Art. IX.—On Tipula heterogama, a New Species of Crane-fly in New Zealand.

By G. V. Hudson, F.E.S.

[Read before the Wellington Philosophical Society, 31at July, 1912.]

The male of this handsome crane-fly is often seen resting on fences about Wellington and the suburbs, but, owing to her semi-apterous condition, the female is seldom noticed.

The expansion of the wings of the male is 1 ½ in., and the length of the body slightly over ½ in. General colour reddish-brown. Head ochreousbrown, with the eyes black. Prothorax dull ochreous, with two dark-brown triangular marks and two oval spots; rest of the thorax dark reddish-brown. Abdomen dark reddish-brown, with the central segments black and the terminal appendages large and conspicuous; the entire abdomen is highly polished. Legs dark-brown and rather stout.

The length of the body in the female is about ¾ in., and the length of the rudimentary wings less than ⅓ in. (In Tipula obscuripennis they are distinctly longer.) The general colour is blackish-brown, and shining. The abdomen is elongate-pointed, with a conspicuous reddish-brown ovipositor. The legs are short and rather stout.

The late Captain Hutton, who did so much valuable work amongst the New Zealand Diptera, regarded this species as a variety of T. obscuripennis. I am now quite convinced, however, that it is a good species, and have italicized in the above description some of its most essential distinctions. I hope, however, that in the near future a more detailed description will be drawn up by an expert in the order.

During the early part of this winter I made many observations on living examples of both Tipula heterogama and Tipula obscuripennis whilst the insects were under natural conditions in my garden, and this has enabled one to repeatedly apply the test of syngamy, and thus fix beyond a doubt the relative males and females and the absolute distinctness of each of the species. Tipula heterogama appears in the perfect state about the end of April, and continues abundant until the end of May. It is indifferent to low temperatures, and I have counted as many as six males resting on the south side of my house at night and in the early morning with the thermometer standing at 44° Fher. T. obscuripennis is also a late autumn and early winter species, but its time of greater abundance appears to be about a fortnight earlier than that of T. heterogama. The two species are, however, about together, and this circumstance, coupled with the fact that they both have semi-apterous females, no doubt caused the late Captain Hutton to regard them merely as varieties of one species.