Antsirabenus setigerous, Heiss, 2008

Heiss, E., 2008, A new genus and two species of apterous Mezirinae from Madagascar (Heteroptera, Aradidae), Linzer biologische Beiträge 40 (1), pp. 303-309 : 306-307

Antsirabenus setigerous nov.sp. ( Fig. 2, 5 , photo 3, 4)

M a t e r i a l e x a m i n e d: Holotype male, Madagascar, S Diego Suarez (Antseranana), Montagne d’ Arbre 26-29.X.1995 E. Heiss leg. ( CEHI); paratypes: 5 females collected with holotype.

D i a g n o s i s The new species shares all essential characters of A. granulatus , however it is distinguished by smaller size (6.5-7.2/9.0- 10.8 mm), antennal segment II shorter than III (longer in A. granulatus ), different size and shape of anterolateral expansion of pronotum, more transverse scutellum and sinuate lateral margins of deltg V-VII (fig. 1, 2, 5, 6).

D e s c r i p t i o n: General shape, granulation of abdomen and appendages and colouration as in A. granulatus , therefore mostly the distinguishing characters are described.

H e a d: Slightly longer than wide (33/31.5); genae produced anteriorly over clypeus, longer than antennal segment I, apices diverging; antennae 1.55 ✕ as long as width of head, all segments of subequal length but II slightly shorter than III, relative length of I:II:III:IV = 13:11:12:13; postocular tubercle small and acute.

P r o n o t u m 2.9 ✕ as wide as long (47/16); anterolateral expansion smaller than in granulatus and more rounded; median elevations of disk distinctive, sublateral ones not developed.

S c u t e l l u m: 2.7 ✕ as wide as long (30/11), structure as of A. granulatus .

A b d o m e n Basic structures as in the type species, however the inverted T-shaped structure on mtg III is triangularly elevated at posterior margin, lateral margins of fused deltg II+ III and IV straight and posterolateral angles slightly produced, those of deltg V- VII sinuate with posterolateral angles rounded and distinctly produced (fig. 5) ; posterior margins of deltg II-VI are more raised than in A. granulatus . Venter with lateral metathoracic scent gland canals long and straight, the cleft opening is anterolaterally visible from above. Spiracles II-VII ventral, VIII lateral and visible from above.

G e n i t a l i c s t r u c t u r e s: The single male available was not dissected.

F e m a l e: Generally as male but of larger size, structures of terminal segments as of A. granulatus .

M e a s u r e m e n t s: Length 6.5 mm; width of pronotum 2.35 mm; width ocross metanotum 3.0 mm; width of abdomen 3.0 mm. Females: Length 7.2-7.8 mm; ratio length of antennae/width of head 1.44-1.48; width of pronotum 2.45-2.60 mm; ratio width/length of scutellum 3.08-3.18; width across metanotum 3.6-3.8 mm; width of abdomen 3.9-4.25 mm.

E t y m o l o g y: Referring to the setigerous granulation covering body, legs and antennae.

D i s t r i b u t i o n a n d e c o l o g y: To date only known from the rainforest of

Montagne d’ Arbre, where it was found feeding on decaying logs of a leaf tree laying on the forest floor. Is most probably also an endemic species.

Figures

Fig. 1-10: Antsirabenus nov.gen. 1, 3, 4, 6-10 A. granulatus nov.sp.; 2, 5 A. setulosus nov.sp.; (1, 2) paratypes female, dorsal view; (3) metathoracic scent gland canal, lateral view; (4) claw; (5, 6) outline of abdomen of males; (7-10) right paramer in different positions (10 = ventral side). Abbreviations: (em) median elevation of metanotum; (pa) setiform parempodia; (ps) pseudopulvilli; (sc) metathoracic scent gland canal. Scale: Fig. 1-3, 5, 6 = 1 mm; fig. 7-10 = 0.1 mm.