Role of vision and mechanoreception in bed bug, Cimex lectularius L. behavior

Abstract

The role of olfactory cues such as carbon dioxide, pheromones, and kairomones in bed bug, Cimex lectularius L. behavior has been demonstrated. However, the role of vision and mechanoreception in bed bug behavior is poorly understood. We investigated bed bug vision by determining their responses to different colors, vertical objects, and their ability to detect colors and vertical objects under low and complete dark conditions. Results show black and red paper harborages are preferred compared to yellow, green, blue, and white harborages. A bed bug trapping device with a black or red exterior surface was significantly more attractive to bed bugs than that with a white exterior surface. Bed bugs exhibited strong orientation behavior toward vertical objects. The height (15 vs. 30 cm tall) and color (brown vs. black) of the vertical object had no significant effect on orientation behavior of bed bugs. Bed bugs could differentiate color and detect vertical objects at very low background light conditions, but not in complete darkness. Bed bug preference to different substrate textures (mechanoreception) was also explored. Bed bugs preferred dyed tape compared to painted tape, textured painted plastic, and felt. These results revealed that substrate color, presence of vertical objects, and substrate texture affect host-seeking and harborage-searching behavior of bed bugs. Bed bugs may use a combination of vision, mechanoreception, and chemoreception to locate hosts and seek harborages.

Fig 1. Experimental setup for determining bed bug preference to colors.

a) colored harborages, b) colored interceptors.

Fig 2. Experimental setup for determining the response of bed bugs to vertical objects.

a) tubular object, b) rectangular object, c) brown tubular object vs. black tubular object, and d) 30 cm vs. 15 cm tall brown tubular object.

Fig 3. Probability of bed bugs staying under colored paper harborages.

A) black, green, yellow, and white, and B) red, green, blue, and yellow. Twenty bed bug nymphs were used in each replication and each group was replicated four times. Different letters above the bars indicate significant differences (P < 0.05).

Fig 4. Probability of trapping bed bugs in interceptors with different exterior textures.

A) white paper surgical tape dyed black (dyed tape), white paper surgical tape painted black (painted tape), black polyester felt (felt), and white paper surgical tape (white tape), and B) dyed tape, painted tape, felt, and black texture paint on plastic (textured painted plastic). Fifty bed bugs (25 nymphs and 25 adult males) were used in each replication and each group was replicated eight times during four consecutive days of testing. Different letters above the bars indicate significant differences (P < 0.05).