Annual Report of the Government Entomologist.
AbstractAntestia lineaticollis, Stâl (coffee bug) is the most serious pest of coffee. Outbreaks of it appear to be occurring more frequently, and the annual loss to planters is estimated to exceed 1/215, 000. The 'collection of all stages and the breeding of parasites do not appear to be uniformly successful, indicating that the bug migrates from surrounding breeding places, though it has not yet been found on any food-plant other than coffee. Stephanoder es hampei, ferr. (coffee berry borer) was found in large numbers on several estates. Pseudococcus citri, Risso (root mealy bug) continues to be a serious pest, the ant, Acropyga gowdeyi, Wheeler, probably being partly responsible for the reinfestation of coffee roots. Tobacco soap solution is only temporarily effective against it and has to be repeated about every 8 months. Metadrepana glauca, Hmp., eating the foliage, has been controlled by hand collection and spraying. Diarthrothrips coffeae, Will., can only be controlled by spraying. The coffee trees that are attacked by Bixadus sierricola, White (stem borer) are those adjacent to forest land. The larvae feed for a time in the bark on the lower part of the stem and then bore into the wood, making large burrows. The stem may be ringed, and the plant soon dies. In advanced cases stumping may be necessary, but where the mechanical strength of the stem has not been appreciably affected, carbon tetrachloride, carbon bisulphide or petrol may be injected into the burrows, which should be subsequently plugged with clay. Cut stems or dead trees should be burnt at once. A leaf eating weevil, Isaniris sp., is recorded for the first time on coffee in Uganda; handpicking or spraying with lead arsenate or Paris green is recommended for its control. Other pests of coffee are Pseudococcus virgatus[Ferrisia virgata], Ckll., Asterolecanium coffeae[Saissetia coffeae], Newst., and the Noctuid, Achaea catocaloides, Gn. The latter is apparently a general feeder, living normally in the forest, from which it spreads to coffee, maize and beans, being particularly injurious to coffee. On this crop it was controlled by dusting with Paris green and burning the bush vegetation between the forest and the coffee.
The cotton pests recorded are Eanas insulana, Boisd. (bollworm), which has also been bred from dînèrent species of Hibiscus; Aphis gossypii, which is preyed upon by the adults and larvae of the Coccinellids, Chilomenes vicina, Muís., and C. lunata, f. ; the cotton-stainers, Oxycarenus rufiventris, Germ., 0. fieberi, Stâl, 0. hyalinipennis, Costa, the latter occurring also on Hibiscus cannabinus, and Dysdercus nigrofasciatus, Stǻl, found on the fruits of Abutilón indicum; Coryna apicicornis, Guér., and another beetle of this genus, not of very great importance as pests; and an unidentified Aleurodid.
A Coccid not hitherto recorded was found infesting the roots of tea. A great deal of damage was done to sweet potatoes by Acraea acerata, Hew. Busseola fusca, Hmp., is recorded for the first time as a stem-borer in maize in Uganda. An unidentified stem-boring caterpillar and a Buprestid were found attacking the rain tree (Pithecolobium saman).