Food preference and foraging activity of ants: recommendations for field applications of low-toxicity baits.

Casper Nyamukondiwa,Pia Addison

doi:10.1093/jis/14.1.48

Abstract

Control of ants using baits of low toxicity cannot be effective without knowledge of bait distribution patterns and bait station densities, which are determined by ants’ foraging activities. Furthermore, the success of toxic baits also depends upon attractiveness of bait carriers. Here, we assessed ground and vine foraging activity and food preferences for the three ant species ( Linepithema humile (Mayr) (Hymenoptera: Formicidae), Anoplolepis custodiens (F. Smith) and Crematogaster peringueyi Emery) under field conditions. We found that L. humile ’s vineyard foraging activity was high and that movement of ant bait by C. peringueyi and A. custodiens in the vineyard was relatively low. Consequently, more bait stations need to be dispensed for more effective control of C. peringueyi and A. custodiens than for L. humile . Different bait densities are discussed for the various ant species. Food preference trials indicated that vineyard foraging ants preferred wet bait attractants over dry ones, making liquids the most ideal carriers for baiting these ants. Linepithema humile was attracted to 25% sugar water, while C. peringueyi was attracted to both 25% sugar water and honey. Anoplolepis custodiens was attracted to tuna but was also attracted to 25% sugar water. Thus, future bait formulations should be tailor made to suit these specific food requirements if baits are to be successful in ant pest management.

Highlights

In vineyards, the mutualism between ants and the vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), results in population explosions of both insects, thereby causing pest injury and economic losses (Kriegler and Whitehead 1962; Way 1963; Myburgh et al 1973)
Linepithema humile was attracted to 25% sugar water, while C. peringueyi was attracted to both 25% sugar water and honey
A significant drop in A. custodiens foraging activity occurred on the ground after 2 m (Figure 2)

Summary

Introduction

The mutualism between ants and the vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), results in population explosions of both insects, thereby causing pest injury and economic losses (Kriegler and Whitehead 1962; Way 1963; Myburgh et al 1973). Linepithema humile is a cosmopolitan, invasive pest in agricultural and urban areas (Suarez et al 2001) that nests predominantly in the soil, while C. peringueyi and A. custodiens are of southern African origin, the former nesting in the canopy and the latter in the soil (Addison and Samways 2000). Current recommendations for control include the use of chemical stem barriers, which target only ground nesting species by preventing access into the canopy (Addison 2002). This control method is designed to break the mutualism between the ants and mealybugs so that natural enemies, primarily encyrtid wasps, can effectively control P. ficus without ant interference (Samways 1990)

Methods

Results

Conclusion