BOCAK, REVISION OF DIATRICHALUS FROM NEW GUINEA 5 
Differential diagnosis: Pronotum with median lanceolate areola only, lateral 
carinae missing or very weak (Figs 4-8), elytra with shortened primary costa 1 (Figs 
1-3), antennae of both sexes more or less acutely serrate, never with long lamellae 
(Figs 44-55), phallus stout, apical part projected, internal sac prolonged, more or 
less sclerotized (Figs 9-42), vaginal glands inserted laterally, spermatheca long, slim, 
rod-like. 
Redescription: Body medium-sized, dorsoventrally flattened, coloration vari- 
able but considerable number of species mat black or black with metallic blue shine, 
rest of species with brigthly coloured pronotum and basal part of elytra. Never light 
yellow. Head small, hypognathous, partly concealed by pronotum, cranium com- 
pact, without rostrum, gular sutures inconspicuous, distance of posterior tentorial 
pits bigger than the length of gula, posterior tentorial arms slim, eyes prominent, 
usually smaller than their frontal distance. Mouth parts well developed, mandibles 
stout, curved in right angle, more than twice as long as labrum, labrum wider than 
long, emarginate in distal part, lateral processes long, epipharynx large, with sparse 
setae, hypopharynx flat, lateral processes weak, apical part less sclerotized. Maxillae 
with small cardo (one fifth of stipes length), lacinia very reduced, only membrane 
and several setae present, galea well developed, membranous, with relatively dense 
setae, maxillary palpi with broad apical segment bearing papillae at apex; labium 
with robust praementum, postmentum very tiny, labial palpi with apical segment ro- 
bust, widest at apex, with irregular unpigmented papillae at apical margin. Antennae 
strongly compressed, serrate in both sexes or shortly flabellate in males of some 
species. Pronotum usually wider than long, with one more or less broad longitudi- 
nal areola in the middle, lateral margins often elevated, basisternum trapezoidal, rel- 
atively broad. Mesosternum narrowly connected with metasternum, mesoscutellum 
slightly emarginate at apex. Postnotum without keel. Elytra flat, with four primary 
longitudinal costae at humeri, primary costa 1 considerably shortened, reaching at 
most one fourth of elytral length, remaining costae mostly reaching elytral apex, 
costa 3 sometimes shortened, costa 2 and 3 often fused before apex; secondary costae 
irregular to completely absent in some species, legs relatively strong and short, 
strongly compressed. 
Male genitalia with relatively short and robust phallus, apical part ventrally pro- 
jected, hiding apical opening, internal sac without pair of basal thorns, nearly always 
strongly sclerotized in apical part, phallobasal membrane sometimes extensive but 
never sclerotized. Ovipositor with slender, long valvifers, sometimes incompletely 
fused at base, vagina relatively short, basal part of glandular duct often robust, ac- 
cessory glands inserted laterally. Spermaduct robust at base, spermatheca slender, 
very long. 
Sexual dimorphism: I have not found any apparent sexual dimorphism in the 
genus Diatrichalus. The males are generally smaller and slimmer, as usual in all Lyci- 
dae. The difference in the eye size is slight in most species and I have not found any 
difference in the shape of antennae, which are serrate in both sexes. 
Distribution and diversity within the genus: Diatrichalus is very wide- 
ly distributed and its range includes Australia, Tasmania, New Guinea, Solomon Is- 
lands, Indonesia, Philippines and Malaysian Peninsula. This genus is very speciose in 
the studied area and until now 28 species are known from New Guinea and 13 
species from all adjacent regions. New Guinea is the area with the highest diversity, 
much less species are known from Australia as well as from Wallacea and only sev- 
