Lonchaea polyhamata

Macgowan, Iain, 2018, Definition of the Lonchaea polyhamata species-group (Diptera, Lonchaeidae) with a description of new species, Zootaxa 4446 (3), pp. 325-342 : 326

Lonchaea polyhamata species-group.

Diagnosis. Within the genus Lonchaea the L. polyhamata species group is distinguished as follows;

Description. Male: Eyes with a sparse covering of short pale hairs, these less or equal to width of an ocellus. Frontal and interfrontal setulae short, not more than 0.2x length of orbital seta. postpedicel predominantly black, length to depth ratio in range of 1.9–2.4:1. Arista short pubescent. Proepimeron and proepisternum each with 1 seta. Anepisternum with 3 anterior and 4 posterior setae. Katepisternum with 2 setae near dorsal margin ( MacGowan & Rotheray, 2008. Fig 25 ). Calypteres pale with a pale fringe. Wings light fumose, wing length 4.0– 4.5mm. Legs entirely black.

Male terminalia: Epandrium, portion anterior to suture well-developed as a distinct sclerite ( Fig 1 t 9 & t10 ). Surstylus usually with 2–3 large projections on posterior or ventral surface but without setae on medial surface. ( Figs. 2, 3 Sur). Hypandrium only loosely connected to hypandrial apodeme, posterior process of hypandrium well developed ( Fig.1 ), phallus a small simple structure ( Fig. 1 ), parameres greatly elongated and ornamented ( Figs. 1 , 3 Para ). A pair of ventrally directed processes located at base of cerci ( Fig. 3 V pro).

This species group is distinguished within the Afrotropical Lonchaea by the short—haired eyes, 2 setae on katepisternum and slightly fumose wings. The structures within the male genitalia are diagnostic namely; epandrium with a discrete sclerite anterior to the suture the long posterior apodeme of hypandrium and the large, extended, often ornamented parameres. At present this species group is retained within the genus Lonchaea but given the distinct morphology of this group, future DNA analysis may reveal whether it merits generic status.

Distribution. The L. polyhamata species group as defined here comprises 7 species all Afrotropical with a known distribution ranging from South Africa to Kenya.

Ecology. Unfortunately no rearing data is directly associated with the specimens described in this paper. However the elevated altitude at which the specimens were captured is perhaps significant indicating that members of this species group are associated with cooler sub-montane areas: Lonchaea dama —estimated altitude of capture location— 2000m, L. mbeya — 2200m, L. njombe — 2000m, L. taita — 1800m, L. zomba — 1400m, L. polyhamata— 1500m and L. teratosa- 800m. This cooler environment may influence features such as the presence of eye pilosity which is more generally associated, at least in the Palaearctic region, with species of Lonchaea which emerge as adults in the lower temperatures of early spring.

Figures

FIGURE 1. Lonchaea zomba sp. nov. Exploded view of the hypandrium and associated structures

FIGURES 25–28. Lonchaea teratosa McAlpine. 25. Epandrium and associated structures lateral view. 26. same ventral view. 27. same posterior view. 28. Hypandrium and parameres lateral view.

FIGURES 9–12. Lonchaea njombe sp. nov. 9. Epandrium and associated structures lateral view (parameres and phallus removed). 10. same ventral view. 11. same posterior view. 12. Paramere lateral view.

FIGURES 2–4. Lonchaea dama sp. nov. 2. Epandrium and associated structures lateral view. 3.same ventral view. 4. Paramere lateral view. Cerc = Cercus, Sur = surstylus, V pro = ventral process, Epand. = epandrium, para = paramere, t10 = tergite 10, as = anterior sclerite.