Medomega Manestella, Metz

Winterton, Shaun L. & Lambkin, Christine L., 2012, New Australian stiletto flies: revision of Manestella Metz and description of Medomega gen. n. (Diptera, Therevidae, Agapophytinae), ZooKeys 240, pp. 1-119 : 2-4

Manestella Metz

Manestella Metz, 2003: 10. Type species Psilocephala tristriata Mann, 1933: 331, by original designation.

Diagnosis.

Body length rarely exceeding 5.0 mm. Body usually covered with dense glaucous grey pubescence with darker brown or grey markings on head and scutum, admixed with numerous, dark setae; head length approximately equal to or slightly longer than height; male frons narrow with eyes often contiguous; parafacial pile absent, pubescence with silver velutum band laterally between antennal base and eye; face concave, grey pubescent; male with one or more rows of postocular setae; antennae shorter than or equal to head length; scutal pubescence glaucous, marked with dark brown, markings frequently as two medial stripes anteriorly, fused posteriorly, laterally stripes broken or irregularly tessellated; prosternal depression without setae; metanepisternum with post-spiracular setae absent; setae absent on posterior surface of mid coxa; femoral velutum patches absent; hind femur without subapical av setae; fore femur without macrosetae; hind coxal knob present; wing markings typically brown infuscate and white translucent, mottled or banded, sometimes uniform infuscate, often with additional spur veins and/or extra crossveins; vein M3 sometimes incomplete; cell m3 open; abdominal tergite 2 usually with patch of short setae medially; gonocoxites with diffuse velutum patch ventrally (sometimes absent); inner gonocoxal process present; dorsal and ventral apodemes of parameral sheath joining along distiphallus, both forked; female with three spermathecae; small rounded spermathecal sac present; spermathecal ducts joining to common spermathecal sac duct; acanthophorite spines A1 and A2 present, well developed.

Comments.

Manestella contains some of the smallest stiletto flies, with a typical body length range of 3.5-5.0 mm. Females of the largest species attain a mere 5.5 mm total body length. External and male genitalic morphology are relatively conserved in this genus, and body colouration is generally grey and brown pubescent with mottled scutum and wings. The male abdomen often has a silver velutum covering. Atypical for therevids, there is considerable variation in wing venation in species in this genus, with individuals sometimes showing different arrangements of veins in each wing (e.g. spur veins or incomplete M3). Manestella is closely related to Medomega gen. n. based on characters such as the apodemes of the parameral sheath joining midway along the distiphallus rather than proximal to the basiphallus; numerous strong setae commonly on the head, thorax, and apices of the gonostylus and inner gonocoxal process, as well as a characteristic glaucous pubescence overlying much of the body. Manestella can be identified using the dichotomous key to Australasian genera in Winterton (2011).

Included species.

Manestella caesia sp. n.; Manestella campestris sp. n.; Manestella canities sp. n.; Manestella cooloola sp. n.; Manestella fumosa sp. n.; Manestella incompleta sp. n.; Manestella nubis sp. n.; Manestella obscura sp. n.; Manestella ocellaris sp. n.; Manestella persona sp. n.; Manestella poecilothorax sp. n.; Manestella tristriata (Mann); Manestella umbrapennis sp. n.; Manestella vasta sp. n.; Manestella vespera sp. n.

Key to Manestella species

Most key couplets rely heavily on male characteristics as females are difficult to distinguish for many species. External characters are used where possible throughout the key, but male genitalic dissections should be examined to confirm identity. Unassociated females cannot be confidently separated for most species of Manestella except for Manestella poecilothorax sp. n.; females are unknown for Manestella persona sp. n., Manestella nubis sp. n., Manestella umbrapennis sp. n. and Manestella vasta sp. n.