108 



SIXTH ANNUAL REPORT 



iiS^33W 



^GERIA ACERNI 



and lateral view 



eration deserves notice. It may be called 

 the Legged Maple Borer, because the pos- 

 session of sixteen legs at once distinguishes 

 it from the Flat-headed Borer. It is, indeed, 

 in structure similar to, and belongs to the 

 same family as, the common Peach-tree 

 Borer (Rep. 1, Fig. 17), and the more com- 

 mon Currant-stem Borer (^K tipuliformis^ 

 Linn). 



The worm (Fig. 29, a) burrows under the 

 bark of our soft maples, feeding on the in- 

 ner bark and sap-wood and never penetrat- 

 ing deeply into the more solid heart-wood. 

 It is so numerous at times that it completely 

 girdles, and thus kills outright, trees of con- 

 siderable size ; while smaller trees are 

 rs' fe's'T^cocoom Weakened, and rendered liable to be broken 

 3f^?^hrSis1]lhf afu^ isby wind, even where the worms are less nu- 



(itteu left remaining in the hole of 



exit. merous. 



The burrowings of the worm are filled with its dark brown pellets 

 of excrement, and cause the bark to crack open and loosen. The 

 cocoon (Fig. 29, h) is loosely formed of white silk, and covered with 

 the same brown excrement, and when about to give forth the moth, 

 the chrysalis works its way partly out of the bark (Fig. 29, d) through 

 a passage which, as larva, it had providently prepared, having left but 

 the thin epidermis, which the chrysalis easily pushes through. The 

 moth (Fig. 29, c) is a very pretty species, particularly distinguished 

 by the large anal tuft of bright orage-red hairs. It was first described 

 in 1860, by Dr. B. Clemens, under the name of Trochilium acerni^^' 



* Proc. Ac. N.at. Sc. Phil. ; 1800, p. 14. 



This insect is catalogued in Grotc and Bobinson's " List of the Lepidoptera of N. A.," by the 

 name of JEyeria acerni Walkor; and as tlie natural inference is that Walker was the original describer, 

 the reader may as well be reminded that the " List" refeiTed to is gotten np on the plan of attaching 

 as anthority the author who places a species in the last- accepted genus, and not the first describer of the 

 species — a plan which I deprecated in my 4th Report (p. 55, note). I am glad that Mr. Crotch in his 

 recent " List of the Coleoptera of N. A. , " has thrown liis influence against this imjnst and misleading 

 custom. . Authors do not seem to have come to any satisfactory unanimity as to wh;it are the distinguish- 

 ing features between Mgeria Fabr. and Troe/w/ii«7» Scopoli; and how slight and trivial the difl'erences 

 are, may be jndged by the following diagnoses, given by Harris in 183!) (Sillimnn's jUn. Journ. of Sc. , 

 XXX VI,, p. 288). 



Thochilidm. — Wings narrow, entire, all of them, or the hind pair at least, h-ausparent. Antennte 

 short, stout, arcuated, gradually thickened nearly to the end, whicli is curved but not hooked; under- 

 side generally tringed with a double row of very short bristles in the males. Tongue very short. Body 

 thick ; abdomen slightly tufted at the end. 



^Egkria. — Wings narrow, entire, all of them, or the hind pair at least, transparent. Antennas 

 mostly elongated, sometimes short, iirciuited, grachi.ally thickened nearly to the end, which is curved 

 but not hooked; underside geiierally I'riiigcd \\ itii a <linililc row of short bristles in the males. Tongue 

 long. Body slender; aljdonieii nciirly or (pute cylindrical, ending with a flat or trilobed tuft. 



The present species woultl come mider JSgevia, according to these definitions, but Clemens re- 

 garded the ^geria, as employed by Han-is, as .synonymous with Trochilium, and so placed the insect 



