Strategies to Exploit and Disrupt Dispersal Behavior of Structure Invading Pests

<p>NON-TECHNICAL SUMMARY: <br/>Urban pests represent a serious problem for people residing in urban settings. Many pest infestations have been associated with acute and chronic medical issues. Allergens related to cockroaches and other pests are prevalent in inner city residential areas and are a leading factor of asthma in children from these areas (Bush 2008). These pests can mechanically vector pathogens such a campylobacter, staphylococcus and salmonella and E. coli, which in combination with a lapse in proper food handling may lead to food borne illness (Garcia et al. 2012). Peoples' response to pests have occasionally caused further health issues, substantial structural damage and in some cases death (Rubin et al. 2002, US Centers for Disease Control 2011). While these effects can happen to anyone in society, it seems there are disproportionate effects to those in
low income areas and people with Limited English Proficiency (Lu et al. 2013). The cost of pests in urban areas may be substantial as people attempt to use over-the counter pesticides for controlling pests, hire pest management professionals to address the issue, or resort to illegal applications of potentially dangerous products. In commercial establishments, the costs of pest management are problematic as food processing facilities regularly shut down to undergo whole plant treatments with techniques such as Ultra-low Volume insecticide foggings, fumigation or heat treatments (Kells 2008). Reducing the negative effects and costs of pests and improving pest management in structural habitats, particularly in multifamily housing, should be a priority. To avoid problems with pests, those involved with pest management research recommend the use of integrated pest management practices for
earlier detection of pest activity and more targeted responses to effectively control the pest. However, in reviewing the EPA's definition of IPM (EPA 2006), Structural IPM practices are not well defined. Practices include: monitoring and inspections to detect pest activity, sanitation and exclusion, and insecticides (among other practices). However, Kramer (2004) notes most definitions of IPM still retain an agricultural bias. There is a need for more research related to how different components of IPM can be used within the whole program for structural habitats. IPM topics for structures are typically presented in no particular order leaving the affected person (or industry) challenged in attempting to formulate a cohesive program with the end point goals of pest suppression (and elimination), maximizing safety while performing economically. Pest insects and arthropods have
behavioral and physiological characteristics that promote or limit their dispersal abilities and knowing these characteristics are critical for improved IPM programs. Two components of structural IPM programs that impact dispersal, yet, are regularly underrepresented in research include sanitation and exclusion (S&E). These two program components directly affect a pest's use of the habitat. Understanding pest dispersal behavior, and how these animals perceive and respond to their environment, permits a better understanding as to which key S&E practices could have direct and real impact on pest biology. Understanding dispersal characteristics enables changes in IPM programs that work to enhance those factors limiting establishment. Previous research has shown key weak points in pest biology that could limit dispersal at "pinch" points while a pest is about to enter an
inter?habitat zone or limit a pest's ability to establish at another site. There are several examples, associated with the Kells' lab, where better understanding of pest dispersal behavior has helped indicate practices and weak points which aid in preventing or reducing successful dispersal. Recognizing an arrestment component to the aggregation pheromone in bed bugs (Olson et al. 2009) demonstrates a potential means of better monitoring key sites within habitats for new occurrences of this pest. The discovery of a residual human host kairomone (McQueen and Kells, 2013 in press) enables travelers to avoid bringing bed bugs home by bagging dirty laundry and excluding these pests from hitchhiking. Although not an urban structural pest the discovery that Tamarack acts as a trap crop for Orthotomicus erosus enables possible steps to prevent this insect from establishing in new areas
of North America (Walter et al. 2010). Recent work with mold mites (Tyrophagus putrescentiae), indicates that mites tend to explosively disperse and are less likely to move in the habitat until a point is reached in population density where a trigger causes a mass exit from prime habitat (Freitag and Kells, 2013a in prep). Also this explosive dispersal is regardless of humidity and mites have been shown to temporarily survive lower humidity levels than previously thought (Eaton and Kells, 2009). Such information suggests the requirement to directly sample (vacuum extract) potential habitat to more accurately determine mite activity versus using traps. To prevent mite dispersal, using acaricide dust barriers against this mite may have utility, especially in low humidity environs (Freitag and Kells 2013b). Each of these examples demonstrates how discovering key features in a pest's
life history can lead to ways of anticipating pest dispersal for the purposes of prevention and control. To effectively teach society how to improve IPM programs, requires a basic understanding of pest biology and characteristics that we can use to our advantage for effectively preventing spread or anticipating when (and where) dispersal may occur. Block the Bug 2020 is an extension campaign to ensure maximal utility of practices that limit pest dispersal, but without a basic understanding of pest dispersal for key animals (at least), it remains an empty shell with teachings subject to opinion and conjecture. This research, in combination with other work planned in situ, will provide a critical base of information making Block the Bug 2020 more applicable, relevant and effective.
<p>APPROACH: <br/>1. The population characteristics of key urban insects that result in dispersal. This objective will include studies to evaluate the influence of population size and pest density on the subsequent movement of pests from an identifiable harborage site to new sites. Possible test insects for this objective include bed bugs, German cockroaches, warehouse beetles, red?legged ham beetles, and mold mites, as these are currently major pests in a number of urban and stored product situations nationwide and dispersal characteristics are unknown to varying extents (i.e., some initial work has been published on German cockroaches and bed bugs, but less so for the other species). This objective utilizes arenas designed to have a primary starting point and an identifiable dispersal point (e.g., arenas with a harborage and a point where dispersal could be considered as
having occurred). Conditions of harborage availability, humidity and food availability can be defined at both points. Placing the pest insect in these arenas at different densities enables us to determine at what stage in population development insects initiate movement and what type of changes in movement characteristics occur as the population continues to develop. 2. The significance of subsequent behaviors to locate new sites. This objective will focus on the determination of chemical and physical cues that may promote location of new resources and habitats in which to thrive. This objective evaluates the principal dispersal stage of the insect and conditions encouraging dispersal and their resultant movement to new patches. Utilizing the similar arenas in objective 1, but permitting choice in selecting pathways enables specific cues (and combinations) to be evaluated for promoting
habitat selection. Also, the dispersal?choice arenas will be compared against four?arm olfactometry apparatus to determine if similar results will permit use of a simpler choice experiment, thereby alleviating the need for a complex set up. Selection of stimuli will be based on current literature, materials that are typically found in situ and compounds perceived as possibly providing cues to habitat location.