5 (2) Rather broad and depressed; mandibles typically concealed; 



labrum usually not visible from in front . .PSEPHENIDAE. . . 110 

 Body relatively elongate; mandibles visible; labrum usually 



visible from in front PTILODACTYLIDAE 118 



6 (4) Riparian, usually not under water; agile fliers; rather 



soft -bodied; pubescent, but without tomentum; procoxae 



transverse and with trochantin exposed LARINI 7 



Aquatic; typically slow-moving, clinging to submerged 

 objects; rarely flying except at night; hard-bodied; 

 with tomentum on various ventral parts; procoxae 

 rounded and trochantin concealed ELMINI 10 



7 (6) Less than 4 mm long; antennae clubbed; pronotum with sub- 



lateral sulci (Fig. 17): Phanoaerus claviaomis 



More than 5 mm long; black, antennae not clubbed; pronotum 



without sublateral sulci (Fig. 18) Lara 8 



Figs 17-18 Dorsal view of adult: 17- Phanoaerus claviaomis; 

 18- Lara avara. 



8 (7) From 5.5-6.5 mm long; pronotum with hind angles acute but 



scarcely more prominent than middle lobes; elytral 

 pubescence uniform (Fig. 19): Lara gehringi 

 From 6.8-8.1 mm long; pronotum with hind angles acute and 

 prominent; alternate elytral intervals with the pubescence 

 decumbent, so that the elytra appear dark with sericeous 

 lines 9 



9 (8) Elytra 6.0-6.5 mm long; elytra wider in proportion to 



pronotum; pronotum with more prominent angles (Fig. 21) : 



Lara avara amplipennis 

 Elytra about 5.2-5.5 mm long; elytra narrower in propor- 

 tion to pronotum; pronotal angles less prominent (Fig. 20): 



Lara avara avara 



26 



