423 



oleic acid costing about 4 shillings, making 1| gals, of nicotine 

 oleate, a spray as effective for the control of Aphids, if not more 

 so, than one containing free nicotine, and at less than half the 

 cost. 



Since nicotine oleate is not volatile, it should not be used as a 

 spray on plants that are to be eaten, such as lettuce; while on dormant 

 trees, its use with a rather non-volatile oil such as linseed, cotton seed 

 or fish oil, should be valuable for the destruction of insect eggs or 

 scale-insects. 



Application has been made for a patent for this compound, and 

 this, when obtained, will be given to the public so that anyone will 

 be able to manufacture it. 



Severin (H. H. p.). Oils tested to trap Trypetidae and Ortalldae. — 



Milily. Bull. Cal. State Commiss. Hortic, Sacramento, \Tii, no. 6, 

 June 1918, pp. 419-423, 2 figs. 



Within recent years, experiments in trapping fruit-flies by means 

 of various oils have s1io\\ti that in India, the males of Dacus 

 zonatus, Saund. (peach fruit-fly) and D. diversus, Coq. (three-striped 

 fruit-fly) were attracted by citronella oil, as was also D. ferrugiyieus, F. 

 (mango fruit-fly), which ranges from India and Ceylon to Java, but 

 that Dacus [Bactrocera) cncurbitae, Coq. (melon fly) in India and Ceylon 

 never came to this oil [see this Review, Ser. A, iv, p. 66]. Observations 

 on the effects of animal, vegetable, and crude petroleum oils on 

 Ceratitis capitata, Wied. (Mediterranean fruit -fly) have already been 

 noticed [see this Revieiv, Ser. A, iii, p. 28]. 



Rhagoletis pomonella, Walsh (apple maggot), avoids oil of citronella 

 and kerosene, but it was found that the exposure of crude petroleum 

 in shallow pans for the purpose of repelling ovipositing females, 

 resulted in their capture. 



Exhaustive experiments extending over six weeks, with 41 different 

 oils in specially prepared traps fitted Avith conical covers to exclude 

 the rain, gave entirely negative results, one female only being taken 

 in turpentine. It having been stated that in the case of D. zonatus 

 and D. diversus the attractive principles of oil of citronella were 

 iso-eugenol and methyl-eugenol, experiments were conducted on 

 R. poynonella with these substances, but with negative results. Tests 

 with these substances upon Epochra canadensis, Lw., under both 

 laboratory and field conditions, gave'entirely negative results, and the 

 same was true of the hydrocarbons and oil of citronella in the case 

 of Straussia longipennis, Wied. (sunflower fruit-fly) and the Ortalid, 

 Seoptera colon, Lw. 



Severin (H. H. P.). Fruit Flies of Economic Importance in California. 

 Apple Maggot {Rhagoletis pomonella, Walsh). — Mihly. Bull. Cal. 

 State Commiss. Hortic, Sacramento, vii, no. 6, June 1918, 

 pp. 430^32, 1 fig. 



Although there seems to be no doubt that the apple maggot, Rhago- 

 letis pomonella, Walsh {R. zephyria, Snow), occurs in California, no 

 reports of apples infested by the pest have been obtained at the 



