219 



The insect hibernates in the egg-stage, the eggs being laid in groups 

 of 3-6 just beneath the bark of the twigs, above and concealed by 

 the buds. In a severe infestation every part of a young twig is 

 utilised except the tip, as many as 48-50 eggs being found in each 

 linear foot. These over-wintering eggs hatch during the latter part 

 of May, and adults appear at the end of June. Females of this brood 

 oviposit during the first two weeks of July, and the adults of the 

 second brood begin to oviposit by the end of August. The eggs 

 are parasitised by Gonatocerus maga, Gir., and also, according to 

 Leonard and Crosby, by G. ovicenakis [see this Review, Ser. A, v, 

 p. 72]. A bug, Podisus maculiventris. Say, has been observed on one 

 occasion to attack an adult. 



The damage caused by this insect consists in the whitening and 

 discolouring of the upper surface of the leaves, and in New Jersey, 

 where it is becoming more abundant and widely distributed, it has 

 been found on the poplars lining the city streets. Detailed descriptions 

 of the egg, five nymphal stages, and adult are given. 



Baumberger (J. P.) & Glaser (R. W.). The Rearing of Drosophila 

 ampelopJdla, Loew, on Solid Media. — Separate from Science, Lan- 

 caster, Pa., xlv, no. 1149 5th Januarv 1917, pp. 21-22. [Received 

 13th March 1918.] 



The mass of fermenting banana generally used in rearing Drosophila 

 is unsuitable for observing the begiiming of oviposition. A trans- 

 parent solid medium of banana agar was therefore used, being made 

 as follows : — Five or six bananas were mashed up in 500 c.c. water, 

 allowed to infuse on ice over-night, and then passed through cheese 

 cloth. Powdered agar-agar was then added at the rate of 1| grams 

 to 100 c.c. of banana infusion, which was heated till the agar had 

 dissolved. The liquid was then filtered through a thin layer of absor- 

 bent cotton into test-tubes. 



If adult Drosophila are inserted into the tubes and these are incu- 

 bated at 35° C, small white eggs may be seen to be deposited every- 

 where on the surface of the agar in a day or two. The fact that the 

 average number of days required to complete the life-cycle on this 

 medium is three days longer than on the ordinary banana mash and 

 that some of the larvae die without pupating, shows that the medium 

 is deficient in available food. Probably the amount of food might 

 be increased by the addition of banana flour. 



Drosophila has also been reared on potato agar, but the results were 

 even less satisfactory than with banana agar, showing that the food 

 supply in potato is very small. 



Bacterial growths, which always develop on the medium, do not seem 

 to affect the larvae, and fungus growths are usually destroyed by the 

 larvae as soon as they hatcL 



Baumberger (J. P.). The Food of Drosophila melanogaster, Meigen. 

 — Proc. National Acad. Sci, Washington. D.C., iii, no. 2, February 

 1917, pp. 122-126. [Received 13th March 1918.] 



During the rearing of Drosophila melanogaster on artificial media of 

 fermented banana agar, it was observed that visible fungus growths 



