82 



in the factories infested had to be opened and disinfected. Evidence 

 was obtained that the pest had been known in one factory for several 

 years, but it is apparently not as yet very widely spread, as it was quite 

 unknown to many planters. According to Peter and Schwarz, Tinea 

 pellionella, L., infests prepared tobacco, and as the author succeeded in 

 feeding the larvae on woollen material, he thinlcs it probable that the 

 pest in question is also a clothes moth which has acquired new habits. 

 Larvae, pupae and adults were killed in five hours by a temperature 

 of 105°-108° F. ; the attack must therefore occur after fermentation 

 is complete, and it is clear that the damage may progress in a ship's 

 hold on the voyage to Europe and that one infested bale may cause 

 the ruin of a whole consignment, though from trials made with bales- 

 in the factory, a certain amount of moisture seems to be required to 

 allow of infestation. Fumigation with carbon bisulphide for 24 hours, 

 as against Lasioderma serricorne, will kill this pest, and as preventive 

 measures, extreme cleanliness and the destruction of moths in the 

 packing sheds and materials, are very necessary. Quantities of larvae 

 were found in the cracks between the floor-boards of the drying shed, 

 and attention to these and similar defects Avould do much to diminish 

 this pest. 



Leefmans (S.). De Cassave-Oerets. [The Cassava Grubs.]— Dep^ 

 Nijverheid, Landbouwen Handel. — Med. van het Laboratorium voor 

 Plantenziekten, no. 13, Buitenzorg, 1915, 118 pp., 7 pis., 4 tables 

 of curves. [Received 16th December 1915.] 



For the past eight years the cultivation of cassava has been carried on 

 on a large scale in Java. Two years after the cultivation was estab- 

 lished, various grubs began to do serious damage to the crops and 

 for six years the planters did what they could to keep down the pests, 

 but with little success, and the matter was put into the hands of an 

 entomologist to devise a remedy. The conditions of cassava culture 

 are such that the plant is always in the ground providing food for the 

 grubs and there is no rotation of crops. The two beetles especially 

 destructive to cassava, are Leucopholis rorida, F., and Lepidiota 

 stigma, F., of which the former does the most damage. This species,, 

 in which the sexes are much alike, is described, two other species being 

 known in Java, viz., L. emarginata, Burm., and L. molitor, Burm. 

 The adults of L. rorida are chiefly on the wing during the west monsoon, 

 the numbers decreasing from October to December. The chief damage 

 is done between March and May. A list of 19 food-plants is given, 

 and there are probably many others, so that there is no hope of catching 

 the beetles in any quantity by the use of trap crops. The natives 

 utilise the marked preference of these beetles for Capsicum annuum, L., 

 by rubbing the red pods on stones, fencing, etc., in the evenings, 

 thus attracting large numbers. As, however, the males only are 

 attracted by this method, it is not considered of much value. 

 Experiments to ascertain the numbers of females captured by different 

 methods showed that digging up the beetles first before they emerged 

 produced 42 per cent., catching them in the ground at dusk 23 per cent., 

 by the capsicum bait method 3 per cent., and by torchlight, by which 

 a large number were taken in copula, 60 per cent. Various practical 



