is restircted (allowed following NOP rule)and Spinosad (allowed).
If you have expereince with this insect
pest or these pesticides please reply to the [log in to unmask] and to
Tony Shelton from Cornell University at [log in to unmask]
Sincerely,
Vicki Morrone
From: Tony Shelton
[mailto:[log in to unmask]]
Sent: Tuesday, July 22, 2008 11:04
PM
To: Great Lakes Vegetable WG
Subject: Resistance in ECB
Has anyone done tests to determine if European corn borer is becoming
resistant to pyrethroids and spinosad? A local extension educator in New
York says that his sweet corn farmers are telling him that they are
experiencing resistance. A few years ago we published a paper that
indicated a dramatic decrease in efficacy for pyrethroids and spinosad against
ECB with increased temperature after some growers claimed 'resistance'.
So now we are wondering if anyone has done some actual lab test for resistance.
Musser, F. P and A. M. Shelton.
2005. The influence of post-treatment temperature on insecticides to Ostrinina nubilalis. Pest
Management Sci. 61:508-510
Abstract:
The influence of post-treatment temperature on the toxicities of two
pyrethroids (lambdacyhalothrin
and bifenthrin), a carbamate (methomyl) and a spinosyn (spinosad) to Ostrinia nubilalis
(H¨ubner) larvae was evaluated in laboratory assays. From 24 to 35
?C, the
toxicities of the pyrethroids
decreased 9.5- and 13.6-fold while spinosad toxicity decreased 3.8-fold. The
toxicity of methomyl did not
change significantly. The results demonstrate that the most effective
insecticide against a pest may vary
with environmental conditions. In situations where comparable products
frommultiple insecticide classes
are available, temperature should be included as a factor in the
decision-making process.
--
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Tony Shelton: [log in to unmask]
Professor, Department of Entomology
International Professor; Associate
Director International Programs
Cornell University/NYSAES, 630 W. North
St., Geneva NY 14456
PH 315 787-2352 FAX 315
787-2326
http://www.nysaes.cornell.edu/ent/faculty/shelton/index.html