Attractant Activity of Host-Related Chemical Blends on the Poultry Red Mite at Different Spatial Scales

Abstract

<p>Many blood-feeding arthropods use volatile organic compounds (VOCs) to detect their vertebrate hosts. The role of chemical interactions in mediating the behavior of hematophagous insects and ticks has been investigated before but remains poorly understood in hematophagous mesostigmatic mites. The poultry red mite <i>Dermanyssus gallinae</i> is an obligatory bloodsucking mesostigmatic mite that feeds on birds and causes damage in poultry farms. We characterized the attractive response of <i>D. gallinae</i> to candidate VOCs previously reported from the odor emitted by living hens. We performed <i>in-vitro</i> choice-test bioassays as well as semi-feld and feld trials using baited and unbaited traps, in the presence and absence of hens. Among different tested combinations of VOCs, a blend of 5 VOCs (mix1.0) was significantly attractive to our reference population of <i>D. gallinae in vitro</i>, whereas the same individual compounds tested alone were not attractive. Ammonia was attractive on its own and increased the mix1.0 attractiveness. The attractiveness of mix1.0 was confirmed at 'natural' spatial scales in the absence of hens both at the lab and on the farm that provided the reference population. The presence of hens inhibited the mix1.0 attractiveness. The attractive power of mix1.0 was not found in other farms. This research is an important step to advance our understanding of host-parasite interactions in hematophagous mesostigmatic mites and paves the way for developing alternative control tools against <i>D. gallinae</i> by interfering with chemical interactions. Moreover, it underlines the importance of assessing kairomonal activity on different pest populations when developing attract-and-kill systems.</p>