The disturbance leg-lift response (DLR): an undescribed behavior in bumble bees

Abstract

Background Bumble bees, primarily Bombus impatiens and B. terrestris, are becoming increasingly popular organisms in behavioral ecology and comparative psychology research. Despite growing use in foraging and appetitive conditioning experiments, little attention has been given to innate antipredator responses and their ability to be altered by experience. In this paper, we discuss a primarily undescribed behavior, the disturbance leg-lift response (DLR). When exposed to a presumably threatening stimulus, bumble bees often react by lifting one or multiple legs. We investigated DLR across two experiments. Methods In our first experiment, we investigated the function of DLR as a prerequisite to later conditioning research. We recorded the occurrence and sequence of DLR, biting and stinging in response to an approaching object that was either presented inside a small, clear apparatus containing a bee, or presented directly outside of the subject’s apparatus. In our second experiment, we investigated if DLR could be altered by learning and experience in a similar manner to many other well-known bee behaviors. We specifically investigated habituation learning by repeatedly presenting a mild visual stimulus to samples of captive and wild bees. Results The results of our first experiment show that DLR and other defensive behaviors occur as a looming object approaches, and that the response is greater when proximity to the object is lower. More importantly, we found that DLR usually occurs first, rarely precedes biting, and often precedes stinging. This suggests that DLR may function as a warning signal that a sting will occur. In our second experiment, we found that DLR can be altered as a function of habituation learning in both captive and wild bees, though the captive sample initially responded more. This suggests that DLR may be a suitable response for many other conditioning experiments.

Learning and memory in the orange head cockroach (Eublaberus posticus)

“…This is standard for Drosophila work, but is not possible for honey bees, leading some laboratories to adopt bumble bees (genus Bombus ) as indoor alternatives. Unfortunately, artificial conditions may even prevent bumble bees from thriving and being practical subjects [ 28 , 29 ]. Taken together, we believe that cockroaches may be an ideal model to complement existing insect models of behavior, and development of a cockroach model would also support much needed model diversity [ 12 , 30 ].…”

Analysis of Habituation Learning in Mealworm Pupae (Tenebrio molitor)

“…For example, a large part of those studies does not have a recent follow-up. Additionally, the largest number of investigations on habituation has focused on the order of Diptera (e.g., flies and mosquitoes; see, Duerr and Quinn, 1982;Corfas and Dudai, 1989) and Hymenoptera (e.g., bees, ants, bumblebees, and wasps; see, Barrass, 1961;Simonds and Plowright, 2004;Varnon et al, 2021). However, little is known about habituation in Coleoptera, the order of insects that contains the most species compared to any other in the animal kingdom.…”