1917] ECONOMIC ZOOLOGY ENTOMOLOGY. 457 



tacking Apples, by L. Caesar (pp. 163-178) ; A Preliminary List of Parasitic In- 

 sects Known to Occur in Canada, by R. C. Trehernc (pp. 178-193) ; and The 

 Entomological Record, 1915, by A. Gibson (pp. 194-230). 



Insect pests [in Sitka district], J. P. Anderson {Alaska Stas. Kpt. 1915, pp. 

 Ifl, 42). — It is pointed out that the cabbage maggot is the worst insect enemy 

 of horticultural crops at the Sitka Station, due to its attacking all the crucif- 

 erous vegetables. Fifteen or 20 per cent of the apples grown at the station were 

 more or less injured during the year by what is thought to be Argyresthm corir- 

 jugella. A green aphis, troublesome in the greenhouse, was satisfactorily held 

 in check by occasional fumigation with a nicotin paper. 



Report of the entomologist for the year 1915-16, A. H. Ritchie {Ann. Rpt. 

 Dept. Agr. Jamaica, 1916, pp. 31-34). — The aleyrodid Aleurocanthns woglumi 

 is reported to have continued its spread in Jamaica, two of the largest citrus 

 groves on the island having been attacked for the first time. The Florida spray, 

 consisting of Diamond paraffin oil and whale-oil soap, is said to act as an ex- 

 cellent control measure. It is stated that this pest may also be controlled by 

 transferring to citrus trees nests of an undetermined black ant which are natu- 

 rally built in the forks of branches of the log\vood. 



Among the enemies of cacao mentioned are the red-banded thrips {Soleno- 

 thrips rxibrocinctus) , which causes defoliation and, in the drier localities or 

 during dry periods of the wetter northern estates, rusting of the pods. The 

 emulsion above mentioned (1: 50) or blackleaf 40 (1: 2000), with 3 lbs. of soap 

 per 100 gal. of spray added as a spreading agent, has been found to be the most 

 satisfactory. 



In addition to citrus and cacao pests, mention is also made of the insect 

 enemies of the mango and field crops. 



Some phases of the locust problem, C. P. Lounsbury {So. African Jour. 

 Sci., 12 {1915), No. 2, pp. 33-45). — A discussion of the locust problem, particu- 

 larly as related to South Africa. 



The cockroach: Its destruction and dispersal, J. J. H. Holt {Lancet [Lon- 

 don], I, 1916, No. 23, pp. 1136, 1137).— The author has tested the effect of liquid 

 volatile bodies, aromatic oils, coal-tar and paraffin derivatives, dusting powders, 

 and food poisons on the cockroach. 



The results of the experiments as a whole seem to indicate " that many of the 

 substances which have been supposed to kill the cockroach have really acted 

 by driving it away and so leading to its disappearance. Such gregarious migra- 

 tions have been observed but have hitherto been otherwise explained. For 

 quick destruction stoving with bromin or sulphur dioxid is apparently best. For 

 domestic application the daily use of creosote, wood naphtha, or the oil of rose- 

 mary, eucalyptus, or citronella placed near the haunts of the cockroaches for 

 two or three weeks should effectually disperse them. Where these are inad- 

 missible on account of their smell, odorless dusting powders may be used. Of 

 these sodium fluorid was found to be the most effective. It is also cheap and 

 keeps indefinitely." 



The green apple bug (Lygus invitus) in Nova Scotia, W. H. Brittain 

 {Ann. Rpt. Ent. Soc. Ontario, 46 {1915), pp. 65-18, figs. 14). — The observations 

 and experiments during 1915 with L. invitus have been summarized as follows: 



" The green apple bug is one of the most serious pests of apples and pears in 

 Nova Scotia, though hitherto, owing to its elusive habits, it has not been rec- 

 ognized as such. It is the cause of ' woody pears ' and one of the causes of 

 gnarled, twisted apples. It is the most common cause of the continued failure 

 to bear of Nonpareil and certain other varieties of apple. It attacks not only 

 the fruit but also the foliage, stems, and blossoms of apples and pears, and in the 

 adult stage has been known to attack plums. 



