164 INSECT EAVAGES. 



DESTRrCTION OF TINE FOKESTS. 



The bulletin of the Superior Conucil of Agriculture of Belgium for 1S75 

 (published iu 1S77) notices the deplorable condition to which large tracfs 

 of evergreen forest, planted on poor lauds of the north, had been reduced 

 through the ravages of an insect eating the leaves and thus destroying 

 the trees, and gives a careful description of its habits and of the reme- 

 dies that had been tried to ])revont further injuries. This insect was a 

 fly {Lophyrus pini) that produces two generations in a year, and the 

 damage is done by its larvie. The cocoon spends the winter among 

 the mosses and litter near the foot of the trees, and api)ears as a perfect 

 insect in the first warm days of A])ril, or perhaps as early as March. The 

 iBsects pair, and the female, which is rather sluggish iu its Hight, does 

 not go far, but circles around the branches, and deposits her eggs, ten 

 to twenty in a leaf, and usually several leaves in a group are thus at- 

 tacked. The young larva? begin to cat the parenchyma of the leaves, 

 leaving the more solid portions, and, by their multitudes, stripping the 

 trees of their verdure. They retire about the first of July into their 

 cocoons, and in a few days a second generation appears, which renews 

 its ravages in August and September. 



The means atteapted for their destruction are as follows : 



1. Surrounding a woodland infected by these insects with a ditch, partJy to isolate 

 tLem and partly for the capture of the worm^, but the latter is of little account, be- 

 cause they generally spend their lives in the same place, unless in vast numbers, when 

 they are forced to emigrate by passing from one mass of timber to another. The ditch 

 may be twelve or fifteen inches wide and of the same depth. A pit should be dug 

 deeper than this every six or seven meters, for burying the worms as they accumulate 

 in the ditch. 



2. In yoang plantations, the worms may be shaken off by striking the trees and 

 catching in cloths stretched under them. A man to shake the trees, and two lads to 

 spread the cloths can b?fore nine o'clock, go through more than half an acre, where 

 the trees are fifteen to twenty years old. If the weather ia not fair, they can work all 

 d 'y, and even in fair \ia;ather many are thus caught. Some have proposed to scatter 

 ora-aches under the trees, npou which the worms would crawl, and then they might he 

 gathered and destroyed, but the cloths are much better and cost less time. Others take 

 the worms directly from the trees, at an early stage of their growth, and while in 

 masses, in June or September, by breakiu? off the branches or shaking oft' the worms 

 into a basket. Some use scissors for cutting off the infected branches, and one man by 

 this means had in one seasan destroyed over nine millions of worms. It is estimated 

 that a man can kill from fifteen thousand to fifty thousand a day, counting the average 

 number in the families at fifty each. 



3. Gatharing the cocoons in winter, as they are hid in the mosses and litter, by re- 

 moving these materials; bii-t this is deemed injurious to the soil, althou^jh they may be 

 used as fertilizers in fields. In doing this, however, we destroy the eggs of niany in- 

 sects even more injurious than the Lophyrm. 



4. In old forests, that have come to maturity, the foot of tho trees may be banked 

 with dry sand, by which the larva) are hindered from coming out. A little may be 

 dt'uo by turning in cattle that trample the ground and destroy the cocoons^ but this is 

 of not much account. Swine, so useful in killing smooth-bodied worms, do not htwe 

 an effect in this case, as they will not eat them. 



.5. Natural enemies. These worms are very sensitive to atmospheric changes, such as 

 cold, wind, and rain, especially at the time of molting, when many perish. The«v 

 are sought with avidity by birds and mic^, and equirrel-t kill many in winter. Several 

 of the culeoptera attack tliem, and they, besides, nourish a great number of ichueumou 

 paasites. 



A general decay of the pine woods of South Carolina began in 1802, 

 and the fact became a subject of careful inquiry among the naturalists 

 and observers of that day. Mr. J. Mease, in a letter to Judge Peters, 

 of Philadelphia,^ attributes this deca^y to an insect, which was first ob- 



' Very considerable injury has l)een done by these insects to the pines of Sonth Caro- 

 lina. In one place, viz, on the Sampit Creek, near Georgetown, in a tract of 2,000 

 acres of pine laud, it has been calculated that 90 trees in every 100 have be«n destroyed 

 by this pernicious insect. The adjoining lands, and many tracts on the Santee and 

 Elack Rivers, have equally suffered. — Memoirs of ihe Fliiladelphia Socitly for Promotion 

 cf AyricuUure, 1815, i, 41. 



