Performance of Eriopis connexa (Coleoptera: Coccinellidae) resistant to lambda-cyhalothrin after extended recovery from knockdown

Abstract

A population of the predatory lady beetle Eriopis connexa (Germar) (Coleoptera: Coccinellidae) was recorded as resistant to lambda-cyhalothrin. Adults exposed to this insecticide have recovered from knockdown after 72 h. Thus, the performance of resistant (R) and susceptible (S) populations of E. connexa not exposed to insecticide (R0 and S0) and R adults recovering from knockdown 24, 48, and 72 h after exposure (R24, R48, and R72) was studied. In addition, the fertility life table parameters were calculated for one generation considering the progenies from R0, S0, and R24 populations. The recovery rate from knockdown was 69.4% for R-adults, and greater recovery rate was observed within 48 h following lambda-cyhalothrin exposure. The S-females produced about 50% more eggs and lived longer, when compared with R-females irrespective of the recovery periods after knockdown. The R-females produced similar number of eggs and exhibited similar longevity across all treatments (R0, R24, R48, and R72). Progenies produced by R- and S-populations did not exhibit consistent differences in development and survival. The fertility life table parameters showed higher intrinsic rate of population growth (r) and lower mean generation time (T) for R0- and R24-females, when compared with those for S0-females. Thus, the time interval needed to recover from knockdown is not related to the adaptive cost of resistance in E. connexa.

Lethal and Sublethal Effects of Insecticides Used in Cotton on Harmonia Axyridis

“…They assumed that such an effect this was resulted from metabolism and/or energy expenditure required for the insecticide excretion. Santos et al (2016) found that E. connexa ladybug recovered from the knockdown effect of pyrethroid insecticides within up to 72 hours.…”

Heterosis and reselection for pyrethroid resistance trait maintenance in the lady beetle Eriopis connexa (Germar)

“…The resistance of E. connexa to lambda-cyhalothrin is possible due to an increased esterase enzymatic profile (Rodrigues et al, 2014(Rodrigues et al, , 2020. In turn, it generates a fitness cost, with resistant beetles having reduced reproductive potential and reduced longevity when compared to susceptible individuals (D' Ávila et al, 2018;Ferreira et al, 2013;Lira et al, 2016;Santos et al, 2016). Other insects such as Aphis gossypii (Glover) expressed longer pre-reproductive period and low reproductive rate (Zhang et al, 2020).…”