Larval Competition Between Invasive Aedes albopictus and Resident Culex pipiens Mosquitoes (Diptera: Culicidae) From Türkiye in the Presence of an Insect Growth Regulator

Abstract

The spread of the invasive mosquito Aedes albopictus in T & uuml;rkiye may influence other vectors and traits related to their ability to transmit arboviruses. Interspecific competition between Ae. albopictus and the resident vector of West Nile virus (WNV), Culex pipiens can influence WNV transmission through changes in the abundance of Cx. pipiens and the phenotypic traits of adults. Furthermore, environmental factors can modify interspecific competition, especially if the factor differentially impinges upon the superior competitor. To improve our understanding of competition's influence on traits of mosquitoes that relate to arbovirus transmission, we tested 2 hypotheses: Exposure to the insecticide pyriproxyfen alters interspecific competition among larval Ae. albopictus and Cx. pipiens, and competitive asymmetry favoring Ae. albopictus over Cx. pipiens alters survival of adult females. Interspecific and intraspecific larval competition were evaluated with 2 detritus types and in the presence or absence of pyriproxyfen. Higher intra- and interspecific competition reduced survivorship to adulthood, lengthened development, and yielded smaller sized adults of Ae. albopictus and Cx. pipiens. The presence of pyriproxyfen had minimal impact on the competitive outcomes. Interspecific interactions exhibited competitive asymmetry with Ae. albopictus being competitively dominant over Cx. pipiens. Survival of adult females was differentially compromised under high competition conditions. Adult survival was lengthened for Ae. albopictus and shortened for Cx. pipiens derived from interspecific conditions relative to intraspecific treatments. These results demonstrate how competitive asymmetry among the larvae of an invasive and resident mosquito can influence recruitment of adults and their survival, factors predicted to be important to transmission of arboviruses.