136 



structs a silken tube from which it does all its feeding thereafter. 

 The damage is to the under surface only and causes a brown patch 

 to appear. 



Lime-sulphur spray used as for the San Jose Scale, during the 

 dormant period offers the best chance of success, fully combatting 

 this pest. (Bui. 79 Fla. Agr. Exp. Sta.) 



INSECTS AFFECTING VEGETABLES. 



GENERAL PESTS.* 



Before taking up in order the insects that attack the various 

 plants grown in our vegetable gardens, attention may be drawn to 

 a number of kinds that are general feeders, not limiting themselves 

 to any particular varieties, 'but attacking almost everything that 

 comes in their way; on that account they are the most serious foes 

 that we have to contend against and in many cases the most difficult 

 to keep under control. 



Aphids (Plant-lice). These are minute pear-shaped, soft-bodied 

 insects that may be found on almost every kind of plant, usually 

 in dense colonies clustered thickly on the terminal twigs and buds, 

 on the under-side of leaves, on stems and other parts, and even 

 under ground on roots. Wherever situated they are occupied in the 

 same manner sucking out the life-juices of the plant and multiply- 

 ing their own numbers by constant reproduction of living young all 

 through the summer. There are a great variety of species, most of 

 them varying shades of green in color, some are shining black, 

 others bright red; some again are covered with waxy filaments re- 

 sembling threads of cotton wool, and others with a dusting of a 

 mealy substance composed of the same material. Singly they are 

 insignificant creatures, but occurring as they do in enormous num- 

 bers and multiplying with amazing rapidity, they are able to seri- 

 ously injure and often to destroy the vegetation that they attack. 

 Fortunately they are devoured by many predaceous insects, such 

 as lady-bird beetles and their larvae and those of lace-winged and 

 syrphus flies and other creatures washed off and drowned by heavy 

 rains, and reduced in numbers by internal parasites ; otherwise they 

 would in time destroy all vegetable life. Ants are usually to be 

 found prowling about the colonies; they do not eat the Aphids, as 

 might be suspected, but are attracted by the sweet honey-dew that 

 exudes from them, and take them under their special protection. 



In gardening operations nature's checks are not sufficient, but 

 require to be supplemented with artificial remedies such as kerosene 

 emulsion, strong washes of soap-suds or tobacco decoction. In 

 greenhouses they can be kept in control by burning the commercial 

 preparation of tobacco. 



Ants. These insects are often suspected of injuring the plants 

 over which they are seen running, but as a rule they are only indi- 

 rectly responsible. A few species, such as the large black Carpenter 

 Ants, form their galleries in trunks of trees, posts and timber and do 



*Except where specially noted otherwise all extracts concerning vegetable in- 

 sects are taken from Bui. 171, Ontario Dept. of Agr., Ontario Agr. College. 



