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The Biology and Control of Asterolecanium coffeae, Newst., the Fringed Scale of Coffee, in Kenya Colony

Published online by Cambridge University Press:  10 July 2009

Extract

(1) Asterolecanium coffeae occurs in all the British East African Dependencies and has been the cause of much loss in certain low-lying coffee areas of Kenya. On the crop-bearing parts of the coffee tree (Coffea arabica) it inflicts injuries of an irreparable nature, and a heavy infestation is extremely difficult to eradicate.

(2) A. coffeae is oviparous, and after deposition the eggs pass through a period of incubation within the “ test ” of the mother. The fecundity of the female is low compared with that of the common Lecaniine scales and mealybugs which infest coffee in Kenya. The average number of eggs produced by a single female is about 50. The male is extremely rare and fertilisation of the female must be a very infrequent occurrence.

(3) The duration of development of the female from egg to egg varies between 60 and 70 days. The duration of the first stadium varies from 7 to 12 days, and that of the second stadium from 18 to 25 days. The pre-oviposition period is 28 days.

(4) The various stages of the female scale are described.

(5) Only one primary parasite of A. coffeae was obtained, namely, Metaphycus lounsburyi, How., and it is frequently abundant towards the close of the dry season, but its effectiveness is nearly always considerably reduced, by the high prevalence of a secondary parasite, Perissopterus busckii, How. A Coccinellid, Chilocorus angolensis, Crotch, preys upon the mobile first instar forms.

(6) A. coffeae is not a honeydew secreting Coccid and is entirely ignored by ants.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1933

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References

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