Chaenusa (Chaenusa) anervata van Achterberg, 2012

Noort, Simon van, Smith, Rosali & Coetzee, Julie A., 2021, Identity of parasitoid wasps (Hymenoptera, Braconidae and Eulophidae) reared from aquatic leaf-mining flies (Diptera, Ephydridae) on invasive Brazilian waterweed Egeria densa in South Africa, African Invertebrates 62 (1), pp. 287-314 : 287

Chaenusa (Chaenusa) anervata van Achterberg, 2012 Figs 1 , 2 , 3 , 4

Holotype.

South Africa • female; Mpumalanga Prov., Lydenburg Fisheries, Lydenburg ; 25°11'S, 30°48'E; 21.xi.2008; J.R. Baars, J.A. Coetzee, G.D. Martin; ex leaf-miner on Lagarosiphon major Hydrocharitaceae ( SANC examined).

Paratypes.

South Africa • 1 female; KwaZulu-Natal Prov., Mooi River, Mearns Dam ; 29°25'S, 29°97'E; 18.xi.2008; J.R. Baars, J.A. Coetzee, G.D. Martin; ex leaf-miner on Lagarosiphon major Hydrocharitaceae ( RMNH not seen) • 1 male: Underberg, Farm Dam on Bushman's Nek road; 30°27'S, 29°14'E; 16.xi.2008 ( SANC examined) • 1 male; Mooi River, Mearns Weir , 29°15'S, 29°57'E, 17.xi.2008 ( RMNH not seen) .

Other material.

South Africa • 1 male; KwaZulu-Natal, Midmar Dam , 29°32'21.35"S, 30°11'40.15"E, June 2019, R. Smith, Collected from Egeria densa infestation with Hydrellia egeriae pupae, reared in lab, MDMR-FOR-R05, SAM-HYM-P092803 ( SAMC) .

Biology.

Parasitoid of aquatic leaf-mining flies ( Ephydridae ): Hydrellia lagarosiphon on Lagarosiphon major ( Hydrocharitaceae) and Hydrellia egeriae on Egeria densa ( Hydrocharitaceae).

Distribution.

South Africa.

Comments.

According to van Achterberg and Prinsloo (2012), this species is similar to Chaenusa glabra Kula, 2009 ( India, Pakistan), which has a two-segmented labial palp (three-segmented in C. anervata and C. seminervata ), females with 12-14 antennal segments (at least 15 in C. anervata and 16-18 in C. seminervata ) and males with 14-17 segments (22 in C. anervata and 17-24 in C. seminervata ). The body is brown or brownish-yellow as opposed to black in C. anervata and C. seminervata (van Achterberg and Prinsloo 2012). Other sexually dimorphic characters in C. anervata encompass the forewing pterostigma, which is light brown in females and dark brown in males; the male first metasomal tergite is generally longer (1.1-1.3 times its apical width) than in the female (1.1 times apical width) (van Achterberg and Prinsloo 2012); in addition, the compound eyes in females converge far more strongly (narrowest ventral width of face 0.55 × broadest dorsal width) towards the clypeus than in the males (narrowest ventral width of face 0.90 × broadest dorsal width); however, the overall relative dimensions of the face relative to the broadest width just below the toruli are equivalent in the two sexes, being slightly wider than high (females H:W = 9:10; males H:W = 10:11).

Figures

Figure 1. Chaenusa anervata Holotype female TYPH 01927 (SANC) A habitus, lateral view B habitus, dorsal view C head and mesosoma, lateral view D head and mesosoma, dorsal view E head, anterior view F head, ventrolateral view.

Figure 2. Chaenusa anervata Holotype female TYPH 01927 (SANC) A propodeum and metasoma, dorsal view B propodeum and metasoma, lateral view C scutellum, metanotum and propodeum, dorsal view D first tergite, dorsal view E wings F data labels.

Figure 3. Chaenusa anervata Paratype male (SANC) A habitus, lateral view B habitus, dorsal view C head, anterior view D wings, inset: data labels.

Figure 4. Chaenusa anervata male SAM-HYM-P 092803 (SAMC) A habitus, lateral view B habitus, dorsal view C head, anterior view D wings, inset: data labels.