54 



the commission and inspectors being more or less jointly responsible 

 for the work done on this parasite and the information gained. As 

 pointed out b} T Mr. Jeffrey, the South African parasite presents such 

 varied phases of development in different localities and situations, 

 under different scale conditions, that it is impossible to form accurate 

 conclusions without a thorough study of its life history made in a 

 systematic manner. The general status of the distributions and • 

 abundance of the parasite and winter conditions are given by Mr. 

 Jeffrey, in letter dated March 7, as follows: 



From the 15th day of last August to the 15th day of January this office has dis- 

 tributed about 25,000 adult flies. They were taken from a colony established upon 

 a pepper tree at Pasadena on the 26th day of August, 1902. During this period of 

 five months of distribution the greatest activities occurred in August and December, 

 32 per cent being sent out in December. You will notice that the time covered is 

 concurrent with that of the greatest development of the scale upon the pepper trees 

 from which we obtained our supplies. But the most active orchard work of the 

 flies must occur in the early summer, when the scale is in the egg stage upon the 

 citrus trees. 



From the first of January to the first of March the Scutellista entered a period 

 of greatest dormancy, in which a large portion died in the larva, pupa, and adult 

 form. We are now breeding them again in large numbers. However, we noticed in 

 several orchards in sunny situations the insects working all through this time of 

 general dormancy as if it were midsummer, the orchards being in all cases young, 

 and, consequently bearing scale in all stages of development. 



From this we conclude that with the exception of a short time in the cooler 

 weather the Scutellista has no period of inactivity, but works in all cases where the 

 scale is in the egg stage. 



Mr. Maskew's notes, received with the above, are ver} T interesting 

 and instructive, and are quoted substantial! y as received below, and 

 are the result of instructions from the Horticultural Commission of 

 Los Angeles County to make weekly observations on colonies liber- 

 ated in his own inspection district: 



October 15. — A few flies. Pupae common but not numerous. Larvae (not identified) 

 very abundant. 



October 19. — Flies more in evidence. Pupae very abundant, Larvae (not identi- 

 fied) becoming more scarce. 



October 30. — Flies very numerous; numbers of them to be seen upon the wood and 

 foliage. Old scale showing evidence of a general exit. Pupae under scale becoming 

 scarce. Larvae (not identified) in all sizes but more rare. 



November. — Scutellista cyanea was found in all three stages during each week of 

 this month, but upon a different class of host plant. The majority were found upon 

 horseweed, cocklebur, pepper trees, and olive, about in the order named from a 

 numerical standpoint. Flies bred from parasitized black scale upon belladonna and 

 chili pepper taken during the month of November, proved to be Tomocera californica, 

 A. mytilaspidis, and one unknown to me which had all the earmarks of a Procto- 

 trupid. 



December. — Scutellista cyanea was found in all three stages during each w r eek of this 

 month, principally upon pepper trees, weeds, and upon chili pepper. 



January. — During each week of this month the parasite was found as follows: 

 Larvae very scarce, pupae and flies abundant, particularly upon chili pepper. A 



