Journal of Economic Entomology (2009) 102, 170-176

R.N.C. Guedes, L.C. Magalhães and L.V. Cosme (2009)
Stimulatory sublethal response of a generalist predator to permethrin: Hormesis, hormoligosis, or homeostatic regulation?
Journal of Economic Entomology 102 (1), 170-176
Abstract: The assessment of pesticide effects in arthropods historically have relied heavily on acute lethal effects. Although the sublethal responses to such compounds are sometimes neglected, stimulatory effects associated with low doses of compounds toxic at higher doses, such as pesticides, have been widely reported in recent years and recognized as a general toxicological phenomenon. Evidence of such stimulatory response has also been reported among mites and a few insect pest-species exposed to pesticides and recognized as a one of the potential causes underlying pest resurgence and secondary pest outbreaks. However, fitness parameters and its implications were seldom considered in these studies and natural enemies are not usually target of attention. Here, we reported the stimulatory effect of sublethal doses (ranging from 0.02 to 172.00 ppb in addition to the control) of the pyrethroid permethrin topically applied to third instar nymphs of the spined soldier bug, Podisus distinctus (Stål) (Heteroptera: Pentatomidae). The parameters estimated from the fertility tables of insects exposed to the increasing doses of insecticide indicated a slight increase in the mean survival time for doses >0.20 ppb and a peak in the net reproductive rate at 1.72 ppb. This trend is coincident and correlated with the intrinsic rate of population growth (n = 18, r = 0.78, P = 0.0001), which also shows apeak at 1.72 ppb, leading to higher reproductive values of insects exposed to this dose. The phenomenon is consistent with insecticide-induced hormesis, for which the potential implications are discussed.
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Link to article at publishers website
Database assignments for author(s): Raul Narciso C. Guedes

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
resistance to pesticides

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Podisus distinctus (predator)