Lethal and Sublethal Effects of Fenpropathrin on the Biological Performance of <I>Scolothrips longicornis</I> (Thysanoptera: Thripidae)

Abstract

Determination of negative nontarget effects of pesticides on beneficial organisms by measuring only lethal effects is likely to underestimate effects of sublethal doses. In this study, the sublethal effects of fenpropathrin on the predatory thrips Scolothrips longicornis Priesner (Thysanoptera: Thripidae) fed on Tetranychus urticae Koch (Acari: Tetranychidae) were evaluated under laboratory conditions. The estimated values of LC50 for female and male predators were 6.53 and 5.47 microg a.i./ml, respectively. Exposure to low-lethal concentrations (LC10, LC20, and LC30) of fenpropathrin significantly affected the biological characteristics of treated females of S. longicornis, the most noticeable effects being a shortening of female life span by > 70% accompanied by large reductions in oviposition period and fecundity. The offspring of females treated with low-lethal concentrations of fenpropathrin likewise had significantly reduced longevity, oviposition period, and fecundity, although not to the same extent as experienced by their mothers. Their juvenile development time was, however, not affected. These effects on the offspring were reflected in reduced rates of population increase and increased doubling times.

Atrazine exposure affects longevity, development time and body size in Drosophila melanogaster

“…For example, sethoxydim causes a 32% decrease in eclosion success of the cabbage butterfly, Pieris rapae , and fluazifop-p-butyl, a 21% reduction (Russell and Schultz, 2010). We also found that when adult flies were maintained on atrazine food they had a reduced lifespan and this is consistent with other studies showing a reduction in insect lifespan as a result of pesticide exposure (Bravo-Hernandez et al, 2014; Oliveira et al, 2014; Pakyari and Enkegaard, 2013). The reduction in larval, pupal and adult survival that we observed may be due to atrazine interacting with the mitochondrial electron transport system.…”

Effects of spirodiclofen on life history traits and population growth of a spider mite predator Oligota flavicornis (Coleoptera: Staphyllinidae) based on the age‐stage two‐sex life table theory

“…Our results suggested that the common field practice of spirodiclofen might slow down the developmental rate of the predatory beetle, and reduce its population size. Although no other studies have examined the effects of spirodiclofen on the life history characteristics of Oligota staphylinids, our results agreed with certain reports on other predatory natural enemies; sublethal spirodiclofen concentration may not affect the population parameters of Amblyseius swirskii, the longevity and fecundity of Scolothrips longicornis . And the recommended concentration of spirodiclofen (120 mg a.i.…”

“…Recent studies have also shown that several predatory mites could be highly compatible with spirodiclofen; however, the adverse consequences that arthropod natural enemies are negatively affected by sublethal spirodiclofen concentrations in different ways, such as physiological events, mortality, longevity and reproduction, parasitism rate and emergence rate and life‐table parameters have also been reported. However, it is not understood comprehensively how spirodiclofen affects the development, survival, fecundity, and population growth of O. flavicornis , which is the primary consideration for the compatibility of natural enemy insects with pesticides.…”

Lethal and Sublethal Effects of Azadirachtin and Cypermethrin on <I>Habrobracon hebetor</I> (Hymenoptera: Braconidae)

“…Treatment of the soybean aphid, Aphis glycines, with a sublethal concentration of beta-cypermethrin decreased the r m and λ values but did not significantly affect adult longevity or fecundity of the F1 generation; population growth of the F2 generation, however, was enhanced by the prior treatment with betacypermethrin (Gao et al 2008). Pakyari et al (2013) reported that sublethal concentrations (LC 10 ,LC 20 , and LC 30 ) of fenpropathrin could shorten the female life span of Scolothrips longicornis significantly, accompanied with large reductions in oviposition period and fecundity; their offspring also had significantly reduced longevity, oviposition period, and fecundity, although not to the same extent as experienced by their mothers. The results revealed that sublethal concentrations of pesticides can have long-term effects.…”