558 MAJOR E. E. AUSTEN ON THE 



note that in life, accoi^ding to the same author, the " finger-shaped 

 bodies" (see text-fig. 1 and explanatory text) are bright green. 

 The dorsal surface of the pi^othoracic segment, though far less 

 heavily armoured than that of the 8th post-thoracic segment, 

 nevertheless, strengthened as it is in the manner already referred 

 to, is quite hard, and may well serve to protect the tunnelling 

 larva against possible injury from sharp splintei'S of wood. 



An intei-esting point with reference to the living larva of 

 > Pantophthalmus 2nctus is noted by Piebrig, who writes that, 

 " when in the tiee-trunk it produces rasping sounds, distinctly 

 audible up to a distance of some four paces." 



The pupal envelope, according to the some observer, is vertically 

 truncated at each end, " the anterior extremity being formed by _ 

 a stout, richly sculptured plate of chitin," which serves to protect 

 the pupa from a frontal attack. Although this armoured shield 

 is not broken through by the imago in emei'ging, it may be that 

 the facial "beak," that is so conspicuous a feature in many Pant- 

 ophthalmidje though not exhibited by all species, or always 

 developed in both sexes, when present assists the fly in making 

 its escape from the pupal envelope. The latter, we are told by 

 Fiebrig, " after the emergence of the imago, projects about half- 

 Avay out of the larval txinnel " ; but the same authority is unable 

 to state whether the pupa makes its way to this point by its own 

 efforts, or whether the pupal envelope is dragged along with it 

 by the escaping fly. 



" Metamorphosis," writes Fiebrig, " appears to be very pro- 

 tracted. A larva .35 mm. in length, and apparently nearly full- 

 grown, was kept under observation from July 31, 1905, onwards. 

 The imago emerged in the afternoon of January 11, 1906, a few 

 weeks before which date it was found that the insect was still in 

 the larval state ; this would point to a pupal stage of very short 

 duration." 



Whether larvas of Pantophthalmidte are of economic importance, 

 as destroyers of timber of commercial value, is an interesting 

 point which awaits determination. So far as can be ascertained, 

 the wood of Erythrina [E. corallodendrum L. ?), in which the 

 larv£e of Pantophthalmios tabaninus Thunb. were found by Mr. 

 F. W. Urich, in Trinidad, is of little or no utilit3^ But the 

 possibility of commercial value is at any rate not excluded in the 

 case of the unknown Paraguayan tree referred to by Fiebrig, as 

 to which we are told that the wood is exceedingly hard and 

 exti'emoly rich in sap, " yielding an abundance of evil-smelling 

 fluid on being injured." 



(g) Pseiulo- Parasites. 



Pseud o-paiasites in the shape of Gamasid mites are of extra- 

 ordinarily common occurrence on Pantophthalmidte, and many 

 instances of such infestation are recorded in the following pages. 

 The mites, on being submitted by the author to his colleague 

 Mr. A. S. Hirst, F.Z.S,, for identification, were found by him in 



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