title: Malathion influences competition between Aedes albopictus and Aedes japonicus.
abstract: Competitive interactions may facilitate or repel invaders into new communities, and these interactions may depend on other environmental conditions such as the presence of pesticides. Malathion is widely used in controlling agricultural pests and mosquitoes worldwide. Small amounts of malathion, previously considered inconsequential, may in fact increase in lethality when combined with biotic stressors in aquatic systems. We tested whether low concentrations of malathion (0.11 ppm) that are often detected in aquatic systems, affect competition between two invasive mosquito species Aedes albopictus (Skuse) and Aedes japonicus Theobald. There were no survivors of Ae. japonicus larvae in malathion. There was a significant negative effect of Ae. japonicus density on Ae. albopictus survival, but this effect was absent in the presence of malathion. There was also a moderate negative effect of Ae. japonicus density on Ae. albopictus female size, but this effect was absent in the presence of malathion. These findings indicate that pesticide-mediated alterations in competition and species-specific differences in susceptibility to pesticides could play a role in enhancing invasive potential of Ae. albopictus.
authors.affiliation: Salt Lake City Mosquito Abatement District, Salt Lake City, UT 84116, USA. banu@slcmad.org
authors.forename: Banugopan
authors.initials: B
authors.lastname: Kesavaraju
authors.forename: Barry
authors.initials: B
authors.lastname: Alto
authors.forename: Ali
authors.initials: A
authors.lastname: Afify
authors.forename: Randy
authors.initials: R
authors.lastname: Gaugler
mesh_terms: D000330:Aedes / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D003163:Competitive Behavior; D017753:Ecosystem; D005260:Female; D008294:Malathion / Q000494:pharmacology*; D013045:Species Specificity
chemical_list: D008294:Malathion