246 



They give promise of materially reducing or preventing infestation 

 provided that they are properly adjusted and tightly sealed during the 

 entire season (15th June to 15th September). The serious objections 

 to their use are that the cost is very great, they are difficult to 

 apply, and they need constant attention in order to maintain a 

 perfect seal. 



Peterson (A.). The Strawberry Root-worm, a Serious Pest on Roses 

 in the Greenhouse. — Rept. New Jersey Agric. Expt. Sta., 1919-20, 

 New Brunswick. N. J., 1921, pp. 468^93, 1 fig., 3 plates, 6 tables. 

 [Received 9th March 1922.] 



Up to the present Typophorus canellus (strawberry root-worm) 

 has been found in only one greenhouse in New Jersey. The adult 

 beetles feed out-of-doors on strawberries, raspberries, blackberries 

 and rose bushes, while the larvae have been found on strawberries. 

 Other investigators report the adults on blackberries, juniper, crab- 

 apples, and other wild and cultivated plants. 



The beetles make small irregular holes through the leaf ; they also 

 feed on young shoots, green stems and occasionally on young flower 

 buds. At times the scarring is severe enough to girdle the stems 

 completely. They feed at night or on cloudy days. In bright sunlight 

 they hide in the soil or beneath leaves. The larvae may seriously 

 damage the roots of strawberries and other plants. 



A description is given of the female adult and all other stages. 

 The eggs are usually deposited in groups of two to five. Experimentally 

 the first group of eggs was observed on the 4th February, and oviposition 

 continued until 22nd April. The majority of eggs hatched in 6-10 

 days and the larvae became mature in 60-70 days. The pupal 

 stage lasts 8-11 days, and the total life-cycle appears to be 80 or 90 

 days, but this may vary considerably under different indoor conditions. 

 The majority of the adults of this first generation appear late in May 

 or in June. Those of a second generation emerge late in September, 

 and then, after feeding to some extent on foHage, enter hibernation. 



Various experiments were undertaken in greenhouses for the control 

 of this pest. The effect of fumigation with hydrocyanic acid gas has 

 already been noticed [R.A.E., A, viii, 312]. Spray tests show that 

 Paris green at the rate of 4-8 oz. to 50 U.S. gals, water does not kill 

 the adults in sufficient quantity to warrant its use, and 8 oz. to 50 U.S. 

 gals, water maj^ scorch the rose foliage. The addition of brown sugar 

 to the spray improved the killing power of every poison tested. Pre- 

 liminary experiments indicate that some dusts, if properly applied 

 in the greenhouse, may be of considerable value. The most satisfactory 

 time to dust the rose bushes is in June or July, when the adults are 

 abundant. Dusting plants during the growing season is apt to be 

 unsatisfactory. As larvae have been found six inches deep in the soil, 

 it is necessary for a fumigant to penetrate all portions of it. Small 

 doses of sodium cyanide, when applied in water or in granulated form, 

 were found to kill the larvae and pupae, but also to injure the plants. 

 Varying strengths of nicotine up to 4 cc. to 1 litre of water were used 

 with very little success. With poisoned baits, sodium arsenate, 2 gm. 

 to 50 cc, gave the most rapid and highest percentage of mortality. 

 Dead leaves soaked with poison bait and scattered on the soil have 

 little or no effect. The most promising method is the suspension of 

 the bait, which must be moist, at one or several points in the centre 

 of each bush. The beetles are not attracted to light. 



