THE MONTHLY BULLETIN. 527 



In this oreliard the Sicilian parasite had been liberated in con.sidernble 

 numl)ers during- the period from August 19, 1914, to Mareh 11, 1915. 

 As the last colony Avas placed in the orchard over four and one-half 

 months previous, there can be no doubt as to the breeding of the insects 

 in the field. The following note is still more convincing proof : 



"Alhambra, July 13, 1915. — Parasites {Paraleptomastix ahnormis 

 Girault) commenced to issue today from material collected at Alhambra 

 from trees where parasites were liberated. ^Material was kept in breed- 

 ing box in laboratory. There were about a dozen infested leaves taken 

 from different parts of the tree. ' ' 



"Alhambra, August 2, 1915. — Noticed Sicilian parasite (Paralepto- 

 mastix ahnormis Gir.) on five different trees. On one tree counted 

 eighteen adults scattered through." 



From the results of this investigation the establishment of the Sicilian 

 parasite at Alhambra is certain. At San Diego also it is breeding in 

 the field and under adverse conditions, as noted by Mr. Branigan : 



''San Diego, September 10, 1915. — "Went to Shaw orchard where 

 Sicilian parasite had been liberated. Found quite a few adults on 

 several trees around the one on which they had been colonized. Could 

 also see cpantities of the skins or host remains of mealy bugs, from 

 which the parasites had emerged, on the lemons. On one lemon I 

 counted at the stem end nineteen skins from which the parasites had 

 issued. In this grove every tree teas fumigated during the latter part 

 of August, 1915." 



This observation is of great interest, as it seems to show that the 

 parasite is more or less resistant to hydrocyanic acid gas, the fumigation 

 having taken place only a couple of weeks before the investigations were 

 made. It is scarcely possible that the adult parasites are thus resistant, 

 but perhaps the pupas and full-fed larva? are not greatly inconvenienced. 



"San Diego, September 10, 1915. — Noted by E. J. Branigan. Made 

 a very interesting observation today in the orchard. Where the Sicilian 

 parasite is breeding and Cocciuellid predators are also working, the 

 predators will devour every particle of mealy bug, but always leave the 

 individuals which are parasitized by the Sicilian parasite, after the 

 pupa is formed. ' ' 



The apparent resistance of this parasite, in certain stages, to fumiga- 

 tion, and the aversion that the Coccinellids seem to have for mealy bugs 

 parasitized by it, after they have reached a certain stage of develop- 

 ment, if found to be generally true, will make it especially adapted to 

 California conditions. That and the fact that it comes from a region 

 of similar climatic conditions leads us to hope that it may in time 

 become something of a factor in the control of the citrus mealy bug. 

 We can at least report satisfactory progress. 



