74 



FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



base 18 a short, broad, sharp-pointed spine, from the tip of which, forward, the sides 

 are straight. The long, thread-like autennie are dull yellow, with a slight duskiness 

 at the end of each joint. The legs are blackish, with the bases of the thighs, and 

 frequently of the shanks also, pale dull yellow, the hind thighs being less thickened 

 towards their tips than the four forward ones. (Fitch.) 



13. The thunderbolt beetle. 



Arhopalus fulminans (Fabr.). 



Order Coleoptera; Family Cerambycid^. 



Excavating a burrow in the soft sap-wood, about three inches long and 0.20 inch 

 in diameter, a worm like the apple-tree borer, which changes to a long-horned beetle. 



This beetle is said by Fitch to iufest the oak, excavating a burrow in 

 the soft sap-wood about three inches long and 0.20 inch in diameter, 

 this burrow having the shape of a much bent bow or a letter U. It 

 changes to a pupa in the same cell, the beetle appearing in July. We 

 have also found that it bores in the chestnut, and for a description and 

 figure of the beetle would refer the reader to the account of insects in- 

 festing the chestnut. 



14. The white-oak phymatodes. 



Phymatodea variabilis (IjIVU.). 



Order Coleoptera ; Family Cerambycid^. 



Boring the trunk and branches of the white oak, a narrow longicorn larva, chang- 

 ing to g reddish-yellow thick-bodied longicorn beetle, more or less marked with blue. 



Several specimens of this beetle were taken by Mr. Alfred Poor from 

 a white-oak stick, June 20. It was collected on a pile of oak cord wood, 

 May 30, by Mr. Calder; and I have a specimen of it from Salt Lake 

 City, Utah, identified by Dr. Horn. It is undoubtedly closely similar 

 in its habits and in the form of the larva to the grape Phymatodes fig- 

 ured in our first report on the injurious insects of Massachusetts, and is 



one of our more common species of the genus. 



Beetle. — It is closely allied to P. amcenus, but is larger 

 and less coarsely punctured, while the antennae are 

 more reddish; the scutellum is concolorous with the 

 wing-covers. The body, legs (except the femora, which 

 are blackish in the middle), and anteunfe are reddish, 

 the tips of the joints of the latter dark, and on the 

 back of the prothorax are two black spots, often con- 

 fluent. The head is black. The wing-covers are Prus- 

 sian blue, smooth, finely punctured, with rather thick, 

 fine, black hairs, bent down wards. Specimens recently 

 changed from the pupa state are brown, and the species 

 is exposed to considerable variation, as its name indi- 

 cates. The male is just half an inch long, the female 

 .60 inch. 



The foregoing description is taken from our second report on the in- 

 jurious insects of Massachusetts. The pupa of this beetle was also 



Fig. 23.— Phymatodes variabilis. - 

 Smith, del. 



