Stegazopteryx ivimkaensis Will, 2004

Will, Kipling W., 2004, A New Genus of Caelostomini (Coleoptera: Carabidae) from Papua New Guinea, The Coleopterists Bulletin 58 (4), pp. 637-641 : 638-641

Stegazopteryx ivimkaensis Will , new species

Type Material. Holotype; female; deposited UCDC. Labeled: ‘‘ PAPUA NEW GUINEA GULF; Ivimka Res. Station, Lakekamu Basin 120 m 78449S 1468309E 24.XI.1999 S.L. Heydon Hg-vapor light’’/‘‘ Holotype Stegazopteryx ivimkaensis Will 2003 [red label]’’. Type has damaged right palpi, broken left antenna (three basal segments remain), left hind leg is glued to point. PARATYPE; female; deposited CASC. ‘‘ Maffin Bay , Dutch N. Guinea, IX-44, E.S. Ross Coll. // Caelostomus subsinuatusC [sic] det. Darl. 60.’’ [approximate location—18569S 1388509E]

Diagnosis. The form of the apex of the elytra ( Fig. 1 ) separates this genus and species from all other Caelostomini.

Description. Small size, overall length 5.2 mm. Deep brown color, shiny and iridescent throughout body, dorsally and ventrally. Palpi, labrum, antennae and legs, except femora, paler and more ferrugenious than venter. Mandibles concolorous with body.

Head. Ocular ratio (width over eyes/width between eyes at level of anterior supraorbital setae) 1.67. Eyes prominent and hemispherical. Two pair supraorbital setae. Microsculture on disc and clypeus lightly impressed reticulate microlines. Frontal impressions sharp, divergently sinuate turning parallel just before front supraorbital setae. Mentum clearly broader than long, anterior margin deeply emarginate; epilobes broadly bordered; mentum tooth apex simple, rounded; paramedial pits moderately deep; one paramedial pair of setae subtends mentum tooth. Submental suture present. Submentum with 2 pairs of lateral setae. Maxillae each with seta in middle of palpifer, stipes with one subapical seta; galae fusiform; lacinia heavily built with few, large spines; penultimate palpomere small, about 2 length of terminal palpomere. Palpomeres fusiform, glabrous except for two setae on penultimate labial palpomere. One pair of long apical setae on ligular glossal sclerite, apical edge bluntly truncate. Paraglossae free, long and glabrous. Labrum with 6 setae on slightly emarginate apical margin. Clypeus truncate, with one seta at each apical corner. Mandibles relatively long, moderately curved. Antennae rather short, just reaching base of pronotum; antennomeres 1–3 and base of 4 glabrous except for one long, apical seta on 1–2, three setae on 3 and three longer and a field of sparse smaller setae on the apical 1/3 of 4, antennomeres 5–11, clearly broader than long, laterally densely pubescent, medially nearly glabrous and shiny.

Thorax. Pronotum clearly broader than head; two pairs of lateral setae, one pair sightly forward of middle set in narrow marginal groove, one pair at terminus of lateral bead at hind angles. Lateral marginal bead evenly narrow throughout; lateral margins sinuate to hind angles; hind angles nearly right-angled and minutely denticulate; apical angles not produced. Basal margin convex medially. Microsculpture scarcely visible, transversely stretched, more effaced on disc and near apical margin; surface shiny iridescent. Basal impressions deep, broad, slightly convergent and reaching more than 1/3 the length of the pronotum. Elytra elongate, rectangular, bluntly truncate at apex; microsculpture as on pronotum. Striae well impressed, shallowly punctate. Parascutellar stria present, connected to stria 1. Base of stria 1 absent. Stria 2 ends short of basal margin. Basal margin entire. Setigerous puncture at end of stria 3. Intervals slightly convex, 7 and 5 prominently carinate apicolaterally. Umbilicate series ‘‘ type b’’ of Straneo (1942), with a group of five punctures near humeri, a small gap and one puncture, a large gap then four punctures, small gap and three punctures, and a single setigerous puncture facing ventrally at apex of carinate interval 7. No dorsal setigerous puncture on elytral disc. Thoracic sterna not punctate. Metepisternum elongate. Metepimeron long and rounded at apex. All trochanters with one seta each. Profemur one seta on posterior face. Protibial antennal cleaning organ well developed, with 2 clip setae; cleaner setal row extending dorsally, ending at slightly larger medial seta; ventral ctenidia well developed; both proximal and distal spurs simple. Protarsomeres in female short, compact, symmetrical shaped, 1 subequal to length of 2 þ 3, 1 ― 4 with two rows ventral setae; tarsomere 5 glabrous ventrally, two dorsolateral setae. Tarsal claws on all legs smooth. Mesocoxa with one lateral and one medial seta. Mesofemur anterior face with 5 setae; dorsal face with row of 8 setae. Mesotiba with four rows of setae along length; well developed ctenidium. Mesotarsomeres compact, without extenal sulci, scattered ventral setae mesoapically. Metacoxae with single medial seta each; anterior sulcus complete, straight, appressed to anterior margin. Metatrochanter short, less than half length of femur. Metafemur dorsal face with 2 seta near apex, 2 setae on anterior face. Metatiba with four rows of fine setae. Metatarsomeres compact, nearly globose form, ventrally with scattered mesoapical setae.

