Insecticide Resistance in Bed Bugs
Bed bugs, Cimex lectularius, have reestablished themselves as key urban and community pests throughout the world after decades of relative obscurity. Applications of insecticides have often been recommended, employed within eradication strategies, and cited as 'most common' within the pest control industry. This approach has proven problematic since widespread pyrethroid resistance has been reported in "modern" bed bugs, with some populations entirely unaffected by label rate applications. One of the goals of the insecticide research line is to continue monitoring the status of susceptibility of field-collected populations to current and new insecticides to detect insecticide resistance at early stages. Also we are interested in understanding the mechanisms of insecticide resistance in bed bugs. This information is crucial to design control programs that reduce the impact of insecticide resistance. Our lab is acting as a reference lab for screening new insecticide materials.
Environmentally Friendly Products for the Management of Cockroaches
Cockroaches directly affect more people in the U.S.A. than any other group of arthropods. Of the five or six cockroach species associated with man, the Turkestan cockroach, Blatta lateralis, has become the most important peridomestic species in urban areas of the Southwestern United States. Hundreds of Turkestan cockroaches are seen in animal feed mills, around sheep feeders, and places where animal manure accumulates. These cockroaches frequently invade human environments through holes, cracks, and gaps between doors and floors. There are concerns about the escalation of Turkestan cockroach infestations in urban areas and their geographical expansion to other areas of the U.S.A. Infestations of Turkestan cockroaches in indoor areas can lead to airborne exposure to allergens derived from saliva, feces, and shed exuvia of cockroaches that trigger both asthma and allergies in sensitized people. This species is also a potential vector of microorganisms that are pathogenic to animals and humans, including Salmonella spp. a bacterium
that is a threat to public health in the Southwestern United States. The impact of this insect is also reflected in the cost associated with control. Current methods for the control and elimination of Turkestan cockroaches and other peridomestic cockroaches rely on the use of synthetic insecticides. Application of these insecticides in peridomestic and domestic areas is a public concern due to risk of exposure to these insecticides that can result in toxicity. Plant-derived insecticides are an alternative to traditional insecticides, particularly in sensitive environments such as hospitals, daycares, and schools. Essential oils have been used for pest control for hundreds of years in Asia and are considered safe because of their relatively short residual period and their low toxicity to humans, animals, and wildlife. The goal of this research line is to identify effective essential oils and constituents against cockroaches that can be used for the management of these pests. The Urban Entomology Laboratory has standardized an array of insecticide and behavior assays to evaluate the effect of botanical compounds on the Turkestan cockroaches. For this, we are using a modern computerized video tracking system that allow us to identify and characterize compounds with repellency properties. Due to their repellency properties, these essential oils/essential oil constituents can be used by PMPs as part of an integrated pest management programs to repel cockroaches at points of entry into a structure.
Host Seeking Behavior in Blood Feeding Insects
My program has identified kissing bugs as pests with urban relevance for New Mexico and neighboring states. Kissing bugs are bloodsucking insects of considerable significance to human health, because in addition to producing a bite that can cause serious allergic reactions in some people, they vector American trypanosomiasis, also known as Chagas disease. The economic and medical impact of this disease is underappreciated, and it is one of the most neglected tropical diseases in the world. Kissing bugs threaten to spread Chagas disease to nonendemic areas where they are present, including the United States. Triatoma rubida is considered an important vector of Chagas in Northern Mexico and the Southwestern United States. Public health problems presented by kissing bugs in the southern United States are being exacerbated by the rapid expansion of human populations into kissing bug habitats. In Southern Arizona and New Mexico, hungry kissing bugs of the species T. rubida, attracted by artificial light, invade homes during spring and summer. The attraction of T. rubida to lights and their subsequent invasion of human environments has important epidemiological significance because it enhances the possibility of contact between these insects and humans. This research line aims to study the environmental and host-associated cues that these insects use to find and acquire a blood meal. A detailed understanding of the responses of these kissing bugs to host-associated cues will lead to the identification of effective compounds that can be used in trapping systems for monitoring and controlling infestations of these pests. We employed a modern video tracking technique and an olfactometer system to analyze responses of T. rubida to host-associated cues and detail aspects of this orientation. The research of this line is highly innovative because we used state-of-the-art bioassays with modern automated video tracking techniques that enabled us to quantify behavior changes of T. rubida at an unprecedented level. Recently, my laboratory initiated collaborative work with Dr. Camilo Khatchikian at University of Texas at El Paso in the project “Population Structure of the Chagas Disease Vector Triatoma rubida”. Studies on the structure of T. rubida populations is a fundamental component for examining genetic variation and distribution of T. rubida in southwestern states that will complement our efforts to understand the epidemiology of these Chagas disease vectors.
Finally, a new research line is studying the integration of thermal, hygric and chemical signals by bed bugs in the host-seeking process. Responses to combinations of attractants are being evaluated with short- (olfactometers, sphere-track devices) and long-range (artificial chambers) bioassays.
