Page:Transactions NZ Institute Volume 33.djvu/31

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Series ORTHORRHAPHA.

Key to the New Zealand Families

Third joint of the antennae annulated.
Costa stopping at the tip of the wing. ...	Stratiomyidae.
Costa continued all round the wing. .. .	Tabanidae.
Third joint of the antennae simple.
Thorax and abdomen inflated. .. .. .	Cyrtidae.
Thorax and abdomen not inflated.
Five posterior cells.
Empodia styliform; fourth posterior cell
often closed. .. .. .	Asilidae.
Empodia absent; fourth posterior cell
always open. .. .. .	Therevidae.
Four posterior cells. .. .. .	Bombylidae.
Three posterior cells.
Second basal cell separated from the discal	Empidae.
Second basal cell united to discal . .	Dolichopodidae.

Family STRATIOMYIDAE.

“Three basal cells, much prolonged; veins of the main trunks very crowded anteriorly; both intercalary veins usually existing; costal vein reaching only to the middle of the wing. Third joint of the antennas annulated, sometimes divided into several portions. Tibiae without spurs; empodia much developed, pulvilliform” (Loew).

Key to the New Zealand Genera.

Scutellum with four spines.
An intercalary vein from the discal cell. .. .	Exaireta.
No intercalary vein from the discal cell. .. .	Beris.
Scutellum with two spines.
Posterior veins of the wing weak. .. .	Odontomyia.
Posterior veins of the wing strong. .. .	Clitellaria.
Scutellum without spines. .. .. .. .	Cyclogaster.

Sub-family Beridinae.

Abdomen showing seven segments.

Genus Exaireta, Schiner (1867).

Antennae filiform, the flagellum with ten rings generally indistinct near the end ; no style, but a few bristles on the point. Eyes not contiguous in either sex. Scutellum with four long spines. Abdomen flat, with seven segments. Third longitudinal vein of the wing forked; an intercalary vein from the discal cell which sometimes does not reach the margin.

Key to the Species.

Thorax black. .. .. .. .	E. spiniger.
Thorax bright bluish-green.
Length, 10 mm.. .. .. .. .	E. alpina.
Length, 4 mm.. .. .. .. .	E. opposita.
Thorax dark reddish-brown or bronzy.
Abdomen ferruginous, with a black tip. .. .	E. apicalis.
Abdomen purplish, without a black tip. .. .	E. straznitzkii.