Dual attractant toxic sugar baits (D-ATSB) containing two host kairomones, L-lactic (LA) and 1-octen-3-ol (O), and fruit-based attractants were evaluated through olfactory, consumption and mortality, and semi-field experiments to determine if host kairomones could first, enhance attraction of a fruit-based (attractant) toxic sugar bait (ATSB), and second, increase the efficacy of a fruit based attractive toxic sugar bait (ATSB). Four combinations of LA and O were incorporated into the ATSB and evaluated in an olfactometer to determine if these combinations could enhance attraction of Aedes aegypti (L.) to the bait. Ae. albopictus (Skuse) and Ae. aegypti were used to determine bait consumption through excrement droplet counts and percent mortality, of the most attractive D-ATSB (1% LA and 1% O) from the olfactory study. Semi-field evaluations were conducted in screened portable field cages to determine if the D-ATSB applied to non-flowering plants controlled more mosquitoes than the fruit-based ATSB, and ASB. Mosquitoes were exposed to D-ATSB and the two controls for 48 h and collected with BGS traps. The catch rates of the BGS traps were compared to determine efficacy of the D-ATSB. During olfactometer evaluations of D-ATSB, Ae. aegypti mosquitoes were more attracted to 1% LA and 1% O compared to the fruit-based toxic sugar bait alone. Both species of mosquito consumed more fruit-based non-toxic bait (ASB) and ATSB than the D-ATSB. For both species, percent mortality bioassays indicated D-ATSB controlled mosquitoes, as compared to non-toxic control, but not more than the fruit based ATSB. Semi-field evaluations, BioGents sentinel traps at 48 h confirmed that ATSB (positive control) controlled Ae. albopictus, but there was no statistical difference between ASB (negative control) and the D-ATSB. No differences were observed between the mosquitoes caught in any of the experimental formulations for Ae. aegypti. L-lactic (1%) and 1-octen-3-ol (1%) added to a fruit-based sugar bait increased attraction of Ae. aegypti and may have future implications in mosquito trapping devices. The addition of the host kairomones did not enhance the consumption and efficacy of the ATSB in laboratory or semi-field evaluations for both mosquito species. We attribute to the absence of other host cues leading to lack of alighting onto bait surfaces to imbibe the toxic bait, as well as a possible decrease in palatability of the bait caused by the addition of the host kairomones.

A common method of adult mosquito control consists of residual application on surfaces and aerial spraying often using pyrethroids. However, not all insects that contact insecticides are killed. Sublethal exposure to neurotoxic compounds can negatively affect sensory organs and reduce efficiency of host location. Flight tracks of host-seeking female Culex quinquefasciatus, Anopheles albimanus, and Aedes aegypti in a wind tunnel were video-recorded to compare activation of host-seeking and patterns of flight orientation to host odors. During host-seeking flights, all three mosquito species differed significantly in flight duration, velocity, turn angle, and angular velocity. Mosquitoes were then exposed to sublethal levels (LD₂₅) of pyrethroid insecticides to evaluate the effects of the neurotoxicants 24 hours post-exposure. Significant reductions in time of activation to flight and flight direction were observed in mosquitoes exposed to deltamethrin and permethrin. Additionally, pesticide-treated Cx. quinquefasciatus mosquitoes flew significantly slower, spent more time in flight, and turned more frequently than untreated controls.

The Asian citrus psyllid, Diaphorina citri, vectors huanglongbing (HLB), the most serious disease affecting citrus globally. D. citri and HLB have spread to the major citrus growing regions of North America causing billions of dollars of damage in Florida alone. The visual behavior of D. citri is not well characterized and more knowledge is needed to improve attractive traps for monitoring and control of the D. citri. Bioassays were conducted to evaluate attraction to light transmitted through different colored filters. The addition of ultra-violet light (< 400 nm) enhanced attraction of D. citri to transparent visual targets made of green or yellow filters. However, attraction to blue targets was unaffected by UV light. This is the first study to demonstrate a phytophagous insect responding to a hue that is a combination of long and short wavelengths. Further testing is needed to determine how D. citri uses such discriminatory powers in the field. Our results further imply that D. citri utilize color vision, as the less intense yellow and green hues were chosen over white light. In summary, this research provides an increased understanding of D. citri visual behavior and can be used for the development of a more attractive D. citri trap than those currently available.

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a primary pest of citrus due to its status as a vector of the citrus disease, huanglongbing. We evaluated the effects of light of specific wavelength and polarization on phototactic behavior of D. citri using a horizontal bioassay arena. Wavelength-associated positive phototaxis was associated with short wavelength UV (350–405 nm) targets whereas little or no responses were seen in longer wavelength targets in the visible spectrum from green to orange (500–620 nm). Distance walked towards the visual target was greater for UV/blue wavelengths (350–430 nm) than for longer wavelengths. Distances walked towards 365 nm light were greater than to white light, and distances travelled to green, yellow and orange light were similar to those in darkness. A reduced light intensity decreased responses to white and UV (365 nm) light. Polarized light was discriminated and D. citri travelled greater distance in response to white vertically polarized light than to horizontally polarized or unpolarized light of equal intensity. Responses to polarized 405 nm light were greater than to unpolarized light, although without an effect of polarization plane. For 500 nm light, there was no difference between responses to polarized or unpolarized light. There was no effect of age on responses to 405 nm light although 1 day old psyllids travelled faster in the presence of 500 nm green compared to 4–7 day old psyllids. Movement in response to UV and relative stasis in response to longer wavelength light is consistent with observed behaviors of settling on foliage for feeding and dispersing out of the canopy when flush needed for reproduction is scarce.

Combinations of female wingbeat acoustic cues and visual cues were evaluated to determine their potential for use in male Aedes aegypti (L.) traps in peridomestic environments. A modified Centers for Disease control (CDC) light trap using a 350–500 Hz frequency-sweep broadcast from a speaker as an acoustic stimulus, combined with a black poster-board half-cylinder behind the trap as a visual stimulus, captured a significantly greater proportion of males in a laboratory arena during daylight than a CDC trap with the visual stimulus alone or a CDC trap alone without stimuli. Traps of each treatment type captured relatively more males when they were placed at darker positions in the arena. Potential applications are discussed for the incorporation of these findings into trapping programs to reduce transmission of human pathogens vectored by Ae. aegypti.