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difficulties stand in the way of complete success in controlling the 

 numbers, but by employing 25 men on 78 acres to go over the ground 

 once at dusk, 20,617 males and 1,547 females were caught, while 

 search from dusk till one hour after nightfall yielded 3,452 males and 

 3,029 ferjiales, and on a limited area the results of this method were 

 distinctly good, the damage being reduced to about one-third. It was 

 observed as far back as 1912 that numbers of the beetles passed the 

 day in trees, but these consisted largely of females which have already 

 completed their oviposition. The fact that these beetles, especially 

 the females, live in the ground during their most dangerous stages 

 makes any really useful control measure exceedingly difficult, and 

 the author is of opinion that there is no method by which they can be 

 caught in quantity, though efforts should be directed towards 

 destroying them as soon as they emerge. Investigations into the 

 depth at which the eggs are laid in the soil, gave results varying from 



8 inches to three or four times that depth, though 75 per cent, of the 

 observations gave a depth of over 12 inches ; the majority of the 

 larvae were found at 20 inches below the surface. They are markedly 

 cannibalistic in their habits. No very serious damage is done between 

 October and January, but the plants then begin to droop owing to 

 damage to the roots. In the earlier stages of attack the injection of 

 carbon bisulphide into the soil between the plants should give good 

 results. When the plants are very young, the grubs eat the stems 

 and the young roots, causing death. Many thousands of grubs of this 

 and other species are to be found in the vegetable rubbish which 

 should be cleared off the ground between the plants. The larvae of 

 Lenco'pholis also attack maize, ground-nuts, arrowroot and sweet 

 potato. The life-cycle is as follows : — The beetles emerge from the 

 soil about the middle of October, the egg-stage lasting 19 to 23 days 

 in October and November and the larval stage about nine months, from 

 December to August. The resting stage of the larva previous to 

 pupation lasts 8 to 32 days, the pupal stage four to five weeks and the 

 emergence of the beetles, with about seven weeks of inactivity, occupies 

 the time between August and October ; one generation thus lasts 

 about a year. 



Lepidiota stif/ma, F., is not so common in cassava fields as Leucopholis 

 rorida, F., and is somewhat local. Care is required to distinguish the 

 sexes. Capsicum does not attract the beetles, but they come to light 

 and are occasionally found above ground, though more strictly a night 

 feeder than L. rorida. This beetle feeds on many plants, including 

 tamarinds, Arachis spp., kapok. Citrus spp., avocado, etc., tamarind 

 being the favourite food. Laboratory observations on the larvae were 

 almost impossible owing to their cannibalistic habits. The life-cycle 

 is as follows : Egg-stage, 15 days in November ; larval stage, about 



9 months, December to August ; resting stage of larvae, 12 days in 

 September ; pupal stage, one month in October ; the imago occurs 

 from October to December, the cycle thus covering a year. The 

 larvae of this species are reported to have destroyed nearly 30 acres 

 of sugar-cane in one locality. The larvae of Xylotrupes gideon, L., 

 which do great damage to sugar- cane, are also serious pests of cassava. 



The following list of minor pests of cassava is given, the bionomics 

 of each species being discussed :—Euchlora subcoemlea, Hope 

 {nigra, F.) ; Anomala obsoleta, Blanch. ; A. anchoralis, Lansb. ; 



