270 [November, 



question of apterous insects has veiy often been dealt with, and many 

 adequate explanations have been given to account for the loss of flight 

 under the most varied conditions. The present paper, however, is 

 solely concerned with those insects in which the wings of the female 

 are so abbreviated as to render that sex incapable of flight, the male 

 retaining his flying powers quite unimpaired. Before proceeding 

 further it will be desirable to consider the following list of Lepidoptera 

 in which the females are semi-apterous.* In addition to general 

 remarks this list gives, as far as is known, the food-plant of the larva 

 of each species as well as its distribution, and the time of the 

 year when the perfect insect appears. In the Psychidce, which are 

 represented in New Zealand by two species, i.e., CEceticus onmivorus 

 and Oroplwra unimlor, the females are not only apterous, but have 

 rudimentary legs and are incapable of walking, being in fact mere 

 egg-bags. I have not included these insects in the present paper, as 

 tlie species here dealt with have the females normally developed. 



A. New Zealand Species. 



Metacrias stratcgica. — Appears middle of November to end of January; 

 food-plant : varioiis generally distributed grasses. Freqtients the flat country 

 near Invercargill and has also been taken on the Richardson Range, South 

 Canterbury. The males fly in warm sunny weather only. (Philpott.) 



Metacrias erichrysa. — Appears in January; food-plant: Senecio bellidioides 

 (Meyrick), a common species. A strictly movintain insect, at present only 

 i-ecorded from the Tableland of Mt. Arthur at elevations of over 4,00() ft. The 

 males fiy with great rapidity in the hottest sunshine. 



Metacrias huttonii. — Appears in December and January ; food-plant : various 

 common grasses. Another strictly alpine species frequenting the mountains 

 arovmd Lake Wakatipu at elevations of about 4,000 ft. The males fly very 

 rapidly in hot sunshine. 



Hybernia indocilis. — Appears] July to January; food-plant: a common 

 Leptospermum (?). According to the late Mr. R. W. Fereday the male is found 

 plentifully at rest on bare ground amongst Leptospcrmmn aiiid the female on the 

 stems. 



Atomotricha ommatias. — Appears in August and September; food-plant: 

 unknown. Found on fences during cold nights in August and September. The 

 female if touched hops two or three inches. (Philpott and Sunley.) 



Brachysara sordida. — Appears in June and July ; food-plant : unknown. 

 Found on fences during cold nights in the depth of winter. (Sunley.) 



* Twelve British Tim inn with semi-apte>-ou.s females are not included in my li.st. The larvaj 

 of all these feed on plai.ts of universal distribution. One species ajjpears in March, four in April, 

 one in May, cue in October and November, one in November and DecemVjer, and four at Mid- 

 summer. Detailed habits of these insects are not available to me, but the species stated to appear 

 in midsummer belong to the genera Fi(H((n and Tahporia. They are obscure forms, and their 

 precise habits may not ho fully known at present. 



