167 



digger pine (P. sabiniana) and big-cone spruce {Pseudotsiiga macro- 

 carpa), the species being apparently confined to California ; Chryso- 

 bothris falli, sp. n., from yellow pine and Jeffrey pine ; C. laricis, Van 

 Dyke, probably breeding in the lodge-pole pine ; and C. exesa, Lee, 

 taken on mesquite {Prosopis juliflora.). 



GiRAULT (A. A.). The North American Species of Cerchysius, Females 

 (Hym., Chalcid.). — £'w^o>H. News, Philadelphia, Pa., xxix, no. 2, 

 February 1918, pp. 65-66. 



In this paper a key to the genus Cerchysius is given, and the female 

 of C. whittieri, sp.n., a parasite of Saissetia (Lecaniiim) oleae at San 

 Francisco is described. 



Pembertox (C. E.) & WiLLARD (H. F.). Fruit-fly Parasitism in 

 Hawaii during 1916.— J/. Agric. Research, Washington, D.C., xii, 

 no. 2, 14th January 1918, pp. 103-108. 



'Much careful data with regard to the parasitism of the fruit-fly 

 [Ceratitis capitata] in Hawaii during 1916 has been accmnulated in 

 continuation of the work of previous years [see this Review, Ser. A,iii, 

 p. 412.]. The exact degree of infestation of large quantities of host 

 fruits by the fruit-fly is tabulated, showing the infestation in various 

 localities and also the amount of parasitism among the larvae from 

 month to month and the seasonal efiicacy of each parasite. Seasonal 

 differences in the value and prolificness of certain species of introduced 

 parasites have been most striking ; particularly is this shown in the 

 inspection of records from fruit collected from the same localities 

 month by month from trees that bear fruit which is normally a host 

 of the fruit-fly continuously throughout the year. The work of 1916 

 has demonstrated the fluctuations that may occur in the abundance 

 of different species. Diachasma tryoni. Cam., was found to rise in 

 nmnbers in the summer and autumn and to decline during the winter 

 and spring months. Changes in temperature seem to be responsible 

 for this. Opius humilis, Silv., although a more hardy and prolific 

 species than any of the other introduced ones, showed directly the 

 reverse in its seasonal rise and fall, which was apparently entirely 

 dependent upon the rise and fall of D. tryoni. Shght changes in 

 temperature do not seem to have any visible effect upon the activities 

 of 0. humilis, since in the winter and spring, with the decline of D. tryoni, 

 it rapidly ascends and becomes the most effective check upon the 

 fruit-fly. 



The problem of the control of C. capitata in Hawaii by means of 

 parasites is only partly solved. Although the four species already 

 established are accomplishing a certain measure of control, the 

 continued destructiveness of the pest in Hawaii remains only too 

 obvious. An average parasitism of 40 per cent, of all the larvae 

 developing is, numerically considered, of much importance, but from 

 the standpoint of the practical needs of the horticulturist it brings 

 little rehef. The first table given in this paper shows the extent of 

 infestation of host-fruits by larvae of C. capitata in the course of the 

 year, the exact average condition of fruit-fly abundance, injury and 

 parasitism being recorded. In the mango {Mangifera indica), guava 



