2:39 



either in or near an Aphid colony. Allogmpta obliqua, Say, is one of 

 the commonest species, and is found from May to October. The 

 larvae are very general feeders, having been found in one season on 

 Brevicon/ne (Aphis) brassicae, Aphis rumicis, A. cardui, A. pomi, 

 A. gossypii, Myzus cemsi, and Macrosiphum sp., on \vild lettuce and 

 wild asters. They were very abundant on all hosts except A. pomi, 

 which generally lives too much exposed to sunlight to afford the 

 shelter required by Syrphid larvae. Sphaerophoria cylindrica, Say, is 

 also abundant from May to November, especially on Aphids on 

 low-growing plants. Syrphus americanus, Wied., is of considerable 

 importance in reducing the number of Aphids attacking cultivated 

 plants and fruits. S. ribesii, L., is probably the best-known species, 

 and is very common in orchards and gardens from May to November, 

 attacking many of the Aphids Usted above and also Eriosoma lanigerum 

 and Aphis viburnicoh. It is particularly useful in checking currant 

 Aphids. S. torvus, Z., is a most important species. Eggs are laid in 

 early spring on the first colonies of Aphids appearing on the shoots of 

 various plants. The young larvae develop on clusters of stem-mothers 

 and frequently destroy whole colonies. Again, in autumn, they prey 

 upon the return migrants and sexiiales. Paragus tibialis, Fall., is 

 predaceous on Acijrthosiphon (Macrosiphum) pisi and also on^, cardui 

 on thistles; P. bicolor, F., is similar in habit, but is nmch less 

 numerous. 



Observations on the immature stages of these species and the 

 number of Aphids they destroy show that when food is plentiful the 

 larvae frequently kill two or three Aphids in succession without 

 sucking them dry, and, in these circumstances, the larval and 

 pupal stages appear to be of shorter duration, the abundance of food 

 evidently producing rapid maturity. Growth is also more rapid 

 in warm weather. Further extensive investigations on the immature 

 stages of Syrphids would be advantageous. 



Ferris (G. F.). Notes on Coccidae. vi. (Hemiptera).— C'ona^. 

 Entoin. London, Onf., lii, no. 3, March 1920, pp. 61-65, 

 Ifig. 



The species dealt with in this continued list include Pm'ococms 

 linclorius, CklL, of which the habits and morphological characteristics 

 are described; Targionia yuccarum, Ckll., of which T. covilleae, 

 Ferr., is a s>Tionym; Aspidiotus herculeanus, Doane & Hadden; 

 Psevdodiaspis yuccae, Ckll. ; and Lepidosaphes haivaiiensis. Mask. 

 [moor si, D. & F.) 



Warren (E.). Zoology, Physiology, Hygiene and Sanitary Science. 

 Section D., Presidential Address. Termites and Termitophiles.- - 



*S. African Jl. Sci., KingiviUiamstown, xvi, no. 2, September 1919, 

 pp. 93-112, 3 plates. 



This paper offers a comparative study of the modifications of 

 structure and habit occurring in the termitophile faunas of the southern 

 Continental land-masses, and discusses the possibility of deducing 

 therefrom some evidence regarding the occurrence of land connections 

 between the continents in past geological periods. 



(684) A2 



