580 Agricultural Experiment Station, Ithaca, N. Y. 



the caterpillars of these two species are practically alike. Dr. 

 Riley's description of his green fruit worm agrees with his pre- 

 served specimen of -Y. grotci, and he states that the moth of this 

 species (a variety, he then considered it) '' heads his series." Mr. 

 Edwards described a caterpillar of what he supposed was X. lati- 

 cinerea, but his description applies to the caterpillars of X. grotei, 

 and not to those of either of the other two species under dis- 

 cussion. 



The indications are that the caterpillars of X. grotei spin 

 slight cocoons within which they change to pupte, as in the case 

 of X. antennata. But we cannot say whether there are any dif- 

 ferences in the pupae of these two species or not. 



Natural Enemies. 



Fortunately for the fruit grower, these green fruit worms have 

 several deadly enemies. One correspondent reported that red- 

 winged blackbirds had been seen either catching and eating the 

 caterpillars or carrying them away to feed their young. Doubt- 

 less other birds which frequent orchards also include the worms 

 in their menu. 



The indications are, however, that the caterpillars suffered 

 much more from the attacks of at least two minute foes among 

 their own kind. From the material sent to the insectary, we bred 

 two minute hymenopterous parasites. Apparently the most nu- 

 merous and efficient one of these little enemies is shown much 

 enlarged at e, plate 4; they are only about 1-5 of an inch in length. 

 It was named Meteorus hyphantriw by Dr. Riley in 1886. That 

 year it did valiant work in checking the fall web-worms {Hyplian- 

 tria cunea). Its method of working is to deftly insert an egg into 

 the body of an unwary and defenceless caterpillar. A grub 

 hatches from this egg and proceeds to live on the internal fats 

 and juices of its host — the caterpillar. The host leads a linger- 

 ing existence, and finally, a short time before death ensues, the 

 parasitic grub bores its way out through the skin of its host and 

 proceeds to spin the curious brown cocoon, shown natural size at 

 a, and much enlarged at h, plate 4. Just how the grub manages 

 to make these suspended cocoons is not known. Apparently it 



