Insects Injurious to Vegetables* 



Arthur Gibson, Chief Assistant, Division of Entomology, Central Experimental Farm 



one pound in 



[T is unfortunately true that every kind 

 of vegetable crop grown is attacked 

 and liable to be much reduced in value 

 by various insect enemies. At the Central 

 FExperimental Farm hundreds and hund- 

 freds of letters are received every year 

 from farmers, fruit growers, market gar- 

 deners and others, asking for advice con- 

 cerning injurious insects. It has been 

 estimated that from ten per cent, to twen- 

 ty-five per cent, of every crop grown is 

 destroyed by insects. 



It is important that the grower should 

 know something concerning the life-his- 

 tory of the insects he has to fight. Most 

 insects have four distinct stages, the egg, 

 the larvae (caterpillar, grub or maggot), 

 the pupa or chrysalis, and the perfect 

 insect. A little close observation will 

 soon enable one to distinguish between' 

 these stages and such knowledge gained 

 will be valuable when a certain kind ap- 

 pears in destructive numbers. 



It is important too that we should be 

 able to tell whether the insect when feed- 

 ing bites its food, or whether it simply 

 inserts its beak or tube into the plant and 

 takes up its food in a liquid form. As 

 soon as an insect is noticed injuring a 

 crop, this point should be decided upon 

 at once, because it can be easily realized 

 that with insects that bite and swallow 

 their food, something of a poisonous nat- 

 ure must be put on to the plant which will 

 be eaten with it and thus kill the insect. 

 If such a remedy was supplied for an in- 

 sect that sucks up its food, it would of 

 course be without any results, because 

 the insect would simply insert its beak 

 through the poison and take from within 

 the juice which it required for its nour- 

 ishment. 



WHITE CABBAGE BUTTEEFLT 



Every year the small white cabbage 

 butterfly, known generally as the cabbage 

 worm, destroys large numbers of cab- 

 bages, cauliflowers, etc. In eastern On- 

 tario it was much complained of during 

 1908. There are at least two broods of 

 this insect in a year and in some seasons 

 an additional late supplementary one. 



The well known green caterpillars, 

 which when full grown are about an 

 inch long, at first eat the outside leaves, 

 and it is at this time that they can be 

 best destroyed. Gardeners should, there- 

 fore, watch for the first appearance of 

 the caterpillars and apply a mixture of 

 pyrethrum insect powder and cheap flour, 

 in the proportion of one pound of the 

 insect powder to four of cheap flour. Be- 

 fore using, the whole should be thorough- 

 ly mixed together and allowed to stand 

 in a tightly closed vessel for twenty-four 

 hours. It is easily and quickly applied 



* KxtractH from a paper read at a meeting of the 

 h o( the Ontario VeB< 

 Other Insccta will be referred to in later 



Ottawa branch of the Ontario Vegetable Growers 



ABRociation. 



issues. 



to the plants by means of one of the dus- 

 ters, or other such contrivances now sold 

 by seedsmen. No danger whatever at- 

 tends the use of insect powder on such 

 plants as cabbages. The rather prevalent 

 custom of using Paris green and other 

 arsenicals on such vegetables was always 

 condemmed by the late Dominion En- 

 tomologist, Dr. Fletcher. 



THE ZEBRA BUTTERFLY 



The zebra caterpillar which attacks 

 turnips, cabbages, peas, clover and po- 

 tatoes is probably known to every mar- 

 ket gardener. The moths emerge in 

 spring and lay their eggs in clusters on 

 the undersides of the leaves. For a little 

 time after hatching the young caterpillars 

 feed together, but as they get larger they 

 wander off by themselves. There are two 

 broods in the year. The caterpillar when 

 mature is about two inches long of a 

 velvety black color with two bright yel- 

 low stripes along each side. 



If cabbages or cauliflowers are attack- 

 ed the pyrethrum insect powder as recom- 

 mended for the cabbage worm, should 

 be used to destroy these caterpillars. 

