The effect of Oecophylla longinoda (Latr.) (Hym., Formicidae) on coconut palm productivity with respect to Pseudotheraptus wayi Brown (Hem., Coreidae) damage in Zanzibar

Abstract

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 Pseudotheruptus wayi damage conducted from July 1992 to January 1993 on the island of Unguja, Zanzibar. The red weaver ant Oecophylla longinodu, the most important predator of P. wayi, was present on 34% and 37% of the total palms in Survey I and 11, respectively. A change in the presence of 0. longinoda on the palms was observed during both surveys. Approximately 50% of the palms were free of 0. 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 0. longinoda colonies was 57 nuts while palms without 0. longinoda had an average yield of 41 nuts. Palms with varying degrees of 0. longinoda colonization showed an increasing annual yield with a corresponding increase of 0. longinoda activity. Intense 0. 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 0. longinodu activity on palms. The average number of nuts per inflorescences ranged from about 2.7 nuts on palms without 0. 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.

The Importance of Ants and High-Shade Management to Coffee Pollination and Fruit Weight in Chiapas, Mexico

“…Despite that ants are considered less efficient pollinators, ants may pollinate plants as effectively as winged insects especially when considering germination, seedling survival, and growth to reproductive maturity in addition to seed set (Gomez 2000). Ants benefit plant reproduction indirectly by limiting floral predators (Yano 1994;Oliveira 1997;Sporleder and Rapp 1998;Oliveira et al 1999). Ants also may augment pollination success by attacking pollinators subsequently increasing their movement and thus pollen transfer between flowers (Altshuler 1999).…”

Efficacy of the African weaver ant Oecophylla longinoda (Hymenoptera: Formicidae) in the control of Helopeltis spp. (Hemiptera: Miridae) and Pseudotheraptus wayi (Hemiptera: Coreidae) in cashew crop in Tanzania

“…The use of hydramethylon has proven to be a successful method in controlling this ant species on coconut farms, 8,13,14 thus improving the effectiveness of AWA in controlling sap-sucking pests because it does not spend energy on defending its territory. 14 The high colonisation levels of cashew trees by AWA can also possibly be ascribed to the presence of large numbers of insect symbionts (trophobionts) such as the scale insect, Coccushesperidum Linnaeus (Homoptera: Coccidae), and the red tea bug, Hilda patruelis Stål (Homoptera: Tettigometridae) (Olotu M, personal observation), which have been reported to be closely associated with AWA on cashew trees (Stathers TE, unpublished). 15 A prerequisite is, however, that the host plant should be able to support associated Homoptera from which the ant can obtain honeydew for food.…”

“…Weaver ants, Oecophylla smaragdina Fabricius (Hymenoptera: Formicidae), are used as biocontrol agents in cashew and mango orchards in Australia . The African weaver ant (AWA), Oecophylla longinoda Latreille (Hymenoptera: Formicidae), has already been used to control P. wayi in coconut in East Africa, cashew pests [ H. schoutedeni , Pseudotheraptus devastans Distant and Anoplocnemis curvipes Fabricius (Hemiptera: Coreidae)] in Ghana and fruit flies [ Ceratitis spp. and Bactrocera invadens (Diptera: Tephritidae)] in mango in Benin .…”

Foraging behavior and Preferences for Alternative Supplementary Feeds by the African Weaver Ant, Oecophylla longinoda Latreille (Hymenoptera, Formicidae)

“…Adequate palm protection is realized when two or more nests of O. longinoda are found in the palm crown (Way 1953) or when 60-70% of the palms are colonized by O. longinoda (Way and Khoo 1992). As Sporleder and Rapp (1998) reported, the population of P. wayi sinks to zero after a long and stable occupation of palm trees by O. longinoda.…”