Oviposition in Heliconius erato (Lepidoptera, Nymphalidae): how Essential Is Drumming Behavior for Host-Plant Selection?

Abstract

Quantitative studies on the behavioral events involved in oviposition by phytophagous insects are scant. One of these events is drumming behavior, a rapid extension of forelegs after landing on a host, which remains largely under studied. In this study, quali- and quantitative analyses of Heliconius erato phyllis (Lepidoptera: Nymphalidae) oviposition events and drumming behavior in relation to both preferred (Passiflora misera and P. suberosa) and non-preferred (P. caerulea and P. alata) hosts were performed. For the first time, drumming behavior is described by images made during the butterfly oviposition process. The same set of females was assigned to both single- and multiple-choice tests under insectary conditions, and their behaviors toward each host were recorded on video. The resulting images were analyzed frame by frame. Both frequency and duration of behavioral events related to oviposition varied on preferred vs non-preferred hosts. On preferred hosts, behaviors that were associated with egg deposition (inspecting flight, drumming and abdomen touching) were pronounced; subsequently, oviposition occurred within a few seconds. On non-preferred host plants, behaviors that did not predict oviposition (flying and resting) predominated, and oviposition on these hosts was negligible. Drumming occurred on all plants and resulted in a faster decision-making process on high-quality hosts (prompt acceptance) as well as on lethal hosts (prompt rejection) compared to the host that confers poor larval performance (delayed rejection). Thus, drumming is crucial for decision-making related in host-plant selection by H. erato phyllis, and influences other behaviors involved in the oviposition process.