28 STUTTGARTER BEITRAGE ZUR NATURKUNDE Ser. A, Nr. 622 
4. Identification key of males of the New Guinean species of the genus 
Diatrichalus 
In most species the identification of females is impossible without extensive series 
representing both sexes. The key is using characters common in both sexes as long as 
possible but in many cases it was necessary to use only the shape of male genitalia or 
the ratio expressing the relative size of male eyes. 
1 Whole dorsal side of body dark brown to black, often with apparent metallic shine .. 13 
— Atleast some part of the body brightly coloured, usually yellow, read or light brown... 2 
2 Pronotum dark brown to black, without any lighter part................. 00 cee eee 3 
— Pronotum light yellow, yellow or red at lateral margins or at least narrow lateral margins 
lisht brown ara oN Ogg Rees en A Aes eh lect dy ee ra 6 
3 Only humeral third to half of elytra yellow to pale ochre ............. ser 022000: 4 
— Lightly yellow coloured part of elytra present also in the apical half of elytra......... 5 
4 Male genitalia open, without any process in the middle of ventral part of the phallus (Fig. 
30), humeral part of elytra very pale ochre, the transition between light and dark part of 
the elytra gradual, eyes relatively large, their interocular distance 1.06 times longer than 
their AAR Lic MECC emt ee ee eae cee ku Re techn D. humeralis sp. n. 
— Male genitalia without apparent process in the middle of ventral part of phallus (Fig. 14), 
humeral part of elytra yellow, the transition between light and dark part of the elytra 
sharp, eyes much smaller, their interocular distance 1.63 times longer than their maximum 
CHC sn ee ee ae Fa kh mann ee ae ee D. sedlacekiae sp. n. 
5 Only two rounded white to light yellow patches present in apical third of elytra, humeral 
part of elytra dark brown to black, male genitalia relatively robust (Fig. 27) ........... 
En Seg anit PRO Khe rn COR as ge ARE ik End OE VE GR OE Mee EE ES D. bipunctatus sp. n. 
— Humeral third of elytra and wide transverse band in apical third of elytra yellow, phallus 
more slender (Fig: 29). we x cscs eins Se ee hirern D. fasciatus sp. n. 
GL iwholeelytradarkbrowmto black... 5 0 tied frees toch hae ae 7 
— Atleast some part of elytra brightly coloured or light brown ...........--.000 eee ee 8 
7 Only middle part of pronotum darker, dark part occupying less than half of pronotal 
width, secondary costae weak, but mostly present, only seldom interrupted, reticulate 
cells quadrate, male genitalia with constricted apical part of phallus and with another con- 
striction in apical thitd (Fig. 34)" A ween cami eee neces D. secretus (Waterhouse) 
— Only narrow margins of pronotum light brown, combined width of both light pronotal 
margins represent approximately one quarter of pronotal width, secondary costae com- 
pletely missing in the middle part of elytra, small vestiges present at humeri only, elytral 
reticulate cells strongly transverse, phallus simply elliptic in apical part (Fig. 17) ....... 
Lh eRe a) aha Mare ra a het (ste gs ES iN ne UE Me er, D. wauensis sp. n. 
8 Head and basal antennal segments (1-4) yellow (Aru Is., not yet known from New 
Gute aioe an eo Aye ec eta irc ed ch be era eee arte D. aptus (Kleine) 
-.. Head:and basal antennal segments dark brown to black .............02:e reer ern 9 
9 Pronotum, humeral two thirds of elytra and partly ventral side of thorax yellow, male gen- 
italia with very long, slender process of internal sac (Fig. 18) ....... D. mancus (Kleine) 
— Middle part of pronotum dark brown, elytra otherwise coloured .................. 10 
10 Pronotum and elytra light brown, disc of pronotum partly darker ...D. habbema sp. n. 
— Elytra never unicoloured, always with some combination of dark and bright parts ... 11 
11 Humeri and interspace between primary costa 1 and 3 in basal two thirds of elytra yellow, 
body slender, 4 parallel-sided, male genitalia as in fig. 28 ............. D. striatus sp. n. 
— Elytra otherwise coloured, either lateral margins and elytral suture yellow or only prima- 
ry-costae lichter.elytra widened, posteriorly ux. sa u. nn ao eos oats ea RN 12 
12 Base of humeri light as well as lateral margins of elytra, primary elytral costa light brown 
in whole length, third elytral primary costa only slightly shortened, reaching at least three 
quarters of elytral length, male genitalia as in fig. 32 ......... D. pallidihumeralis sp. n. 
