344 Miscellaneous. 



Nyctemeridae. 



37. Nyctemera hiformis $ . 



Nichthemera (sic) biformis, Mabille, Bull. Soc. Zool. France, vol. iii. 

 p. 88 (1878). 



38. Hylemera fragilis. 



Hylemera fragilis, Butler, Ann. & Mag. Nat. Hist. ser. 5, vol. iv. 

 p. 230. n. 24 (1879). 



Previously received from Antananarivo. 

 [To be continued.] 



MISCELLANEOUS. 



On ilie Resistance of Aphides to Severe Cold. 

 By M. J. Lichtensteiu. 



The author remarks that he has endeavoured to show that, just as 

 a plant can reproduce itself by seeds and by buds, the \me-Phyl- 

 loxera (P. vastatrix) is also able to reproduce both by fecundated 

 eggs and by subterranean budding colonies — the duration of which 

 latter may be as indefinite as that of the plant, given the necessary 

 nourishment and warmth. This last condition seems indispensable 

 for the agamic reproduction, but not for the existence of the insect. 

 During December last, when temperatures of —11° or — 12° C. 

 (= + 12° # 2 or 10 c -4 F.) prevailed, the author found not only that the 

 underground Phylloxera did not suffer at all, but that he could 

 collect upon trees and plants in his garden numerous Aphides (he 

 mentions Aphis persica?, euonymi, hederaz, brassicce, and capsellce, 

 and Rhopalosiphon berberidis), all stupefied by the great cold and 

 often covered with snow or hoar-frost, but perfectly alive. The 

 Aphides were all in the budding phase ; but close by them, upon 

 the same plants, there were eggs laid in the autumn by the fecun- 

 dated females, which had long before disappeared. 



The Aphides were carried into a room at a temperature of 8°-10° 

 C. (=46 o, 4-50° F.), and the twigs to which they adhered planted 

 in damp sand. In two or three days they all began to breed, 

 bringing forth living young. Suspended by the cold, the faculty of 

 gemmation was by no means extinct. 



As there are perennial and annual plants, so among the Aphides 

 there are species which die out every year, except the eggs, and 

 others with indefinite reproduction by gemmation. All the above 

 species are perennial ; and it is curious that while warmth imme- 

 diately causes the false females, or budding pseudogynes, to recom- 

 mence their gemmation, the true egg does not hatch, and seems to 

 await the shooting of the plants upon which it is fixed. 



M. Lichtenstein believes that the annual species are much more 

 numerous than those of unlimited duration. Thus the Phylloxera? 

 of the oak (P. quercus, coccinea, and corticalis), the Aphides of the 



