56 INSECTS INJURIOUS TO GARDEN AND ORCHARD CROPS. 



carriage, to other Gulf and neighboring States, and it is not impossible 

 that in due time it will gradually work its way northward from the 

 Lower Austral region, in which it is now established, to the Upper Aus- 

 tral. From the proximity of Augusta to the State line of South Caro- 

 lina its establishment in that State is already practically assured. 



It seems probable that this pest has come to stay, yet on the other 

 hand there exists a possibility that it may succumb, at least in a 

 measure, to its parasitic and predaceous enemies and to climatic condi- 

 tions unfavorable to its further increase. Until we know more of the 

 distribution of the species in its supposed native home in the Old 

 World # we can not speak with positiveness of its probable future dis- 

 tribution in America. In any case, it is an insect that will bear close 

 watching, and it is to be hoped that all who have the opportunity to 

 assist in these observations will not fail to do so and to keep this 

 Department apprised of developments. 



NATURAL ENEATIES. 



The natural enemies of cruciferous insect pests are of considerable 

 value in keeping their hosts in check, and some dependence must be 

 placed upon these agencies in restraining the undue multiplication of 

 this web worm. 



In spite of the short time that we know of its occurrence in this 

 country, we are already certain that at least one natural enemy and 

 probably two are at work in decimating this pest. One of these is 

 the Tachina fly," Exorista piste Walk., which has been reared from the 

 caterpillar of Sell ul a undalis at this office. The first example of this 

 parasitic fly-issued October 27. 



A very abundant parasite reared with this species is the Ichneu- 

 monid, Limner ia tibiator Or. It was reared from the latter part of 

 October until the last week of December. It has not been positively 

 ascertained to prey upon this larva as it is a well-known eDeiny of the 

 diamond-back moth, Phi tell a cruciferarum, which was also present in 

 smaller numbers, but as it is also known to attack the cabbage looper. 

 Plusia brassicce, and Mineola indiginella, it seems probable that it is in 

 reality an enemy of this webworm. 



REATEDIAJL MEASURES. 



The logical remedy for this webworm is one of the arsenites, prefer- 

 ably Paris green, applied in the form of a spray, at the rate of about 1 

 pound to 120 to 160 gallons of water, upon the first appearance of the 

 larva? in the season and as often thereafter as the occasion may justify. 



From what we already know of the life economy of this insect it is 

 obviously a difficult species to successfully combat. The fact that the 

 larva- live in more or less complete concealment in webs which they 

 form upon their food plants, aud from the further fart that there are 

 undoubtedly several generations produced during the season, it follows 



