Increases in crop pests caused by Wasmannia auropunctata in Solomon Islands subsistence gardens

Abstract

The impacts of Wasmannia auropunctata (the little fire ant) on the native biota and subsistence agriculture in the Solomon Islands are poorly understood. This species was originally introduced as a biological control against nut‐fall bugs (Amblypelta sp.) around 30 years ago and in the intervening time has spread throughout the Solomon Islands, aided movement of produce and planting material. It is now itself a major pest of coconut, cocoa and subsistence agriculture. In this study, we show the negative effects of this invasive ant on subsistence agriculture in the Solomon Islands. We do this by (i) assessing the presence of insect pests that develop a mutual relationship with W. auropunctata on four common subsistence crops; and (ii) measuring the impact of a significant pest (Tarophagus sp.) and its natural predator the bug Cyrtohinus fulvus, in the presence and absence of W. auropunctata on taro crops. The existence of insect pests that form a mutual relationship with W. auropunctata was measured in a total of 36 gardens of the four subsistence crops. This was conducted through standardized visual searches, plus identification and collecting from randomly selected plants within the gardens. A number of additional insect pests causing major problems to subsistence crops have also developed mutual relationships with W. auropunctata. Infested taro gardens have more Tarophagus sp. compared with taro plants that are free of the little fire ant. The presence and abundance of Wasmannia therefore has the potential to inflict considerable crop loss in rural subsistence gardens in the Solomon Islands.

The threat of invasive species to bats: a review

“…infestation (Fasi et al. ), but has been observed attacking native cuscus Phalanger orientalis (Wetterer & Porter ). Similarly, ants might displace the Solomons flying fox from roosting trees (Bowen‐Jones et al.…”

The Effects of Laboratory Rearing Diet on Recruitment Behavior of Wasmannia Auropunctata (Hymenoptera: Formicidaea)

“…Ants (Hymenoptera: Formicidae) are important terrestrial invertebrates in terms of biomass and filling niches essential for healthy ecological functioning (Andersen 1988;Abbott 1989;Holldobler & Wilson 1990;Porter & Savignano 1990;Folgarait 1998). The vast majority of the more than 12,000 described species (Ward 2007) are innocuous, but some are renowned for their destructive impacts on habitats to which they are introduced and regarded as pests (Zimmerman 1970;Beardsley 1980;Howarth 1985;Cole et al 1992;Reimer 1994;Daly & Magnacca 2003;Krushelnycky & Gillespie 2008;Bleil et al 2011;Fasi et al 2013).…”

“…The International Union of the Conservation of Nature's Invasive Species Specialist Group (Lowe et al 2000) has listed this species as having negative impacts on agriculture, quality of residential life, and native ecosystems throughout their introduced range (B. M. Drees et al, unpublished; Davis & Van Schagen 1993;Abedrabbo 1994;Haines et al 1994;Feener 2005;Cooper et al 2008;Arakaki et al 2009). This ant species has been reported to reduce biodiversity, farm phytophagous insects that vector plant disease (Smith 1929;Spencer 1941;Fabres & Brown 1978;Fowler et al 1990;Delabie & Cazorla 1991;Delabie et al 1994;Jourdan 1997;de Souza et al 1998;Wetterer et al 1999;Armbrecht & Ulloa-Chacon 2003;Le Breton et al 2003Walker 2006;Fasi 2009;Vonshak et al 2009;Berman et al 2013;Fasi et al 2013;Vanderwoude et al 2016), and are linked to the occurrence of tropical keratopathy (clouding of the cornea resembling cataracts) in wild and domestic vertebrates (Roze et al 2004;Theron 2005;Rosselli & Wetterer 2017). In addition to ecological impacts, W. auropunctata is considered a major nuisance pest due to its painful stings in residential and agricultural environments (Spencer 1941;Fabres & Brown 1978;Fasi et al 2016).…”

Ultrasonic monitoring to assess the impacts of forest conversion on Solomon Island bats

“…Makira has an area of 3191 km 2 and consists of a narrow coastal plain leading up to undulating hills with steep forested central ridges, with elevations of up to 1200 m (Allen et al 2006). It has a wet tropical climate characterized by high humidity, with very little annual variation and almost no seasonality (Danielsen et al 2010;Fasi et al 2013). Makira contains a total of 17 bat species (from 10 families), of which 10 are echolocating species (Flannery 1995;Lavery et al 2016).…”