286 



host's body. The pupal stage is passed within the dead skin of the 

 mealy bug, whence the adult issues, the entire life-cycle occupyinar 

 from 25 to 45 days. Pseiidococcus bakeri and P. sacchari are occasional 

 of the parasite. 



The most convenient way of rearing this and other parasites of 

 P. citri in the laboratory has been found to be the use of infested green 

 lemons or potato sprouts. For the latter method, shallow trays are 

 tilled with a layer of potatoes, the interspaces being filled with moist 

 sand, and are kept in the dark until the potatoes sprout. Mealy bugs 

 are then introduced and breed rapidly. Wlien new host-material is 

 required in any breeding cage, the older tray is placed on the lower 

 shelf with the fresh tray above. In this way all the parasites which 

 may occur on the old tray as young larvae or pupae within the mealy 

 bugs are retained. The process of shifting the trays downward as 

 each fresh tray is added is continued until all parasites have reached 

 maturity, when the older material is discarded. By this method, 

 thousands of parasites have been produced daily. For transmission 

 to field colonies, they are placed in a glass cylinder with a cork at 

 one end into which is inserted an 8 mm. glass tube which projects 

 into the cylinder and prevents the escape of the parasites. The cylinder 

 is filled with finely shredded paper on which the insects can rest. 

 When liberated the cylinder is tied to a tree and the cork removed. 

 About five to ten thousand insects constitute a colony. 



The economic importance of Pamleptomaslix abnormis lies in the 

 fact that it fills a gap in the natural control of the mealy bug, as there 

 is no other parasite in California which effectively destroys the first 

 and second stages of the insect. Its adaptation to environmental 

 conditions is almost perfect and it has proved able to survive 

 fumigation carried out against scale-insects, probably passing this 

 period as larvae and pupae within the young mealy bugs. Spraying 

 does not destroy it. Its introduction therefore seems an important 

 step towards control of this citrus pest, 



Hyslop (J. A.). Notes on an introduced Weevil {Ceuthorrhynchus 

 margiiiatus, Payk.). — Jl. Econ. Entom., Concord, N.H., x, no. 2, 

 April 1917, pp. 278-282, 1 fig. 



Ceuthorrhynchus marginatus, Payk., appears to have been established 

 on dandelion in the eastern States for some years without having 

 attracted much attention. The larvae are to be found in the flower- 

 heads just prior to their throwing off the withered petals. When the 

 s;eed-heads open, the larvae crawl out, drop to the ground and burrow 

 down at the base of the plant about half an inch below the surface, 

 ^vhere they construct small, oval earthen cells in which they pupate. 

 The larvae feed principally on the seed, but on several occasions were 

 found on the withered flower-petals. By the first of July all the 

 adults had emerged. On the 20th October adult beetles were to be 

 found under the litter at the base of dandehon plants and these insects 

 undoubtedly hibernate as adults. As the insect can destroy about 

 one-quarter of the seed of a noxious weed, it is an important economic 

 factor. The dandehon, however, is now being extensively used as a 

 green vegetable in certain parts of the country, and there this weevil, 

 when abundant, would therefore constitute a crop pest. 



