69 



either fly or attempt to conceal themselves on the ground. The eggs 

 are adapted to moist soil and the surface of the growing plant. Experi- 

 ments on the control of the insect showed that lead arsenate spray 

 (1 07.. to 1 gal. water) killed less than 9 per cent., but almost relieved 

 the plants from attack for three days. Bordeaux mixture was not so 

 effective as a repellent. 



D. trivittata, Mann, (western striped cucumber beetle) is found with 

 D. soror on pumpkins, cucumbers, squashes, etc., but is of small 

 importance. It differs from D. soror in being a more general feeder 

 and in having two generations annually. The larvae are sometimes 

 destructive to cucumbers. The eggs are deposited 2 inches below the 

 surface of the soil on the tap root of the plant. Upon hatching, the 

 larvae work upwards on the root, and appear above the surface in two 

 or three days. The edges of the leaves near the roots turn white and 

 the whole plant withers and may ultimately die. Tobacco extract, 

 one teaspoonful to a gallon of water, is a successful remedy. 



Matheson (R.). Experiments in the Control of the Poplar and Willow 

 Borer {Crypt orrhynchus lapafJd, Linn.). — Jl. Econ. Entom., Concord, 

 viii, no. 6, December 1915, pp. 522-525, 2 tables. 



Gryptorrhynchus lapathi, L., is an important pest in nurseries in New 

 York State and also causes serious damage to ornamental poplars and 

 willows. The eggs are deposited in two- or three-year-old nursery 

 plants and are laid exclusively in the corky portions of the tree. They 

 are found most commonly near buds and branches or in growths caused 

 by pruning. Eggs laid in August, September and October hatch 

 during the same months. The young larvae hibernate in small 

 chambers just below the surface of the outer bark. Feeding recom- 

 mences in early spring, when the cambium is attacked. In late June 

 they bore into the heartwood, forming pupal cells. Pupation takes 

 place in July and adults begin to emerge in late July and August. 

 The weevils feed for a short time before oviposition begins. 



Early observations made by the author led him to the conclusion 

 that this insect could be destroyed by some contact spray applied to 

 the trunks of the trees in autumn after the leaves had fallen, or in 

 spring before the larvae had begun feeding actively. During March 

 1914, badly-infested nursery trees were sprayed from the ground up 

 to the young growth with scalecide of varying strengths, carbolineum 

 and carbolineum emulsion. The latter was prepared from 1 lb. 

 sodium carbonate, 1 qt. hot water, and 1 qt. carbolineum avenarius. 

 The trees were examined on 14th May 1914. No ill effects on the 

 growth could be observed. In the controls the larvae were abundant. 

 Plants treated with scalecide showed as high an infestation as the 

 control. In those sprayed with carbolineum, either pure or as emulsion, 

 no trace of infestation could be found. Later examination on 18th 

 June confirmed the previous observations. During the autumn of 

 1914 and the spring of 1915, experiments ^yith kerosene emulsion, 

 carbolineum and carbolineum emulsion were carried out on a larger 

 scale. Examination in June showed that the area as a whole was 

 severely infested, but that the rows treated with carbolineum or 

 carbolineum emulsion were free from borers. Kerosene emulsion 

 applied pure in autumn seemed to have had a slight effect. 



