232 



THE AMEEICAN ENTOMOLOGIST. 



had bred this beetle from a larva found in decay- 

 ing pine -wood, and which resembled in every 

 respect, so far as our description went, the one 

 sent b5^ Mr. Lummis. "We have lately bred to 

 the perfect state three of these Grape-root bor- 

 ing larvsB, and one which was found in an 

 Apple-root, and they all four of them prove to 

 belong to a differ- 



[Fig. 171.1 ° 



ent though a very 

 closely allied spe- 

 cies to the one we 

 suggested by in- 

 ference. The bee- 

 tle we have bred 

 from these larvas 

 is the Broad-neck- 

 ed Pi'ionus {Prio- 

 nits laticolUs, Dru- 

 ry), of which we 

 herewith present a 

 likeness(Fig. 171.) 

 It is usually of a 

 darker color than 



Color-Mahogany-broivn, verging ^he Cylindrical Or- 

 on black. ., , 



thosoma, and as 

 may be seen upon comparing the figures, it differs 

 materially from that species b}^ its larger size and 

 broader form. Our figure represents the female, 

 which differs from the male in having shorter 

 and narrower antennse, though her body is usu- 

 ally larger. 



Tliere is another species, the Tile-horned Pri- 

 onus {Prionus imbricornis, Linn.,) so called 

 from the joints of the male antenme lapping over 

 one another like the tiles or shingles of a roof — 

 which very closely resembles the Broad-necked 

 Prionus, and in Illinois is much commoner. It 

 may be distinguished at once from this last by 

 the antenme of the male being about 19-jointed, 

 and those of the female about IG-jointed;* 

 whereas both sexes of the Broad-necked Piio- 

 nus have 12-jointed antenna. In other respects, 

 these two beetles are almost exactly alike, so 

 that, if the antennas happen to be broken, it is 

 not very easy to tell one from another. So far 

 as we are aware, it is not known upon what 

 kind of tree the Tile-horned Prionus feeds; and 

 from the very great similarity of these two 

 beetles, their larvas will probably resemble each 

 other very closelj'. 



The Prionus family to which all these in- 



* Having fxamined nearly 20 males ol' this species, we 

 have found the antenual joints to vary in number from IH to 

 ■20, the same s|.)eeiraen often having a dilVerent number of 

 joints in the rigltt and left antenna. lu one ^ f'le anteima; 

 are both of them l(l-j.iintPil, in another g they are both of 

 them 17-jointed. The tj pical number of joints in the Cole- 

 opterous antenna is only 11; and the number being so vari- 

 able in these miany-jointed antennas is in accordance with 

 the general rule, that multiple parts ar*e often variable. 



sects belong is distinguished from the more ex- 

 tensive Cerambyx family of the Long-horned 

 beetles, by suudiy peculiarities, but principally 

 by the broad flat thorax and tlie large robust jaws, 

 and by the upper lip being nearly or quite obso- 

 lete. It has generall}^ been supposed that their 

 larvse were equally well characterized by having 

 the first segment of the body smaller than the sec- 

 ond, but although Rosel described and figured 

 the larva of an European species (P. coriarius) 

 with the first segment smaller than the second,* 

 Mon. E. Perris has figured the larva of another 

 European species (P. obscurus, Oliv.), which 

 has the first and not the second segment largest, f 

 while the two N. A. representatives of the 

 family which we have herewith figured likewise 

 have the first segment largest in the larva state. 

 Above at Figure 169 we have represented, of 

 the natural size, one of the immense Grape-root 

 boring larvffi of this Broad-necked Prionus, 

 and belowt will be found a technical descrip- 

 tion of it drawn up from several living speci- 

 mens. Though no account of this insect's injuries 

 to the Grape-vine had been published up to the 

 summer of 1868, we find that its work has been 

 known for several years amongst the practical 

 vineyai'dists of the Western , or to speak more cor- 

 rectly, of the Middle States, and Mr. George Hus- 

 manu, of Bluffton, Mo., has known it since 1850. 

 Last summer, while visiting certain orchards 

 and vineyards in companj' with the ad interim 

 committees of the Illinois and Missouri State 

 Horticultural Societies, we discovered it in the 



*See Westwood, Introd 

 ^A7males de la Soc. Ent 

 fLarva of Prionm laticollis, 

 len full grown, 3 inches. Col 

 rtlv translucent, with glaucous 



;i distinct dorsal line of the last coloi 

 Segment I rather horny, somewhat 1 

 jcther, broadening iiosleriorlv, s 

 n-hiter than the rest of the body 

 smteriorly, and a si 



I., p. 360. 



de France, )8n6, PI. (i, Fig 362. 



ase length 



-ish-white, 



h shadings, and 



Id bill 



: 13 distinct segments. 

 >nger than -J, 3, and 4 to- 

 lightly shagreened and 

 th a i-ust colored mark 

 g the middle . Segments 

 2 and 3 shortest and broadest, the body tafiering thence grad- 

 ually to extremity, though there is usually a lateral ridge on 

 segiiient 12 which dilates it rather moT'e "than the segments 

 immediately preceding it. This segment 12 is also the long- 

 est, the terminal one being quite small and divided into 

 three nearly equal lobes. A swelled huraij crossed with two 



[F.s 17"] 



impressed transverse lines, 

 segments 4, 5, 6, 7, 8, 9, and 10. 

 ■Stigmata rust-colored, 9 in num- 

 ber, the first and largest being 

 placed on a,fold in the sutiu-e be- 

 tween segments 1 and 2. Head 

 brown, verging to black on ante- 

 rior edge." "Mandibles large, 

 strong, black. Math one blunt 

 rounded tooth, giving them a 

 somewliat triangntar appearance; 

 antennae 3-join"ted and brown, 

 especially at tij); labrum fulvous, 

 fuzzy an'd with a brown base; 

 maxillary palpi 4-jointed, the 

 basal joint much swollen, the 

 terminal joiut brown, and a ring of the same color atsntitres 

 of the other joints; labial paljji 3-jointed, the basal joint 

 also swollen, and the terminal joint and sutures of the others 

 brown. Six rudimentary 2-jointed fuscous feet as shown at 

 Fii^ure 172. Venter tubercled as on the back, these tubercles 

 being especially prominent on segments 6, 7, 8 and 9, where 

 they recall prolegs. The yoimg larva differs only in laclgng 

 the rust-colored mark on segment 1. 



