carbon dioxide, heat and chemical lure trap for the bedbug, Cimex lectularius

A trap for the collection of bedbugs, Cimex lectularius Linnaeus (Hemiptera: Cimicidae), is described. The trap was baited with CO₂ (50-400 mL/min), heat (37.2-42.2 °C) and a chemical lure comprised of 33.0 μg proprionic acid, 0.33 μg butyric acid, 0.33 μg valeric acid, 100 μg octenol and 100 μg L-lactic acid, impregnated into a gel. Laboratory studies, conducted in a square arena measuring 183 cm on each side, showed that traps with and without baits captured adult bedbugs, but traps with CO₂ emissions of 50-400 mL/min caught significantly (P < 0.05) more bedbugs than traps without CO₂. In an infested unoccupied apartment, traps with heat and with or without the chemical lure were tested without CO₂ on 29 trap-days and with CO₂ on 9 trap-days. The numbers of bedbugs captured were 656 and 5898 in traps without and with CO₂, respectively. The numbers of bedbugs of all development stages captured were significantly greater in traps with CO₂ (χ² = 15 942, d.f. = 1, P < 10⁻⁹). A non-parametric two-way analysis of variance evaluation of six different traps with or without CO₂, heat or a chemical lure monitored over 19 trap-days in an infested apartment showed that trap type was highly significant (n = 2833 bedbugs collected) (P < 10⁻⁷). The trap with CO₂, heat and a chemical lure captured more bedbugs than the other traps, but only caught significantly more fourth and fifth instar nymphs than all other traps. Otherwise, the catches in this trap did not differ significantly from those caught by traps that contained CO₂ and heat only. The total numbers of bedbugs collected for each trapping date (pooling all six traps) followed an exponential decline over the trapping period. This type of trap, which caught bedbugs in unoccupied apartments with and without furniture, and in an occupied apartment, may have utility in studying the ecology of bedbugs, in detecting bedbug infestations and in reducing numbers of bites by trapping host-seeking bedbugs.