Megastigmus transvaalensis (Hussey, 1956)

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 : 104-105

Taxon classification Animalia Hymenoptera Torymidae

Megastigmus transvaalensis (Hussey, 1956)

Material examined.

3♀♀, 7♂♂, Kenya, Kikuyu Escarpment, Central Province, 1.0290°S, 36.6025°E, 2100 m, coll. 85, ex. Rhus vulgaris seeds, 29 Apr 1999, R. Copeland leg.; 2♀♀, 3♂♂, Kenya, Burguret, Central Province, 0.1128°S, 37.0375°E, coll. 2162, ex. Rhus natalensis seeds, 16 Aug 2002, R. Copeland leg.; 3♀♀, 7♂♂, Kenya, Nairobi Province, 1.2212°S, 36.8963°E, 1610m, coll. 2787, ex. Schinus terebinthifolius seeds, 28 Apr 2004, R. Copeland leg. (4♀♀, 10♂♂ RSC; 4♀♀, 7♂♂ ARC)

Male and female specimens fit the description of the species by Hussey (1956a) and Grissell and Prinsloo (2001), then detailed by Roques and Skrzypczyńska (2003). Figures 150-155 present the most important characteristics of female specimens from Kenya whereas Figures 156-162 show those of males.

Host plants.

Schinus molle , Schinus terebinthifolius , Rhus natalensis , Rhus vulgaris ( Anacardiaceae ). A seed feeder. Schefer and Grissell (2003) presented a molecular analysis of the populations of this species, suggesting its origin in Austral Africa but we were unable to amplify any specimens of the Kenyan populations we obtained.

Distribution.

Adults emerged from 14.8% of the fruits of Schinus molle , 14.7% of those of Rhus vulgaris and up to 6.1% of Rhus natalensis fruits (Table 3).

Diagnosis.

Females can be distinguished from these of other species associated with fruits of Anacardiaceae and showing a predominantly orange body by the relative size of the ovipositor and the shape of the forewing stigma. In Megastigmus transvaalensis , the ovipositor is 1.4 × as long as gaster length (Figure 151) whereas it is nearly twice as long as the gaster in Megastigmus laventhali (1.8 ×; Figure 76) and only a bit longer than gaster in Megastigmus thomseni and Megastigmus pistaciae (1.1 –1.2×; Figure 137). The stigma is conspicuously elongate, and quite rectangular in Megastigmus transvaalensis (2.0 × as long as wide; Figure 155), less elongate in Megastigmus thomseni (1.7 ×, according to the drawing by Hussey 1956a) whereas it is oval and rounded in Megastigmus pistaciae (1.2 –1.3×; Figure 141).

Genitalia allows the separation of males from those of other species reared from seeds of Anacardiaceae . The aedeagus part above digitus is conspicuously shorter than digitus length (0. 5 ×; Figure 162) whereas this part is more elongated in Megastigmus pistaciae (0.8 ×; Figure 148), Megastigmus hypogeus (1.2 × as long as digitus length; Figures 127, 134), Megastigmus ozoroae (1.8 ×; Figures 53, 60) and Megastigmus lanneae (1.8 ×; Figures 107, 115).