Megastigmus somaliensis Hussey, 1955

Roques, Alain, Copeland, Robert S., Soldati, Laurent, Denux, Olivier & Auger-Rozenberg, Marie-Anne, 2016, Megastigmus seed chalcids (Hymenoptera, Torymidae) radiated much more on Angiosperms than previously considered. I- Description of 8 new species from Kenya, with a key to the females of Eastern and Southern Africa, ZooKeys 585, pp. 51-124 : 105-106

Taxon classification Animalia Hymenoptera Torymidae

Megastigmus somaliensis Hussey, 1955

Type material examined.

Holotype ♀ "Bristish Somaliland; ex. seeds of Juniperus procera ; coll. i.1954, em. 25.ii.1954, J.T. Lawrie; Brit. Mus. 1956-294; Com. Inst. Ent. coll. 13661; B.M. TYPE HYM. 5.1623a; NHMUK010263946 5.1623a"(BNHM). Paratypes 4♀♀, 2♂♂, same collection data as holotype (BNHM);

Additional material.

1♀ "Abyssinia, Mulu, above Muger Valley; circa 8000 ft., 18-23. 12. 1926, Dr. H. Scott" (BNHM); 1♀ "Abyssinia, Mt. Chillálo Digula; circa 9500 ft., 27.11.1926, from foliage giant juniper, Dr. H. Scott" (BNHM); 3♀♀, 2♂♂, Kenya, Central Prov., Mt. Kenya Forest, 0.0308°S, 37.1230°E, 2125m, coll. 3034, ex. Juniperus procera seeds, 2 Nov. 2004, R. Copeland leg. (2♀♀, 1♂, RSC; 1♀ ARC; 1♂ destroyed).

Male and female specimens obtained from Kenya fit the general description of the species by Hussey (1956b). Figure 163 presents a view of female body whereas Figures 164-167 show the major morphological characteristics of male specimens from Kenya. Body colour is dark orange in the Kenyan specimens instead of pale orange in the type material from former British Somaliland, at present Somalia. However, at least one dark orange female was noticed in the BNHM collection, which had been collected in Digula, Abyssinia, at present Ethiopia.

Host plants.

Juniperus procera . A seed feeder clustering in the molecular phylogeny of Megastigmus with the other species developing in seeds of Juniperus in Europe (Figure 14). This species clearly belongs with strong support to the " Cupressaceae clade" whatever the marker and the analysis. It is close to Megastigmus amicorum , a seed chalcid which is widely distributed on Juniperus from the Mediterranean basin. The host of Megastigmus somaliensis , Juniperus procera , is the only juniper out of more than 60 species growing in the Arabian Peninsula and in Africa ( Mao et al. 2010). It suggests that the host and the associated chalcid originated from regions more northern than the ones where they are presently observed, which could explain the phylogenetic proximity with other juniper seed chalcids.

Distribution.

Sampled in highland forest and woodland in central and northwestern Kenya (Figure 1). Also present in Somalia and Ethiopia.

Diagnosis.

This species, as well as the related Megastigmus asir which also attacks Juniperus procera ( Ghram and Shati 2011), are easily differentiated from the other Afrotropical Megastigmus by the 7-8 pairs of hairs on the lateral parts of scutellum (Figure 166) whereas at most 5 pairs are present in the other species. Females of Megastigmus somaliensis are distinguished from those of Megastigmus asir by the shape of the forewing stigma and the sculpture of the propodeum. In the first species, forewing stigma is oval (1.6 × as long as wide measured from the drawing of Hussey 1956b) whereas it is much more elongate Megastigmus asir (2.2 × as long as wide when measured on the corresponding wing photo in Ghram and Shati (2011), although the authors mentioned in their text this value to be 1.5 ×). Propodeum is rugose and irregularly striated in Megastigmus somaliensis whereas it is smooth in Megastigmus asir ( Ghram and Shati 2011). The propodeum of males shows the same differences, the one of Megastigmus somaliensis additionally presenting a very short median carina in its anterior part (Figure 166). Forewing stigma is quite similar in the two species (1.4 × as long as wide in Megastigmus somaliensis - Figure 167- vs. 1.35 × in Megastigmus asir ; Ghram and Shati 2011).