Apoderiger Wasmann, 1897

Genus Apoderiger Wasmann, 1897 View in CoL

Apoderiger Wasmann, 1897: 263 .

Type species: Apoderiger cervinus Wasmann , by monotypy.

Soalala Dajoz, 1982: 512 View in CoL . Type species: Soalala spinosa Dajoz View in CoL , by original designation; synonymy in Besuchet, 2008: 65.

Apoderiger View in CoL – Jeannel 1954: 312 (redescription); 1960: 202 (in key); 1960: 203. — Célis 1970: 248 (diagnosis, key to species). — Besuchet 2008: 65 (synonymy of Soalala View in CoL ).

Diagnosis

Head elongate, at least twice as long as wide; temples shorter than frontal rostrum; lacking frontal foveae, with pair of minute dorsal tentorial pits, situated behind eyes. Neck region subcylindrical, long, about as long as or slightly shorter than posterior part of head capsule, separated from head capsule by deep occipital constriction, partly retracted into prothorax. Antenna trimerous; terminal antennomere very long, dilated and curved distally, its apex truncate, with dense short and long setae. Pronotum transverse, clearly wider than long, lacking antebasal and lateral foveae. Elytra more than 1.50 × as wide as long; lacking basal foveae; humeri strongly prominent; posterior margin of elytron lacking trichomes. Abdomen with composite tergite convex, lacking impressions, keels and lacking trichomes; three paratergites of composite tergite present, first paratergite in anterior portion with trichome; posterior margin of composite tergite with pair of small, bump-like, wide-distant or with pair of long, triangular, short-distant projections. Legs long and slender; femur lacking interlocking ridge; mesotibia differently modified in pre or apical portion. Aedeagus elongate, slender, 2.5–3.0× as long as wide; basal bulb well-separated from distal lobe; endophallus with or lacking sclerites; dorsal diaphragm round or elliptical.

Description

BODY ( Fig.1 View Fig ). Yellowish-brown, elongated, more about 2.5 × as long as wide. Length 1.4–2.2 mm.

HEAD. Elongate, at least twice as long as wide, widest at level of eyes; rostrum narrow, rounded at anterior margin; eyes oval, slightly prominent, situated slightly behind midpoint of head capsule; temples shorter than frontal rostrum, behind eyes slightly convergent posteriad; lacking frontal foveae, with pair of minute dorsal tentorial pits, situated behind eyes; clypeus partly visible on sides. Neck region subcylindrical, long, about as long as or slightly shorter than posterior part of head capsule, separated from head capsule by deep occipital constriction, partly retracted into prothorax, with well-defined gular plate ( Fig. 2A View Fig ); posterior tentorial pits ( Fig. 2A View Fig ; ptp = gular foveae of Chandler 2001) small, circular, well-separated, situated in front of transverse impression demarcating neck region ventrally; pre-tentorial gular-submental region elongate, subrectangular and smooth.

ANTENNA. Trimerous ( Fig. 2C–E View Fig ), semi-circular in cross-section, very long, exceeding posterior margin of pronotum; scape slightly longer than pedicel, both small, subrectangular; terminal antennomere (flagellomere) very long, more than 10 × as long as wide, dilated distad and variably shaped, curved distally, its apex truncate, with dense short and long setae.

MOUTHPARTS. Rudimentary but well-developed, completely hidden in transversally elliptical bucal cavity ( Fig. 2A–B View Fig ); labium with transverse, sub-rectangular mentum ( Fig. 2A–B View Fig ), anterior margin of mentum slightly rounded, its anterior half with long setae placed in two rows, lacking ligula. Maxilla reduced, with large, hemispherical cardo ( Fig. 2B View Fig ); basistipes ( Fig. 2B View Fig ) minuscule, with one seta; galea and lacinia atrophied. Maxillary palpi ( Fig. 2B View Fig ) reduced to one palpomere. Mandibles ( Fig. 2B View Fig ) ovaly projecting on outer portion. Labrum ( Fig. 2B View Fig ) transverse with almost straight anterior margin; anteroventral margin with some peg-like sensilla ( Fig. 2B View Fig ); clypeus ( Fig. 2B View Fig ) large, transverse, with rounded anterior margin which is bearing bunch of long setae.

PRONOTUM. Transverse, clearly wider than long, about half of length of head; lacking squamouse setae; lateral margin rounded, in anterior and posterior half convergent; lacking antebasal and lateral foveae; lacking sulci or carinae.

PROSTERNUM ( Fig. 3A View Fig ). Laterally fused with hypomera; basisternal region longer than coxal region, with sparse setae, with pair of small, widely separated asetose lateral procoxal foveae ( Fig. 3A View Fig ; lpcf = term of Chandler 2001; in fact, these foveae are situated on prosternum, anterad procoxal cavities), median procoxal fovea absent; prosternal process ( Fig. 3A View Fig ) rounded, not separating procoxae. Hypomera divided by incomplete hypomeral ridges ( Fig. 3A View Fig ) into narrow, elongate inner hypomeral region ( Fig. 3A View Fig ) and broad, smooth outer hypomeral region ( Fig. 3A View Fig ), latter with shallow hypomeral groove ( Fig. 3A View Fig ).

