STRAWBERRY PESTS 



1941 



injurious, but in its new surroundings fre- 

 quently outruns its natural checks. At 

 tlie present time it extends from Canada 

 to Virginia and probably even further 

 south, and westward to the Mississippi 

 valley, very often in harmful numbers. 

 In the adult stage, it measures with ex- 

 panded wings about three-fifths of an inch. 

 Its color is light reddish brown, the fore- 

 wings streaked with wavy darker brown 

 and white lines. 



Life History and Habits 



This moth makes its appearance in the 

 strawberry fields in early May, and may 

 be expected in full force about the mid- 

 dle of and extending up to June 1st. 



The insects mate soon after their ap- 

 pearance and egg-laying begins at once. 

 Larvae hatch from these eggs in from 

 five to seven days, and at once make their 

 way to the upper surface. At this time 

 the minute creatures are light green in 

 color, with a proportionately large head 

 and rather long hair. When first noticed 

 they are about an eighth of an inch in 

 length and are feeding along the midrib 

 or a large vein. For a day or two the 

 minute caterpillar feeds thus without pro- 

 tection, gnawing into the vein or along- 

 side so as to weaken the tissue, and then 

 it begins to draw the upper surfaces of 

 the leaf or lobe together by means of 

 fine silken threads, until there is a com- 

 plete fold that forms a shelter for its 

 maker. 



It feeds continuously within its shel- 

 ter, and improves it by making the fold 

 more complete and more secure, and 

 sometimes actually making a roll of an 

 entire leaf. 



The life cycle is about 45 days. Three 

 broods hatch during the summer but the 

 last does not complete its transforma- 

 tion until the following April. 



The important parts of this record are 

 that the eggs are laid on the underside 

 of the leaves; that the larvae wander to 

 the upper surface as soon as hatched and, 

 for a day or two, feed openly on this 

 upper surface, and that for the rest of 

 their growing period the insects feed in 

 a shelter that cannot be reached by any 

 effective insecticide. 



Injuries Caused 



Although this is best known as a straw- 

 berry pest, it is Eot confined to that planr, 

 but attacks blackberry and raspberry as 

 well. While the first brood is almost con- 

 fined to strawberries, the second and third 

 may be more abundant on blackberry and 

 raspberry, and, at all events, their in- 

 juries on these plants are all caused after 

 midsummer. On strawberries only the 

 first brood is really injurious and the 

 middle broods seem better controlled by 

 natural checks. 



Each of the adult female moths lays 

 an average of about 70 eggs, and a single 

 larva is sufficient to spoil a small leaf. 



Fig. 1. strawberry Leaf Roller 



On varieties in which the foliage is 

 thin and scant, the injury is serious, and 

 may reach 75 per cent of the total crop 

 and an impairment of 25 per cent in the 

 value of the remainder, 



Remedial Measures 



Destroy all old leaves in the fall and 

 promptly turn under any beds not longer 

 in use. 



Spray with arsenate of lead, four to 

 five pounds to 100 gallons of water. TMs 

 must he done at the time the eggs "begin 

 to natch, so that the young larvae will get 

 the poison before they roll the leaves. 



As for the apparatus, any outfit that 

 gives a fine spray under good pressure 

 will answer. On small patches a knap- 

 sack pump with vermorel nozzle will serve 

 every purpose. A barrel pump mounted 

 on a cart will do for two lines of hose, 

 and a geared machine will serve to spray 

 four rows at once. 



Strawberry Root Borer 



Sesia rutitans Hy. Edw. 



A. L. LOVETT 



This root borer is a serious pest of 

 the strawberry, occurring in the North- 



