178 



several kinds of tree-banding material with the object of reducing 

 the cost of this method of control. The study of the gipsy-moth as 

 a cranberry pest has been continued, special attention being given 

 to the dispersal of small caterpillars over the bogs on account of the 

 wind drift, the increase of the gipsy-moth under normal field 

 conditions, the relation of disease and parasites, and the effect of 

 defoliation on different species of trees. The investigation of the 

 so-called wilt disease of Lymantria dispar has revealed many facts con- 

 cerning the obscure causative organism of this disease, which is an 

 important factor in the reduction of the number of the pest and also 

 attacks many native caterpillars. Many colonies of the Japanese 

 egg-parasite, Schedius kuvanae, were liberated in Massachusetts and 

 New Hampshire, and Anastutus bifasciatus was colonised in Maine, 

 New Hampshire and Massachusetts. Satisfactory results have been 

 obtained from the parasites, Ajianteles lacteicolor, Meteorus versicolor, 

 and A. melanoscelis, and the Tachinid flies, Compsilura concmnala 

 and Zygohothria nidicola. Calosoma sycophanta continues to exercise 

 effective control, though less numerous than in the previous year. 



In connection with the control of insects affecting deciduous fruits, 

 an effective band trap against the codling moth on apples has been 

 devised, which allows the larvae to enter to pupate, but prevents the exit 

 of the moths [see this Review, Ser. A, v, p. 113]. Orchard spraying 

 and dusting experiments on a large scale are being carried out, and 

 investigations of apple-tree borers have been continued and extended. 

 It has been found that the common service tree is very largely 

 responsible for the distribution of the round-headed apple-tree borer 

 {Saperda Candida). The results of investigations indicate that the 

 stigmonose injury to apples is connected with the puncture of the 

 fruit by Aphids and especially the rosy aphis. Experiments in the 

 use of poisonous gases against the woolly apple aphis {Eriosoma 

 lanigerum) and the peach-tree borer {Aegeria exitiosa) have been 

 continued with satisfactory results. For nursery stock the use of 

 carbon bisulphide has been found impracticable, but tests of 

 ])aradichlorobenzene have yielded promising results. Field experi- 

 ments in the control of the grape-berry moth {Polychrosis viteana) 

 show that the best measure is the application of 3 lb. arsenate of 

 lead to 50 U.S. (421 Imp.) gals, of water immediately after the fall 

 of the grape blossoms. The so-called blackhead fire- worm {Rhopobota 

 vacciniana) was unusually abundant and destructive on cranberries, 

 but may be controlled by spraying infested bogs with 40 per cent, 

 nicotine sulphate while the insects are in the larval stage. 



Investigations into the arsenical and other poisonous spray residues 

 present on fruits at harvest time, the comparative merits of dust 

 versus liquid sprays in orchards and vineyards, and the effect on the 

 honey bee of spraying apples with arsenicals during bloom and after 

 the fall of most of the petals, have been carried out. It has been 

 found that when trees in full bloom are sprayed, many bees are 

 killed, while spraying at the customary times under normal conditions 

 has no injurious effect. 



Investigations of southern field-crop insects showed that the boll 

 weevil {Anthonomus grandis) was the principal pest to be consideretl 

 ill relation to cotton culture. A new type of poison-dust gun and also 

 a form of lead arsenate containing a higher percentage of arsenic 



