132 ENTOMOLOGICAL NEWS. fMch., 'l2 



seasons. On the other hand, Anthocharis helia, of the desert fauna, has 

 but one generation, flies in the spring, and often the chrysaHd trans- 

 forms into a butterfly only at the end of two years of hibernation. 

 By hibernation is to be understood in Egypt not that state of torpor 

 produced by cold, but the phase of inactivity which can appear at any 

 season, in summer as well as in winter, summer offering, in the desert, 

 the same conditions of aridity as winter in cold countries. This 

 phase of torpor can appear in the different states of the life-cycle 

 of Lepidoptera, as the egg, the caterpillar (Agrotis nili, A. ypsilon), 

 the chrysalid (Prodenia littoralis, Anthocharis helia), or the imago 

 (Prodenia littoralis). The duration of each generation is subordi- 

 nated to the more or less favorable conditions for its development 

 which the insect meets at different seasons of the year. — (A. Andres, 

 Bull. Soc. Entom. d'Egypte, 1910, pp. 89-96, 191 1.) 



Entomological Iviteratuire. 



COMPILED BY E. T. CRESSON. JR., AND J. A. G. REHN. 



Under the above head it is intended to note papers received at the 

 Academy of Natural Sciences, of Philadelphia, pertaining to the En- 

 tomology of the Americas (North and South), excluding Arachnida and 

 Myriapoda. Articles irrelevant to American entomology will not be noted; 

 but contributions to anatomy, physiology and embryology of insects, how- 

 ever, whether relating to American or exotic species, will be recorded. 

 The numbers in Heavy- Faced Type refer to the journals, as numbered 

 in the following list, in which the papers are published, and are all 

 dated the current year unless otherwise noted. This (*) following a 

 record, denotes that the paper in question contains description of a new 

 North American form. 



For record of Economic Literature, see the Experiment Station Record, 

 Office of Experiment Stations, Washington. 



2— Transactions, American Entomological Society, Philadelphia, 

 3 — The American Naturalist. 4 — The Canadian Entomologist. 7 — 

 U. S. Department of Agriculture, Bureau of Entomology. 8 — The 

 Entomologist's Monthly Magazine, London. 9 — The Entomologist, 

 London. 11 — Annals and Magazine of Natural History, London. 

 18 — Ottawa Naturalist. 21 — The Entomologist's Record, London. 

 22 — Zoologischer Anzeiger, Leipzig. 35 — Annales, S'ociete Ento- 

 mologique de Belgique. 38 — Wiener Entomologische Zeitung. 40 — 

 Societas Entomologica, Zurich. 47 — The Zoologist, London. 49 — 

 Annales historico-naturales Musei Nationalis Hungarici, Budapest. 

 89 — Zoologische Jahrbucher, Jena. 94 — "Das Thierreich" herausge- 

 geben von d. Deutschen zoologischen Gesellschaft, Berlin. 102 — 

 Proceedings, Entomological Society of Washington. 119 — Archiv 

 fur Naturgeschichte, Berlin. 152 — California Agricultural Experi- 



