Gallastichus mutuus Rasplus & La Salle, sp. nov.
Creators: name: Rasplus, Jean-Yves
name: Salle, John La
name: Delvare, Gérard
name: Mckey, Doyle
name: Webber, Bruce L
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Ormyridae
Gallastichus
Gallastichus mutuus

description: Gallastichus mutuus Rasplus & La Salle sp. nov.   
(Figs 1 A–E, 2A–D, 4A)  
 Diagnosis. Lower face and frons with piliferous punctures. Submedian lines of scutellum present, complete or nearly so. Propodeum with two submedian carinae. Outer rim of spiracle visible, not covered by a flap of the callus. Fore wing long and densely pilose. Submarginal vein bearing 1 dorsal thin hair.   
 Description. Female. Body length 2.3–2.7 mm. Head dark brown, with lighter brown markings at mouth margin. Antennal scape yellow-orange, dark brown on dorsal margin, pedicel ventrally yellow-orange, flagellum dark brown. Colour of mesosoma and gaster variable; mesoscutum at least with a dark brown patch anteromedially, remainder varying from yellow-orange to almost entirely dark brown; scutellum mainly yellow-orange, although submedian lines indicated by dark brown posteriorly; remainder of mesosomal structures generally a combination of orange-yellow to dark brown. All legs and coxae yellow-orange. Gaster varying from mainly dark brown to having extensive yellow-orange markings.   
Face and frons with scattered, small, setigerous punctures (Fig. 1 A). Scape longer than eye, with flattened ventral expansion and extending dorsally above level of vertex (Fig. 1 B). All funicular segments longer than wide (Fig. 1 D). First funicular segment almost 6 × as long as wide, second and third funicular segments about 3.5 × as long as wide. Clava three segmented, about 5 × as long as wide. Mesoscutum largely smooth anteriorly, weakly posteriorly (Fig. 2 A), without a median line or groove, but with deep notauli, and with 1 or -2 adnotaular setae (Fig. 2 C). Scutellum with submedian grooves weakened to absent (Fig. 2 C). Dorsellum with large median plate (Fig. 2 C). Propodeum with paired carinae medially, which diverge posteriorly, area between carinae sunken anteriorly (Fig. 2 C). Fore wing with a single seta on the dorsal surface of the submarginal vein  
 Male. Body length 1.5–1.7 mm. Head, body and gaster predominantly dark brown, with relatively few lighter markings. Fore coxa yellow-orange, middle and hind coxa dark brown. Legs yellow-orange. Base of each funicular segment swollen, tapering apically. First three funicular segments 3.4–3.6 × longer than widest part, fourth funicular segment about 3.0 × longer than widest part. Clava three segmented, 3.5 × longer than widest part.   
 Etymology. The species name is indicative of the mutualistic relationship seen in this gall community.   
 Material examined. Holotype ♀: CAMEROON, 1 km W of the village N'kolo-Bondé, c. 200 m from the Béla - Bipindi road, (03°13'N, 10°15'E, 90 m asl), ex galls on Bikinia letestui (Pellegr.) Wieringa subsp. letestui (Fabaceae: Caesalpinioideae) (CBGP). 50♀, 20♂ paratypes: same collection date as holotype (1♀, SAMC; 4♀, 3♂ ANIC; 2♀, MNHN; 2♀, PPRI and 41♀, 17♂, CBGP).   
 Discussion. Gallastichus mutuus is unusual in that it induces galls in extrafloral nectaries on new leaves. Chalcidoid gall-inducers are known to induce galls in a variety of plant tissues and organs, such as leaves, stems, ovaries, seeds (La Salle 2005), and in one case even the elaiosomes associated with seeds (Hardwick et al. 2005). However, this is the first recorded instance of a chalcidoid gall being induced in extrafloral nectaries.
description: Published as part of Rasplus, Jean-Yves, Salle, John La, Delvare, Gérard, Mckey, Doyle & Webber, Bruce L, 2011, A new Afrotropical genus and species of Tetrastichinae (Hymenoptera: Eulophidae) inducing galls on Bikinia (Fabaceae: Caesalpinioideae) and a new species of Ormyrus (Hymenoptera: Ormyridae) associated with the gall, pp. 51-59 in Zootaxa 2907 on pages 53-55, DOI: 10.5281/zenodo.277771