236 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



THE FKUSTEATIKG EETIjS^IA. 



{Betinia frustrana Scudder MSS.) 

 Order Lepidopteea ; family Tortkicidae. 



Infesting tlie new growtli of Pinus inops and P. rigida (and perhaps of other species), 

 spinning a delicate web around the terminal bud, and miDing both the twig and the 

 bases of the leaves ; one or several small yellowish larvae, which trauslbrm within 

 grayish cocoons, either in their burrows or fastened to tbe twigs, and become small 

 copper-colored moths, with wing expanse of I'J'""' (.47 inch). (Plate V, fig. 2.) 



About tlie middle of May, 1879, tlie scrub-pines {Pinus inops) in Vir- 

 ginia, near Washington, were found to be greatly injured by small lepi- 

 dopterous larvae. On many trees there was scarcely a new shoot to be 

 found which was not infested at its tip by from one to four yellowish 

 black-headed caterpillars. They were so completely concealed while at 

 work that their presence would scarcely be noticed, and the efiect of 

 their work was h.ardly visible until the twig was almost completely de- 

 .stroyed. Upon close examination a delicate web was seen inclosing the 

 base of the bnd and the surrounding new leaflets, resembling much the 

 nest of a sm all spider. VVlien this web was removed, one or several little 

 yellow caterpillars were seen either retreating into a mine in the bud 

 or into the bases of the leaves, which were also mined, or, not infre- 

 quently, they dropped from the twig, suspending themselves by a silken 

 thread. The bud was often so hollowed that it dropped to pieces almost 

 at a touch. 



At the time when they were first noticed larvae of almost all sizes 

 were to be found. iSome were apparently almost full-grown, while others 

 hadevidently not been long hatched. The nearly JiiU-grown specimens 

 measured 8"""' (.31 inch) in length. The first pupae were obtained 

 early in June. Most of tiie larvae transformed within the burrows which 

 they had made, first spinning more or less of a silken envelope about 

 themselves. Others, however, issued from their mines, and sj)uu rather 

 tough grayish cocoons botweeu the leaves. The pupae were short, stout, 

 and brown in color, with each segment furnished dorsally with two ser- 

 rated lines, one consisting of large and the other of fine teeth. 



The first moths issued June 13, the pupae having previously worked 

 their way, by means of the spines just mentioned, into such positions 

 that they could give forth the moths without injur.)' to the latter, and a 

 few weeks later almost ^very shoot had one or more of the empty pux)a 

 skins protruding from it. Si)ecimens of the moths vrere sent to Professor 

 Fernald, who determined them as identical with Mr. Scudder's manuscript 

 species Retinia frustrana. In August Mr. Scudder gave a short account 

 of this insect before the entomological section of the American Associa- 

 tion for the Advancement of Science, at Saratoga. He had found it in 

 such numbers upon the island of Nantucket in the young trees of Pinus 

 rigida, planted there some years ago to repair the damage done by burn- 

 ing during the war of 18113, as to seriously threaten the success of the 

 experiment. Mr. Scudder intends publishing an account of the work- 

 ings of the insect in that locality very shortly. 



In the latter ]iart of July specimens of the twigs of Pinus rigida were 

 received from Mr. S. H. Gage, of Ithaca, which had evidently been in- 

 fested by the same insect, although no living inhabitants were to be found. 

 In September other specimens were received from the same gentleman, 

 and this time two pupae and one larva were found. According to Mr. 

 Gage, the insect is not very common in that locality. 



