139 



The action of nitrate of soda or sulphate of ammonia is a great stimulus 

 to plant growth and root development, making the cane more 

 resistant to the attacks of grubs. 



The use of arsenious poisons recently suggested for the destruction 

 of the grubs is very promising. As it is already known that they feed 

 largely upon humus and decomposing soil substances, it would seem 

 to be a simple matter to apply poisoned organic bodies to the soil 

 preparatory to cane-planting. Humus has a marked affinity for 

 arsenic, which has a deflocculating action upon soil, making it more 

 retentive of moisture. Chemical tests of certain soils of Hawaii, which 

 have been treated with arsenic for the destruction of weeds for the 

 past five years, show that all the poison has remained in the top four 

 inches of soil without injuring in any way the roots of the growing crop. 

 If arsenic proves useful at the same time as a weed-killer and a poison 

 for grubs, it will undoubtedly be a profitable procedure. Experiments 

 are now in course of progress to test the various suggestions outlined. 

 Meanwhile, advice for cane-growers may be summarised into the 

 general recommendation to conserve the humus and apply lime ; later 

 it is hoped to publish the best method of poisoning the grubs. 



Jarvis (E.). Sugar-Cane Pests. — Queensland Agric. Jl., Brisbane, viii, 

 no. 3, September 1917, p. 175. [Received 24th January 1918.] 



Attention has been principally devoted to the study of the external 

 anatomy and metamorphosis of certain of the more injurious cane 

 beetles. A treatise dealing with the life-history and habits of Lejpidiota 

 frenchi, Black., has been prepared. The occurrence is recorded at 

 Gordonvale in May 1917 of a new Lepidopterous pest of sugar-cane of 

 minor importance, viz. : — the Hesperid, Padraona hypometoma, 

 Lower, which was observed eating the leaves of young cane plants 

 growing in pots. Three other species of Hesperids have previously 

 been recorded attacking sugar-cane in this district [see this Review, 

 Ser. A, iv, p. 345]. The butterfly, Mekinitis leda, L., and the moth, 

 Mocisfrugalis, F., have also been recently recorded as destroying the 

 foliage of sugar-cane. 



Freeman (G. F.). Alfalfa in the Southwest. — Univ. Arizona Agric. 

 ExjoL Sta., Tucson, Bull. no. 73, 1st June 1914, pp. 233-320, 

 2 plates, 19 figs. [Received 25th January 1918.] 



The lucerne seed crop is attacked by several insects, of which the 

 most important is the Chalcid, Bruchophagus funebris, which oviposits 

 in the ovules soon after the flower has bloomed, or in the young seeds 

 in pod. By the time the seed is mature the larvae are full grown, 

 having devoured all the interior of the seed, the winter being passed 

 by them in seeds fallen from the previous crop or from casual roadside 

 plants. Adults appear early in June and continue to emerge throughout 

 July and August, and since the time of incubation may vary from a 

 little less than six weeks to nearly a year, there is no discernible 

 interval between the appearance of the first and second and succeeding 

 broods. The amount of damage varies with the season, and increases 

 as the season advances, becoming so severe in October that seed 

 maturing at that time is not worth harvesting. 



(C458) a2 



