Ditylometopa Kertész

Woodley, Norman E., 2009, A review of the genus Ditylometopa Kertész (Diptera: Stratiomyidae), Zootaxa 2032, pp. 39-47 : 39-40

Genus Ditylometopa Kertész

Ditylometopa Kertész, 1923: 114 . Type species, Ditylometopa elegans Kertész , by original designation.

Diagnosis. Ditylometopa can be separated from other Neotropical clitellariines by its front femur which has a carinate, triangular process on the ventral surface ( Fig. 7 ). In fact, no other stratiomyid that I am aware of has such a feature, so it seems clear that this character state is autapomorphic for the genus. Females of Ditylometopa have the medial region of the upper frons bulging, with a narrow median carina. This character state is also autapomorphic for Ditylometopa . Other character states exhibited by Ditylometopa are briefly summarized:

Medium-sized soldier flies, 5.6–6.9 mm in length. Male. Head ( Figs. 1, 2 ) strongly holoptic on upper frons, eyes large, dorsal ommatidia enlarged. Antennae shorter than head, flagellum slightly spindle-shaped, the first six flagellomeres subequal in size, seventh and eighth narrower and slightly offset in the form of a short style, eighth bluntly to sharply conical. Oral cavity with posterior margin produced, rounded. Palpus small, two-segmented, partly hidden by oral margin. Thorax with scutellum trapezoidal, disc evenly convex, with two marginal spines that are less than half the length of the scutellum. Wing evenly set with microtrichia but alula mostly bare; R2+3 arising distal to r-m by about its length; R4 present; M1, M2, M3, and CuA1 all arising from discal cell, equally well developed, M1, M2, and CuA1 reaching wing margin, M3 ending just before wing margin. Abdomen nearly round in dorsal view, about as long as wide.

Female. Differs from male as follows: Eyes smaller ( Figs. 3, 4 ), widely separated by upper frons, ommatidia uniform in size. Palpus slightly larger than in male.

Remarks. Specimens of Ditylometopa are rarely collected, and nothing is known about the biology of the genus. Most specimens have been taken by mass trapping methods in low elevation tropical forests. The only specimen I have personally collected was sitting on a leaf along a forest trail.

Figures

FIGURES 5 – 7. Morphological details of Ditylometopa species. 5, D. elegans, dorsal view of female abdomen. 6, D. centralensis, dorsal view of female abdomen; note: this image makes the abdominal hairs appear denser than they actually are. 7, D. elegans, posterior view of front femur of male.

FIGURES 1 – 4. Habitus images of Ditylometopa species. 1, D. elegans, male. 2, D. centralensis, male. 3, D. elegans, female. 4, D. centralensis, female.