289 



sfrobus] is the preferred food, a list is given of known food-plants, 

 including species of pine, larch, spruce, fir, junipers, birch and white 

 ash. The adults emerge from hibernation in the soil from late April 

 to late May, and immcdiatel}- begin feeding near the place of emergence, 

 where they remain until mid- June. At this time they migrate in 

 swarms to some locality where, preferably, a white pine logging 

 operation has recently taken place, to which they are attracted 

 considerable distances by the odour of fresh pitch. Eggs are laid in 

 freshly cut pine logs or in the roots of freshly cut pine stumps, in small 

 perforations in the bark. In log piles, oviposition is generally on the 

 underside of the logs, many eggs being laid close together. When 

 breeding around stumps, the beetles ovipost from a few inches to a 

 foot or more below ground in the roots. The eggs hatch in from ten 

 days to two weeks, and the grubs immediately burrow beneath the 

 bark, of which they loosen large areas. After about two months 

 they are mature, and in early September pupate beneath the bark in 

 individual cells, penetrating about a quarter of an inch into the 

 sapwood. Adults begin to emerge in late September and continue 

 in October. The adults move from one seedling to another, stripping 

 them of their bark, and frequently killing three- or four-year-old 

 seedlings within a very few days. It has been found impossible to 

 maintain a stand of white pine on cut-over areas until three years 

 after cutting, 98 per cent, of damage occurring in the first two 

 years. Moisture is essential to the beetles, and larvae can be killed 

 in infested logs by turning the tunnelled areas to the sun. 



The use of repellents, poison baits and banding materials has been 

 tried without much success. There are few natural enemies ; parasites 

 have not as yet been discovered, and the mode of life of the insect 

 protects it from this form of enemy. Birds, especially woodpeckers, 

 feed upon the larvae, but as the beetles feed at night few of them are 

 killed. Moles are probably more useful in feeding on the adults. 

 The fungus, Sporotrichnm gJohuIiferum, undoubtedly is an important 

 factor in control, especially under moist conditions, which are essential 

 to it, and in which it spreads so rapidly that artificial dissemination is 

 unnecessar}'. 



Infestation that requires dealing with by forest management falls 

 under two heads, namely, that occurring on cut-over areas, and that 

 occurring in pure stands of seedlings such as forest nurseries, planta- 

 tions and natural reproduction on open pasture land. On cut-over 

 areas, as the beetles are attracted by the odour given off by pine 

 stumps, slashings, etc., it is advised that the slash be piled over the 

 pine stumps and burnt in early spring. This destroj's the odour of 

 pitch and also chars the stumps, and thus lowers their attraction for 

 the beetles. Large, adjacent cuttings in consecutive 3'ears should 

 be avoided. In plantations, besides burning the slash, all coniferous 

 seedlings on cut-over areas should be eliminated by pulling up and 

 burning them. When the adults emerge and find no food available, 

 they will migrate, and in the following year the plantation could be set 

 out without much risk of infestation. On open land, pasture-grown 

 pines of large size should not be cut when seedlings are present until these 

 are at least 3| ft. in height. If cut then, the slash should be burnt over 

 tlie stumps or carted away. Freshly sawn limiber should not be 

 stacked in open pasture where seedlings are present. If possible, 

 such logs should be sawn before the beetles emerge from hibernation 

 in the spring. If this is impossible, the logs should be turned so that 

 the sun's rays may reach the larvae and destroy them. 



