New York Agricultural Experiment Station. 403 



reared from cherry invariably had shaded areas along the outer 

 margins of the wings, while those from apple had for the most part 

 white primaries. 



Taking all characters into consideration, the prevailing white 

 anterior wings of the adults, habits of larvae, coloration of pupae, 

 texture and massing of cocoons in the web, the species we have 

 reared on apple seems unquestionably to be identical with the form 

 commonly known in Europe as malinellus. 



CROSS-FEEDING EXPERIMENTS. 



The contradictory results obtained by various writers in feeding 

 tests with padellus and malinellus l^y interchanging their host plants 

 led us to make some tests along similar lines. Three small sections 

 of wood, each containing a colony of padellus larvae, were, at about 

 the period for their migration from the egg masses, placed near 

 opening apple buds and slightly moistened each day to prevent 

 drying. None of the larvae emerged and all eventually died. Later 

 living larvae were taken from their hibernating quarters on cherry 

 and transferred to apple buds which were just showing the tips of 

 the first leaves. These apparently did no feeding, nor did they make 

 any efforts to burrow into the apple leaves. After struggling for 

 several days on the surfaces of the leaves and frequently precipi- 

 tating themselves to the ground, they finally succumbed. Their 

 efforts were feeble as if they had suffered from the handling and 

 confinement during storage of the nursery stock or the conditions 

 incidental to their removal or opening of their hibernating quarters 

 were abnormal and injurious to them. 



Tests with older caterpillars of 7nali7iellus were more satisfactory. 

 Twenty full-grown specimens of malinellus, reared on imported 

 apple seedlings, were placed in a cage containing twigs from Baldwin 

 apple and Montmorency cherry. Webs were at once spun over both 

 fruits but the insects fed only on the apple and apparently made 

 no effort to attack the cherry. This experiment was repeated with 

 a similar number of insects, but only a single twig of apple was 

 used which was placed in the center of a number of shoots of Mont- 

 morency cherry. The caterpillars quickly selected the apple twig 

 and after consuming the apple leaves they extended their webs 

 over the cherry foliage but in no case did they feed upon it. 



A third test was then made with thirty caterpillars which were 

 confined to a young Mahaleb cherry seedling. They were at first 

 very restless and seemed to exhibit an aversion for the foliage; 

 but later this was overcome and apparently under the stress of 

 hunger several were observed to eat the leaves with relish. Most 

 of the insects, however, fed very little. Twigs of an imported 

 apple seedling were then introduced into the cage which were attacked 

 in a ravenous manner. In spite of an abundance of apple foliage 

 a caterpillar was occasionally observed nibbling on cherry leaves. 



