I am fascinated by natural history, despite woeful skills as a naturalist, and enjoy asking questions that address the evolution of biological diversity. My undisciplined curiosity, combined with wonderful students and collaborators means I’ve been involved in diverse research projects on many different species. Mostly, these projects address the evolutionary significance of social and reproductive behaviour of terrestrial invertebrates, and how this behaviour is mediated through signals and cues. A current focus is on olfactory communication, which has led to investigations that attempt to understand the selection pressures shaping the diversity of insect antennal morphology. Taking a more applied turn, we are also investigating how air pollution is influencing chemical signal ‘attenuation’, and the capacity of insects to detect these odours.

Diversity of insect antennae

Many insects obtain information from their environment by detecting odours that acting as signals or cues. We are interested in the selection pressures that are responsible for shaping the diversity of insect antennal morphology.

Sexual selection and ‘organs of sense’

Darwin suggested that sexual selection might favour features of ‘organs of sense’, that improve the males’ ability to be first to reach the female. We are addressing this largely neglected insight by examining the sources of variation in both female signalling and male antennal morphology, in gumleaf skeletoniser moths Uraba lugens (not in the photo).

Impact of air pollution on insect odour perception

We know air pollution can damage your health, but we are investigating whether it can also affect insect chemical communication. We have discovered that PM derived from air pollution collects on the antennae of house flies, and then compromises their ability to detect important odours. We are expanding this analysis to include the impact of both industrial and wild fire PM on other insects.

Spider silk properties

The mechanical properties of the silk of orb-web spiders are quite well know, but remarkably less is known about the silk of other ‘non-model’ species, or about other features of spider silk. We have studied the properties of the silk of the basket web spider (right), which maintains its structural integrity so that the basket can stand up unsupported. The spider is a specialist predator of ants, so the silk is unlikely to have ant deterrent properties we have discovered in orb-weaving spiders. On the other hand, the surface of the silk may have odours that attract ants, in the same way that the silk of orb-web spiders has putrecine, which attracts flies.

Invertebrate symbioses

Arguably, natural history’s most intriguing systems, symbioses require communication. In cooperative systems, the different species produce and receive signals to identify themselves as appropriate partners, while in exploitative systems one species may attempt to conceal its identity. We have examined these questions in a range of systems, including spiders and ants, lycaenid butterflies and ants, and triadic symbioses of spiders.

Reproductive strategies

While a PhD candidate, back in the day, I happened to watch a female European garden spider Araneus diadematus, capture and consume a courting male. This brief but fascinating observation triggered a long term interest into the reproductive strategies of male and female orb-weaving spiders, and especially the evolutionary significance of sexual cannibalism in Nephila and Argiope. (Photo: André Walter)