RT Journal Article SR Electronic T1 No impact of biocontrol predator on development time or size of surviving Aedes albopictus under optimal nutritional availability JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.09.16.460697 DO 10.1101/2021.09.16.460697 A1 Marie C. Russell A1 Lauren J. Cator YR 2021 UL http://biorxiv.org/content/early/2021/09/17/2021.09.16.460697.abstract AB Background Cyclopoid copepods have been applied successfully to limit populations of highly invasive Aedes albopictus mosquitoes that can vector diseases, including chikungunya, dengue, yellow fever, and Zika, to humans. However, there is concern that changes in certain vector traits, induced by exposure to copepod predation, might increase the risk of disease transmission. In this study, we tested whether cyclopoid copepod predation has sublethal effects on the development time or adult size of Ae. albopictus under the scenario of an invasion in southeast England, which lies at the northern edge of the vector’s expanding global range.Methods Third instar Ae. albopictus larvae, hereafter referred to as “focal individuals”, were placed in individual Petri dishes, each containing four newly-hatched Ae. albopictus larvae, which were counted, removed, and replaced daily. All focal individuals were provided with fish food ad libitum, and half were exposed to Megacyclops viridis copepod predators. The day of pupation was recorded for each focal individual, and the wing length of each focal adult was also measured.Results Exposing late instar Ae. albopictus to predation decreased their chances of surviving to adulthood. Mortality of the focal individuals was 12.9% in the predator treatment, and 2.9% in the controls. Three focal larvae that died in the predator treatment showed signs of melanization, indicative of wounding. Among surviving Ae. albopictus, no significant difference in either pupation day or wing length was observed due to copepod predation.Conclusions We found that M. viridis predation on smaller Ae. albopictus larvae does not significantly affect the pupation day or adult size of surrounding larger larvae that are less vulnerable to copepod attacks. This study controlled for density effects on size by maintaining a constant number of newly-hatched prey larvae surrounding each focal larva. Those working to control Ae. albopictus populations in the field should be made aware that increased adult body size can occur if copepod biocontrol agents are applied at lower than necessary levels. The absence of a significant sublethal impact from M. viridis copepod predation on surviving later-stage larvae in this analysis supports the use of M. viridis as a biocontrol agent.Competing Interest StatementThe authors have declared no competing interest.