One of the most remarkable longhorn beetles I've ever seen: Aristobia horridula, hitching a ride on the ferry from mainland Thailiand to Koh Chang island in 2012. The pom-pom-like extensions on the antennae maximize surface area for chemoreceptors, allowing the beetle to detect tiny amounts of pheromone from conspecifics.
A cute little leaf beetle trundles through the undergrowth in Monverde, Costa Rica. (Chrysomelidae, subfamily Eumolpinae, possibly Brachypnoea)
Net-winged Beetle (Lycidae: Lycinae: possibly genus Calopteron) from Costa Rica. The brick-red coloration serves to warn predators of its toxicity. As a result, other insects like flies, moths, wasps and other beetles have adopted this color scheme in what is known as a mimicry complex.
