Thieves, bats and fruit flies: local ecological knowledge on the weaver antOecophylla longinodain relation to three ‘invisible’ intruders in orchards in Guinea

Abstract

We held interviews with 100 mango and cashew growers in Guinea, West Africa. Fewer than 20 questions dealing with the tree-inhabiting weaver ant Oecophylla longinoda were developed, based on local context and related research conducted on farmers' knowledge in other countries. More than half of the growers reported that ants protect their orchard from thieves. Apart from deterring snakes, about 46% of the growers mentioned that weaver ants reduce damage by fruit-eating bats; some reported that bats do dislike the smell of weaver ants. Whereas the relationship between ants and humans or conspicuous fruit bats is well understood, a quantitative appreciation of the effect of Oecophylla on small insect pests, such as fruit flies, is more complex. Despite the fact that 57% of the growers reported that Oecophylla had a positive effect on mango fruit quality, many classified Oecophylla as a pest due to its nuisance during harvest, and they requested the plant protection staff to help them with pesticides. Strategies to strengthen local ecological knowledge are discussed.

The Conflict Between Pteropodid Bats and Fruit Growers: Species, Legislation and Mitigation

“…However, 40 % of farmers also felt that the weaver ant itself is also a form of pest, as it rolls up leaves and is a nuisance during harvest (Van Mele et al 2009). Yet this species is considered by entomologists and ecologists to be a potential biological control agent (Van Mele 2008).…”

“…Overall, according to the farmers, five species of insects, followed by squirrels, caused greater damage than bats. The majority of farmers did not carry out any pest management (Van Mele et al 2009). Entwistle and Corp (1997) examined the diet of Pteropus voeltzkowi), which is endemic to the island of Pemba, off the coast of Tanzania.…”

Grower Perception of the Significance of Weaver Ants as a Fruit Fly Deterrent in Tanzanian Smallholder Mango Production

“…By contrast, 86 out of 100 growers in Guinea noting fruit flies as their biggest problem (Van Mele et al, 2009a). This diminished view of fruit flies as a pest is due, in part, to the common practice of harvesting mangoes at early maturity stage, with little or no flesh softening, when the fruits are less attractive to the flies (Mayamba et al, 2014).…”

Effet de la densité des fourmis rouges [<i>Oecophylla longinoda latreille</i> (<i>Hymenoptera: formicidae</i>)] des manguiers sur la teneur en sucres et acides organiques de la mangue [<i>Mangifera indica</i> L. (<i>Sapindales: Anacardiaceae</i>)]

“…Sachant que le rapport sucre/acide est un indicateur du goût perçu par le consommateur (Lechaudel et al, 2005 ;Signoret, 2004), les résultats actuels s'écartent des résultats d'enquêtes réalisées auprès des acteurs de différentes filières horticoles dans de nombreux pays. En effet, la plupart des acteurs (producteurs, collectrices-revendeuses, consommateurs) enquêtés déclarent qu'il existe une différence de qualité entre les fruits (mangues, agrumes, cajou) protégés par les oecophylles et ceux non protégés, notamment du point de vue du goût, de la couleur, de l'arôme, de la texture et de la durée de vie post récolte Van Mele et al,2009). Au cours des travaux préliminaires, l'enquête effectuée dans la région de Parakou auprès des acteurs de la filière mangue (producteurs, collectricesrevendeuses, consommateurs) a révélé que la mangue protégée par O. longinoda a un goût plus sucré que celle non protégée selon 79,41% des enquêtés (Houngbo, 2012).…”