In natura sit-and-wait behaviour and predation success of a Neotropical dance fly (Diptera: Hybotidae).

In this study, we provide detailed ethological notes on the predation behaviour of Chvalaea yolkamini Jaume-Schinkel, Soares & Barros, 2020, a neotropical sit-and-wait dance fly from Mexico, with description and video evidence of hunting and feeding behaviours. Furthermore, we analysed in situ predation success in relation to biotic and abiotic factors (prey size, prey taxonomic group, temperature, humidity and perch height). We observed 94 individuals for a total of ~15.68 hours. Chvalaea yolkamini uses its hind legs armed with spikes to strike and handle prey, while its short proboscis pierces and sucks on intersegmental areas as they are less sclerotised. Feeding time ranged from 1.27 to 15.24 minutes. In addition, C. yolkamini was more successful when attacking large-sized prey, but apparently the limit for prey size is the predator's own size. The individuals were more successful when ambushing large Brachycera than relatively small nematocerous Diptera and Hemiptera. No influence of temperature and humidity was detected, but higher perches favoured predation success. Our study supplies the first detailed information on the perching and hunting behaviour of a sit-and-wait hybotid fly. We advance hypotheses that may be investigated by including covariables, such as wind and prey colouration, with a view to further our comprehension of the sit-and-wait behaviour in predatory animals. [ABSTRACT FROM AUTHOR]