Sublethal effect of beta‐cypermethrin on development and fertility of the Asian multicoloured ladybird beetle Harmonia axyridis

Abstract

The Asian multicoloured ladybird beetle, Harmonia axyridis, is utilized as a major natural enemy of aphids in the field, greenhouses and orchards. However, it has been looked as invasive predator distributing in worldwide. To refine integrated pest management (IPM) against aphids, it is important to evaluate the effects of insecticides on physiology and behaviour of the high adapted predators. Beta‐cypermethrin, a broad‐spectrum insecticide, not only kills aphids at lethal concentrations but also affects natural enemy of aphids. In our study, the age‐stage, two‐sex life table was used to evaluating sublethal effects of beta‐cypermethrin on the predatory ladybird beetle H. axyridis. In the parent generation, the pre‐oviposition period of H. axyridis was significantly shortened (8.93 days) after exposure to LC5 beta‐cypermethrin (5% lethal concentration) as compared with control (10.06 days). However, the oviposition period was significantly longer (46.17 days instead of 43.90 days), and fecundity (eggs per female) was significantly increased by 49.64% when compared with control. In the F1 generation, the length of the juvenile stage was not affected, but the oviposition period increased significantly (38.19 days compared to 31.39 days in the control). This positive effect was translated to the fecundity that increased significantly by 62.27% as compared with control. According to the life‐table analysis, the intrinsic rate of increase (rm) was significantly higher in treatment (0.140 per day) than that in the control (0.123 per day). In addition, the net reproductive rate (R0) increased significantly by 91.53%. These results would be useful in assessing the overall effects of beta‐cypermethrin on H. axyridis and even for discussing the ecological mechanism of the unexpected extension of H. axyridis during IPM programme.

Pesticide-mediated interspecific competition between local and invasive thrips pests

“…However, sublethal concentrations of insecticides may also induce positive effects on insect bionomics2627. Sublethal concentrations of beta-cypermethrin lead to increased fecundity of Harmonia axyridis 30. When treated with sublethal concentrations of avermectin as immatures, Panonychus citri have shorter generation doubling times and greater intrinsic growth rates than untreated immatures28.…”

Modification of Flight and Locomotion Performances, Respiratory Metabolism, and Transcriptome Expression in the Lady Beetle Harmonia axyridis through Sublethal Pesticide Exposure

“…The LC 5 of beta-cypermethrin for H. axyridis was 3.158 mg L −1 as it was estimated in a sister study by Xiao et al ( 2016 ). The ladybirds were exposed to the insecticide using the method of exposure to pesticide residues in glass tubes (see Desneux et al, 2004a , b , c ).…”

“…Numerous studies have reported that sublethal doses of pesticides may impact arthropods (Liang et al, 2012 ; He et al, 2013 ; Pan et al, 2014 ; Chen et al, 2015 ; Fekri et al, 2016 ; Guedes et al, 2016 ) and notably natural enemies such as coccinellids (Desneux et al, 2007 ). Studies showed that various aspects of the biology of coccinellids may be altered by pesticides, including development (Yu et al, 2014 ), prey consumption (Wang and Shen, 2002 ; Singh et al, 2004 ; He et al, 2012 ), reproduction (Galvan et al, 2005 ; Rahmani and Bandani, 2013 ; Xiao et al, 2016 ), and metabolic mechanisms related to detoxification (Zhang et al, 2012 ; Tang et al, 2014 ). Evaluating the side-effects of sublethal doses of pesticides may help depicting possible adaptations of predatory insects to sublethal toxic pressures; it may also provide more information to improve the application of biological control agents in combination with sprayed pesticides in agricultural IPM systems.…”

“…However, H. axyridis has many biological and physiological features that are adaptable. For instance, we found that H. axyridis treated with a sublethal dose of beta-cypermethrin developed faster and showed significantly increased fertility (Xiao et al, 2016 ). There are no reports analyzing changes in flight and locomotion performances of H. axyridis exposed to sublethal doses of pesticides.…”

Lethal and behavioral sublethal side effects of thiamethoxam on the predator Harmonia axyridis

“…TMX applied systemically did not adversely affect the functional response of H. axyridis; therefore, systemic application of TMX (e.g., stem application) might be available to minimize potential negative effects on natural enemies in Chinese cabbage fields. Moreover, a reduction in the consumption capacity of H. axyridis may affect its reproductive capacity, which would inhibit population growth and consequently affect performance in pest management programs (Stark & Banks, 2003;Desneux et al, 2007;Xiao et al, 2016b). Therefore, further, longer term studies are required to fully investigate the possible effects on the development and fecundity of H. axyridis after exposure to TMX and/or consuming TMX-contaminated prey.…”