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Re: [SANET-MG] honey bee motion for EU
Hi Stephan Gallagher,
You have asked me a very important question but it is one that really
requires fuller experimental studies, preferably studies conducted by
independent investigators. As you are probably aware , Dipel (Bt
spores) is often used to treat the entrances to honey bee colonies to
discourage mite parasites. However, the interaction between Dipel or
pure Cry toxins and fungal parasites or bee viruses on honey bee larvae
or adults has not been studied to my best knowledge.
However, as the abstracts below show, Nosema infected corn borer larvae
much more susceptible to both Dipel and pure cry toxin. The point is
that fungal parasite infected bees may be sensitive to Dipel and Bt
toxin and Bt may enhance parasite and virus infection to a similar but
less pronounced impact than do the neonicotinoid pesticides which are
very potent indeed. Recent reports suggest that the insect immune system
is focused on a long standing battle between fungal parasites and the
insects and things that impair the insect immune system such as the
neonicotinoids and Bt need careful scrutiny before the bees are
eliminated by tipping the contest in favor of the fungal parasites not
Finally, I have been impressed by the apparent unwillingness of
regulators to considers the kinds of interaction mentioned above and the
granting agencies seem unwilling to support such important research.
Hope my reply answered your question? sincerely, joe cummins
. Pierce CM, Solter LF and Weinzierl RA. Interactions between Nosema
pyrausta (Microsporidia: Nosematidae) and Bacillus thuringiensis subsp.
kurstaki in the European corn borer (Lepidoptera: Pyralidae). J Econ
Entomol. 2001 Dec;94(6):1361-8.
Larval susceptibility to Bacillus thuringiensis was determined for
Nosema pyrausta-infected and uninfected European corn borers, Ostrinia
nubilalis (Hübner), in bioassays using a commercial formulation of B.
thuringiensis subsp. kurstaki, Dipel ES, incorporated into diet. LC50
values for N. pyrausta-infected larvae were significantly lower (P <
0.0001) than for uninfected larvae and declined with increasing levels
Reardon BJ, Hellmich RL, Sumerford DV and Lewis LC. Growth, development,
and survival of Nosema pyrausta-infected European corn borers
(Lepidoptera: Crambidae) reared on meridic diet and Cry1Ab. J Econ
Entomol. 2004 Aug;97(4):1198-201.
The LC50 of infected larvae was about half that of uninfected larvae,
indicating that infected larvae are more vulnerable to toxin. This work
has implications for resistance management of O. nubilalis and
demonstrates that it is important to determine whether N. pyrausta is
present when testing susceptibility of larvae to transgenic corn hybrids.
Stephen Gallagher wrote:
Is there any way to determine whether topical application of natural
Bt as intermittant foliar spray could play a role on bees within an
organic system, similar to that of GM Bt built into crops? Does the
parasitic fungus exist widely in unmodified environments, thus making
any use of Bt problematic, at best, or is its pressence itself a
result of practices of "conventional" agriculture?
Nathan Creek Organic Farm CSA
----- Original Message ----- From: "jcummins" <jcummins@UWO.CA>
Sent: Saturday, June 23, 2007 8:09 AM
Subject: [SANET-MG] honey bee motion for EU
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