Studies on Theraptus Sp. (Coreidae); the Cause of the Gumming Disease of Coconuts in East Africa.

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Date
1925
Authors
Way M.J
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Abstract
Theraptus sp. is widespread in the coastal region of British East Africa where it severely damages developing coconut fruits. The female may layover 100 eggs. There are five nymphal instars and, in the field, it is probable that about nine generations are produced each year. Damage to coconuts is similar to that caused by AmblypeLta cocophaga China in the Solomon Islands. Female coconut flowers and young nuts may be destroyed by a single feeding puncture. Damaged 1O-16•week-old nuts may reach maturity but are undersized and often distorted by lesions from which gummy material exudes. Over 70% of 5-10-week-old nuts may fall "naturally"; thus Theraptus damages many nuts which would fall in any case. However, after natural nutfall has ceased, the pest b13comes concentrated on the few remaining nuts which are susceptible to damage for about four weeks more. One Theraptu8 may make over 200 feeding punctures in its lifetime. Consequently, a population density of less than two per palm may cause severe damage. Palms bearing many female flowers per spadix suffer more severely from attack than those bearing few, although normally they give higher nut yields.
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Bulletin, 44, p. 657-667
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