INSECTS INJURIOUS TO THE STRAWBERRY 451 



legs, which at once distinguish the saw-fly larvae from true 

 caterpillars. The adult saw-flies are about one-quarter inch 

 long, with two pairs of blackish, well-veined wings which are 

 folded over the abdomen when at rest. The body is black, with 

 a row of lighter spots on either side of the abdomen. The flies 

 emerge in late April in Missouri or about a fortnight before the 

 plants flower freely. The eggs are inserted just beneath the 

 epidermis of the leaves and hatch in about two weeks, just as the 

 plants begin to bloom. The larvae eat holes in the leaves and 

 " where numerous, they will defoliate the plants to such an extent 

 as to greatly injure or completely destroy the crop of fruit, and 

 may even kill the plants themselves." When at rest or disturbed 

 the larvae coil themselves up in a spiral on the under side of the 

 leaf as shown in Fig. 322, but if suddenly disturbed they will often 

 drop to the ground. By the last of May the larvae are full grown 

 and enter the soil, where they make small cells, lined with a 

 gummy substance, and in them hibernate until the next spring, 

 when they pupate and the adult flies emerge. 



Injury *by the saw-fly has been reported from the northern and 

 central States from Missouri and Nebraska to Maine. 



A nearly related species * with almost identical habits has done 

 similar injury in Iowa, Illinois and Indiana. The larvae are a deep 

 green, much wrinkled, with a blackish stripe along the back and 

 an obscure blackish stripe on each side, and the head brown. 



Control. Inasmuch as the larvae commence to hatch just as 

 blooming commences Professor Stedman has shown by experiments 

 that spraying the foliage at this time with arsenicals will entirely 

 protect it from the larvae. If they commence work before their 

 presence is noticed, the foliage may be sprayed until the first 

 berries are about one-third grown without any danger of poisoning 

 them. Hellebore 1 pound to 3 gallons of water was also effective, 

 as was dusting with pyrethrum. Although there may be some 

 prejudice against the use of arsenicals, where properly applied 

 at the right time there is no reason why they should not be used. 



* Monostegia ignota Norton. See F. W. Mally, " Insect Life," Vol. II, 

 p. 137. 



