534 



L. pcrennc. In captivit}', the adult lives 50 days in spring and summer, 

 but in the field longevity is probabty very variable and entirely depen- 

 dent on meteorological conditions. Many investigators have recom- 

 mended ploughing infested fields, but experiments in this direction 

 indicate that ploughing in a badly infested crop would fail to destroy 

 the pest effectively. Subsequent rolling, on heavy land, would pro- 

 bably form a crust sufiiciently dense to prevent emergence on a large 

 scale, but this method would not be successful on medium or light 

 land. Nitrogenous manures are not likely to repay the cost of applica- 

 tion on average land in England. Hymenopterous parasites have 

 previously been recorded in America [/^. ^4. E., A, viii, 184]; those 

 reared for the first time from 0. frit in England are an unidentified 

 Proctotrupid ; the Braconid, Chasmodon apterus, Nees ; two Cynipids 

 of the subgenus Psichaera, which are of interest because other members 

 of the genus Eucoila are known to be parasitic on Diptera ; Aphidius 

 granarius, Marsh.; the Chalcid, Dicyclus fuscicoriiis, Wlk., and 

 unidentified species of at least two other genera. 



TiLLYARD (R. J.). The Introduction into New Zealand of Aphelinus 

 niali, a valuable Parasite oJ the Woolly Aphis. — N.Z. J I. Agric, 

 Wellington, xxiii, no. 1, 20th July 1921, pp. 7-19, 5 figs. 



Arrangements were made in 1920 to ship from America a parcel of 

 parasitised individuals of the woolly aphis [Eriosoma lanigenini] 

 to Wellington, N.Z., with the object of establishing there the parasite 

 Aphelinns mali, Hald. The infested apple twigs were collected from 

 widely separated localities, in the hope that a good mixed strain of 

 A. mali would result, and on their arrival, on 13th January, they were 

 transferred to a special breeding cage. Great care was taken to 

 eliminate any possible hyperparasites before individuals of A. mali 

 were liberated on the trees. The only individuals that survived were 

 three males and two females, which were all placed on one apple tree. 

 At the beginning of May very cold weather set in, and the emergence 

 of A . mali ceased. By the end of the summer, however, 142 individuals 

 were found. A graph shows the emergences of this first brood and 

 demonstrates the effect of weather on the dates of appearance. The 

 period of emergence in this case covered 29 days, being notably 

 affected by rain and cloud, and especially by sudden drops in 

 temperature. Males predominated at the beginning and females at 

 the end of the brood. 



A short account of the life-history of A. mali is given. What its 

 seasonal history in New Zealand may be is not yet known, but it 

 promises to increase sufiiciently to stock the whole of New Zealand 

 within two years if the winter mortality is not too heavy and if 

 satisfactory methods of distribution are developed. 



Chermes attacking Spruce and other Conifers. — Forestry Conim., 

 London, Leaflet no. 7, August 1921, 7 pp., 4 figs. 

 A general account is given of the injury caused by various species of 

 Chermes to spruce and other conifers. The species recorded as 

 occurring in England are Chermes viridis, Ratz., C. (Cnaphalodes) 

 strobilobiiis, Kalt., C. {Dreyfusia) nilsslini, Born., C. {D.) piceae, 

 Born., C. {Pineus) pint, Born., and C. (P.) strobi, Htg. The only 

 representative of the spruce-Douglas fir Aphids, Chermes cooleyi. 

 Gill., is a West American species, but the gall-forming generation on 

 Sitka spruce is not so far known to occur in Britain. 



