184 ZOOLOGY. 



2, The maggots of the second generation are found 

 in average cases during July, on the as yet scarcely 

 ripe grains of late summer corn, principally those of 

 oats and barley, often occurring also in the haulms 

 of grasses. They keep between the awns, and suck 

 the juices of the soft developing grains, which are 

 rendered incapable of growth, and in any case remain 

 light. The maggots of the second generation develop 

 more quickly than those of the first or third ; they are 

 mature in three weeks. The pupa rest is very short, 

 and the flies appear in August, September, or October. 

 They lay their eggs on the leaves of winter com or 

 winter grasses, and from these eggs are developed 

 (3) the maggots of the third generation, which are to 

 be found, during September and October, in the heart 

 of winter corn and grasses, injuring these plants in 

 exactly the same way that the maggots of the first 

 generation injure the summer com. The insect passes 

 the winter as a pupa in winter com plants or grasses. 

 It is but very rarely that all three generations infest 

 the corn of any particular region ; as a rule, only the 

 first, second, or third generations do this, or the first 

 and third ; in such cases the other generations live on 

 grasses. Remedies : Extermination of the insect is 

 impossible, since it can always go from corn to grass 

 plants. Oats and barley are almost always attacked 

 in spring, if in the immediate neighbourhood there is 

 winter rye inhabited by the maggots, for the flies, 

 when they emerge the next spring, seek out the 

 summer corn. This may, however, be made im- 

 possible, or at least difficult, if a field of peas, clover, 

 lupines, rape, or some other crop not of gramineous 

 nature, is interposed between. fields of winter com 

 and those of oats, barley, or similar late sown crops 

 of summer corn. Sowing the summer corn (especially 

 oats and barley) as early as possible. 