MESONOTUM AND METANOTUM. Not studied.

MESOVENTRITE. Fused with metaventrite, with sparse setae being denser on metaventral disc, lacking foveae; mesocoxae separated, width of isthmus about half of diameter of mesocoxal cavity; mesoventral and anterior metaventral process subequal in length, truncate; disc of metaventrite slightly convex in anterior part, declining to posterior margin, lacking projection, patch of trichome-like setae or strong median longitudinal keel; metaventral posterior process ( Fig. 3A View Fig ) wide, short, with straight posterior margin or long, semitriangular, with pointed and setose projecting posterior part exceeding part of abdominal sternites.

ELYTRA. 1.60–1.70× as wide as long, 1.50–1.70 × as long as pronotum, with unevenly distributed short setae; lacking basal foveae; with or without discal and sutural striae; postero-lateral corner of elytron obliquely bevelled mesad, lacking projection; humeri strongly prominent; posterior margin of elytron lacking trichomes.

ABDOMEN. With composite tergite convex, lacking impressions or keels, lacking trichomes; three paratergites of composite tergite present, first paratergite in anterior portion with trichome; posterior margin of composite tergite with pair of small, bump-like, wide-distant or with pair of long, triangular, short-distant projections.

ABDOMEN ( Fig. 3B View Fig ). With first visible sternite (III) narrow, more than 6 × as short as second visible sternite (IV) which is almost twice as long as third (V); all sternites simple, lacking any modification.

LEGS. Moderately long and slender; femur lacking interlocking ridge; mesotibia differently modified in pre or apical portion, sometimes with mesotibial preapical tooth ( Fig. 3C View Fig ); tarsomere 1 minuscule ( Fig. 3C View Fig ), 2 much longer, 3 considerably longer than 2, with subtriangular distal lamella ( Fig. 3C View Fig ).

AEDEAGUS ( Fig. 4A–J View Fig ). Elongate, slender, 2.5–3.0× as long as wide; basal bulb well-separated from distal lobe, ratio length of basal bulb /length of distal lobe variable 0.9–2.4; endophallus with or lacking sclerites; dorsal diaphragm round or elliptical.

Sexual dimorphism

Females always with short, wide posterior metaventral process, mesotibia always simple, lacking any kind of modification.

Host ant

Paratrechina amblyops rubescens (Forel, 1892) is the only host ant known so far for the genus.

Distribution

The centre of the distribution of the genus Apoderiger is the eastern part of central Madagascar, where four species are present, A. banari sp. nov., A. sikorai sp. nov. in the massif Anjozorobe – Andasibe, A. cervinus on the Imerina Plateau and one, the most southern record of an undescribed species, in the Ranomafana National Park. There are three isolated species located more to the north, A. spinosus on the western coast, Soalala district, A. grandis sp. nov. on northeastern part, Manongarivo Special Reserve and A. torticornis in Antongil Bay, north-eastern part ( Fig. 5 View Fig ).

Remarks

Two well-defined groups of species can be recognized within the genus which are readily separated by the different structure of a pair of projections on the posterior margin of the composite tergite. The first group, containing A. spinosus ( Dajoz, 1982) and A. sikorai sp. nov., has posterior margin of composite tergite with pair of small, bump-like, wide-distant projections and strongly curved distal portion of terminal antennomere. The second group, with A. torticornis , A. grandis sp. nov. and A. banari sp. nov., has posterior margin of composite tergite with pair of long, triangular, short-distant projections which are or not exceeding posterior margin of abdomen and slightly curved distal portion of terminal antennomere. Except A. cervinus , because of unknown male, the remaining species of the genus can be separated using the following key.

Key to males

( Apoderiger cervinus View in CoL is missing in the key because the male of this species is unknown).

1. Posterior margin of composite tergite with pair of small, bump-like, wide-distant projections ( A. spinosus View in CoL species group) .............................................................................................................. 2

– Posterior margin of composite tergite with pair of long, triangular, short-distant projections ( A. torticornis View in CoL species group) ........................................................................................................... 3

2. Small species, about 1.40 mm long; apex of mesotibia with inner projection ................................... ................................................................................................................... A. spinosus ( Dajoz, 1982) View in CoL

– Large species, about 1.70–1.85 mm long; apex of mesotibia lacking inner projection, only with small preapical tooth ( Fig. 3C View Fig ) .............................................................................. A. sikorai s p. nov.

3. Triangular paired projections on posterior portion of composite tergite shorter, not exceeding posterior margin of abdomen; posterior subtriangular metaventral process exceedingly over first visible sternite (III) ................................................................................................ A. banari sp. nov.

– Triangular paired projections on posterior portion of composite tergite longer, clearly exceeding posterior margin of abdomen; posterior metaventral process wide, short, with almost straight posterior margin, not exceedingly over first visible sternite (III) ..................................................... 4

4. Elytra with discal and sutural striae; large species, about 2.2 mm long; head less than 1.60 × as long as pronotum .......................................................................................................... A. grandis sp. nov.

– Elytra lacking discal and sutural striae; small species, about 1.8–1.9 mm long; head more than 1.75 × as long as pronotum ............................................................................... A. torticornis Jeannel, 1960 View in CoL