94 THE EEPORT OF THE No. 36 



Their general trend of migration, in all cases observed, has been towards the north- 

 west. We believe that they are oriented by light. As in the adult stage these 

 cutworms display a positive phototropism to artificial light, and also to subdued 

 daylight, such as is experienced soon after sunset. Also, like the adults, they avoid 

 strong daylight. The latter tendency causes them to remain below ground on 

 bright, sunny days. It happens, however, that when the cutworms are sufficiently 

 numerous to assume the migratory habit, they have been unable to obtain enough 

 food to appease their hunger. Hunger causes them to migrate, and it may become 

 so intense that it overcomes their aversion to exposing themselves to direct sun- 

 light, so that they come above ground by day, and crawl rapidly in search of food. 

 This search is haphazard. They are not making for any definite feeding ground, 

 of which they have some knowledge. They crawl, therefore, in the line of least 

 resistance — that is, away from the sun, or in a more or less northerly direction. 

 We have disturbed adults hiding under clods at noon time, and they too, in nearly 

 every case, flew more or less due north. In the evening, when the sun is low, its 

 weakened light seems to attract, as does that of an artificial light, and the cut- 

 worms crawl towards it. It is at this time of the day that migration usually 

 begins. Once more this agrees with the adult habits; for the moths begin to fly 

 at dusk, and an examination, soon after sunset, of the windows of a barn shows that 

 most of the moths of this species are congregated on the western windows. 



The food plants include practically all weeds, field, and garden crops. Larvas 

 even ascended young Manitoba maples and ate the bark off the twigs, thus killing 

 the trees. They are entirely superficial feeders, and never cut off plants below 

 ground as do the common cutworms. 



The pupae are found in the usual earthern cells made by the Agrotine species. 



The moths fly from the middle of June till the end of September or early 

 October. They may sestivate during the hottest part of the summer, and so appear 

 to be double brooded. There is, however, one brood only. During the first flight 

 the ova remain undeveloped, but the moths feed freely and accumulate fat body. 

 After the period of aestivation the eggs have begun to develop, and they are laid 

 during the autumn. 



The moths are a serious domestic pest, and gain access to well screened houses. 

 Contrary to general belief, very few of them are attracted into houses by the 

 lights. A lighted lamp merely attracts around it the moths already in the house. 

 The majority of moths enter houses between the shingles or through cracks around 

 doors and windows. They enter these crevices in the early morning for protec- 

 tion from the daylight, working so far in that many of them are unable to find 

 their way out again. Many of these crevices communicate, by however devious 

 a course, with the interior of the building and the result is that a number of the 

 moths gain admission to houses from which the smaller house flies, which avoid 

 dark chinka and crannies, are effectively excluded. The moths are attracted only 

 from a short distance by light, and in this connection it may be mentioned that 

 light traps in the fields proved to be an absolute failure. The majority of moths 

 migrate to buildings soon after they emerge, and remain there until they are 

 mature. 



The destruction of the larvae by poison can be accomplished with comparative 

 ease. This is done most economically by the use of a poisoned bait applied to 

 specially prepared furrows. In wet seasons a vertically sided furrow can be used 

 but under the conditions prevailing in southern Alberta the soil is usually too dry 

 for its construction without expensive hand labor. Under such circumstances it 

 can be replaced by a dusty sided furrow, made by drawing a heavy log through a 



