AT the meeting of the Manchester Literary and Philosophical Society on January 9, Dr. C. Gordon Hewitt, Dominion entomologist, gave an account of the ravages of insect pests in Canada, and the means taken by the Dominion Government to combat them. The annual opening up of vast tracts of country, previously wild, destroys the balance of nature, and swarms of insects, finding fresh stores available, devastate the new growths. Some of these insects are of native origin, but are more frequently introduced. Thus the Hessian fly, Mayetiola destructor, Say, appeared in 1816; the wheat midge, Diplosis tritici, Kirby, in 1828; the chinch bug, Blissus leucopterus, Say, in 1866; and the Colorado potato-beetle, Leptinotarsa decemlineata, Say, in 1870. The larch sawfly, Lygaconematus erichsonii, Hartig, reached Canada in 1882, and in a few years destroyed the mature larches over practically the whole of eastern Canada. The pear-leaf blister-mite, Eriophyes pyri, Nalepa, was first reported from Nova Scotia about 1887, and has since spread across Canada from the Atlantic to the Pacific.