Sublethal Exposure to a Neurotoxic Pesticide Affects Activity Rhythms and Patterns of Four Spider Species

Abstract

Four species from three families of spiders were exposed to sublethal concentrations of the neurotoxic pesticide malathion: Schizocosa ocreata (Hentz 1844), Rabidosa rabida (Walckenaer 1837), Frontinella communis (Hentz 1850), and Salticus scenicus (Clerck 1757). Spider activity was recorded using a proprietary computer vision system equipped with artificial intelligence routines. Exposure to malathion changed the spiders' propensity to move, levels and patterns of activity, and distance moved. Dosed spiders increased their activity between 12 and 40%, depending on the species. Continuous recordings for > 24 h revealed the peak activity for dosed R. rabida and S. scenicus was shifted ~ 1 h earlier than controls. Spiders exposed to malathion also significantly increased the distance they moved per locomotory bout. This is consistent with the action of an organophosphate neurotoxin acting as an acetylcholinesterase inhibitor. Thus, exposure to sublethal doses of malathion appears to affect the neural basis for these spider's normal diel periodicities, time budgets, and patterns of locomotion, probably reducing their efficiency as agents of biological control.

Spiders (Araneae) in the pesticide world: an ecotoxicological review

“…Similarly, in the linyphiid T. tenuis , reduced levels of movement were recorded 83. Contact with a surface treated with malathion shifted activity peaks in the lycosid Rabidosa rabida (Walckenaer, 1837), as well as in the salticid Salticus scenicus (Clerck, 1757),84 which became active earlier than normal.…”

“…There is only indirect evidence. Contact with a surface treated with malathion elevated activity in few species: two lycosids Schizocosa ocreata (Hentz, 1844) and R. rabida , one linyphiid Frontinella communis (Hentz, 1850) and one salticid S. scenicus 84…”

Chemical Control of Spiders and Scorpions in Urban Areas

“…The spiders were tested in combinations where one or both sexes were exposed to the insecticide. The data indicate that while there was no effect on the patterning of courtship behavior, the control males initiated courtship more rapidly than those that had been exposed [32].There was also an alteration in the walking patterns, generally leading to an increase in locomotion [33]. The insect growth regulators tebufenozide and fenoxycarb are safe for spiders and predatory mites [34].…”

Biological Control of Insect Pests in Agroecosystems

“…Pesticides have been widely studied and have been shown to have a negative effect on natural enemy populations in many different studies (Chabert and Gandrey, 2005;Koss et al, 2005;Langhof et al, 2003;Tietjen and Cady, 2007). Both direct and indirect effects on the third trophic level have been highlighted.…”