Resistance to ß-cyfluthrin in populations of the pest lesser mealworm, Alphitobius diaperinus
Résumé
The lesser mealworm, Alphitobius diaperinus, is
an invasive tenebrionid beetle infesting poultry
facilities worldwide. As large population outbreaks
occur regularly in broiler farms, insecticides are
massively sprayed to control populations in
poultry houses. In some countries, there has been
evidence that A. diaperinus can develop resistance
to several classes of insecticides. Here, we
evaluated the insecticide susceptibility of several
A. diaperinus populations collected in 2018 from
various poultry farms in Northern Brittany
(France). The adults were exposed to increasing
doses of four different insecticides (technical-
grade): two pyrethroids (ß-cyfluthrin, permethrin),
and two organophosphates (azamethiphos and
pirimiphos-methyl). Results revealed the existence
of significant resistance to ß-cyfluthrin in three
out of 11 populations. One population in particular
was extremely resistant to ß-cyfluthrin. For this
population the highest tested dose, equivalent to
500 times the recommended application rate (i.e.
10 g pure ß-cyfluthrin per m²), was not even
sufficient to induce a low level of mortality.
In contrast, for permethrin, azamethiphos, or
pirimiphos-methyl, the results from dose-response
bioassays did not suggest the occurrence of
resistance. Hence, insecticides containing ß-cyfluthrin
as active ingredient, which has a long use
history in France, should be avoided in poultry
facilities