Weevil - Pachyrhynchus

Weevil - Pachyrhynchus

Pachyrhynchus are weevils from the family Curculionidae and are found mainly on Southeast Asian islands. These flightless beetles have striking colors and fused wing covers. The eggs are laid in plant tissue, from which the larvae develop and feed in the stems of their host plants.

The diversification of the genus suggests dispersal across islands. It is believed that these insects feed on their host plants to move from one island to another. The wood-boring lifestyle of the eggs and larvae and the air space under the wing covers may facilitate floating. However, experiments with Pachyrhynchus jitanasaius show a low survival rate of adults in water. The larvae, however, survive in seawater and may be the main dispersal stages.

Further research shows that Pachyrhynchus eggs can survive in certain bird stomachs, which could explain the successful spread of the genus.