Truplaya ferox (Diptera: Mycetophilildae), a new Malaysian keroplatid from bamboo phytotelmata with larvae predaceous on ants

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Like ali known species of Orfellini, the larva os T. ferox is predatory. According to the classification proposed by Matile 1981, 1990) the Keroplatidae are divided into three

subfamilies, Arachnocampinae. Macrocerinae and Meroplatinae, the lalter comprising two tribes. Κeroplatini and Orfellini. The Arachnocampinae, monotypic with the genus Arachno an a Australian and New Zealand glow-wornis), and the known Macrocerinaea re predatory. In the Keroplatinae the Keroplatini are mostly spore-laeders, while ali knownorfellini are predaceous With the Arachnocampinae heing the sister-group of the Macrocerinae Φ Κeroplatinae, one may think that the predatory regi me of the Meroplatidae

The webs of Macrocera larvae and of other mur genera os orlallini tested on this trait Beaver, l979: Placliter. 1979) have an acid pH 2.4-2. T). In Macrocem this is due to ox alicacid secreted by the labies glands Buston, 1933: Plactiter. 19J9). In Arachno mya, the pHis acid, but no Oxalates were mund in the labiat glands Matile. 1990). Plactiter has noted that the strongly acid pH was a character of the predatory larvae of Keroplatidae, helping tokill ille prey hut the presence of oxalic acid has not been experimental ly demonstraledet se here mari in Macroceria. It is likely that the dropleis of ferox are also highly acid The larvae of Truplayia ferox prey on a wide spectrum os insects. with anis constitutingthe bulk of their prey Table l). The likely reason for this is that ants are the most common potentiat prey in the larvae s habitat. Also me internode inhabiting web-buit ding spiclers whicli are not speciali ed ei ther. have a similarly broad mod spectrum and also catch mostlyants Fig. 1 T). The large number of anis among the prey indicates that a large proportion Ofthe mod of both Truplam ferox larvae and web Spiders originates Dom the bamboo Surface. Ants may occur there in large numbers visi ting trophobiontic Homoptera in the leas region. The cavlty of living bamboo internodes, in contrast and qui te different hom the conditions

in dead internodes), is a very nutrient-poor habitat. Only at the beginning of the succession i e , shortly after a hole has appeared in the wall. the water inside the internode is inhabited by numemus mosquito larvae. These laed on microorganis ins breuking down the surtace of the bamboo wall. In the later stages of succession, when the nutritious outer layer of the wallhas decomposed. the internode inhabitanis depend on nutrient input froni the oulside se g. animais taring refuge in the internode). Therefore only law insect species with long larvaldeVelopinent, e .g., the beelle Scirtes or the predatory mosquito larva Toxorhynchites, whicheasily tolerates extended staming. Occur in Such internodes. Anoster bellavi oural trait of the new species is remarkable - the young larvae may seat Off the entrance of their hole wim a membranous sheet. This is the first observation os such

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a bellaviour in me predaceous Κemplatidae. It implies a physical or chemicat change in thesecretion of the labial fluid at a certain time. A possibie explanation for this phenomenon may be that the membrane in the entrance hole prevenis ne ly eclosed infecis that developedin the water Dom leaving the intemode. Shortly after an intemode hole is made, in the earlystage of succession, the water is inhabited hy many mosquiis larvae. At the fame time me Trupi a larvae are still young and have only smali neis consisting of a few threads. It is possible that the mosquiloes, which ny towatas light to leave the internode. hvmp into the

transparent membrane again and again and are then caught hy the Truplayia-larva, whichsinys neu me intemocle entrance and is Oriented tOwatas the membrane.