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The effect of Oecophylla longinoda (Latr.) (Hym., Formicidae) on coconut palm productivity with respect to Pseudotheraptus wayi Brown (Hem., Coreidae) damage in Zanzibar
Author(s) -
Sporleder M.,
Rapp G.
Publication year - 1998
Publication title -
journal of applied entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 60
eISSN - 1439-0418
pISSN - 0931-2048
DOI - 10.1111/j.1439-0418.1998.tb01530.x
Subject(s) - biology , palm , predator , inflorescence , horticulture , botany , ecology , predation , physics , quantum mechanics
A total of 1025 coconut palms of the East African Tall variety (EAT) in 41 small‐holding plots were examined twice in a survey of Pseudotheraptus wayi damage conducted from July 1992 to January 1993 on the island of Unguja, Zanzibar. The red weaver ant Oecophylla longinoda , the most important predator of P. wayi , was present on 34% and 37% of the total palms in Survey I and II, respectively. A change in the presence of O. longinoda on the palms was observed during both surveys. Approximately 50% of the palms were free of O. longinoda during the surveys. Strong colonies occupied 12% of the palms during both surveys. The remaining palms were either weakly occupied or the predator was found only once. The average annual yield of palms with strong and stable O. longinoda colonies was 57 nuts while palms without O. longinoda had an average yield of 41 nuts. Palms with varying degrees of O. longinoda colonization showed an increasing annual yield with a corresponding increase of O. longinoda activity. Intense O. longinoda colonization resulted in a significant reduction of female flower formation as well as less damage due to P. wayi. The number of 7–8‐month‐old nuts increased significantly with each increase in O. longinoda activity on palms. The average number of nuts per inflorescences ranged from about 2.7 nuts on palms without O. longinoda to 4.1 nuts on those with stable colonies. The formation of female flowers per inflorescence, the level of P. wayi damage and the retention of nuts varied seasonally, among the plots, individual palms and also within inflorescences on the same palm. Palms with strong weaver ant colonies displayed less fluctuations in flower production and netset which resulted in a more stable harvest.