495 



mustard aud turnip. Yoiuig shoots and developing fruit are injured 

 by the adults and nymphs, which puncture the plant tissues and 

 extract the juices. Eggs are laid in clusters on the underside of the 

 leaves, the incubation period in the insectary being 5 days. There 

 are five nymphal stages, development during the summer being more 

 rapid than in autumn. Eggs have been found in the field in Louisiana 

 as early as 13th April, and as late as 8th November ; and in that 

 latitude four generations may develop in a year. Adults are found 

 hibernating during the winter months, but also occur in the field 

 during mild weather. The Tachinid, Trichojwda pemiipes, ¥., was 

 found to be parasitising about 25 per cent, of the adults of N. viridula 

 collected. Occasional instances have been observed of N. viridula 

 being preyed upon by the Pentatomids, Podisus maculiventris, Say, and 

 Euthyrhynchis floridanns, L., and by the Bembecid wasp, Bicytes 

 quadrifasciata, Say. 



Contact insecticides, in order to be effective against N. viridida, 

 have to be used in such strength that injur}- to the plants is very likely 

 to result. It is considered that hand-picking is the most satisfactory 

 control measure when valuable vegetable crops are severely attacked. 

 As adults are frequently found congregating on turnip and mustard 

 in late autumn, it is suggested that these or similar plants might 

 serve as a trap-crop. 



The Small Cabbage Moth.— Queensland Agric. Jl., Brisbane, ix, no. 6, 

 June 1918, pp. 204-206, 6 figs. [Received 12th September 1918.] 



This })aper deals fully with the life-history of and remedies against 

 the cabbage moth [Plutella tnaculipennis] in the hope of a united 

 effort being made to limit its ever-increasing numbers. 



The insecticide most strongly recommended consists of : -Gas or 

 coal tar 1 gal., soap 2 lb., water 180 gals. ; or if required for 

 use in small quantities, the formula may read : — -Gas or coal tar, 1|, or 

 f or I bottle ; soap, 9 or 5 or 2| oz. ; water, 50; or 25 or 10 gals. It is 

 best to spray with this mixture when it is freshly made, care being 

 taken to reach the under-sides of the leaves. 



Illingworth (J. F.) & Jarvis (E.). Predaceous Enemies of the 



Sugar-Cane and their PaTasites.— Queensland Agric. JL, Brisbane, i 

 ix, no. 6, June 1918, pp. 229-230. [Received 12fch September 1918.] 



Cultural measures recommended against the sugar-cane grub 

 [Lepidiota albohirta] are : — (1) cultivation of the cane during summer 

 weather, followed immediately by ploughing the cultivated areas ; 

 (2) late plantmg and persistent cultivation during the period of 

 oviposition and for a few weeks subsequent to the disappearance 

 of the beetles ; (3) ploughing or fallowing land in December ; and 

 (4) covering the ground densely with Mauritius beans during the 

 flight of the beetles. 



An enemy previously reported as preying on grubs of L. frenchi is 

 probably a species of Phascologale. From the analysis of stomach 

 contents of the bandicoot it is probable that it is another such enemy, 

 and not, as is sometimes supposed, a source of damage to cane stools. 



From information received from the Queensland Museum it is 

 stated that the common digger-wasp, hitherto known &s Dielis formosa, 



