51 



machines for fumigating the nests of which are described and 

 illustrated. Another ant, Soknopsis geminata, may cause con- 

 siderable damage by constructing covered galleries on the trunks a,nd 

 larger branches ; sometimes these pests also make a circular incision 

 in the tree and injure the young leaves, shoots and fruit. The only 

 remedy is to clean the trunks periodically and sprinkle the base of the 

 tree and the surrounding soil surface with a strong solution of soap 

 or 5 per cent, creoline. Pachnaeus litus oviposits on the leaves. The 

 larvae drop to the ground and descend to the roots, and, if sufficiently 

 numerous, may kill the tree. The damage is particularly severe m 

 well cultivated orchards, as the beetles concentrate on the trees mstead 

 of ovipositing on grasses, etc. The adults injure the ripening fruit 

 and leave scars that reduce their market value. The larvae can be 

 treated with 5 per cent, creoline solutions but this is a dangerous 

 remedy as the trees may be killed by excessive doses. The adults 

 can be sprayed with poison while they are feeding, but this remedy 

 is useless in rainy weather. Fowls and birds will destroy many of the 

 beetles, and others can be shaken into a cloth stretched below the tree 

 during the early morning while the dew is still on the leaves. The 

 same remedies can be applied to June bugs, which are also the cause 

 of scarred and deformed fruit. 



Whiteflies and scale-insects should be treated with copious sprays 

 of whale-oil soap, given every 20 days. The black fly, Aleurocanthios 

 icoglumi, has recently been discovered infesting a small area, but as 

 this area has promptly been isolated and energetic measures taken 

 to combat the pest it is hoped that it will soon be exterminated. A 

 minute mite is responsible for mottling and discolouring the rind of 

 the orange and thus lowering its value, without however afiecting 

 the quality of the fruit. The remedy is to dust the tress with sulphur 

 every 30 days, or sprinkle them with flour and sulphur or with a lime- 

 sulphur solution. Thrips, if present on the trees, should be treated 

 with a tobacco solution, once when the trees are in bloom and once 

 or twice while the fruit is small. 



RoiG (J. T.) & FoRTUN (G. M.). Las Variedades Cubanas de Boniato. 



[Sweet Potato].— ^'stacion Exp. Acjron., Santiago de las Ve^fas, 

 Cuba, Bol. 33, November 1916, 76 pp., 31 plates. [Received 3rd 

 December 1919.] 



The most destructive insect pest of sweet potato in Cuba is Cylas 

 formicarius (sweet potato weevil). No efficient remedial measure 

 against this species has been found, the introduction of insect enemies 

 having proved inadequate. Tubers planted from August to October 

 are least likely to suffer, if the crop is gathered not more than six 

 months later. The damage is also minimised by digging the furrows 

 very deep. Only healthy sets should be sown and two successive 

 crops should not be sown in the same ground. 



Minor insect pests include a leaf-miner, Agromijza jucnnda, Wulp, 

 a mite, Eriophyes ipomaea, Cook, and two species of whiteflies, 

 one being Aleurodestrachoides, Bacg., and the other being imidentifieci 

 A Lepidopterous caterpillar has been found devouring the leaves, 

 but without causing serious injury. 



