479 



Weld (C. J). Studies on Chalcid-flies of the Subfamily Leucospidinae, 

 with Descriptions of New Species. -Proc. U.S. Nat. Mus., 

 Washington, D.C., Ixi, art. 6, no. 2427, 1922, pp. 1-43, 4 plates, 

 2 figs. 



Keys are given to the genera of Leucospidinae, and to 34 species 

 of the genus Lcncospis, 13 of which are new and arc described. 

 A list is included of 40 species of Leuccjspidinae described since 

 Schlettercr's monograph of 1890. 



Departmental Activities : Entomology. — //. Dept. Agric. Union S. 

 Africa, Pretoria, v, no. 1, July 1922, pp. 17-20. 



Brithys pancratii, Cyr. (lily borer) feeds in the interior of leaves 

 and stalks, and can be successfully checked by spraying the infested 

 plants with lead arsenate. 



The wattle bagworm [Acanthopsyche jnnodi, Heyl.] has severely 

 attacked plantations in 1922. As it is probable that the larvae are borne 

 largely by warm winds and carried rather high in the air, screens of 

 immune trees on the heights of a valley where the pest is serious might 

 intercept them, but in most places they probably reach vegetation 

 more from above than from the side. 



Glenn (P. A.). Relation of Temperature to Development of the 

 Codling-moth. — //. Econ. Ent., Geneva, N. Y., xv, no. 3, June 

 1922, pp. 193-198. 

 The observations here described were made during 1915, 1916 and 

 1917, and were concerned with the relation of temperature to the 

 development of the codUng moth [Cydia pomonella, L.]. The purpose 

 of the study was to find some, temperature unit so related to develop- 

 ment that the total number of units accumulating during the period 

 of any stage of the insect would be the same for all temperatures. 

 The day degree (one degree acting for a period of one day) was used 

 as the unit of temperature. 



In the case of the eggs, 50° F. was the lowest temperature at which 

 development took place. The rate of development increased with the 

 rising temperature up to 88°, after which it was retarded. The 

 incubation periods varied from 5-52 to 14 days, with average tempera- 

 tures from 61 -6° F. to 84° F. The sum obtained by multiplying the 

 day degrees above 50° by the number of days in the incubation 

 period proved to be fairly uniform for the lower temperatures ; but 

 when the temperature was over 88° it was found necessary to subtract 

 twice the degrees above 88° from those above 50° in order to obtain 

 the effective day degree. On multiplying these day degrees by the 

 number of days in the incubation period, a figure in day degrees is 

 obtained that is uniform for aU temperatures. To obtain the same 

 results for the larval or pupal periods the principle is the same, though 

 the figures are slightly different, the lowest temperature at which the 

 larvae develop being about 50° and the pupae at about 52°, while 

 the maximum development occurs at 85° and 87° respectively ; thus the 

 effective day degree for any day may be found by subtracting twice 

 the number of degrees above the degree of maximum development 

 from the number of degrees above the lowest degree at which develop- 

 ment occurs, the sum of the day degrees thus obtained for the entire 

 period being the theoretical thermal constant. Tliis constant for the 

 incubation period is about 163, for the larval period 673, and for 

 the pupal period 241. For practical purposes it is necessary to use the 



