Chaenusa (Chaenusa) seminervata 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) seminervata van Achterberg, 2012 Figs 5 , 6 , 7 , 8 , 9

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; Mpumalanga Prov., Belfast, Lakenvlei Wetland ; 25°60'S, 30°05'E ( RMNH not seen) • 1 male; KwaZulu-Natal Prov., Stillwater Dam, Rosetta ; 29°30'S, 29°97'E; 17.xi.2008; J.R. Baars, J.A. Coetzee, G.D. Martin; ex leaf-miner on Lagarosiphon major Hydrocharitaceae ( RMNH not seen) • 4 males; Dieu Donne Farm Dam, Sani Pass ; 29°68'407"S, 29°48'949"E; 16.xi.2008; J.R. Baars, J.A. Coetzee, G.D. Martin; reared from leaf-miner on Lagarosiphon major ( Hydrocharitaceae) ( SANC examined, 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-R01, SAM-HYM-P092800 ( SAMC) • 1 female, idem, except MDMR-FOR-R02, SAM-HYM-P092801 ( SAMC) • 1 male, idem, except MDMR-FOR-R04, SAM-HYM-P092802 ( SAMC) • 1 male, idem, except MDMR-FOR-R09, SAM-HYM-P092804 ( SAMC) • 1 male, idem, except MDMR-FOR-R10, SAM-HYM-P092805 ( SAMC) • 1 male, idem, except MDMR-FOR-R14, SAM-HYM-P092806 ( 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.

The Neotropical species Chaenusa aurantium Kula & Martinez, 2009 was reared from an undescribed species of Hydrellia in Argentina under evaluation for control of Egeria densa in the United States ( Kula et al. 2009). Chaenusa seminervata keys to C. aurantium (terminal maxillary palpomere is brown) in the key to New World species ( Kula and Zolnerowich 2008; Kula et al. 2009), but it is distinct from C. aurantium in head colour, sculpture and setation of the frons, as well as mesoscutal, mesopleural and propodeal sculpture. Sexual dimorphism of Chaenusa seminervata is exhibited in the following characters: females with 16-18 antennal segments, males with 17-24 segments; the forewing pterostigma is light brown in females and dark brown in males; in addition, the compound eyes in females converge less strongly (narrowest ventral width of the face 0.75 × broadest dorsal width) towards the clypeus than in C. anervata , but still more strongly than in males (narrowest ventral width of the face 0.81 × 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 = 10:12; males H:W = 9:11).

Figures

Figure 5. Chaenusa seminervata Holotype female TYPH 01928 (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 6. Chaenusa seminervata Holotype female TYPH 01928 (SANC) A propodeum and metasoma, dorsal view B propodeum and metasoma, lateral view C mesosoma and first tergite, dorsal view D propodeum and first tergite, dorsal view E wings F data labels.

Figure 7. Chaenusa seminervata female SAM-HYM-P 092801 (SAMC) 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 8. Chaenusa seminervata female SAM-HYM-P 092801 (SAMC) A metasoma, dorsal view B metasoma, lateral view C scutellum, metanotum, propodeum and first tergite, dorsal view D first tergite, dorsal view E wings, inset: data labels F vertex of head.

Figure 9. Chaenusa seminervata male SAM-HYM-P 092802 (SAMC) A habitus, lateral view, inset: data labels B habitus, dorsal view C head and mesosoma, lateral view D head, anterior view.