DISEASES AND INSECTS 



DISEASES AND INSECTS 1039 



1312. Mouth-parts of a 

 biting insect. 



one-half have been introduced from foreign countries, 

 mostly from Europe. It is a significant fact that usually 

 these imported insects become much more serious pests 

 here than in their native home; 

 this is doubtless largely due to 

 the absence of their native ene- 

 mies, to more favorable climatic 

 conditions here, and to a less 

 intense system of agriculture in 

 this country. Most of our worst 

 insect pests of the fruits, of the 

 garden crops, of the granary, of 

 the household, of the greenhouse, 

 and practically all of our most dangerous scale insects, 

 are of foreign origin. Man will continue to encroach on 

 and disturb nature's primitive domain, and commer- 

 cial operations will never cease, nor is there much hope 

 of ever effectually quarantining our shores against 

 these little foes; hence there seems to be no practicable 

 way to stop this increase of the insect enemies of the 

 horticulturist. The one who is the best fitted by nature, 

 and who best fits himself with a knowledge of these 

 pests and how to fight them, will usually be the one 



to survive and reap 

 the reward of profit- 

 able crops. No part of 

 a plant, from its roots 

 to the fruit it produces, 

 escapes the tiny jaws 

 or the sucking beaks 

 of insects. 



Root-feeding insects. 

 Many of the small 

 fruits and vegetables 

 are often seriously in- 

 jured by insects feed- 

 ing on the roots. The 

 grape-vine fidia (the 

 grub of a small beetle) 

 and the grape phyllox- 

 era plant-louse live on 

 grape roots. Straw- 

 berries often succumb 

 to the attacks of the 

 grubs of several small 

 beetles known as straw- 

 berry-root worms, and 

 to the large white 

 grubs of the May 

 beetles. The roots of 

 cabbages, radishes and 

 other cruciferous plants are often devoured by hordes 

 of hungry maggots. These underground root-feeding 

 insects are difficult pests to control, like any other 

 unseen foe. Sometimes they can be reached successfully 

 by injecting a little carbon bisulfide into the soil around 

 the base of the plant. The cabbage maggots can be 



Erevented 

 irgely by the 

 use of tarred 

 paper pads 

 placed around 

 the plants, or 

 by pouring a 

 carbolic acid 

 emulsion at 

 the base of 

 the infested 



1313. San Jose Scale. 

 Showing the mature winter scale; 

 also the insect itself, with its thread- 

 like feeding organs. 



1314. Hemipterous insect. Known to 

 entomologists as a true bug. 



plants. The strawberry root-feeders are best controlled 

 by frequent cultivation and a short rotation of crops. 



Borers. These are the larvae of several different 

 kinds of insects, which burrow into and feed upon the 

 inner bark, the solid wood, or the interior pith of the 

 larger roots, trunks, branches, and stems or stalks of 

 many horticultural plants. Nearly every kind of fruit 

 trees is attacked by its special kind of borer, as are 



also many of the smaller vine and bush-fruits and 

 garden crops. Borers are often the most destructive 

 of insect pests. The two apple-tree borers, the round- 

 headed (Fig. 1316) and the flat-headed species, and the 

 peach-tree borer (Fig. 1311) doubtless cause the death 

 of as many apple and peach trees in America as all 

 other enemies combined. The fruit-bark beetles, or 

 "shot-hole" borers, usually attack only unthrifty or 

 sickly fruit trees, and a tree once infested by them is 

 usually doomed. Two borers, one the grub of a beetle 



1315. Tomato worm attacked by parasitic insects. 



and the other the caterpillar of a moth, sometimes tun- 

 nel down the stems of currants and gooseberries. Rasp- 

 berries and blackberries (Fig. 1317) also suffer from 

 two or thee kinds of borers, one working in the root, 

 one in the stem, and a maggot bores down and kills the 

 new shoots. A caterpillar closely allied to the peach- 

 tree borer lives in squash vines, often ruining the crop. 

 The potato-stalk weevil sometimes does much damage 

 in potato fields. Sometimes one can prevent borers 

 from getting into a fruit tree with a paper bandage 

 closely wrapped around the part liable to be attacked, 

 or by the application of some "wash." Most of the 

 washes recommended will prove ineffectual or dangerous 

 to use. Gas-tar has given good results, but some re- 

 port injury to peach trees from 

 its use; hence one should first 

 experiment with it on a few trees. 

 No way has been found to keep 

 borers out of the small fruits or 

 garden crops; usually if infested 

 canes, stems or plants are cut out 

 and burned early in the fall or 

 whenever noticed, most of the 

 borers will be killed. When borers 

 once get into fruit trees, the 

 "digging-out" process is usually 

 the only resort, although some 

 report that they readily kill the 

 depredator by simply injecting a 

 little carbon bisulfide into the 

 entrance of his burrow and quickly 

 closing it with putty. 



Bud- and leaf-feeding insecte. 

 The buds and leaves of horticul- 

 tural crops often swarm with 

 legions of biting and sucking in- 

 sects. A mere enumeration of the 

 different kinds of these pests would 

 weary the reader. Some insects, 

 like the rose chafer, work on 

 several different kinds of plants, 

 while many others attack only 

 one or two kinds. In apple or- 

 chards, the opening buds are seized 

 upon by the the hungry bud-moth wh e *g" a a g f w r 

 and case-bearing caterpillars, by beetle emerged. 