 When other plants are being injured, 

 Paris green, in the proportion of one 

 pound to 160 gallons of water, may be 

 applied with a spray pump. 



COLORADO POTATO BEETLE 



The potato beetle is responsible for 

 far too much damage. There is absolute- 

 ly no reason for the widespread less 

 caused by this insect. The mature beet- 

 les, usually called by farmers "the po- 

 tato bug," pass the winter in the ground. 

 Towards the end of May, they come out 

 again and the females soon deposit the 

 bright orange eggs on the underside of 

 the leaves. These hatch in about a week 

 and the larvae at once attack the fol- 

 iage. There are three broods in the year, 

 the last brood emerging in September. 



The poisoned Bordeaux mixture, now 

 so widely used for fungous diseases and 

 leaf-eating insects, will not only protect 

 potatoes from the attack of the Colorado 

 potato beetle but will also prevent injury 

 by early rot and the more destructive 

 potato rot. The first spraying should be 

 done early in June, the second early in 

 July, and the others about the ist, 15th 

 and 31st of August. 



TURNIP AND CABBAGE APHIS 



Much damage has been done of recent 

 years, particularly to Swede turnips, by 

 this well known grayish plant-louse. At 

 the time the turnips are being hoed and 

 thinned, the colonies of these insects 

 should be searched for and any plants 

 found to be infested should be cut out 

 and the plant lice crushed under foot. 

 When the insects are too numerous for 

 this treatment much good may be done 

 by spraying the restricted areas in time, 

 with the ordinary kerosene emulsion, or 



153 



whale oil soap, one pound in six gal- 

 lons of water. 



This plant louse spreads very quickly, 

 especially during dry autumns, and much 

 can be done to prevent widespread in- 

 festations if the plants are watched and 

 the remedies applied early. The cabbage 

 and turnip aphis deposits its eggs on the 

 jeaves of cabbages and turnips in aut- 

 umn. Therefore, all remnants of these 

 plants should be gathered up and burned, 

 or plowed down, as soon as the crops- are 

 harvested. 



The Asparagus Bed 



James F. Nicholson, Ottawa 



No asparagus should be cut after the 

 first of July. During the cutting season, 

 give a good dressing of salt during show- 

 ery weather. A good idea is to give the 

 beds a good dressing of some fertilizer 

 after the cutting season is over to pro- 

 mote growth of crowns for the following 

 year. Fertilizing in spring has little ef- 

 fect on the croWns the same season. 



PROPAGATION 



Asparagus is propagated by seed sown 

 in the spring. To get good one-year-old 

 plants, sow thinly and then thin the 

 plants to three or four inches apart, 

 taking care to select only the strongest 

 plants to stand. Plants with many small 

 shoots should not be planted. By keep- 

 ing the seed bed hoed and free from 

 weeds, the plants will be in fine condition 

 for planting out the following spring. It 

 is a mistake to use plants that are two or 

 three years old for planting. Use one- 

 year-old plants and cut the third year 

 after planting. The best varieties are 

 Palmetto and Colossal. 



To save seeds select some of the finest 

 shoots as they grow and stake firmly to 

 prevent breakages, by wind. When fully 

 ripe, the largest and finest berries of the 

 deepest red color should be selected. 



SOIL 



The best soil for asparagus is a 

 friable loam, but good crops may be ob- 

 tained from any good sandy loam made 

 porous by the application of large quanti- 

 ties of manure. The situation should be 

 open to the sun and yet sheltered from 

 strong winds. 



MAKING THE BEDS 



Strike out your rows with a plow four 

 feet apart and as deep as possible. Put 

 in some good rotten manure in the bot- 

 tom of the trench. Plant one and one- 

 half feet apart and cover with hoe. Keep 

 the ground well cultivated through the 

 summer. Cut down the tops in fall and 

 give a good dressing of rotten manure 

 and work in with a cultivator. 



Produce those vegetable crops that 

 are in greatest demand in the home mar- 

 ket. 



