32 



THE AMERICAN ENTOMOLOGIST. 



that has the least appearance of being a larval 

 Bark-louse. Positively there is no such thing 

 to be found on them; and I am perfectly satis- 

 fled, so far as any one can be satisfied of a nega- 

 tive fact, that in this entire orchard there does 

 not exist a single living Oyster-shell Bark-louse. 

 Subsequently, at Mr. Menzo Dunlap's, near 

 Champaign, I carefully examined four apple- 

 trees, which had been received eleven years ago 

 from a nursery in Uook Co., North Illinois, and 

 three of which were pretty thickly covered with 

 the scales of the Oyster-shell Bark-louse, the 

 other one not so thickly. After an hour's 

 search, I failed to find a single larval Bark-louse 

 upon any of these four trees. On some of the 

 adjoining trees there were a few scales to be 

 found, but no larvae. Mr. Dunlap told me that 

 all these four trees looked quite yellow in 1867, 

 while this year their foliage was of a healthy, 

 dark-green color. It was quite evident, too, 

 upon inspection, that the growth made in 1868 

 was already twice as long as that made in 1867. 

 Hence I conclude that this whole generation of 

 Bark-lice imported from the North had, in this 

 Southern region, died out and wasted away to 

 nothing. I have elsewhere shown that, upon 

 the authority of the Cobden fruit-growers, 

 this Bark-louse can not live in South Illinois 

 when introduced there from more northerly 

 regions. Hence we may lay it down as a gen- 

 eral law, that IN THE SOUTHEKN HALF OF ILLI- 

 NOIS THE OtSTER-SHELL BaEK-LO0SE CAN NOT 



PERMANENTLY EXIST. The practical importance 

 of this law to the fruit-growers of Illinois can 

 • scarcely be over-estimated. 



Cobden alias South Pass— The "Masonic Bug"— 

 Freaks of the Curcnlio— A Defect in its Instinct 

 —The Melancholy Chafer attacks Pears— Prnit 

 spoiled by Honey Bees. 



June 26th. 



I reach Cobden alias South Pass (the first is 

 the railroad name for this headquarters of the 

 fruitgrowers, the second is the Post-offlce name) 

 in the small hours of the morning, but in time 

 to get a good night's rest at the hotel. In the 

 course of the forenoon my headquarters are 

 agreeably established at the hospitable mansion 

 of Parker Earle, the President of the South Illi- 

 nois Fruit Growers' Association. On going out 

 with my net collecting, I capture sundry rari- 

 ties in the insect line, and especially six speci- 

 mens of a be'autiful little Chafer (Trichius delta, 

 Forster) , with a distinct white triangle on its tho- 

 rax, which, so far as I am aware, has never hith- 

 erto been met with further north than Louisiana. 

 In allusion to the triangle on its thorax, I have 



christened it " The Masonic Bug." It occurred 

 on the flowers of the New Jersey Tea-plant or 

 Ked-root (Ceanothus Americanus) . Certainly 

 this region of country is the Bug-hunters' para- 

 dise, as Macoupin county is the Bug-hunters' 

 pandemonium. 



Mr. Earle informs me that in 1868 he had 

 pears and peaches growing side by side, and 

 that the pears were stung by the curculio as 

 badly as the peaches. Now, Dr. Hull of Al- 

 ton has found that, by intermixing plums 

 and peaches in alternate rows, the peaches are 

 thereby protected from the attacks of the curcu- 

 lio. Hence it would seem to follow that, al- 

 though the curculio prefers the plum to the 

 peach, yet it does not prefer the peach to the 

 pear. This, if correct, is a clear case of defect- 

 ive instinct in the little world of bugs, showing 

 that the mother curculio can not tell the differ- 

 ence between one fruit — the peach — in which 

 her future larva will thrive, and another fruit — 

 the pear — ^in which her future larva is almost 

 certain to die in infancy. For, although the 

 curculio larva thrives about as well in early 

 peaches as in plums, yet it has never yet been 

 proved to reach maturity in the pear ; eggs de- 

 posited in that fruit either failing to hatch out, 

 or the larva that hatches out from them perish- 

 ing prematurely. All the pear growers, how- 

 ever, tell me that the spot in the pear where the 

 curculio has deposited its eggs, even when the 

 egg does not hatch out at all, forms a hard 

 woody depression in the fruit, in which all fur- 

 ther vegetable growth ceases. Consequently, 

 although the stung pear does not faU from the 

 tree, it becomes gnarled, deformed, and un- 

 saleable. 

 Mr. Earle has detected the Melancholy Chafer 

 [Fig. 230 (Euryomia melancholica, G. and 

 P., Fig. 23) — a rather rare beetle, 

 which however occurs both in North 

 and South Illinois — eating into the 

 blossom end of his pears, and caus- 

 ing a clammy exudation therefrom. 

 "We find quite a number of pears upon 

 bro^iMd^hltiithis trees, that have been operated 

 upon in this manner ; and as he has deposited 

 a specimen caught in the very act in friend 

 Holcomb's collection, the species can be identi- 

 fledwith certainty. If all farmers, gardeners, 

 and fruit growers would adopt the same wise 

 plan — ^i. e., preserve and label insects whose 

 habits they have personally observed— what a 

 valuable mass of materials for delineating the 

 history and habits of our noxious insects might 

 soon be gathered together I This Chafer, how- 

 ever, so far as can be seen at present, does not 



