Data and code from: Chemical cues in a bee kleptoparasite trigger an evasive response in a facultative eusocial orchid bee

Brood parasites often evade host detection through chemical mimicry or
chemical insignificance, whereas alternative strategies such as chemical
deterrence are rarely documented. We used the host-parasite model of the
orchid bee Euglossa viridissima and its specialised kleptoparasite, the
megachilid Hoplostelis bivittata, to study this relationship in
primitively eusocial bees. We hypothesised that H. bivittata employs a
chemical strategy to enter the nest and avoid host aggression, and that
response rapidity increases with chemical distance. To test this, the
cuticular hydrocarbon profiles of host and parasite were first compared,
followed by bioassays analysing the response of host bees to conspecifics,
the kleptoparasite, and the stingless bee Melipona beecheii as a control.
Bioassays involved live and frozen specimens, as well as dummies coated
with parasite cuticular extracts of the different species. Notably, host
E. viridissima showed aggression toward conspecifics and M. beecheii, but
consistently fled from live and frozen H. bivittata, including dummies
covered in the parasite’s cuticular extract. We conclude that cuticular
hydrocarbons in H. bivittata, mediate an evasive response in its host E.
viridissima allowing nest parasitation. This is the first evidence of
deterrence in a Neotropical brood-parasitic bee, expanding our
understanding of chemical mediation in host-parasite arms-race
interactions in primitively eusocial orchid bees.