420 [November 



food from sycamore to oak or vice versa ^ some one of the number would 

 have suffered the change of food without dying; as, out of the six oak- 

 feeding Antlphola in (^age No 5, one grew and flourished for 22 days 

 and finally spun up, though its food was changed to bass, and none of 

 the remaining five died in confinement. 



Cly'IUS (arhopalus) pictus Drury (pp. 296 — 7). I have here de- 

 monstrated, that the race that has the habit of preying upon the hickory 

 is distinct from the race that has the habit of preying upon the locust; 

 or, which amounts to the same thing, that a 9 p'V/«s bred in the hick- 

 ory does not oviposit in the locust. I have also shown that there is a 

 very remarkable difference in their habits, the locust-feeding race, as 

 is well known, coming out in September, and the hickory-feeding race, 

 according to Mr. Bland, in the spring (p. 297, note). Mr. Bland, in 

 reply to some recent enquiries on the subject, has been kind enough to 

 inform me. that '• the spring species can be found in abundance upon 

 the hickory the first warm days in May and June, and that it appears 

 to confine itself to this tree ; while the fall species appears upon the 

 locust, and can also be taken upon various plants that are in blossom, 

 in September." He adds that ■' he has made diligent enquiry among 

 the Philadelphia collectors in regard to the time of capture, and they 

 all assert that they lose sight of Arhopalus picfiis from the middle of 

 June until September." Up to the autumn of 1864 I was not aware 

 that any specific distinctions existed between the imagos of these two 

 races, but I have recently ascertained that there are some very remark- 

 able ones in the % , though neither Mr. Bland nor myself can discover 

 any in the 9 . I have now before me of the hickory-feeding race four 

 S % three $ 9 , one of these S S split by myself out of a stick of 

 hickory wood seven years ago, the other S S 9 9 obligingly commu- 

 nicated to me by Mr. Bland. I have also before me of the locust- 

 feeding race 15 S S 4 9 9, viz. 13 % % taken in coifu, that there 

 might be no possible doubt of their sex, on flowers in September, 2 S S 

 taken in September on the trunk of a locust, 899 taken on flowers 

 in September, and 1 9 received from Mr. Bland and labelled as be- 

 longing to the locust-feeding race. The following distinctions between 

 the S S of the two forms are perfectly constant according to the types, 

 except where otherwise stated. 



