160 EXPERTMEKT STATION RECORD. 



destroyed by niueh weaker s-olutions of insecticides than are usually employed. 

 Brief notes are j^iven on the various insect parasites of the species and on the extent 

 and economic importance of this parasitism. 



Suggestions about combating tlie San Jose scale, H. P. Gould {Mm-yland 

 Ski. Bid. 73, pp. 15S-166, figs. 2).—\ number of experiments were conducted for the 

 purpose of determining the effect of different percentages of kerosene on peach trees 

 and on the San Jose scale. During these experiments it was found that considerable 

 damage was done to peach trees by spraying them with a 20 per cent kerosene mix- 

 ture during a dormant period, while the same mixture applied during the period 

 between March and the blossoming period gave more satisfactory results. It was 

 found that tobacco whale-oil soap solutions caused some injury to the foliage if they 

 were used of strength sufficient to destroy the adult San Jose scale. A 5 per 

 cent solution of kerosene had little effect on the scale, while the 20 per cent solution 

 destroyed practically all of the scales. The 5 per cent solution did not injure the 

 foliage, and the 20 per cent solution was only slightly more injurious to the foliage 

 than the 10 per cent solution. The trees should not be sprayed at a time when the 

 solution will freeze, since considerable damage to peaches results from this process. 

 No differences were noted in results whether the kerosene was applied on cloudy or 

 clear days. 



A brief popular discussion is given of the comparative value of crude petroleum as 

 an insecticide and regarding whale-oil soap and fumigation with hydrocyanic-acid 

 gas as remedies for the San Jose scale. 



Observations on a new species of scale injurious to citrus fruits in Italy, 

 G. DEL GuERCio {Nuove Relaz. R. Staz. Ent. Agr., 1. ser., 1900, No. S, pp. 3-26, pi. 1).— 

 The author describes the scale insect in all its stages under the name Ceroplastes 

 simensis. The food plants of this scale are Citrus aurantium, C. Umonum, C. deliciosa, 

 and MuhlenhecBa j^kdyclados. The life history and habits of this scale are described 

 in some detail. For preventing the larvae from attaching themselves to the woody 

 parts of the plants, the author had good success in using a mixture containing oil of 

 tar, 10 to 15 liters; neutral carbonate of soda, 7 to 10 kg.; water, 80 to 90 liters. Tar 

 soaps also proved effective. For the first treatment concentrated tar soap is recom- 

 mended, containing soft soap, 1 kg.; water, 3 liters; oil tar, 1 liter. For the .second 

 treatment the mixture should contain about 2 per cent oil tar, and the third H per 

 cent. Branches which were painted with the insecticide showed upon examination 

 that all the insects had been destroyed. The scales of other species of scale insects 

 were thoroughly penetrated. In combating this scale it is also recommended that 

 Muhlenheckia jjlaiydados in the vicinity of citrus orchards should be destroyed. 



Brief notes are given on the life history, habits, and means of combating C. rrisci 

 and species of Aspidiotus, Mytilaspis, Diaspis, etc. 



Means of infestation by the olive fly and methods of checking its further 

 spread, G. del Gcercio (Xuore Reluz. R. Staz. Eiif. Agr., 1. xer., 1900, Xa. S, p]). 

 27-86, pi. Iffigs. 2). — The author discusses in a critical manner the literature relat- 

 ing to Dams olese. The in.sect is described in all its stages, including the varieties 

 fiimsta and fiaviventris. The' life history, habits, and metamorphosis of the fly are 

 described in detail, and notes are given on the relative severity of infestation of dif- 

 ferent varieties of olives. From this study it appears that the fly passes successively 

 from one variety to another of olive from its first appearance in July and August to 

 the time of its greatest prevalence in November and December. Experiments were 

 conducted for the purpose of testing the efficiency of plowing and cultivating the 

 soil in destroying the pup?e of the fly. From these experiments it was found that 

 burying the pupte in loose soils and rolling and drenching the soil with water had 

 no effect in preventing the flies from emerging. In loose soils inundation did not 

 destroy the pupse. In compact soils, on the other hand, whether with or without 



