150 



corn. A common species of spider (I^o. 649) was observed to prey 

 upon both this and the Tarnished Piant-Bug, Lygus pratensis. 



Diabrotica 12-pu7ictata. — As stated in my report for the year 1887j* 

 the larvae of this species sometimes become seriously injurious to young 

 corn in Louisiana. In accordance with the suspicions expressed at 

 that time, viz, that the species would soon be heard from farther north, 

 the same habit and method of attack were the following year noticed 

 in both Arkansas and Indiana. In the former State we observed the 

 ravages of the larvae in St. Francis County early in May, and in the 

 latter State they were found in the fields of the experiment station on 

 July 12. In Louisiana the depredations of these larvae were studied in 

 fields of corn, preceded the year before by a crop of cotton. In Indiana 

 the field had been for several years devoted to timothy meadow, and 

 had been plowed in the fall and again in June, some time before the 

 crop (which was intended for the truck market) was planted. 



When first observed at La Fayette, on July 12, the larvae varied in 

 length from 0.5°^™ to 15"^"^ in length, the latter being, doubtless, nearly 

 full-grown, as examples placed in a breeding-cage, fed for some time 

 after and developed to adults August 2 to 5. Adults were observed 

 pairing on August 9 and during the season until October j yet we 

 failed to get larvae originating from eggs from adults confined in breed- 

 ing-cage, on growing corn, during this entire period. Nevertheless, as 

 adult beetles and larvae occurred simultaneously in both Louisiana and 

 Indiana, it seemed probable that there are at least two broods North 

 and possibly more in the South. 



The largest larvae observed were 15°^°^ in length, body gradually in- 

 creasing in size from head to posterior extremity. Head small, brown 

 above, darker at sides; jaws, dark brown; antennae, white, three-jointed; 

 head beneath, nearly white; mouth parts, other than the jaws, nearly 

 white. On the head are many bristles, these being shorter and more 

 closely placed in the vicinity of the mouth ; eyes wanting. The three 

 thoracic segments are shorter and better defined than the others, the 

 first being coriaceous and yellowish-brown above. The legs, six in 

 number, are nearly white, short, fleshy at base, and armed with short 

 bristles. Encircling the base of each leg is a loop-shaped, dark line, 

 with the stem of the loop extending upwards on the outer side to a 

 small, poorly defined, semi-circular brown patch, whose base is formed 

 by a distinct dark line. There are sparsely placed bristles on the body, 

 the last segment of which is obtuse and provided beneath with a pair 

 of tubercles or false prolegs and above with a circular brown leathery 

 patch, which forms a conspicuous feature of Diabrotica larvae. In this 

 case the posterior margin of this patch is produced, forming a slight 

 ridge and bearing a long, erect bristle. Color of body white, with tinge 

 of yellow ; wholly opaque. 



* Report of Commissioner of Agriculture, 1887, pp. 148, 150. See, also, Mr. H. 

 (Jarman, in Insect Life, Vol. II, p. 179. 1889. 



