The Quince Curculio. 387 



are the eggs. The only chance to reach any of the grubs while in the 

 fruit is to gather up and destroy at once the comparatively small 

 proportion of the infested fruits which fall to the ground before the 

 grubs leave them. It is often very difficult to determine, without 

 mutilating it, if a quince is infested while it still remains on the tree, 

 so that the picking off and destroying infested fruit is not practicable. 

 After the grub leaves the fruit, making its familiar ''worm-hole " exit, 

 infested fruit is easily distinguished, but then *'the bird has flown." 



Cultivation of the soil. — The fact that the grubs leave the fruits, 

 enter the ground a short distance, and there remain for many months, 

 has led several writers to recommend that a thorough cultivation of 

 the soil, either in the fall or spring, would disturb and destroy many 

 of the grubs. Theoretically, this should prove an effective remedial 

 measure. But the experience of some of our largest and most success- 

 ful quince growers who have cultivated their orchards thoroughly, 

 both in the fall and spring, for several years, proves quite conclusively 

 that cultivation has but little, if any, effect in reducing the numbers of 

 the curculio. 



We were unable to understand the reason for this until we saw the 

 grubs do a very simple thing in our breeding cages here at the 

 insectary in April, 1897. Mr. R. A. Barnes, of Lockport, N. Y., had 

 kindly sent us a lot of soil, from his quince orchard, in which there 

 were many of the grubs undisturbed in their earthen cells, made the 

 fall before. \Ve broke into these winter cells or homes and removed 

 the apparently inactive or dormant grubs, and placed them on the 

 surface of some other soil in our cages, intending to cover them with 

 soil later. What was our surprise a few minutes later to discover that 

 t!ie grubs had waked up from their winter's nap and had disappeared. 

 Investigation later showed that they had burrowed into the soil and 

 formed another earthen cell, just as they had done the previous fall. 

 If ence our thorough breaking up of the soil, resulting in their being 

 subjected to practically similar, or even more adverse conditions than 

 would result frc^m cultivation, had not even discouraged the grubs. 

 We disturbed, in a similar manner, some of the grubs several times, 

 and always with the same result, that they quickly burrowed into the 

 soil again. We believe, therefore, that the non-success of cultivation 

 either in the fall or spring, as demonstrated in practice in several 

 badly infested orchards, is due principally to the fact that the grubs 



