THE PRACTICAL ENTOMOLOGIST. 



83 



tural History of this insect are the following: — 1st. 

 Why does it only occur at the bottom of a clover- 

 stack or a clover-mow? If, as Mr. Wray believed, 

 the eggs were laid in the green clover before it was 

 cured, it would be found generally distributed 

 throughout the whole mass of clover-hay. Besides, 

 an insect whose natural habit it is to feed on green 

 clover leaves- — as must be the case if the eggs, as 

 Mr. Wray believed, were laid on the green clover — 

 could scarcely live on dry clover-hay; or at 

 all events it would not flourish so exorbitantly 

 as this larva appears to have done, even if a few 

 specimens might bear the unnatural change in their 

 food. 2nd. Itseems impossible that the parent moth 

 can deposit her eggs in the clover hay after it is 

 stacked, whether in the barn or in tlie open air; 

 for in that case the worms would be found either 

 exclusively or generally on the outside part of the 

 stack or mow; whereas all accounts agree that they 

 occur exclusively in the lowermost layer of the 

 clover-hay, to which the mother moth could not 

 possibly gain access to lay her eggs there. 3rd. 

 It seems impossible that the clover-worm could 

 have attained its full larval growth while feeding 

 on the green clover, and have been afterwards 

 carted off among the hay; for on that hypothesis 

 they would occur evenly throughout the stack 

 or the mow, not exclusively at the bottom. And 

 besides, Mr. Randolph says, that "their excrement 

 was mixed all through the hay," which proves that 

 they must have fed very extensively on the hay 

 after it was finally put away. -tth. Is it not the 

 case that the clover-worm feeds exclusively on dry 

 clover-hay, and never on green clover leaves, and 

 that the parent moths deposit their eggs, at the 

 bottom of an empty mow in the barn, among what 

 little scatterings may be remaining from last year, 

 whence they ascend into the new crop when it is 

 put away into the barn ? It is true, that both Mr. 

 Wray, Mr. Randolph and Mr. llemingtou found 

 the clover-worms very abundant, not only in mows in 

 a barn, but in stacks in the open air. But it is 

 possible that these gentlemen may be, all of them, 

 in the habit of stacking their clover year after year 

 on the same spot of ground, and upon the same 

 foundation ; the eifect of which would be precisely 

 the same, as if they had stacked in a barn where 

 clover had been put away year after year. 5th. It 

 is evidently only under certain peculiar circum- 

 stances that clover-worms can breed, at all events 

 in such injurious numbers as to be noticed by the 

 farmer ; for the accounts of their occurrence are 

 few and far between. What those peculiar circum- 

 stances may be, remains for future investigation ; 

 but I incline to believe that the essential condition 

 is, that the infected clover-hay should be stacked 

 in a place where clover was stacked the preceeding 

 year. 



The above are thrown out merely as suggestions, 

 to be confirmed or disproved by future observation 

 and experiment. If my hypothesis prove correct, 

 the remedy to be employed against this Noxious 

 Insect is plain, simple and effective : — Never stack 

 clover /or two successive years on the same spot of 



ground; or if you are compelled hy circumstances 

 to do so, thorowjldy cleanse and sweep out the 

 foundation upon which you build, or the bottom of 

 the mow, if you stack in a barn, so as to destroy 

 the eijrjs from which the future clover-worms would 

 hatch out. 



Rock Islanb, III., May 28, 1866. 



CLICK-BEETLES. 



Messrs. Editors:— I notice Harris (Tnj. Ins. p. 

 45), and Prof. Tenney, (Nat. Hist., p. 427). have 

 stated that the Elateridx, or spring beetles, are en- 

 abled to spring from the ground by drawing out 

 the spine and forcibly striking it against the edge 

 of the sheath, thus springing from the ground by 

 the force of the concussion. 



Prof Jaeger (Life of N. Am. Ins. p. 50) says, 

 that the body being bent backward causes the spine 

 to fly out of the sheath like a watch-spring, throw- 

 ing the beetle into the air. 



As the result of numerous microscopic observa- 

 tions, I have come to the following conclusion : — 



The upper part of the sheath is prolonged to- 

 ward the thorax, so that the spine, when drawn 

 completely out, rests on its edge. Then, the in- 

 sect pi-essing with some force on the thorax, the 

 spine slips off" the edge and flies back into the 

 sheath. That portion of the back immediately 

 above the spine, of course, forcibly strikes the 

 ground, and the concussion throws the insect into 

 the air. 



There is hardly any elasticity to the spine, cer- 

 tainly not enough to throw the insect up in the man- 

 ner described by Jaeger. Besides, the spine plays 

 easily in and out of the sheath as any close observer 

 can see. Yours truly, W. 



M.iRLBORo' Mass., M.vv 28, 1S6G. 



Observations, by Benj. D. Walsh: — Your 

 statement is quite correct, and agrees entirely with 

 what Westwood says on the subject. {Introd. I, p. 

 235.) Prof Jaeger's book contains several errors, 

 and cannot be safely depended on, any more than 

 Emmons' New York Report. For instance, he 

 figures the common Limcnitis Disippus as Danais 

 archippus — two very distinct insects which even 

 belong to different Families, though their style of 

 coloration is remarkably similar. 



How to destroy Caterpillars on Fruit Trees. 



The following mode of destroying the insects in- 

 jurious to fruit trees, communicated to me by M. 

 Scheffer of Mbdling, is so simple and yet so effica- 

 cious, that I cannot do better than to lay it before 

 my readers : — 



M. Scheffer lays loosely rolled-up pieces of old 

 cloth or blotting-paper in the forks of his trees. 

 The caterpillars eat during the night, and while 

 the dew is on the leaves in the morning, but they 

 seek protection from the heat of the day, and creep 

 into these rolls for that purpose. Thus it is only 

 in the middle of the day that these rolls should be 

 examined, and the caterpillars concealed in them 

 destroyed. — Kiillar. 



