1916 ENTOMOLOGICAL SOCIETY. 173 



banded species. The eggs of this last species, laid in the cages, began to hatch in 

 seven days after they were laid. The young larvae once they began to emerge 

 out of the mass did so in a very short period and were seen to be very active 

 from the moment of emergence. They were placed upon succulent shoots at the 

 base of a tree and caged in but for some unknown reason died before reaching 

 maturity. 



Natural Enemies. 



1. Spiders, ants, syrphid-fiy larvae and pentatomids each destroyed some larvie 

 but not a large number compared with the total. 



2. A number of instances were observed where very active Leaf-roller larva? 

 devoured their more sluggish brothers, the sluggishness being due either to disease 

 or preparations for moulting or pupation. 



3. Birds feed to some extent upon them, but there were very few birds in 

 the Johnson orchard. 



4. Disease almost all through the larval season destroyed a considoraV)le 

 number, especially towards the end of the season. Pupae, too, were evidently 

 diseased, for many were found that shrivelled up and turned black. Some of 

 these had been parasitized but many had not. The dead larva; were not killed 

 by spraying as they were found also on unsprayed trees. 



5. Tachinid parasites were present in moderate numbers. There were two 

 species of these: Masicera eufitchice, Townsend, and Exorista coesar, Aldrich, n. sp. 

 The latter were far the more numerous. (Dr. J. M. Aldrich kindly indentificd 

 the Tachinidae for me.) 



6. At least two and possibly three species of Ichneumons were common but 

 we have not yet been able to get them determined. 



Apparently not more than 5 per cent, of the larvce were destroyed by parasites. 

 They would probably have been much more abundant if the weather had been 

 warmer. The month of June was very cold and on cold days parasites scarcely 

 appeared at all. Disease evidently plaA'ed a greater part in control than parasites. 



For some reason more than half of the eggs of the first lirood moths of 

 rosaceana failed to hatch though the larvae could be seen very plainly inside, but, 

 as stated above, we found only four e^g masses of this species. 



Methods of Control. 



We, probably like everyone else who has examined the work of Torlrix 

 (Caco'ciu) argiirospila, found it hard to believe that a caterpillar that left the 

 leaves in such an eaten, ragged condition could not be satisfactorily combated with 

 arsenical sprays but our experience this year leads us to agree with Herrick, Childs 

 and several others that arsenical sprays are not satisfactory. They kill a consider- 

 able number but not nearly enough to prevent great loss. There are two reasons 

 for the failure of these poisons to be effective: — (1) "While the larva' are still small 

 and will die if they eat the poison, their habits of feeding prevent the great majority 

 of them from getting access to it. "* This is because as soon as they hatch they usually 

 seek an opening bud or leaf just beginning to unfold itself, and work into the 

 centre of these, feeding in the interior and therefore unpoisoned part, and retard- 

 ing for a considerable time the opening. On Spy trees, at least, unfolded leaves 

 suitable for the later hatching larva^ to hide in are present until the blossoms arc 



