Submitted by Neil Tsutsui on
Eusocial insects are categorized by their multi-generational, cooperative societies that are premiere examples of altruism and the ideas of kin selection theory. Chemical recognition systems in Hymenoptera (ants, bees, and wasps) maintain these tight knit colonies as a way for individuals to discriminate between nestmates and non-nestmates. In some cases, social parasites have evolved in tandem with host ant species, hacking the recognition codes of heterospecific colonies in order to have access to host nests. Mimicking the chemical profile of an ant host has been a successful strategy for many insect social parasites, however, little is known about the strategies for manipulating host behavior across the several lineages of facultative ‘slave-making’ ants. Here, I propose answering the question, “What are the mechanisms involved in the host specificity of a facultative social parasite?”.
The Tsutsui lab has been at the forefront of understanding the chemical world of ants, the multimodal uses of these chemical profiles and, more specifically, the effect of obligate social parasitism on a host’s chemical recognition. Obligate forms of parasites have undergone a series of adaptations that allow them to specialize on a host whereas facultative forms are considered to be at an ‘impressionable’ stage of their evolution towards obligate parasitism in terms of the adaptations that drive host specificity and parasitic behavior. With this project we aim to build on our knowledge of the chemical strategies used in the raid, capture and establishment of host workers by their parasites by testing if (1) facultative parasites are choosing to specialize on species they are most closely related to, both genetically and chemically, and testing (2) the behavioral plasticity of facultative parasites when exposed to varying proportions of host workers in a nest.
The latter objective will explore the level at which facultative parasites have invested their behaviors into the ‘slave-making’ syndrome and to what level they have foregone the ability to conduct colony tasks associated with being a free-living nest. This study, when analyzed comparatively across the other forms of obligate social parasitism, will be a necessary step to understanding this woefully understudied group of facultative social parasites.
Field work: travel to field sites across Northern California, learn to identify microhabitats associated with nests, assess natural history and behavior, collect workers and whole colonies, and learn basic specimen preservation in the field
Lab work: extract whole body chemicals, operate GC/MS, analyze chemical profiles, extract DNA, run PCR, learn basic tools for constructing phylogenies using the chemical and genetic characters obtained from specimens, establishing lab colonies and animal care
Both field and lab work will be done alongside a team of researchers; and will require training even if the student has prior experience.
Lab: UC Berkeley, Valley Life Sciences Building
Field: UC Reserve, Sagehen Creek Field Station
Enthusiastic, curious, and experienced. Students who have had some experience camping outdoors for long periods of time are preferred. Experience working in a wet lab is not required but qualities such as careful attention to details and meticulous note-taking will be essential to successful technique. Overall, the student should be ready to engage in critical, scientific thought in the field and while analyzing lab samples.