106 



sweet corn being chiefly aflected. Examination showed the damage to 

 be caused by this insect, and we had some extended observations made 

 on its habits by Mr. Pergande, from whose notes the following facts are 

 summarized : 



The general aspect of the field was as though it had been attacked by 

 Crambus, the central leaf wilting and drooping and the whole plant 

 exhibiting a withered appearance. In a great many of the rows not a 

 single plant was left, every one having been attacked and destroyed as 

 soon as it made its appearance above the ground, and in many cases 

 the plant was killed almost as soon as sprouted. The corn still stand- 

 ing was about six inches high and the greater portion of it had been 

 recently infested, as was plainly indicated by the withering of the cen- 

 tral blades. Examination of these plants almost invariably disclosed the 

 larva, sometimes buried for two-thirds of its length, actively at work 

 in the heart of the plant immediately above the roots, working in pre- 

 cisely the manner of Crambus, of which, however, no si)ecimens could 

 be found. 



Two or three of the Diabrotica larv^^, which are here ^Iso known as 

 the '^bud worm," were occasionally found in a single hill of corn. 



LarvfB collected June 18 changed to pupie June 22, and the beetles 

 appeared July 0. A number of the beetles were at once placed in ajar 

 with earth and corn plants to ascertain the facts regarding their ovi- 

 position. On the day following, July 7, large numbers of eggs had been 

 placed below the surface of the soil near the plants, in cracks, or im- 

 mediately about the base of the plants. They were placed either singly 

 or in groups of two or twelve, or even more. 



From these eggs larvie were subsequently obtained. These, when 

 first noted on July 15, were already of considerable size, but were not 

 carried to full growth on account of the difficulty of obtaining the plants 

 of corn. 



The above indicates that this insect is at least double-brooded, in 

 which respect it differs from the closely allied D. Jongicornis, which is 

 single-brooded and winters usually in the egg, though occasionally in 

 the adult state. 



The second brood of Diabrotica 12-putictata doubtless winters over, 

 and deposits eggs about the young corn or other plants in the spring. 

 Eggs of the last brood are also perhaps deposited in the fall, and 

 winter over, as is usually the case with longieornis. 



Mr. Webster's experience with this insect in Tensas Parish, La., dur- 

 ing Ai)ril, 1887, published in our Annual Report for 1887, is, we believe, 

 the first i)ublished record of the corn-feeding habit of this insect. 



No pupae, as stated, were found, but the larvjB and beetles were col- 

 lected and forwarded to the Dei>artment in quantity, and the connection 

 between the two was unequivocally shown by comparison \nth the com- 

 l)lete material already in our possession. In addition to these records, 

 we have received the larvai from Mr. J. M. Thomas of Abbeville, S. C, 



