March 1S91. 



PSYCHE. 



47 



the first insects to become active in 

 spring, and at this time is to be found 

 on grasses, clovers and other plants 

 feeding on leaves, flowers or pollen. 

 It is during this time, and before the 

 corn is up, that the ova develops in the 

 ovaries of the females. During the fall 

 and winter those taken and dissected 

 contained no developed eggs. In the 

 latter part of May last spring when the 

 corn was a few inches high, the females 

 collected contained ova in an advanced 

 stage of development. 



I was unfortunately unable to find the 

 eggs after oviposition, but there can be 

 no doubt but that they are placed like 

 those of D. lojtgicornis in the ground at 

 the roots of corn. A search in corn 

 fields June 3, 1889, resulted in no lar- 

 vae. On June 10, they began to ap- 

 pear, and by the close of the month 

 were mostly well grown. On July 5 

 pupae were found in confinement from 

 larvae brought in June 30. The pupae 

 began to appear out of doors about the 

 same time and the beetles came forth 

 from them during the first two weeks 

 of July, all apparently being out before 

 the 2 1 st. The first brood was thus 

 matured earlier than in 18S9, a result, 

 doubtless, of the forwardness of the 

 season of 1S90. 



Remedial Treatment. 



A complete remedy for the pest may 

 prove hard to find. If the insect spent 

 the winter in corn fields in the egg state, 

 as has been determined by Prof. S. A. 

 Forbes to be true of D. longicornis, 

 we might hope to avoid injuries by 



rotation of crops. Since it hibernates 

 in part at least as an adult, and is capa- 

 ble of prolonged flight, rotation would 

 not avail. The food habits, too, of 

 larva and imago are such as to favor it 

 in the struggle for existence. As a beetle 

 it is a voracious and indiscriminate 

 feeder, and nothing, seemingly, in the 

 way of succulent vegetation comes 

 amiss. Tomato leaves, clovers, potato 

 leaves and tubers, turnips and cabbage 

 have been used to feed beetles kept in 

 confinement. During the latter part of 

 August they are very common here in 

 the ends of corn ears, eating out the 

 silks. It is possible they may do some 

 harm in this way, but I can not see 

 that the affected corn fails to develop 

 the usual number of grains. At times 

 it is scarcely possible to find an ear of 

 corn that does not harbor one or more 

 beetles. 



Enemies. 



Some predaceous beetles and larvae 

 have been found during summer and 

 fall in the earth with young root worms, 

 but not in any great numbers. Among 

 birds I find only the brown thrush re- 

 corded as eating the beetles. 



Several parasites occur in the fluids 

 of the beetles, and can perhaps be ex- 

 pected to check any extraordinary in- 

 crease in the numbers of the root-worm. 

 The most common of these is one of 

 the protozoans, a large Gregarina. prob- 

 ably the same species as that noted some 

 yeai's ago in the fluids of D. longi- 

 cornis. The fluids of examples occa- 

 sionally swarm also with a small nema- 

 tode worm, and in one instance a large 



