ENTOMOLOGY. 



419 



cides. As all leaf lice absorb their food b}' suction, contact poison 

 is the only one of use, thoug-h finel}- divided arsenites will kill large 

 numbers. The better method is a ver}- forcible spray with kerosene- 

 emulsion or with fish-oil soap. Even cold water applied forcibl}- will 

 dislodg-e and kill many. As the formula for kerosene-emulsion 

 has been g-iven so frequently it is only necessary to state that two 

 gallons of kerosene, one gallon of water and one-half pound of hard 

 soap should be emulsified and added to twelve parts of water. This 

 fluid will kill all lice with which it conies in contact. Whale-oil 

 soap, at the rate of one pound in six gallons of water is also a very 

 useful liquid; a strong decoction of tobacco might also be used. 



■-aii. 



Fig. 5. a. plum in whicli eggs liave been deposited; /?, hole from which plum- 

 gouger has issued (also e) ; c, d, egg of the same ; /, punctures made in feeding 

 by plum curculio: g-.waxy secretion; h, work of the same; m, n, eggs of the same; 

 k, apple injured by apple-curculio; 1, egg of same. 



Plant-lice. During a drj' spring and earlj" summer, plant-lice of 

 all kinds increase beyond belief, and if it was not for our many 

 friends among insects that constantlj' wag'e war ag-ainst 

 the lice, it would be almost impossible in our dry region 

 to protect ourselves against them. All leaf-lice increase in 

 summer bj" budding-, or by producing- living j^oung-, and for 

 man5^ generations nothing but females can be found. Later 

 in the season, or when the sap in the plants infested bj^ them 

 does not flow any more in such rich streams as earlier in the season, 

 the lice become Winged and search for places in which to deposit 

 winter eggs for another season. (Fig. 6, d.) They usuallj^ select for 

 this purpose the terminal twigs of the tree, and prefer the fuzzy 

 scales of the buds. Here immense numbers of eggs are laid, not 

 alone by the lice under consideration, but by other species as well, 

 as, for instance, bj^ the hop-louse. At first green, these eg-g-s gradu- 

 ally assume a darker color, until at last thej^ are shinj- black, and are 

 thus readily detected. Such eggs, shown in the accompanying fig-- 

 ure, are surrounded by a tough integument, and are not so easil}' 

 killed by insecticides. Several thorough coatings with soft soap 



