424 



NOTES AND COMMENTS [june 



a little above and behind the aims. Both these ducts and the 

 reservoirs are lined with chitin and evidently formed by invagination 

 of the ectoderm. The likeness of the discharge of these beetles to 

 that of artillery is increased by Dr. Bordas' observation that after 

 dark the emitted vapours show a phosphorescent light. 



Economic Entomology. 



We have received Miss Ormerod's twenty-second report on Injurious 

 Insects, and notice with satisfaction that a general. index to her whole 

 valuable series is in course of preparation by Mr. E. Newstead of 

 Chester, who has undertaken to collaborate with her in the prepara- 

 tion of a second series of reports. In these a special feature is to be 

 the utilisation of short notes on means of prevention and remedies, 

 which may be furnished to Miss Ormerod by her correspondents, less 

 space being devoted to descriptions and figures of insects already well 

 known. Among less familiar pests mentioned in the present Report 

 are the gall-midge, Diplosis pyrivora, Riley, whose maggot feeds within 

 pears, causing a stunted and aborted growth ; and the " rustic " moth 

 Hydroecia micacea, Esp., whose caterpillar bores into potato stems. 



From the U.S. Department of Agriculture, we have received 

 Part 6 of the Bibliography of American Economic Entomology, compris- 

 ing titles of publications from June 1888 to December 1896. This 

 work will tell the student of insects of many papers which do not gain 

 notice in the ordinary zoological bibliographies. 



The latest bulletin (No. 19) of this Department is by Mr. E. H. 

 Chittenden and deals with some insects injurious to garden and 

 orchard crops. Of considerable biological interest is the ladybird 

 beetle, Epilachna borcalis, Fb. Unlike most of its family this insect 

 is a vegetarian, and feeds largely, both in the larval and perfect stages, 

 on the leaves of " squash " and pumpkin. It has the curious habit of 

 marking out a circular area on the leaf within which it eats. A 

 hemipterous insect (Anasa tristis, D. G.) which feeds on the same 

 plants, and another {A. armigera, Say) which devours cucumber leaves, 

 are carefully traced from the egg through five nymphal stages. 



Mr. M. V. Slingerland of the Cornell University, Ithaca, N.Y., con- 

 tributes to the Photogram (vol. vi. pp. 141-145) an instructive article 

 on the application of photography to economic entomology. A want 

 of definition in detail is often to be noticed in photographs of insects, 

 but Mr. Slingerland's methods seem to give remarkably clear pictures. 

 " Long exposures with all the light it is possible to get" and "a slow- 

 developer" are recommended for the best results, and in many cases 

 the use of a yellow ray filter greatly increases the effect. 



