COLLECTING INSECTS

New Zealand Herald, Volume LXXV, Issue 23047, 26 May 1938, Page 23

COLLECTING INSECTS

PROFESSOR IN ENGLAND KITES AND TOWING NETS [from our own correspondent] LONDON. May 4 Collecting insects at heights up to 2000 ft. has recently occupied a great deal of the time of Professor A. C. Hardy, of Hull. His collections have been made with the aid of kites. In this way ho hopes to learn much about the spread of insect pests, not only from one part of the country to another, but from the Continent. According to a preliminary report, most of these high-flying insects are weak in flying power. What they lack in strength they make up on wingspread. Presumably, like human "gliders," they rely largely on air currents. Among corn pests alone, Professor Hardy has found the wheat aphis at heights up to 1600 ft., the fruit fly often at 600 ft., and the minute corn thrips, which shrivels up the ears of wheat, at 450 ft. The aphis, which flies highest, has a wing-spread of more than three times its body-length. When the first drop in numbers is over, after leaving ground level, there is little further falling off in the insect population from about 750 ft. upward. In some cases, there are even moro of a particular insect between 1000 ft. and 2000 ft. than between 150 ft. and 250 ft. The towing nets which Professor Hardy uses are designed to open automatically at any desired height, closing again at the end of the sampling period. The general method is much the same as that used in ocean collecting. • Other insect collections have been made from the aerial masts of the beam wireless station at Tetney, Lincolnshire. There, nets have been flown simultaneously over a five-sixths of a mile frontage at heights of up to 277 ft. For sampling at ground level, Professor Hardy makes use of railway trains. Other collections made over the North Sea suggest that a few hundred miles of salt water aro no necessary barrier to insect travellers.