3TROPICAL HOUSEHOLD ANTS: PEST STATUS, SPECIES DIVERSITY, FORAGING BEHAVIOR, and BAITING STUDIES

Abstract Questionnaire-based surveys of homeowners revealed that ants were the most economically important and abundant household pest after mosquitoes and cockroaches in Malaysia. Twenty-five spe-cies of ants were found indoors and outside buildings; all species nest outdoors except Monomorium pharaonis, Monomorium floricola, Tapinoma melanocephalum, and Solenopsis molesta. Surveys of houses and food stores indicated the most common species were Pheidole sp., T. melanocephalum, Monomorium destructor, and Paratrechina longicornis. A survey of homeowners ’ attitudes and knowledge of ants showed that 62 % found ants daily in their homes. Most respondents tolerated < 50 ants indoors; 65 % used aerosol sprays for control, 6 % used ant baits. Homeowners were not aware that ants can mechanically vector pathogenic organisms. Bacteria, fungi, and yeasts were isolated from ants collected from food outlets. Most ant species responded to peanut butter attractant, except P. longicornis and T. melanocephalum, which preferred honey. Attractancy to peanut butter and honey changed in an 18-month study of M. pharaonis. All species, except Pheidole sp. preferred liquid bait. Foraging of P. longicornis, M. pharaonis, and Solenopsis geminata was negatively correlated with temperature; their peak activity was 2-4 hours after sunset. Most baits gave>75 % reduction after one week post-treatment. Key Words household ants, Malaysia, pest status, food preference, foraging, bait