210 



in New England are probably carried by the wind in a north and 

 north-easterly direction and thus distributed. 



The most notable example in applied entomology of the practical 

 value of a knowledge of instinctive behaviour is seen in beekeeping. 

 It is through such undervStanding of the relations and reactions of 

 insects to the physical and biological factors in their varied environ- 

 ments that applied entomologists will be enabled to solve some of the 

 greatest problems that have to be faced both now and in the future. 



In the discussion following the President's address, Mr. A. D. Hopkins 

 remarked that the mountain pine beetle, Dendroctonus monticolae, will 

 destroy mountain pine, yellow pine, lodgepole pine and sugar pine, 

 but if it becomes established in one species of pine through many 

 generations, the beetles on emergence show a decided preference for 

 the species on which they have bred, and will not, in fact, attack any 

 other. 



CooLEY (R. A.). The Spinach Carrion Beetle, Silpha bituberosa, Lee. 

 — Jl. Econ. Entom., Concord, N.H., x, no. 1, February 1917, 

 pp. 94-102, 1 plate. 



This species is native to North America and while abundant and 

 injurious in the Northern States is very seldom recorded in the South. 

 Sugar-beet and spinach are favourite host-plants, though the insect 

 has been recorded as feeding on Monolepis nuttalliana and Chenopodimn 

 album, as well as on squashes and pumpkins. In Montana, while injury 

 only occurs to sugar-beet, the weeds, M. nuttalliana and Solanum tri- 

 jlorum^ and lucerne seem to be the normal food-plants, the larvae also 

 feeding abimdantly on young wheat. It is not clear whether S. bituberosa 

 feeds normally on carrion, as do other members of this genus ; in 

 the author's opinion this seldom, if ever, occurs. Injury to sugar-beet 

 occurs mainly in early May, both adults and larvae being abundant 

 and injurious, though the greater part of the damage is done by the 

 larvae. The presence of the beetles is generally due to migration 

 from an adjoining field where some favourite food-plants occur as 

 weeds. 



A description of this beetle and details of its life-history and habits 

 are given. Eggs are laid in the soil, the earliest date of oviposition 

 being unknown. The larvae feed on the edges of the leaves, the 

 attacks being made chiefly at night and the insect remaining hidden 

 in the soil during the day. When fully grown, after about 24 days and 

 following three successive moults, the larva burrows into the soil 

 to a depth of one or two inches and there pupates. The adult feeds 

 freely soon after emergence, but gradually spends longer and longer 

 periods in the soil, until it finally disappears for hibernation. There 

 is apparently but one brood in a year. 



The remedies suggested include the keeping of all fields in the 

 vicinity of beet crops as free from weeds as possible ; when feasible, 

 the beet foliage may be treated with an arsenical, but as the plants 

 are generally attacked when quite small, this is seldom practicable. 

 Poisoned bran mash scattered among the weeds near the fields where 

 the insects are abundant has proved the best control. Another 

 method is to place the poisoned bran under burlap bags in the beet 

 fields. The adult beetles are attracted by the covering afforded 

 and are killed by eating the poison. 