Abdomen. All visible sterna sparsely and shallowly punctate laterally, 4–6 entirely punctate. Sterna V–VI with shallow basal crenulation. Sterna IV–V with one pair paramedial setae; female with 2 pair, rather deep, subfoviate paramedial setae on 6. Sternum I. Male genitalia unknown, Female genitalia, reproductive tract and defensive gland not dissected.

Etymology. The genus name is female gender, formed from Greek stegazo, awning and pteryx [or pterux], wing, calling attention to the apicolaterally expanded portion of the elytron. The specific epithet is based on the type locality, Ivimka Research Station.

Systematics

Straneo (1942) and to a lesser degree, Jeannel (1948), made significant contributions to understanding the tribe as a whole. However, the group clearly needs modern revision and the Austral-Asian taxa have never been properly treated taxonomically.

Based on these studies, a combination of characters are found to be typical in Caelostomini; basal puncture of elytron at base of stria 3, angular base of stria 1 absent, setae of palpifer positioned well forward of base and male median lobe oriented to right when in repose ( Straneo 1938, 1942 in part). However, one or more of these is not present in some taxa attributed to Caelostomini (sensu Straneo 1942 and extended by Liebherr 1986 and Lorenze 1998). These divergent taxa may form a basal grade in the tribe (e.g., likely for Diceromerus Chaudoir ) or be only distantly related and mistakenly placed in Caelostomini based on general body form (e.g., Brachidius Chaudoir , Cratocerus Dejean and Oxyglychus Straneo ). Males are not known for Stegazopteryx but the type specimen has all the other characteristics of Caelostomini as listed above.

Given the present state of systematics for the group, the relationship of Stegazopteryx to other caelotomine taxa is unclear. In small details, like punctuation and head form, Stegazopteryx is similar to Caelostomus albertisi Straneo , and it may prove to be closely related to New Guinea species. In addition to the general modification of the elytral apex, Diachipteryx and Stegazopteryx also share similarly moniliform antennomeres 5–11, otherwise unknown in the tribe, but found in several other carabid taxa, e.g., Morionini .

Identification of specimens is relatively simple. In Darlington’s (1962:499) key to New Guinea Pterostichini , S. ivimkaensis will run to couplet 3 together with Caelostomus . It is readily separated from that genus by the truncate elytral apex.

In Straneo’s key to Caelostomini genera and subgenera (1942:41) S. ivimkaensis will run to couplet 24(13) with Diachipteryx . The modified elytral apex in Diachipteryx and Stegazopteryx separates them from all other Caelostomine genera, including all genera in Straneo’s key, as well as Caecocaelus Straneo , Dromistomus Jeannel , Abacaelostus Straneo , Leleuporites Straneo , Madapelmus Dajoz , Pachycaecus Straneo , Hannaphota Landin 1, Cyrtolaus Bates and Barylaus Liebherr , caelostomine genera not covered in Straneo’s key.

The following will separate Diachipteryx and Stegazopteryx :

a. Apex of elytra bluntly truncate not emarginate ( Fig. 1A ), elytron with interval 7

forming a shelf-like carina apicolaterally; pronotum with mediolateral and

basolateral pairs of setae. (New Guinea) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Stegazopteryx ivimkaensis new species a9. Apex of elytra medially emarginate ( Fig. 1B ), elytron convex apicolaterally,

interval seven not pronouncedly carinate; pronotum with only basolateral pair of

setae. (Africa) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Diachipteryx paradoxus Alluaud

Life History/Habitat

In general, Caelostomini are most frequently collected under the bark of rotten logs (my observations in Malaysia and Madagascar; and Darlington in New Guinea (1962:509)) or in debris that collects in plants well above the forest floor (e.g., in

1 H. distincta is listed by Lorenze (1998) as a member of Caleostomini, however, based on the holotype, it is almost certainly a member of Platynini .

Pandanus spp in Madagascar). The peculiar body form of S. ivimkaensis suggest it may have a life history unlike other caelostomine ground beetles. The female type was collected at mercury vapor light, so no further details are known for this species. According to Steve Heydon (UCDC), the collector of the type specimen, the light was set up on the front porch of the research station, at the top of a small hill overlooking the basin where there was nothing but virgin lowland tropical rain forest as far as the eye could see. Other pterostichite species associated in samples from the area, that are also thought to be inhabit rotting wood and debris, include Cosmodicus rubripictus Sloane , Cosmodiscus brunneus Darlington , Caelostomus picipes Macleay , C. albertisi and Brachidius crassicornis Chaudoir.

Figures

Fig. 1. Line drawings of Coelostomini. A) Type secimen, habitus of Stegazopteryx ivimkaensis; B) Elytra of Diachipteryx paradoxus Alluaud (based on figure in Straneo 1942); C) same of Caelostomus picipes MacLeay. B and C with setation ommited.