268 



the desirability of a pi-eveiitive wash, I may state that iu some portions of the country 

 the apple-tree borers are prevented from entering the trunks of apple trees by painting- 

 the trunks -with soft soap reduced to the consistency of a thick paint by the addition 

 of a strong solution of washing soda. — [November 12, 1891.] 



Biological Notes on Micracis, Chramesus, and Coscinoptera. 



The remarks in Insect Life, vol. iv, p. 94, concerning Micracis suturalis and M, 

 acuJcata Lcc, require a little consideration. Whatever may have led Messrs. Eich- 

 hoff, Judeich, and Nitsche to express the opinion that the life duration of Scolytidae 

 is only one year (normally), certain it is that the foregoing species, as well as Chra- 

 mesus i'corice Lee, are bieimial, uninfluenced appreciably by indoor breeding, and 

 even triennial, when the wood in which they breed is kept two years. Narrative. — 

 A hickory tree was deadened early in 1888, was cut down about the middle of Aprils 

 1889, and a barrel of the limbs placed in the open air in the yard, covered on top 

 with canvas, protected by a cover of boards. A number of Chramesus icorue ap- 

 peared five or six weeks afterward, but no Micracis, as certainly would have been the 

 case had these species been annual alone, as in this case indoor breeding could 

 scarcely have been a retarding factor. Next season, 1890, from May 15 to July, great 

 numbers of C. icorio; and M. aculeaia emerged, with M. suturalis in less abundance. 

 The same barrel of wood this season, 1891, yielded quite a number of the former two 

 species and a few of the latter; had the tree remained standing, I conclude no 

 Micracis would have appeared the first year from the egg, and that all would have 

 emerged the second year, as the condition of the limbs the third year would certainly 

 have been adverse to so prolonged a development. There is a possibility that some 

 of the Scolytida? may be either annual or biennial, one of the determining factors 

 being the time ot oviposition, May or August. (For further observations, see Ca>K 

 Ent., vol. XXIII, p. 65.) 



The article of Mr. Cockerell's cited (ib., j). 148) has not been seen. The reason for 

 suggesting that the chrysomelide larviis sent by him foiind iu an ants' nest were most 

 probably Coscinoptera vittigera was that that species came abundantly from the same 

 region with the larvse. The article in the American Naturalist on the ants' nest 

 habit of C. dominicana had not been seen, nor the figures in the Sixth Missouri Report 

 and third volume of the American Entomologist consulted. Narrative. — Five larvte, 

 probably half grown, were received perhaps in April, Only two of the cases wete 

 unbroken. All were placed in a cage, with earth and dead old leaves ; all soon died 

 except one in a case, which fed for five or six weeks, doubling the size of its case, 

 finally closing it, not abruptly, but roundly. The larviB were of a dirty pale color, 

 with a yellow head dashed with brown, and had formidable mandibles. The case 

 externally was entirely smooth, without ribs or inequalities, the euds were nearly of 

 the same diameter and shape, that at the head being smaller; it seemed to be com- 

 posed of particles of ash-gray earth united by a secretion, and was not readily solu- 

 ble in cold Avater. This case did not much or at all resemble the figure of C. domi- 

 nicana given in the Sixth Missouri Report, but rather that of Chlamys plicata, without 

 its gibbosity. The larva died without pupating, with its head at the entrance. Tc^ 

 absolutely determine the species the imago must be bred. The larva of these sac- 

 bearing ChrysomelidjB are possibly carnivorous as well as feeders on old leaves, as 

 suggested by the experiments ofW. S. Barnard (American Ento7nologist, vol. iii, 227), 

 and from which it is proven that C. dominicana can breed without the intervention 

 of an ant's nest. An ant's nest, however, must prove very attractive to such larvae, 

 as there is found an abundance of good food, plenty of clay prepared from which 

 to construct their cases, and also good shelter from the disintegrating elfects of pro- 

 longed rains. — [John Hamilton, M. c, Pennsylvania, December 11, 1891. 



