Chrysoctonus Mathot

Huber, John T. & Triapitsyn, Serguei, 2015, Redescription of Chrysoctonus and description of Chrysoctonoides (Hymenoptera, Mymaridae), a new genus from the Australian Region, ZooKeys 505, pp. 79-101 : 80-83

Taxon classification Animalia Hymenoptera Mymaridae

Chrysoctonus Mathot Figs 1-6, 7-12, 13-19, 20-24, 25-27, 28-30, 31, 32, 33-34, 35-40

Chrysoctonus Mathot, 1966: 224. Type species: Chrysoctonus apterus Mathot. Type locality: Democratic Republic of the Congo, Yangambi, 0°46'N, 24°27'E, in forest litter.

Myrmecomymar Yoshimoto, 1990: 28. Type species: Myrmecomymar masneri Yoshimoto. Type locality: Canada, Ontario, Spencerville. Syn. n.

Diagnosis.

Female. Body length 425-890. Wingless (Figs 7, 9, 33, 36, 37). Head (Figs 1-6, 33, 35, 37) with eye small and ocelli absent; subantennal sulci absent; vertex with many appressed, diverging setae medially surrounded by bare area; occiput separated from vertex by curved suture above foramen. Antenna with 4-8 funicle segments, the basal ones short (Figs 33, 34). Mesosoma (Figs 7-10, 36, 37) with pronotum entire, from about half as long as to longer than the short, strongly transverse mesoscutum; notauli apparently absent; scutellum with frenum not demarcated, about as long as or longer than mesoscutum; metanotum narrow, hidden under scutellum; propodeum flat, reticulate, with denticles medially; propodeal spiracle small, several times its diameter from anterior margin of propodeum. Metasoma (Figs 13-19, 33, 38-40) with petiole tubular, about 1.5 × as long as wide, strongly reticulate; gaster with gt1 the largest tergum, with lateral panels covering at least half of gaster, and with a cluster or row of setae anterolaterally; gt2 the next largest tergum; cercal setae long. Gaster without spiracle on gt6.Ovipositor slightly exserted beyond apex of gaster (Figs 18, 19, 38-40).

Male. Body length 425-760. Fully winged. Head (Figs 20-23) with normal eyes and ocelli. Flagellum 11-segmented (Figs 24, 25), each segment equally wide with parallel sides and several rows of short setae, each much shorter than segment length. Mes osoma (Figs 11, 28-30) with pronotum short, in dorsal view barely visible; propleura abutting medially along most of their length (Fig. 29); prosternum small, triangular; mesoscutum as long as scutellum, without notauli (Figs 25, 50); scutellum with (Fig. 28) or without campaniform sensilla, and fenestra wide, occupying most of scutellum. Fore wing with venation more than half wing length (Figs 26, 27); microtrichia unevenly distributed on wing surface; hind wing short and narrow. Metasoma (Fig. 31) with gt1 the largest segment. Genitalia (Figs 30, 32) with aedeagal apodeme at least as long as half length of gaster.

The greatest range in number of funicle segments of any genus of Mymaridae is found in Chrysoctonus species: one specimen from Panama had 4 segments and two from Costa Rica had 8 segments; the usual number appears to be 5 segments.

The only described species in Myrmecomymar is transferred here to Chrysoctonus as Chrysoctonus masneri (Yoshimoto), comb. n.

Hosts and habitat.

Hosts are unknown. Specimens from the type locality were collected in August in pan traps placed near the base of trees in a forest normally flooded in spring and early summer (L. Masner, personal communication). Other specimens of the type species and other, undescribed, species were collected in Canada from a sedge pond, hollows and hummocks in a bog, peat bog, old forest, Carya grove, and spring flood debris. In the USA specimens have been collected from a hardwood forest, beaver swamp, oak forest, and forest hammock. In Central and South America and various Caribbean islands specimens were collected from wet cloud forest litter, forest litter, compost pile, forested creek, montane oak forest, cloud forest, rainforest, palm forest, and thicket forest, from about sea level to 2000m. The habitat types strongly suggest that females parasitize hosts found in moist soil or associated with water. The holotype of Chrysoctonus apterus and other African specimens were collected from forest litter.

Distribution.

Western Hemisphere and Afrotropical Region. Specimens have been seen from 22 countries in the New World, from southern Canada to northern Argentina and Uruguay, and 4 countries in central Africa.