Effects of Sublethal Doses of Malathion on Responses to Sex Pheromones by Male Asian Corn Borer Moths, Ostrinia furnacalis (Guenée)

Abstract

We evaluated the sublethal effects of malathion treatment on the behavioral responses of male Asian corn borers, Ostrinia furnacalis (Guenée), to their sex pheromones. Doses of malathion causing 1-50% mortality were topically applied to Asian corn borer male moths. The survivors were tested for behavioral and electroantennogram (EAG) responses to their sex pheromones. Sublethal doses of malathion affected males' ability to locate a pheromone source. In wind tunnel tests, male moths treated with sublethal doses of malathion took 2.5 to 12 times as long to take flight as control moths. Malathion-treated male moths were 60-96% less likely to locate a sex pheromone source than control moths. Multiple linear regression analysis revealed that the proportions of males performing each key stage were significantly correlated with the doses of malathion, but not with the time since treatment. Sensitivity and specificity of perception to pheromones in male moths were also disrupted by sublethal doses of malathion. The EAG responses of males treated with malathion decreased 0.13 mV on average compared with control moths. In addition, the ratios of pheromone components that elicited the largest responses shifted from approximately 5:5 to 1:9 (E/Z) and 9:1. We conclude that treatment with sublethal doses of malathion significantly reduced the likelihood that male Asian corn borers could successfully locate a normal female releasing sex pheromones.

Induction by Chlorpyrifos, of the Confusion of Males in Discriminating Female Sexual Pheromones Used for Mate Finding by Two SympatricTrichogrammaSpecies (Hymenoptera: Trichogrammatidae)

“…In Grapholita molesta, the recognition of pheromones by males was decreased after an exposure to permethrin, carbaryl, and chlordimeform (Linn and Roelofs 1984). Such a decrease was also observed with Ostrinia furnicalis males exposed to malathion (Zhou et al 2005). For T. brassicae, chlorpyrifos at LD 20 and LD 0.1 signiÞcantly decreased the response of treated males toward sex pheromones (Delpuech et al 1998a, b).…”

Pest Insect Olfaction in an Insecticide-Contaminated Environment: Info-Disruption or Hormesis Effect

“…In the corn borer Ostrinia furnacalis , treatments with the organophosphate malathion decrease the ability of males to respond to the female-produced sex pheromone (Zhou et al, 2005). The pyrethroids permethrin, deltamethrin, and cypermethrin, sodium channel activators, disrupt male attraction to sex pheromone in the pink bollworm, Pectinophora gossypiella , the corn borer O. furnacalis , and the noctuid Trichoplusia ni (Haynes and Baker, 1985; Haynes et al, 1986; Moore, 1988; Clark and Haynes, 1992; Wei and Du, 2004).…”

“…In the corn borer O. furnacalis , electroantennogram (EAG) responses to pheromone were disrupted after malathion treatment (Zhou et al, 2005), whereas no effect of the sodium channel blocker indoxacarb on EAG responses was observed in the microlepidopteran Plutella xylostella (Wang et al, 2011). At the sensillar level, deltamethrin disrupted the responses of ORNs to pheromone in males of two Mamestra species (Lucas and Renou, 1992).…”

Sublethal pesticide exposure disrupts courtship in the striped lynx spider, Oxyopes salticus (Araneae: Oxyopidae)

“…This can result in inappropriate and costly behaviours when it interferes with an animal's ability to perceive threats, prey or potential mates (L€ urling and Scheffer 2007;Griesinger et al 2011;Wrinn et al 2012). In many arthropods, chemical communication via pheromones is extremely important, and pollutants such as pesticides can impact pheromone detection (Delpuech et al 1998a(Delpuech et al ,b, 1999Wei and Du 2004;Zhou et al 2005;Griesinger et al 2011).…”