Australasian/Oceanian Diptera Catalog -- Web Version

Go to A/O Catalog Home Page

19. Family DIXIDAE

[Originally] by T. Michael Peters

Adult meniscus midges are small and frail. They do not feed and remain near streams, ponds, or bogs in which immatures live. Adults rest on emergent or overhanging vegetation near the water's edge. Males form small leks in these same locations.

Eggs are deposited in a mass at the water's edge. Larvae are filter feeders and lie in the meniscus or crawl out of the water on rocks, moss, or emergent vegetation. In crawling, larvae maintain an inverted U-shape and alternate pushing the anterior side forward with their prolegs [on abdominal segments 1, and (usually) 2], then the posterior side by using the ambulatory combs on abdominal segments 5-7. In swimming, the anterior part of the larval body is whipped from side to side, dragging the posterior section forward. A float structure surrounding the posterior spiracles is reminiscent of anopheline larvae. Pupae can swim, but usually are encountered above the water's surface, glued to a piece of grass or a rock.

Meniscus midges have been collected on all continents except Antarctica. In the areas covered in this catalog, 4 genera and 16 species are known. Dudgeon (1990) recorded an undetermined species of Dixidae from Papua New Guinea. Worldwide, 7 genera and about 175 species are recognized. The generic classification needs to be revised, and few larvae have been associated with their adult forms. This lack of larval association is unfortunate because larvae are collected more commonly than adults.
Refs.: Peters & Cook (1966, Nearctic spp.), Peters (1981, Nearctic spp.).

Genus DIXA Meigen

DIXA Meigen, 1818: 216. Type species: Dixa maculata Meigen, 1818, des. Curtis, 1832: pl. 409.
longistyla Takahashi, 1958: 5. Japan; Hawaiian is [immigrant]; Korea.

Genus DIXELLA Dyar & Shannon

DIXELLA Dyar & Shannon, 1924: 200. Type species: Dixella lirio Dyar & Shannon, 1924, mon.
PARADIXA Tonnoir, 1924b: 223 (Dixa subg.). Type species: Dixa neozelandica Tonnoir, 1924, des. Edwards, 1932d: 9.
fuscinervis Tonnoir, 1924b: 229 (Dixa). NZ (NZ).
harrisi Tonnoir, 1925c: 311 (Dixa). NZ (NZ).
humeralis Tonnoir, 1923c: 65 (Dixa). Australia (NSW).
neozelandica Tonnoir, 1924b: 229 (Dixa). NZ (NZ).
nicholsoni Tonnoir, 1923c: 64 (Dixa). Australia (NSW).
tasmaniensis Tonnoir, 1923c: 63 (Dixa). Australia (Tas).
tonnoiri Belkin, 1968: 44 (Paradixa). NZ (NZ).
unipunctata Tonnoir, 1923c: 66 (Dixa). Australia (Tas).

Genus DIXINA Enderlein

DIXINA Enderlein, 1936f: 30. Type species: Dixa obscura Loew, 1849, orig. des.
solomonis Belkin, 1962: 111. Solomon Is.
Undetermined sp. -- New Caledonia (New Caledonia) (Maffi & Peyre, 1990: 357).

Genus NEODIXA Tonnoir

DIXELLA Tonnoir, 1924b: 230. Type species: Dixella minuta Tonnoir, 1924, mon. [Preocc. Dyar & Shannon, 1924.]
NEODIXA Tonnoir, 1925c: 311 (n. n. for Dixella).
minuta Tonnoir, 1924b: 230 (Dixella). NZ (NZ).

Genus NOTHODIXA Edwards

NOTHODIXA Edwards, 1930b: 101 (Dixa subg.). Type species: Dixa campbelli Alexander, 1922, orig. des.
campbelli Alexander, 1922a: 20 (Dixa). NZ (NZ).
flavicollis Tonnoir, 1923c: 60 (Dixa). Australia (Vic).
geniculata Tonnoir, 1923c: 61 (Dixa). Australia (Tas).
otagensis Alexander, 1922h: 147 (Dixa). NZ (NZ).
philpotti Tonnoir, 1924b: 227 (Dixa). NZ (NZ).
septentrionalis Tonnoir, 1924b: 226 (Dixa). NZ (NZ).

This page last revised 3 June 2007