INJURIOUS INSECTS. 145 



but where insecticides must l)e used, sprayiug with a mixture 

 composed of about a teaspoouful of Paris Green in two gallons of 

 water, is effectual. Hellebore also, either as a powder, or in water, 

 is said to be efficient, and it has the advantage of not being so 

 dangerous to persons or foliage. 



The larch or tamarack ^is a favoi'ite among many tree growers 

 in this part of the country, and it has been much planted for 

 shade, ornament, and utility. Within the past few years we have 

 often heard complaints of the destruction of the foliage by little 

 greenish white larv;e. The trees are commonly stripped of their 

 leaves by midsummer, and their beauty is quite destroyed. They 

 are rarely killed however, as they have the power of readily send- 

 ing out a new supply of leaves ; but their growth is much retarded 

 and their aspect somewhat changed by frequent attacks. 



These insects are the larvse of little sawflies {Nemaius 

 Erichsonii)^ which deposit their eggs in rows in the tender young 

 twigs and cause those parts of the twigs bearing eggs to bend to 

 the side in which they are laid. They do not appear to have 

 attracted attention here until about 1880, although they were 

 probably present long before. They attack both European and 

 American larches, usually appearing in large numbers and 

 accomplishing their work rapidly. It is a difficult matter to con- 

 trol this pest on large trees, but, if applicable, almost any of the 

 insecticides will prove effective. The insect belongs to the same 

 group as the Currant-worm, so easily controlled by hellebore. The 

 cocoons, with pupa?, are to be found under the trees in autumn 

 and spring, and if all debris was raked up and burned, or the 

 ground trampled by cattle, great numbers of them would be 

 destroyed. 



Aphides and plant-bugs form a class of plant pests which are 

 difficult to keep in subjection. This is partly because of the very 

 rapid development and prolific reproduction, of certain species, 

 and because of their peculiar adaptation for taking nutrition from 

 the plants, without eating any of the plant tissues. These insects 

 are without regular jaws or mouth parts, but in place of these are 

 provided with beaks for sucking liquid food, from either plants or 

 animals, after the manner of the mosquito. It is on this account 

 that the ordinary insect poisons are often useless when applied 

 against them, for the ends of their beaks being within the plant 

 tissue, they take none of the poison with their food. 

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