THE MONTHLY BULLETIN. 



465 



Fig. 141. A form of injury, somewhat uncom- 

 mon, by C. volckei. (Original.) 



'I'lic mature larvae arc about 0/32 inches long and the moths practically the same 

 length from the tip of the head to the tip of the wings. The body color of the 



moth is silver gray and also the 

 short scales of the wings, but 

 the long scales or fringes are 

 brown. The moth is inclined to 

 concealment and has never been 

 observed bj the writer except when 

 reared in captivity. 

 In .May of 1917 o number of 



mature larva' and pupae were for- 

 warded to the Bureau of Entomo- 

 logy, United States Department of 

 Agriculture, and the moths which 

 emerged were determined by Mr. 

 J. X. Ileinrich as a new species 

 and named by him Coleophora 

 volcki i. So far as I am aware 

 the description has not yet been 

 published. 



The genus Coleophora of the 

 lepidopterous family Elachistidae is 

 represented in California by 15 

 species, according to Wood worth." 

 That the subject species is prob- 

 ably native is well supported by 

 the co-occurrence of such a number 

 of the members of this genus. 

 Several searches were made to 

 locate the species on native vegetation, but all of these failed. ITiis summer a 

 pupa case was accidently found on wild blackberry in the Santa Cruz Mountains 

 about thirty-five'miles from the orchards in which the insect has become troublesome. 



Perhaps the most peculiar 

 feature connected with this 

 species is its localized occurrence 

 in the apple orchards of the 

 Pajaro Valley. These infes- 

 tations may be described as 

 colonies separated by consider- 

 able distances. While C. volckei 

 is a comparatively slow breeder 

 with only one generation a year, 

 it is so well protected by its ease 

 and its leaf-mining habits that 

 its spread should be equally sure. 

 The case, and habit of exclusively 

 internal feeding completely pro- 

 tects this species from injury by 

 arsenical sprays in the summer 

 and lime-sulfur in the winter. 

 Oil emulsions, unless applied 

 with great thoroughness and at 

 very heavy concentrations, also 

 fail to kill the hibernating larva;. 

 In fact, it appears that no prac- 

 tical percentage of oil will give 

 control of the insect. 



('. volckei is apparently almost 

 free from injury, by natural 

 enemies as the parasites reared 

 from collections have never ex- 

 ceeded three per cent of the pupae. 4 



Fig. 142. Pupa of C. volckei, natural size. (Original.) 



"Guide to California Insects. 



'Mr. A. B. Gahan of the Bureau of Entomology, U. S. D. A., has identified a para- 

 site reared from this insect as a species of Aficrobracon. 



