Using weaver antsOecophylla smaragdinato control two important pests on African mahoganyKhaya senegalensisin the Northern Territory of Australia

Abstract

African mahogany, Khaya senegalensis, is a high-value timber tree species. Pilot plantings showed that the species performed well in the wet-dry tropical areas of northern Australia, but the yellow looper, Gymnoscelis sp., and the bush cricket, Myara yabmanna, caused severe damage to the trees. The weaver ant, Oecophylla smaragdina, is an effective bio-control agent of a range of insect pests in tropical tree crops and forest trees. To determine whether the ants control these mahogany pests, field experiments were conducted from April 2006 to January 2009 at two sites near Darwin, Australia. The fraction of the total number of trees damaged per year was 4.2-32.4% by yellow loopers and 0-10.4% by bush crickets on trees with weaver ants, but 25-70.4% by yellow loopers and 25-100% by bush crickets on trees without the ants. The damaged trees with weaver ants were attacked on fewer occasions than damaged trees without the ants. Significantly fewer trees with weaver ants were damaged per monitoring occasion (2.1-8.4% at Berrimah Farm and 0.5% at Howard Springs by yellow loopers; 0-2.2% by bush crickets) than trees without the ants (24.2-51.3% at Berrimah Farm and 5.0% at Howard Springs by yellow loopers; 18.1-40.7% by bush crickets). Data suggested that weaver ants were effective bio-control agents of the two pests.

Weaver Ants Provide Ecosystem Services to Tropical Tree Crops

“…Ant treatments had significantly fewer pests and less pest damage than treatments without ants. Outliers are shown as white dots, while the solid black line indicates the median and the box shows the distribution of the dataset compiled from 25 studies (Peng et al, 1995(Peng et al, , 1999(Peng et al, , 2011(Peng et al, , 2012(Peng et al, , 2013(Peng et al, , 2014Sporleder and Rapp, 1998;Peng and Christian, 2004, 2005b, 2008Ayenor et al, 2007;Van Mele et al, 2007;Adandonon et al, 2009;Dwomoh et al, 2009;Hosetti and Rudresh, 2012;Olotu et al, 2013;Pierre and Idris, 2013;Abdulla et al, 2015Abdulla et al, , 2016Abdulla et al, , 2017Anato et al, 2015;Diame et al, 2015;Forbes and Northfield, 2017a).…”

A Review on Distribution Pattern, Nesting Style, Mating Behavior, Colony Organization of Asian weaver ant <em>Oecophylla smaragdina</em> (Hymenoptera: Formicidae) Occupying Strategic Biome-agroforestry Systems of Asia

“…Table 1 shows O. smaragdina presence in diverse environments range, tropical forests and large plantations such as oil palm (Elaeis guineensis) [13,14] and other crops such as cashew nuts (Anacardium occidentale), mango (Mangifera indica) [37], rambutan (Nephelium lappaceum) [38], sweet orange (Citrus sinensis), pomelo (C. grandis or C. maxima), or lime (C. aurantifolia) [39]. They are also recorded in the introduced African mahogany (Khaya ivorensis and Khaya senegalensis) in Southeast Asia [40,41] and Australia [42].…”

“…Table 1 shows ubiquitous distribution of O. smaragdina in diverse biome of Asia (biogeographical unit consisting of a biological community sharing regional climate and a variety of habitats) from protected reserve national parks-ecological sanctuaries [47,48], tropical primary rainforests [49,50]. This include agroforestry systems [42,51], large agricultural plantations dominantly under oil palms monoculture system [52,13] to rural and highly modernised populated urban areas [53,30]. An important diversity of host plants are recorded from different field of study i.e.…”