Coleotichus WHITE 1839

Gerry Cassis & Loren Vanags, 2006, Jewel Bugs of Australia (Insecta, Heteroptera, Scutelleridae), Denisia 19, pp. 275-398 : 306-310

Coleotichus WHITE 1839 ( Figs 3 c-e, 6, 7, 8)

Coleotichus WHITE 1839: 541 (nov. gen.); DALLAS 1851: 5 (description); STÅL 1865: 35 (key); MAYR 1866: 13 (diagnosis); STÅL 1873: 4 (diagnosis); LETHIERRY & SEVERIN 1893: 15 (catalogue); SCHOUTEDEN 1904: 4, 5 (description); KIRKALDY 1902: 172 (Hawaii); SCHOUTEDEN 1905 (monograph); KIRKALDY 1909: 313 (catalogue); GROSS 1975: 80 (description); DISTANT 1920: 143 (catalogue); GROSS 1975: 80 (description); MCDONALD & CASSIS 1984: 538 (genitalia); CASSIS & GROSS 2002: 583 (catalogue)

Type species: Cimex costatus FABRICIUS 1787 by monotypy

Diagnosis: Coleotichus is recognised by the following combination of characters: elongate-ovoid ( Figs 3 c-e); lateral margins of jugae rounded ( Fig. 7b ); posterior margin of pronotum strongly convex ( Figs 3 c-e), covering anterior margin of scutellum; metathoracic peritreme mostly rectilinear, sulcate, with apex anteriorly arcuate ( Fig. 7d ); thoracic sterna strongly keel-like, pro- and mesosternal keels overlapping ( Fig. 7c ); CAI absent; CAII symmetrical or asymmetrical, bifid ( Figs 8c, d ), with rounded or digitiform lobal sclerites; CAIII separated or fused ( Fig. 8d ); and, spermathecal reservoir oval.

Description: Body elongate-ovoid ( Figs 3 c-e); moderately-sized to large species; moderately convex dorsally and ventrally; wing tip extending beyond scutellum; moderately to densely punctate; pale to dark brown, sometimes with red or green iridescent highlighting (e.g. Coleotichus blackbur-niae ; Hawaii), rarely with patterned darker brown markings. Head: triangular ( Figs 3 ce, 7a), moderately convex; clypeus broadly rounded at apex and barely surpassing juga ( Fig. 7a ); jugal margins rounded ( Fig 7b ); lorae strongly demarcated, margins carinate ( Fig. 7b ); bucculae narrow, lateral margins weakly arcuate ( Fig. 7c ). Antennae: AI-AII(a) shortest segments, subequal; AIII-AIV longest segments, subequal or AIV slightly longer. Labium: reaching apex of metasternum ( Fig. 7c ) to abdominal SIV; LII usually longest segment. Pronotum: large, shield-like, strongly convex ( Figs 3 ce); anterior margin concave; anterolateral margins rectilinear, carinate; humeral angles rounded to weakly angulate; posterior region of disc greatly expanded, posterior margin strongly convex, overlapping anterior margin of scutellum ( Figs 3 c-e). Scutellum: elongate, strongly convex, U-shaped, most often strongly tapered posteriorly ( Figs 3 ce); basal aspects of corium and clavus, and connexiva III-VII exposed ( Fig. 3 c-e). Thoracic pleura: external efferent system of metathoracic glands well-developed, raised ( Fig. 7c ); evaporative areas occupying most of metepisternum, and extending to mesepimeron ( Figs 7c, d ); ostiole moderately-sized ( Fig. 7d ); peritreme elongate, mostly rectilinear, with apex weakly curved at apex, gutter-like, medially sulcate ( Fig. 7d ). Thoracic sterna: lateral margins strongly sulcate, prosternal and mesosternal keels overlapping ( Fig. 7c ), with latter contiguous with explanate anterior margin of proepisternum, rounded ( Fig. 7c ); metasternal keels thickened ( Fig. 7c ). Male Genitalia: pygophore ( Figs 7e, f , 8a ) large, subquadrate to suboval, ventral margin convex; genital opening dorsal in orientation, broad, suboval, lateral margins densely setose; parameres ( Fig. 8b ), columnar stem, strongly hook-shaped crown, sometimes base of crown with flange; aedeagus ( Figs 8c, d ), asymmetrical ( Fig. 8c, d ) or symmetrical; phallotheca squat ( Fig. 8c ), sclerotized, without processes; ejaculatory apparatus moderately developed ( Fig. 8c ); ventral conducting canal with 8-10 paired convolutions ( Fig. 8c ); ejaculatory reservoir short, oval ( Fig. 8c ); vesica short to elongate, tapered towards apex, strongly arcuate; conjunctival appendages ( Figs 8c, d ): CAI absent; CAII asymmetrical ( Figs 8c, d ) or symmetrical, greatly enlarged, mostly membraneous, distally bifurcate, CAII(L) with short (acute) or large (sickle-shaped) lobal sclerite, CAII(M) with short acute lobal sclerite, or blunt bifid lobal sclerites; CAIII sclerotized ( Fig. 8c, d ) or membraneous, fused medially or separated, flange-shaped or Sshaped, sometimes bifid. Female Terminalia: ventrally oriented, co-planar; paratergites VIII large, broad, subelliptoid, posterior margin rounded; paratergites IX narrowly elliptoid, medial margins truncate; gonocoxae I transverse, undivided, posterior margin concave, medial margins elevated. Spermatheca: short to moderately-sized proximal fecundation canal; spermathecal reservoir narrowly dilated elliptoid, membraneous; pump with dorsal and proximal flanges; bulb oval.

