52 



CuNLiFFE (R. S.). Yuca. Insectos y Enfermedades. — Estacion Expt. 

 Agron., Santiago de las Vegas, Cuba, Bol. 34, July 1916, pp. 56- 

 59. [Eeceived 3rd December 1919.] 



A section of this bulletin upon the cultivation of cassava {Manihot 

 idilissima and M. aipi), its starch content and usefulness, deals with 

 a description of the insects and diseases that attack it. The insect 

 pests include a Sphingid, Erinnyis (Dilophonota) ello, which is most 

 abundant from March to May and from October to December. Eggs 

 are laid on the upper surface of the leaves and hatch after five days. 

 The larvae pass through five stages, and pupation occurs in the ground. 

 Various parasites attack this moth, including Microgaster flaviventris. 

 If these are not a sufficient check, the plants should be sprayed with 

 Paris green or lead arsenate, using 1 lb. of the former to 50 gals, of 

 water, or 1 lb. of the latter to 15 to 25 gals, of water. As the eggs are 

 conspicuous they can be collected by hand when labour is cheap. 

 The larvae of a Longicorn, Lagochirus obsoletus, cause considerable 

 damage, as in the other countries where cassava is grown. The insects 

 are present throughout the year, but chiefly in the spring and summer 

 months, when the adult beetles oviposit in the trunks and branches. 

 The larvae construct galleries in the stems, lowering the vitality of 

 the tree and decreasing the crop. As the adults eat the foliage, 

 spraying as for E. ello will check their numbers, but all infested stems 

 should be cut away and burnt during February, March and April. 

 Another borer, Cryptorrhynchus sp., has been found in the Isle of 

 San Vicente, for which the same treatment should be given. Lonchaea 

 chalybea does serious damage, particularly to the young shoots, the 

 flies being most common from April to December. The eggs are 

 laid under the young leaves and the young larvae bore into the terminal 

 shoots, causing the formation of a gummy secretion which renders 

 poison-sprays useless. The only remedy is to cut out and burn all 

 infested shoots. Minor pests are a scale, Lepidosaphes alba, which 

 is generally controlled by a parasite, and a mite, Tetranychus telarius 

 (bimaculatus), both of which attack the leaves ; these pests may be 

 checked by spraying with whale-oil soap or lime-sulphur while the dew 

 is on the leaves. A Longicorn, Leptostylus biustus, mines the shoots 

 and stems. The larvae of Pachnaeus litus, which is generally a pest of 

 citrus fruits, attacks the roots of cassava. Hand collection of the 

 beetles in the morning is recommended, as well as turning fowls 

 among the trees, while good cultivation should be practised. The 

 plants are also frequently attacked by a leaf-cutting ant, Atta insularis, 

 the nests of which should be destroyed. 



Johnston (J. E.) Sc Bruner (S. C). Enfermedades del Naranjo y 

 otras Plantas Citricas. [Diseases of the Orange and other Citrus 

 Plants.] — Estacion Expt. Agron., Santiago de las Vegas, Cuba, Bol. 

 38, August 1918, 54 pp., 15 plates. [Received 3rd December 

 1919.] 



One of the commonest blemishes in citrus fruits is the mottling 

 caused by the mite, Eriophyes oleivorus. The fruit may be attacked 

 at any time after the petals have fallen, but the damage is always 

 more severe during periods of dry weather. The Acarids known as 

 red spiders are also important enemies of citrus fruit. Tetranychus 



