322 



found to contain living insects. 72 in the larva and 52 in the pupa state. 

 Fifteen contained dead larvae and 2 dead pupie. Five of the larva? had 

 been i)arasitized. 



We believe, as a result of this examination, that the great majority 

 of the larvpe left undisturbed in the field will transform to adults with 

 success, and that m all probability the beet plantations will be abun- 

 dantly stocked with eggs, probably during June: since in our estimate 

 of three annual generations we allowed for the probable normal occur- 

 rence of a June brood of caterpillars. If we are correct in this suppo- 

 sition the first brood last year must have been overlooked. This may 

 seem astonishing in view of the great numbers of the destructive 

 brood 5 but two thousand larvcie scattered through a field might well 

 escape notice, and their immediate oftspring, under favorable circum- 

 stances, would number nearly a million — enough to defoliate one hun- 

 dred thousand plants. 



All sugar-beet growers in :S'ebraska and adjoining States should, 

 therefore, watch carefully for the advent of the worms in June, and on 

 their first appearance should apply Paris green in solution at the rate 

 of one pound of the poison to two hundred gallons of water. If they 

 are not found in June careful search should again be made the third 

 week in July. 



We reproduce with this note the figures which illustrated our account 

 of the species in the Annual Eeport, and have added at Fig. 45 a repre- 

 sentation of the larval case in out-line at «, with the larva in the lower 

 end. At c we show the pupa enlarged, ventral view, while at h is fig- 

 ured an interesting parasitized specimen. The dotted hne indicates 

 the outline of the entire case, the shaded portion showing the upper 

 section occupied by the parasite, which, at the date of receipt, was still 

 in the larval condition, although just ready to change to pupa. It 

 had spun about itself a compact brown silken cocoon, the end of which 

 is exposed at the point where the dotted line begins. 



The pupa of the web worm is found close to one end of the larval 

 case, its head applied to the extremity of the case, which, however, is 

 entirely closed with silk spun by the larva before transformation. In 

 making its exit the moth must undoubtedly moisten and pierce the 

 silken fibers, as is the case with other cocoon-spinning Lepidoptera. 



This insect did considerable damage during the summer of 1892, but 

 it is a species which is easily treated, and with a little care no serious 

 trouble need be anticipated. 



