34 MONTANA EXPERIMENT STATION BULLETIN 333 



crop the following season is a distinct aid in control. The best 

 method of checking this insect is by the use of a poisoned bait. 

 This is placed in the crown of the plants at the rate of about 

 50 pounds to the acre. Tests of a number of bait formulae rec- 

 ommended by other workers showed poisoned, ground dried- 

 apple bait to be superior in attracting the weevils and in killing 

 them. A formula devised in Montana employing half bran in 

 the bait made it much cheaper and just as effective. The bait 

 consists of 10 per cent by weight of baghouse arsenic, 45 per 

 cent of bran, and 45 per cent of dried apple. Grinding the dried 

 apple by power or in a meat chopper is much easier if the bran 

 is ground with it. Water is added to make a crumbly mass of 

 the bait. It should be applied in the spring when the over- 

 wintering weevils appear, usually in April, and again later in 

 the summer when the newly emerged weevils appear, about the 

 last of June or early in July. Strawberry growers generally do not 

 realize what is killing their plants and of course do not know 

 how to control this pest. Nearly every strawberry grower in 

 western Montana is confronted with this pest and needs to be 

 advised of means of control. At present the dried apple bait 

 for strawberry root weevils is covered by a patent so growers 

 are subject to an infringement suit if they use it. However, 

 growers in other Pacific northwest states make their own dried 

 apple bait and no suit has ever been brought against a grower. 



The strawberry leaf roller (Ancylis comptana Frohl.) is 

 common in western Montana but usually does not develop in 

 damaging numbers. Last season, however, in a few places 

 through lack of information, it had developed to a serious pest. 

 It was readily demonstrated that a lead arsenate spray 1 pound 

 to 50 gallons of water applied before the leaves had rolled was 

 effective in reducing the numbers. Contact sprays of oil and 

 nicotine and nicotine and soap also gave satisfactory results. 

 This latter might be used when there is danger of poisoning the 

 fruit. Two applications of spray are needed, applied before the 

 development of each crop of berries. Again high pressure spray- 

 ing is essential to thoroughly coat the foliage. 



The raspberry sawfly (Monophadnoides ruhi Harris) ap- 

 peared in harmful numbers in several locations in western Mon- 

 tana last year. The immature form of the sawfly looks like a 

 many-legged, fuzzy, green caterpillar. In feeding it eats out 



