Variation in capture height and trap persistence among three Costa Rican understorey butterfly species

Abstract

Abstract:Tropical forest insects are vertically stratified between the canopy and understorey. Using 60 traps set at two heights above the forest floor (30 at 15 cm and 30 at 1 m) we compared abundances in capture height, persistence in traps, and sex of three co-occurring understorey butterflies (Cithaerias pireta,Dulcedo politaandPierella helvina) in Costa Rica. We captured, marked and released 283 individual butterflies (65C. pireta, 79D. polita, 139P. helvina) and showed all three species were captured more often in low traps, andP. helvinawas captured only in low traps. The probability of remaining in traps for 24 h did not differ significantly forD. politaandP. helvina, but was significantly lower forC. pireta. The odds of trapping either sex did not differ significantly forP. helvinaandC. pireta, but they were significantly lower forD. politamales. We experimentally demonstrate that these co-occurring species fly and feed just above the forest floor, but differ with respect to their persistence in traps and attraction to traps by sex. Our study implies that closely related species can exhibit behavioural differences that may influence population abundance estimates in multi-species studies.