Diversity and distribution: The highest area of species diversity in Coleotichus is in the Australian zoogeographic region, with seven of the thirteen described species. A number of the species are widespread, with all three Australian species, found also in New Guinea, or surrounding islands, with C. excellens now known from as far north as Taiwan (see below). The genus is also represented in the Oriental region, with two species known from Indonesia (Borneo and Sumatra). Coleotichus is also represented in Pacific islands and archipelagos, distant from Australia, including Samoa, Hawaii and the Marquesas. The most spectacular species of Coleotichus , C. blackburniae , is endemic to the Hawaiian Islands, where it breeds on koa, a native species of Acacia , where both plant and insect are threatened, the jewel bug by green vegetable bug biological control agents (JOHNSON et al. 2005).

Included species: C. adamsoni VAN DUZEE 1932 Marquesas C. artensis ( MONTROUZIER 1858) Australia, New Caledonia, Fiji, Vanuatu, Samoa, Aru Island C. bakeri TAEUBER 1929 Philippines C. biroi SCHOUTEDEN 1905 New Guinea C. blackburniae WHITE 1881 Hawaii C. breddini SCHOUTEDEN 1905 Micronesia C. bulowi SCHOUTEDEN 1905 Samoa C. costatus ( FABRICIUS 1787) Australia, New Caledonia, Tonga C. excellens WALKER 1867 Australia, Fiji, New Guinea, New Caledonia, Samoa, Philippines, Taiwan, Indonesia (Irian Jaya) C. fuscus VOLLENHOVEN 1863 Ambon, Ceram C. marianensis USINGER 1946 Guam C. ornamentifer BERGROTH 1915 Borneo C. sumatranus BREDDIN 1900 Sumatra

Remarks: Coleotichus is a distinctive genus of Elvisurinae , having greatly enlarged thoracic sternal keels, with the pro- and mesothoracic keels overlapping ( Fig. 7d ). The genus shares some similarities with the nominotypical genus Elvisura , with the pronotum greatly expanded posteriorly, covering the anterior margin of the scutellum ( Figs 3 c-e). The male genitalia resemble those of Elvisura , in the following ways: the CAII have lateral and medial lobes with lobal sclerites, and the CAIII are sclerotized and fused medially (as in C. costatus and C. artensis ) (e.g., Figs 8c, d ). LESTON (1953b) described the male genitalia of Elvisura irro-rata SPINOLA , which serve as a basis for this comparative hypothesis.

WHITE (1839) described Coleotichus on the basis of the Australian species, C. costa-tus . SCHOUTEDEN (1904), in redescribing the genus, established three subgenera ( Coleotichus, Epicoleotichus and Para-coleotichus ) on the basis of the prosternal shape, declivity of the male pygophore, and the shape of the female genital plates. GROSS (1975) redescribed Coleotichus , and used these subgeneric categories, giving credence to the shape of the prosternum in relation to the eyes. Our observations indicate that differences in these characters are more indicative of species relationships, and not diagnostic at the genus level.

MCDONALD & CASSIS (1984) added a description of the male genitalia for Coleotichus , and did not adhere to subgeneric categories, without any explicit explanation. Pending a more detailed comparative morphological investigation and phylogenetic analysis of Coleotichus , the sisterspecies relationships are uncertain, and we know of no new evidence that supports the use of subgeneric categories. Aside from the Australian species, the male and female genitalia of the extralimital species of Coleotichus have not been documented; a necessary prerequisite for any further classificatory hypotheses.

Figures

Fig. 3: Habitus of Australian Elvisurinae species (a) Austrotichus rugosus, Oi (b) Solenotichus circuliferus, Oi (c) Coleotichus artensis, Oi (d) Coleotichus costatus, Oi (e) Coleotichus excellens, Oi. Scale bars: 1 mm.

Fig. 7: Scanning electron micrographs of key characters of Coleotichus costatus (a) Head, dorsal view (b) Head, lateral view (c) Head and thorax, ventral view (d) External efferent system of metathoracic glands, ventral view (e) male pygophore, ventral view (f) male pygophore, dorsal view. Abbreviations: Ea = evaporative area; Ms(k) = mesosternal keel; Pe = peritreme; Pe(k) = proepisternal keel, ventral view; EES = external efferent system. Scale bars = 1 mm.

Fig. 8: Male genitalia of Coleotichus costatus (a) pygophore, dorsal view (b) paramere, lateral view (c) aedeagus, lateral view (d) aedeagus, ventral view. Abbreviations: C = crown of right paramere; CAII(L)L = left second conjunctival appendage, lateral branch; CAII(L)R = right second conjunctival appendage, lateral branch; CAII(M)L = left second conjunctival appendage, medial branch; CAII(M)R = right second conjunctival appendage, lateral branch; CAIII = third conjunctival appendage; DCC = dorsal conducting canal; DS(D) = ductus seminis dorsalis; DS(P) = ductus seminis proximalis; Er = ejaculatory reservoir; F = flange at base of crown of paramere; GO = genital opening; Pt = phallotheca; S = stem of paramere; Sg = secondary gonopore; V = vesica; VCC = ventral conducting canal of ejaculatory apparatus; VM = ventral margin of genital opening.