11 



while the nuile hicks the tufts of hair on the iniiev side of the hind 

 femora at the hasal end, as api)ears in Fiii'. _! ( 1 ). 



Th(> method of oviposition, nnnd)er and cluiraeter of the eg'gs, 

 are similar to those of the other species, and the ne\vly-h:itched 

 maggots make their way into^ the young onions. In from three to 

 four weeks they are fnll gro\\'n, and then measure ahout live- 

 sixteenths of an inch in length. They very closely resemhle the 

 cabbage maggot, but on the posterior oblique extremity, when 

 viewed from above, the two lowest tubercles, instead of being only 

 slightly cleft, are each divided, giving two extra smaller tubercles. 

 Fig. 'J (1). In this species, also, the nuiggot goes from the plant 

 to form the ])n])arium, and the second brood of flies makes its 

 appearance in June. There may be several broods during the 

 season and the later maggots sometimes prove (piite as injurious 

 as the earliei' ones. In ordinary seasons such injury is noted in 

 SeiDtember, and by the end of that month, or lirst of October, the 

 danger of infestati(m is over, since the flies which have not then 

 deposited their eggs will have gone into hibernation. I]ut if the 

 season is long and the warm weather continues, infestation may 

 occur even in October, as was the case during the season of 1900. 



In feeding the maggots may attack the onion at the side, but 

 they generally work up through the center of the bull), beginning 

 at the l)ottom, es]:)ecially when the onion is small. This they can 

 readily do, l)ecause the tissue of the onion is rather soft, and is 

 still further softened by ihe decay caused l)y the maggot injury. 

 The ])l'ants, and particularly the young ones, indicate the presence 

 of tlie insects by their sickly, drooping and wilted appearance. 



The different stages of this species which have jnst licen briefly 

 described arc illustrated on Fig. 1, while the effects of the maggot 

 in young plants are shown on plate Fig. 8. 



REMEDIAL MEASURES. 



Insecticide apjdications against underground insects are rarely 

 satisfactory because of the difficulty of getting them into contact 

 with the species to be dealt with. And this difficulty is at once the 

 cause and the ex]ilan:ition of the widely-different results which 

 have been obtained with minv of the materials used. 



A given substance nny kill the maggots well enough, and, ]ilaced 



