268 REPOET OF THE COMMISSIONER OF AGRICULTURE. 



ive brood of worms) was noticed Juno 25 in Texas, July 10 in Missouri, 

 and July 1 in Kansas. The offspring of this last (third) brood of moths 

 were nowhere noticed as iujurious. 



The worms were reported in small numbers July 15 from Kansas. 

 August 11 full-grown larvte were received from Nebraska, from which 

 State they had not before been reported, and it is possible that these 

 individuals were the offspring of a fourth brood of moths. ^lore proba- 

 bly, however, circumstances being apparently less favorable to their 

 rapid increase, they were the retarded third brood of worms. 



The statements which we have just made have only a general bear- 

 ing, and the same confusion of generations was noticed, in all localities 

 where the insect occurred abundantly, which is always noticeable in 

 the undue development of any species. Larva) of all sizes were work- 

 ing together in Texas, and what we take to be the third brood of moths 

 was flying before many of the second brood of larva) had ceased to 

 work. From the facts at hand it may be safely concluded that there 

 are normally four or five annual generations, and p-ossibly one or two 

 more under favoring circumstances. Dr. J. J. Kacidey, of Ci)etoi>aIi, 

 in writing to Professor Snow, says: " * * * But few of the Vvcbs 

 contain more than one inhabitant. I, therefore, do not think they are 

 gregarious in their habits, but the force of numbers drives them to 

 limited space. The wheat and oats appear to be exempt from their 

 ravages, and this may be accounted for in consequence of the blades at 

 this time being well lifted from the ground, as they are rarely found 

 feeding upon the leaves of plants more than 12 or 15 inches from the 

 root. When the top of the corn-plant is above this height the central 

 portion escapes, and the worms confine their mischief to the lower 

 blades of tbe stalk. These lose their green luster and wither, remain- 

 ing sickly and ])ale; but at the same time the head is pushing forward 

 in vigorous growth, and does not succumb to death like the younger 

 plnnts of smaller stature. * * *" 



Professor Popenoe gives the following account in the ISSO article al- 

 ready cited : 



" The Ibllowing p,oints in its history are the partial result of my study 

 of this insect:. Although I made careful search for the egg, I failed to 

 discover it in situ, but it is without doubt deposited on the lower side of 

 a leaf, or low down among the bases of a cluster of leaves, as newly- 

 hatched larva) are found in both these situations, from which they soon 

 wander to other parts of the plant. As soon as it [the larva] begins to 

 move about, it begins to spin the web, and this is increased in extent 

 as the movements of the larva are extended. It is very active in all 

 stages of growth as a larva, and springs aside qnickly when touched, 

 sometimes tlirowing itself into a coil, but more often running rapidly 

 away. At least in early life, the larva, when thrown off a leaf, will 

 hang by a thread of silk. In case a single leaf is of suliicient size, as 

 in the sweet potato, the well-grown larva is generally found on the up- 

 l)er side, in a shelter formed by drawing partly together the edge of the 

 leaf by the silk of its web. In this shelter it is usually found at rest 

 during the day, hanging by its feet, back downward, to the lower sur- 

 iace of the web. In other plants, several leaves may bo drawn together 

 for a place of concealment. If, indeed, the larva) are not partially 

 gregarious, they are at least not disturbed by proximity to each other, 

 as several may be found, at times, in a common vv'cb,altlioagh I believe 

 this is exceptional. As they are forced to move to new parts of the 

 plant for fresh food, their webs are extended, until finally the entire 

 plant is covered. The young larva) devour only the surface and sub- 



