142 r.Tiins. 



Pr()l):il)ly very fcAV persons have anv idea what the 

 state of thiuirs woukl be if the birds were all destroyed, 

 t)ther thiiiiifs reinaininir as they now are. It ean not be 

 unpi'otitablc for ns to (h'vote a few words to this pai't of 

 our sidijeet. There are in the State of A'erniont jjroba- 

 bly not less than eiiihl hnn<h'ed species of Lepido])terous 

 insects(i. e. the moths and bntl(>rt1ies, ) and in the whole 

 United States there ai'e not less, probably, than fonr 

 thonsand. lint leavinu" the rest of the states let ns con- 

 tine onrselves to onr own. and see what resnlts wc can 

 obtain. If w(^ suppose the nnniber of speeics in this 

 state to be ei^jit hnndre(l the inerease will be soniethinu" 

 like this : each female lays on the averauc three hnndred 

 and tifty e^iis bnt we will ])laec the mmiltei- at three hnn- 

 dred. now sn})j»ose that in this year 1^71, there exist 

 only one i)air of eaeh species, there wonid be dni"in<j; the 

 year 240. OOO co^s ]»rodneed which wonld dev(dop into 

 240, ()()() caterpillars. If half of these were females, nc'xt 

 yi'ar we slionid Iuinc 120,000 })airs of insects which 

 wonld prodnee 8(i,000,0()0 of caterpillars for 1<S7/}, and 

 so on, so that in tive years there wonld come from the 

 uneheeked inerease of only one ])air of each species 121'), 

 000,000,000,000 of caterpillars or two hnndred millions for 

 every simple acic in the state. It is true that as the ar- 

 ranirement of things noM- is not one in a hnndred, if in- 

 deed one in thonsands of these eafofs ever reaehes matn- 

 rit\' bnt the ^retit usfents of destruetion are the birds. 

 The varions species of ichnenman Hies and other parasites 

 destroy irreat nnmbers however. INIakini:" all i)ossible 

 deductions on account of all the destructive iuHuences ex- 

 cept the birds, we have left a very large figure, and if 

 this is multiplied by the number of pairs actually liA'iug on 

 and, as all know, of some kinds there are thousands, the 

 product is something appalling. But astonishing as this 

 view of the case is it is l)y no means complete. 



The Lepidoptera constitute only a small part of the in- 

 .sect world. It is indeed that which prol)ably contains 



