REMEDIAL MEASURES. 175 



may be crushed, and branches bearing the spun web-Hke 

 nests of certain gregarious kinds may be cut-off with pruning- 

 shears (Figs. 69, 70), or they may be burned on the trees by 

 holding torches under them. Larvae fall most readily from 

 trees in the early morning and evening or during moist, cool 

 weather. The larvae of but a few species of beetles can 

 be profitably collected, for instance, cockchafer grubs. In 

 Massachusetts, during the great plague of the gypsey moth, 

 1897, Liparis dispar, L., matting, termed burlap-hands, was 

 'put round the trees and the larvae pupate under these, or 

 rest under them in the day-time and may thus be destroyed. 



The collection of pupae is best effected when they lie in 

 clusters in the moss and dead leaves of the soil-covering, such 

 as the pupae of Noctua piniperda, Panz., or hang low down the 

 stems in bark cracks, or on undergrowth. 



Perfect insects may be collected by simply picking them by 

 hand from the ground, by shaking them, like larvae, from the 

 plants on which they settle, or by means of traps made of 

 strips of bark, laid on the ground flat or rolled-u]), into which 

 the insects crawl ; this is a common method of catching great 

 numbers of the pine- weevil {Ifi/Iohiits abietis, Fabr.). The 

 bark should be fresh and laid with the underside downwards. 

 Other materials used as traps are faggots, logs, and brush- 

 wood. Cockchafers and pine-weevils are the injurious insects 

 chiefly captured in this stage. 



In collecting the imagos of insects, it is necessary to capture 

 the female alone, and that before she has laid her eggs. This 

 can only be done practically in the case of those Lepidoptera, 

 in which the $ can be readily distinguished by her- size and" 

 by the nature of her antenna; from the <? . 



Larvae, pupae, and imagos may be killed by pounding them 

 in trenches, or by pouring boiling water over them, or by 

 quicklime, etc. 



(b) Preparation oj Insect Trenches. These are useful on 

 any but very sandy soil against larvae which wander on the 

 ground, r.g., those of the pine-moth, also against certain 

 beetles, for instance, the pine-weevil, Hyhhius abietis, L. 

 They should be made 10 inches broad, and 12 to 14 inches 

 deep, with vertical walls, and with'holes 8 to 10 inches deep 



