I have been doing fieldwork in Costa Rica for 3 days and I have already met some really amazing caterpillars. I have visited 3 sectors of the Area de Concervacion Guanacaste so far: Santa Rosa, San Cristobal and Pitilla. Though harder to access, Pitilla is the most beautiful part of the ACG I have seen. It is elevated 600 m above sea level and positioned between > 10 000 ha of cloud forest and 1-80 year old regenerating forest which makes the place a hotspot for biodiversity.
My main interest is in caterpillars with eyespots [or "ojos falsos" in Spanish], but given the diversity of species here I am trying to collect data for as many species as I can (photos soon). At the San Gerardo research station I observed a relatively well known snake mimic species - Xylophanes cyrene (Sphingidae) - in its prepupa form. The colour and behaviour of caterpillars in the prepupa form often differ from the earlier caterpillar stages. This and some of the other large prepupa specimens I have seen here remain in a curved "C" shape body posture until harassed at which point they flick to an inverted "C". From photos that I have seen it is a much more convincing mimic before this prepupal stage when it is still a highly mobile caterpillar. I hope to find more caterpillar specimens of this species while I am here: