Acostemma stilleri, Zahniser & Dietrich, 2013

Zahniser, James N. & Dietrich, Chris H., 2013, A review of the tribes of Deltocephalinae (Hemiptera: Auchenorrhyncha: Cicadellidae), European Journal of Taxonomy 45, pp. 1-211 : 177-179

Acostemma stilleri sp. nov.

urn:lsid:zoobank.org:act:202D6A00-1E0B-4990-A9CF-81B700031C68

Fig. 9

Diagnosis

There are 11 valid species of Acostemma , 8 of which are known from Madagascar. The male genitalia of the new species appear to be unique and do not match any of the 6 species for which genitalia were illustrated by Evans (1954) or A. phylia Evans, 1959 . The genitalia of A. suboecia (Jacobi) were not illustrated, but the size of the male is reported to be 12.5 mm, much larger than the species described here. Of the species illustrated by Evans (1954), A. stilleri may be most similar to A. sulcifrons (Signoret) , but the processes arising from the preatrium are much longer in A. stilleri and the the processes arising from the shaft of the aedeagus are differently shaped.

Etymology

This species is named in honor of M. Stiller, the leading authority on South African Deltocephalinae .

Type material

Holotype

♂, MADAGASCAR, Toliara Prov., Parc Nat. de Tsimanampetsotsa, Forêt de Bemanateza, 20.7 km 81° E of Efoetse , 23.0 km 131° SE of Beheloka, 22-26 Mar. 2002, 23°59’32” S – 43°52’50” E, coll. Fisher, Griswold et al., California Academy of Sciences, at light - in spiny forest thicket, elevation 90 m, code: BLF6253. Deposited in coll. CAS.

Paratypes

3 ♂♂ and 1 ♀, same data as holotype ; 1 ♂, MADAGASCAR, Toliara Prov., Mahafaly Plateau, 6.2 km 74° ENE of Itampolo , elev. 80 m, 21-25 Feb. 2002, 24°39’13” S – 43°59’48” E, coll. Fisher, Griswold et al., Calif. Acad. of Sciences, malaise trap - spiny forest thicket, code: BLF5759 ; 4 ♂♂ and 3 ♀♀. MADAGASCAR, Toliaran Prov., Parc National d’Andohahela, Forêt de Manantalinjo , 33.6 km 63° ENE of Amboasary , 7.6 km 99° E of Hazofotsy , 12-16 Jan. 2002, 24°49’1” S – 46°36’36” E, coll. Fisher, Griswold et al., California Academy of Sciences, at light - in spiny forest/thicket, elevation 150 m, code: BLF4813 .

One of the ♂ paratypes from locality BLF6253 is completely cleared and stored in glycerine. Genomic DNA was extracted from this specimen, and DNA sequence data generated from it are included in the analyses here. The specimen bears the voucher number “ DEL 014 ”. 5 paratype males and 3 females deposited at CAS, 3 paratype males and 1 female deposited at INHS.

Description

SIZE. ♂ 8.5-9.5 mm, ♀ 8-10 mm.

BODY. Head as wide as pronotum. Crown slightly produced medially; longer medially than next to eyes; surface texture longitudinally striate; depressed with distinct transition from vertex to frons; upturned at apex. Anterior margin of head with single carina between ocelli. Face with epistomal suture evident just below and mesad of ocelli; face shagreen below epistomal suture, rugose or irregular above. Clypellus long, widening apically. Gena broad.Antennal ledge absent. Forewing wing with several extra crossveins in anteapical and/or apical cells. A1-A2 crossvein present. Profemur row AM with AM1 and 2 or more additional proximal macrosetae; intercalary row with apical setae long, fine and with proximal setae long, thick, extending more than half length of femur; row AV with short, stout setae. Protibia dorsal surface rounded; macrosetae 1+5. Mesofemur row AV with numerous short, stout setae. Metafemur apical setae 2+2+1. Metatarsomere I pecten with 6 long platellae, without tapered setae.

MALE. Pygofer broad, rounded; with numerous short, thick setae posteriorly and posteroventrally; fused to valve. Subgenital plates short; fused to each other; with several macrosetae subapically. Style in lateral view bent apically at nearly 90º angle; apophysis curved, somewhat thick. Connective with anterior arms separate at slightly more than 90º; median stem absent; with short posterolateral pair of arms; fused with aedeagus. Aedeagus lying on top of and fused to connective; preatrium strongly modified into recurved process, bifurcated near connective forming pair of slender acuminate processes; aedeagal shaft with two asymmetrical processes, one arising from base parallel to shaft and terminating near gonopore, the other arising near apex, curved anteriorly, extending beyond gonopore; gonopore apical. Segment X long, narrow; 2.25 x longer than wide.

FEMALE. Sternite VII length ~1.75 x width; pointed and V -shaped apically; lateral margins convex anteriorly, concave posteriorly. First and second valvulae illustrated in Zahniser & Dietrich (2008: figs 5b, 7d) as “ Acostemma sp.”. First valvulae relatively slender; dorsal sculpturing pattern strigate to reticulate or imbricate. Second valvulae slender; with ~6 knob-like dorsal teeth restricted to less than apical 1/4 of valvulae. The eggs of this species are very unusual in having a tuft of lamellate seta-like extensions at one end. This has not been observed in any other Deltocephalinae , but a similar modification was reported by Wei et al. (2007b) in the stegelytrine Patanolidia magnifica Wei & Webb. The setae appear to be more filamentous in that species, and occupy a greater portion of the egg than in A. stilleri . Eggs of numerous species of Deltocephalinae have been observed and are usually unremarkable in structure.

Remarks

At least 20 other species of Acostemma were collected in the Terrestrial Arthropod Inventory of Madagascar project conducted by the California Academy of Sciences (CAS) and Tsimbazaza Botanical and Zoological Park (PBZT), and none were assignable to described species. The available illustrations of the genitalia of Acostemma spp. are not very detailed, and a revision of the genus would add much needed clarity to the taxonomy of the currently known species.

Figures

Fig. 9. Acostemmini. Acostemma stilleri sp. nov. A–I. Standard views (see Material & Methods). F. Plates shown with pygofer. G. Connective and style shown with part of fused aedeagus. H. Aedeagus shown with fused processes, connective, and style. J. Lateral view of style, connective, and base of aedeagus. K. Ventral view of connective, styles, and ventral processes of aedeagus. L. Detail of hairlike extensions of egg. M. Egg. N. ♀ sternite VII.