424 JOURXAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



certain times during the year but are not able to cope with the first 

 brood. 



The parasites reared in greatest abundance were species of Clostero- 

 cerus, especially C. tricinctus Ashm. Next in point of number was 

 Closterocerus utahensis Gahan. Nine specimens of Sympiesis agro- 

 myzce Gahan, nine specimens of Diaulinus pulchripes Crawford, seven 

 specimens of Diaulinus hegini Ashm., three specimens of Derostenus 

 varipes Crawford, two specimens of Derostenus pictipes Crawford, and 

 several specimens of Zagrammosoma multilineata Ashm. w^ere reared. 

 In addition one Pleurotropis sp., one Aphaereta sp., one Mymarid, four 

 Chrysocharis, probably C. parksi Crawford and one Derostenus n. sp. 

 were reared. 



CONTEOL 



Cultivation about the plants at any time after pupation of the last 

 generation and before April 1 will undoubtedly reduce the chance of 

 infestation. In one case, a flower bed at this Station was spaded over 

 in early March before freezing weather was over. The columbines in 

 this bed were entirely free from infestation by the first brood, though 

 the previous year the infestation had been very severe. About 100 

 feet from this bed another plot of columbines left uncultivated until 

 May were badly infested by the first generation. Removal and de- 

 struction of infested leaves in May before the infestation becomes gen- 

 eral should control the depredations of the insect. No other food 

 plants have been found though the nasturtium is recorded as a host 

 by Coquillett. Repeated efforts to breed adults from mines in this 

 plant have resulted in failure. The common miner of nasturtium 

 Jiere appears to be another species. 



NOTES ON THE HABITS OF A DANGEROUS GENUS OF 



WEEVILS 



By W. D WIGHT Pierce, Bureau of Entomology, U. S. Department of Agriculture 



Recently two species of European weevils belonging to the genus 

 Polydrusus have been found in the United States. Four other species 

 are apparently native or have been long established. This genus is 

 composed of very destructive species in Europe and one of the imported 

 species is already doing considerable damage in New York and Con- 

 necticut. 



Because of the possibility of further importations in nursery stock 

 the writer has gathered together the following notes on the habits of 

 the various species of the genus and drawn up descriptions of the 

 stages of one of the introduced species. 



