A new species of Exochomoscirtes Pic, 1916 from Malaysia (Insecta: Coleoptera: Scirtidae) with biological notes on the bamboo-inhabiting members of the genus

Abstract

Seven Exochomoscirtes species inhabiting phyto- or lithotelmata in West Malaysia and North Thailand were reared from larvae. E. hashimi spec. nov. from W. Malaysia was described and E. carinensis and E. meghalayensis were new records for Thailand. Larvae of E. meghalayensis inhabited water-filled tree holes and forest rock pools, while E. hajeki, E. jaechi, E. chiangmaiensis, E. carinensis, E. cf. luteosuturaloides and E. hashimi spec. nov. occurred in water-filled bamboo stems. Bamboo-inhabiting species occupied different types of bamboo habitats such as mature bamboo stems (inhabited internodes up to 21 m high), dead bamboo stems or bamboo stumps. Internodes of nutrient-rich bamboo shoots were not colonized. Adult Exochomoscirtes entered enclosed internode cavities through holes created by insects, woodpeckers and other animals or cracks in bamboo walls. Larvae living in open phytotelmata such as water-filled tree holes or bamboo stumps created pupal chambers made of soil or detritus in the vicinity of their habitats. In species inhabiting enclosed internodes pupal chambers were absent. Larvae pupated inside the internodes firmly attached to the bamboo walls close above water surface. Total development time of bamboo-inhabiting species was about 3 months. Predators of Exochomoscirtes species dwelling in enclosed internodes were chironomid larvae (Dasyhelea), mosquito larvae (Toxorhynchites), small water striders (Lathriovelia), rove beetles (Acylophorus), jumping spiders (Paracyrba), web-building spiders (Theridiidae) and web-building larvae of fungus gnats (Truplaya).
 
 Taxonomic acts
 E. hashimi spec. nov.– urn:lsid:zoobank.org:act:4D2AA5A6-DB2D-4B5F-AE91-E8C985FFA4DD