Toxic bait for the control of Anoplolepis longipes (Jerdon) (Hymenoptera: Formicidae) in the Seychelles. II. Effectiveness, specificity and cost of baiting in field applications

Abstract

Bait containing 1% a.i. aldrin and used at a rate of 10 kg/ha gave good control of Anoplolepis longipes (Jerd.) in the Seychelles, especially when large areas were treated. Typically, 90% or more of the ants were killed, usually within the first few days. Depending on the area baited, population recovery took at least 3–12 months and was largely by re-invasion from untreated areas. The bait was relatively specific but chickens starved for 24 h would eat it when no other food was available. It is concluded that baiting is relatively inexpensive and provides a safe method of controlling infestations of A. longipes over large areas.

Foraging activity and diet of the ant, Anoplolepis tenella Santschi (Hymenoptera: Formicidae), in southern Cameroon

“…A disruption method targeting ants which are more active and responsible for the scale dispersal may be more efficient. Because it has fewer environmental effects, baiting seems to be an appropriate method for ant control (Haines & Haines 1979;Williams 1983;Steyn 1954). Amdro is one of the best known ant baits developed for control of the fire ant, Solenopsis invicta Buren, in the U.S.A. (Apperson et al 1984;Williams, 1983) and tested in South Africa citrus against Pheidole megacephala (Fabricius) and A. custodiens (Steyn 1954;Samways 1985).…”

Toxic bait for the control of Anoplolepis longipes (Jerdon) (Hymenoptera: Formicidae) in the Seychelles. III. Selection of toxicants

“…Aldrin in bait provides effective and inexpensive control of A. longipes in the Seychelles, with little risk of contaminating ithe environment (Haines & Haines, 19796).…”

“…In laboratory bioassays the LT50 of 1 % (w/w) a.i. aldrin for A. longipes workers was 3-5-4 h (Haines & Haines, 19796), so this response time should allow some distribution sf toxicant within the nest under field conditions. Other toxicants were compared with ildrin in similar replicated bioassays.…”

“…In the field, foragers of A. longipes walk, when undisturbed, at an average rate of about 2 m/min over distances rarely exceeding 100 m (Haines & Haines, 19796). Therefore, any toxicant with which there is a delay of about 1 h before poisoning symptoms occur is likely to allow ants enough time to carry bait back to the nest, and a longer delay would facilitate better distribution of toxicant within the nest.…”

“…The most effective bait previously tested contained aldrin and gave good control of ants with little risk of polluting the environment if applied as recommended (Haines & Haines, 19796). However, the incorporation of a toxicant less persistent than aldrin, with lower toxicity to mammals and other vertebrates, would be advantageous.…”