Vol. LI. LONDON, MAY, 1919. No. 5 



POPULAR AND PRACTICAL PZNTOMOLOGY. 



Fragments in the Life-habits of Manitoba Insects. 



by norman criddle, dominion entomological laboratory, 



TREESBANK, MAN. 



Field work such as is carried on by the staff at an entomological laboratory 

 naturally presents many opportunities for insect studies apart from the major 

 problems for which the laboratories were primarily established. Thus the odd 

 hours when more important matters are temporarily absent, or the less frequent 

 occasions provided by the stops between trains, present opportunities for 

 numerous minor studies resulting in the accumulation of various more or less 

 disjointed notes which under ordinary circumstances remain unpublished. As 

 such notes might well prove of interest to others, I have taken adjutage of the 

 Editor's request for an article to bring a few of them together under the above 

 heading. 



Poecilopsis (Apochiema) rachelae Hist. 



This moth has usually beeft-. considered rare but in reality is probably more 

 numerous than is generally supposed. It appears quite early in the spring at 

 the time when the first willows are flowering, though I have never observed it 

 actually resting upon the flowers. It becomes active at the time when the 

 beauties of sunset are darkening into twilight, and for that reason we christened 

 it "the Twilight Moth." At that time the male moths may be seen flying in a 

 jerky, up and down flight not unlike that of the buck moth {HemUeuca) and 

 if we watch carefully, the hovering of the male over a certain spot will occasionally 

 reveal the wingless female. The latter, however, is very difficult to find, and 

 more often than not its discovery is due to accident rather than to search. The 

 females have been found resting upon the ground, on the trunks of trees, or on 

 the smaller twigs of shrubs such as willows. Aspen poplar appear to harbour 

 them most frequently, possibly because the moth shows a wonderful colour 

 resemblance to the bark. Willows, too, are often chosen for resting places, and 

 here again the little bundle of flufT, of which the female moth reminds one, is 

 very like a pussy willow. 



The life-history of Apochiema rachelce was described in the Canadian Ento- 

 mologist by Mr. Arthur Gibson, Vol. XLV, No. 12, 1913, but the egg-laying 

 habits, of which the strange ovipositor had occasioned considerable speculation, 

 remained in some doubt at the tim.e, and the observations which eventually 

 filled the gaps have remained unpublished since 1915. In that year a female 

 Apochiema was found running actively along the ground in broad daylight on 

 April 13, having probably been disturbed by the building operations taking 

 place close at hand. She was placed in a cage in which a goodly number of 

 twigs, rotten wood, sods and other objects were added for ovipositing purposes. 

 During the day time she remained quiet, but as the shades of evening approached 

 she became active and was used to lure males within reach. Later it became 

 evident that she was seeking a suitable situation for her eggs, and as she showed 



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