Precision control of an invasive ant on an ecologically sensitive tropical island: a principle with wide applicability.
Effective management of invasive ants is an important priority for many conservation programs but can be difficult to achieve, especially within ecologically sensitive habitats. This study assesses the efficacy and nontarget risk of a precision ant baiting method aiming to reduce a population of the invasive big-headed ant Pheidole megacephala on a tropical island of great conservation value. Area-wide application of a formicidal bait, delivered in bait stations, resulted in the rapid decline of 8 ha of P. megacephala. Effective suppression remained throughout the succeeding 11-month monitoring period. We detected no negative effects of baiting on nontarget arthropods. Indeed, species richness of nontarget ants and abundance of other soil-surface arthropods increased significantly after P. megacephala suppression. This bait station method minimized bait exposure to nontarget organisms and was cost effective and adaptable to target species density. However, it was only effective over short distances and required thorough bait placement. This method would therefore be most appropriate for localized P. megacephala infestations where the prevention of nontarget impacts is essential. The methodology used here would be applicable to other sensitive tropical environments.
Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag XI, Matieland 7602, South Africa. reneg@sun.ac.za
R
R
Gaigher
M J
MJ
Samways
K G
KG
Jolliffe
S
S
Jolliffe
D000818:Animals; D001000:Ants / Q000502:physiology*; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005843:Geography; D007300:Insect Control / Q000379:methods*; D007306:Insecticides / Q000008:administration & dosage / Q000494:pharmacology*; D058865:Introduced Species; D011157:Population Dynamics; D011744:Pyrimidinones / Q000008:administration & dosage / Q000494:pharmacology*; D014329:Tropical Climate
D007306:Insecticides; D011744:Pyrimidinones; C041642:hydramethylnon