964 NEW YORK STATE MUSEUM 



two held together by threads. Jarring of infested limbs will cause them 

 to drop by a thread in much the same manner as do canker worms. 

 Not infrequently a leaf is fastened to an apple, and the caterpillar works 

 into the fruit under its protection. The character of the injury to the 

 foliage and of the irregular holes eaten in the fruit is well shown in pi. 2 > 

 fig. 5. The insect pupates normally on the leaves, preferably in the 

 shelter of a folded one, though the pupa may frequently be found with 

 no protection. It is prevented from falling by a few threads spun on the 

 leaf in which its spiny tip is fastened. The moths appear about 10 to 12 

 days later and undoubtedly hibernate, since Prof. Slingerland has kept 

 them alive nearly to Nov. 1. If such be the case, the eggs must be laid 

 in the spring, possibly on the unfolding leaves. 



This insect may be found on fruit trees, preferably apple, and is also 

 credited with being injurious to a number of forest trees. The larva of 

 the form described as Y. quercipominella fed on the oak apple, 

 the gall ofCynips spongifica. 



Natural enemies. Little is known about these beyond the record 

 by Dr Fitch, which states that numbers of these caterpillars are destroyed 

 yearly by a small grub or maggot, which lives within the larva till full- 

 grown, when it leaves its victim through a hole perforated in the side and 

 spins a small, white, oval cocoon, which is commonly slightly attached 

 to the surface of the leaf. Dr Harris observed that about 50% of the 

 caterpillars were killed by this beneficial hymenopteron. It was possibly 

 the same insect which was reared in small numbers from the specimens 

 received from Albion. An example of this parasite was sent to Washing- 

 ton (D. C), where it was determined by Mr Ashmead as Dioctes 

 [Limneria] salicicola Ashm., a species he described in 1890 

 from a single specimen reared from a Gelechia larva in a willow gall 

 taken in March 1872 at London (Ont.). Tfhis species is also known from 

 Texas. The parasite is a minute black, four-winged fly with bright yel- 

 low at the base of the antennae, on the under side of the fore part of the 

 abdomen, and rufous legs, which are yellowish at the base. It is about 

 4 mm long and its grayish white, almost cylindric cocoon is nearly 5 mm 

 long and 2 mm in diameter (see pi. 2, fig. 7 and 8). Prof. Slingerland 

 reared Ap an teles perplexus Ashm. M.S., which he thinks may 

 be the form alluded to in 1853 by Dr Fitch, whose description, so far as 

 it goes, applies equally well to both parasites. 



Apparently quite resistant to arsenical poisons. The seri- 

 ously injured orchard mentioned by Mr Rose was sprayed with paris 

 green when the apples were as big as peas and again a week before the 



