322 



the fruit. An undetermined weevil has been defoHating sweet-potato 

 plants, but the damage is not yet serious enough to jeopardise the crop. 

 Large areas of the Union still prohibit the introduction of apples, 

 pears and quinces, as a protection against the codling moth [Cydia 

 pomonella], but such restrictions seem to be an inadequate protection, 

 as the insect has appeared in fresh localities. 



Cotton, on the whole, has been remarkably free from serious insect 

 pests, and the numbers of bollworms were almost negligible in many 

 localities. The Sudan bollworm, Diparopsis castanea, was the one 

 most commonly seen. The Jassid, Chlorita fascialis, seems to be doing 

 considerable damage to the plants b}^ causing leaf-bum and eventual 

 defoHation. Weakened plants are particularly susceptible to this 

 injury. Aphis gossypii (cotton aphis), which is usually a minor pest, 

 has been very troublesome, causing a crinkled appearance of the 

 leaves, the weaker plants appearing stunted. This Aphid is frequently 

 found on melons and other Cucurbitaceous plants. Minor cotton 

 {)ests were a weevil, Ellimenistes laesicoUis, and Dysdercus spp. and 

 Oxvcarenus sp. (cotton stainers). 



The elegant grasshopper [Zonocerus elegans] was troublesome in 

 Natal. A remedy that was found effective when the insects were 

 ^1 in. long was coal-tar on old sheets of iron, or anything rigid, 

 laid out in the fields. When the insects are about Hin. long they 

 scatter over the field, and can then be destroyed in numbers by means 

 of a wire birch. The melon and pumpkin fly [Dacus sp.] has 

 been controlled on cucumbers, pumpkins, marrows and melons by the 

 application of Mally fruit-fly bait, prepared from 1 lb. Paris green, | lb. 

 slaked lime and 25 lb. crude sugar to 50 gals, of water. Apate spp. 

 were, as usual, injurious to ornamental trees by boring into the softer 

 wood and then upwards for a long distance, rendering the infested 

 stems valueless. The object of this attack is not known, as the beetles 

 go elsewhere to oviposit. Grape-vines, Bougainvillea, apples, oranges, 

 pomegranates and silky oaks have all been attacked. Imported timber 

 was found to be infested with Lydus bnmneus (powder post beetle), 

 which frequently attacks Eucalyptus and Acacia poles used as rafters, 

 and also bamboo, which is therefore seldom used without a dressing 

 of coal-tar, applied as soon as possible after cutting and splitting. 

 Wattles and poles are frequently soaked for some days in an arsenical 

 solution, such as a cattle-dip, to make them immune from attack, 

 while soaking in water is thought to dissolve the materials that attract 

 the beetles. Another beetle imported in timber was identified as 

 Schistoceros hamatus, F. 



Locust Destruction. — //. Dept. Agric, Union S. Africa, Pretoria, 

 iv, no. 3, March 1922, pp. 233-235. 



The organisation of anti-locust campaigns in South Africa is described. 

 Over 66,000 swarms were destroyed during the season. Studies of 

 the life-history of the insect [Locustana pardalina, Wlk.] have shown 

 that the female deposits not one cluster of eggs only, as has been 

 supposed, but as many as four. The present season has confirmed the 

 theory that outbreaks of locusts follow a severe drought. The abnormal 

 infestation is probably due to the fact that in addition to eggs laid by 

 the swarms that escaped destruction in 1920-21, the eggs that were 

 deposited in the previous season, and did not get sufficient rain to 

 enable them to hatch, have hatched during the very favourable 

 cUmatic conditions of the present season. It is impossible, owing 



