223 EXPERIMENTAL FARMS 



2 GEORGE V,,A. 1912 



and colouration. It is hairy and measures from one and a quarter to one and a half 

 inches in length. The upper side is dark with two longitudinal yellow stripes along 

 the back. The head is coral red and there are a pair of tufts of black hairs projecting 

 over the head in horn-like manner; a similar but single tuft of hairs projects from 

 the hind end of the body. On the back of the caterpillar, beginning in the fifth seg- 

 ment, there are four white brush-like tufts of hairs and behind these there are two 

 small, glandular projections of a brilliant red colour. The caterpillars usually leave 

 the smaller branches when they have finished feeding and are full grown and wander 

 down the trees to the larger limbs and trunks where they spin their cocoons in the 

 crevices of the bark. Large numbers of the full-grown caterpillars wander some 

 distance, finally spinning their cocoons on fences, the sides of houses and other places. 

 In about a fortnight the moths emerge. The peculiarity of this insect is that the 

 female moth is wingless and consequently is unable to fly. After emerging, the female 

 rarely leaves the neighbourhood of the cocoon, but after mating deposits one to five 

 hundred eggs in a white frothy mass on the outside of the cocoon. The male moth 

 is grayish and measures about one and a quarter inches across the wings; the antennae 

 are large and feather-like, and a white spot in the outer hind angle of each of the fore 

 wi::gs gives the insect its popular name. 



Natural enemies. — A number of species of birds feed on the hairy caterpillars of 

 this insect, including the robin. Surprise has frequently been expressed to me that 

 the English sparrow does not appear to feed on the caterpillar. The English sparrow 

 not only does not feed on this insect, but it drives away those birds which do so, and 

 is itself one of the greatest pests on this account, as it has driven away and thereby 

 reduced in number many of our useful insectivorous birds. The most important 

 natural enemies are parasitic insects. 



Means of control. — The most effectual method of controlling this insect is by the 

 destruction of the egg masses during the winter months. As the insect is in this stage 

 for about six months or longer, ample time is afforded for the carrying out of a 

 systematic campaign of egg destruction. The egg masses may be either collected and 

 burned or destroyed on the trees by applying creosote by means of a small brush which 

 may be attached to a long pole. On fences and other places they may be killed by 

 means of a gasolene torch lamp such as painters use. When all the egg masses on a 

 tree have been destroyed, a band of 'tanglefoot ' about three inches wide should be 

 painted round the trunk. This should be done before May and it will prevent any cat- 

 erpillars which have hatched from eggs which have not been destroyed, from ascending 

 the trunks of the trees; as all the egg masses on the tree will have been destroyed, no 

 caterpillars will be able to gain access to the leaves on account of the band of ' tangle- 

 foot.' A sticky substance similar in nature to ' tanglefoot ' may be made by boiling 

 together equal parts of castor oil and resin. The bands on the trees should be scraped 

 from time to time with a wooden comb to keep the sticky surface fresh. 



When the egg masses have not been destroyed, the trees should be sprayed before 

 the end of June with an arsenical spray such as lead arsenate. This is used in tho 

 proportion of 3 or 4 lbs. of lead arsenate to 40 gallons of water. All cities having valu- 

 able shade trees attacked by this or other defoliating insects, should have a power 

 sprayer. Nothing is more injurious to the tree or unsightly to the eye than the defolia- 

 tion by caterpillars. Many of the cities of the United States regularly spray their 

 shade trees, realizing their value as civic assets; in certain cases the losses which they 

 have suffered in the past compel them to do this. *• 



