Colony dispersion and nesting habits of the ants, Dolichoderus thoracicus and Oecophylla smaragdina (Hymenoptera: Formicidae), in relation to their success as biological control agents on cocoa

Abstract

In mixed cocoa-coconut palm plantations in Malaysia the palm spadices provide large, stable nesting sites for Dolichoderus thoracicus (Smith) in contrast to impermanent sites on cocoa and on the ground. D. thoracicus and the arboreal leaf-nesting Oecophylla smaragdina (Fabricius) both benefit from the mixed system which also provides a more stable food supply from honeydew-producing Homoptera. A scoring method showed that about 50–200 O. smaragdina or 200–2000 D. thoracicus on a cocoa tree can protect it effectively from Helopeltis theobromae Miller (Hemiptera: Miridae). The relatively greater efficiency of O. smaragdina as a biological control agent is associated with its actively dispersive predatory behaviour in contrast to the localized concentration of D. thoracicus workers at sites such as cocoa pods where it tends honeydew-producing Homoptera, and where it acts largely by deterring H. theobromae. Despite its biological control potential, the painfully biting O. smaragdina, unlike D. thoracicus, is normally considered unacceptable to plantation staff. Nevertheless it should be recognized as valuable in integrated pest management of cocoa pests especially where D. thoracicus is difficult to establish.

Plant species diversity for sustainable management of crop pests and diseases in agroecosystems: a review

“…The presence of different shade strata favours generalist predators like spiders and ants , which are natural enemies of mirid bugs (Way and Khoo 1991). On the other hand, Phytophthora is frequently vectored by ants (Evans 1973).…”

“…On the other hand, Phytophthora is frequently vectored by ants (Evans 1973). The influence of shading and of the shade species on the distribution of ants was studied in cocoa plantations in Ghana (Bigger 1981) and Malaysia (Way and Khoo 1991) and in coffee plantations in Costa Rica (Perfecto and Vandermeer 1996). Detailed studies by Perfecto and Vandermeer (1996), focusing on a key mutualism between an ant (Azteca instabilis) and a scale insect (Coccus viridis) in a coffee agroforestry system in Costa Rica, were described in the previous section ("Section 11") since the ability of A. instabilis to establish its nests in shade trees is more closely linked to the architectural characteristics of the trees than to the effects of microclimate.…”

Host plants and associated trophobionts of the weaver ants Oecophylla spp. (Hymenoptera: Formicidae).

“…O. smaragdina has been used by Chinese farmers to protect citrus crops since 304 A.D. [3]. Many studies on the bionomics of this ant genus [4][5][6][7][8][9] are from its application in the field. Farmer-friendly guides on applying O. smaragdina to fruit trees [10] and cashew [11] also exist that synthesize knowledge available on the ant in those habitats.…”

“…Host plants provide foliage the ants need to build nests with. O. smaragdina typically uses leaves of a certain 'normal' size that are not very waxy [8] and has been observed to favour certain plant species [5] but can construct nests with most leafy foliage. The ants can utilize many plants in a wide range of habitats [1].…”

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

“…Two species of weaver ants, Oecophylla longinoda Latreille and Oecophylla smaragdina Fabricius are generalist predators that protect crops against insect pests (Way and Khoo 1991;Peng and Christian 2007;Van Mele 2008;Materu et al 2014). The use of Oecophylla as a biocontrol can lead to increased fruit yield and quality (Barzman et al 1996;Peng and Christian 2005;Olotu et al 2013a).…”