Browsing by Author "Wheatley, P.E."
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Item The Giant Coffee Looper Ascotis Selenaria Reciprocaria Walk(1963) Wheatley, P.E.A leaf-eating Geometrid caterpillar, Ascotis selenaria reciprocaria Walk., not previously recorded from coffee in Kenya, was collected from mature Co flea arabica at the Coffee Research Station, Ruiru, Kenya, for the first time in January, 1961. Four months later the caterpillar caused considerable defoliation of coffee seedlings in nursery beds at the Coffee Research Station. The following month an infestation was seen near Thika on mature coffee and considerable damage was caused by a population of 40 to 50 caterpillars per tree. Shortly afterwards further infestations of varying degrees of severity were found in the Thika and Ruiru areas where much of the Kenya coffee crop is grown. Although at the present time it is clear that Ascotis is only of minor importance as an insect pest of coffee, some concern was felt as medium volume sprays of parathion and methyl-parathion at concentrations of up to 0.06 per cent is failed to control the pest. It was therefore decided to investigate its life history and conduct simple insecticide trials to find an insecticidal treatment which would give satisfactory control of the pest.Item The giant coffee Looper, Ascotis Selenaria Reciprocaria walk. (Lepidoptera: Geometridae)(1963) Wheatley, P.E.; Coffee Research Station, Ruiru, KenyaThe occurrence on Arabica coffee in Kenya of the Geometrid Ascotis reciprocaria sefenaria Walk. is reported, together with observations on its 'life cycle, parasites and interim. Preliminary insecticide trials are described and interim control recommendations are made.Item Insect Pests in the Coast Province of Kenya I-Mango(1960/1961) Wheatley, P.E.; Department of Agriculture, KenyaA wide range of insect pests attack mango. But generally speaking the damage they cause. Although sometimes considerable. is not so severe as on the majority of tree crops on the Kenya coast and insecticidal control measures have been rarely employed in the past. However. The recently developed trade in air freighting mangoes to Europe has created a market for a very high grade of fruit unblemished by fungal or insect attack. Insect blemishes are normally caused by scale insects and the internal quality of the fruit is unimpaired. Therefore the need for insecticidal control measures for scale insects on mangoes depends not only upon the severity of infestation. But also upon the type of fruit which one is trying to produce. The local East African market at present does not discriminate between fruit with and without minor blemishes, but the luxury Covent Garden trade very definitely does and if fruit are to be grown for this latter market, spraying may be necessary even for very low scale infestations.Item The Insect Pests of Agriculture in the Coast Province of Kenya III-Sweet Potato(1960/1961) Wheatley, P.E.; Department of Agriculture, KenyaThe three main pests of sweet potatoes,Cylas, Alcidodes and Aegeria, all live in the vines and tubers of the crop where they are well protected from applications of insecticides. In all cases, however, strict enforcement of cultural control measures will reduce infestation very markedly, leading to higher yields and a more palatable crop. The minor pests listed are normally of little consequence and it will only be in rare cases that the control measures given will be required.Item Laboratory Studies of Insecticides against the Coffee Leaf-Miner Leuooptera Meyrioki Ghesq. (Lepidoptera, Lyonetiidae).(1962) Wheatley, P.E.The coffee leaf-miners Leucoptera meyricki Ghesq. and L. caffeina Wshbn. are serious pests of arabica coffee in Kenya. At the present time sprays containing parathion, methyl-parathion or diazinon are used extensively for their control. To facilitate preliminary investigations into various aspects of insecticidal control of the larval stages of these pests, a laboratory bioassay technique was developed. Larvae ware reared on detached coffee leaves placed on moist filter paper in plastic boxes. When the larvae were in their third instar, the leaves were sprayed in a Potter tower and then kept in a moist air stream for three days before the mines were dissected to enable mortality counts to be made.Item The Successful Establishment of Eretmoceros Serius Silv. (Hymenoptera: Eulophidae) In Kenya(1974) Wheatley, P.E.The Citrus Black Fly, Aleurocanthus Wolglumi Ashby was first collected on Citrus in Kenya in 1913. In the more humid coastal areas of the country this Aleurodid has for many years been a serious pest of the crop. Apart from sucking the sap of the leaves, honeydew excreted by this species supports growth of the "Black Sooty Mould" fungus which renders trees and fruit unsightly and interferes with photosynthesis. In 1958 a survey carried out in the coastal areas of Kenya revealed that although some small degree of control was exerted by Coccinellid predators, no internal parasites occurred.
