Vector Control, Pest Management, Resistance, Repellents Filth Fly Activity Associated With Composted and Noncomposted Beef Cadavers and Laboratory Studies on Volatile Organic Compounds T. R. Dubie, 1,2 J. L. Talley, 1 J. B. Payne, 3 A. W. Wayadande, 1 J. Dillwith, 1 and C. Richards 3 1 Department of Entomology and Plant Pathology, Oklahoma State University, 127 Noble Research Center, Stillwater, OK 74078 (trishd@okstate.edu; justin.talley@okstate.edu; a.wayadande@okstate.edu; Jack.Dillwith@okstate.edu), 2 Corresponding author, e-mail: trishd@okstate.edu, and 3 Department of Animal Science, Oklahoma State University, 310 North Monroe, Stillwater, OK 74078 (joshua.payne@okstate.edu; chris.richards@okstate.edu) Subject Editor: Jason Byrd Received 23 November 2016; Editorial decision 13 March 2017 Abstract Commercial livestock facilities are faced with the challenge of managing large amounts of waste including manure and animal mortalities. One method of disposing of dead animals is composting. The cadavers are en- veloped in carbon material that creates a barrier between the dead tissue and the surrounding environment. Dead tissue can release materials that not only contaminate the soil but also the groundwater and nearby surface water. Animal cadaver composting is designed to facilitate decomposition without the aid of carrion- feeding insects and reduce the presence of common pathogens associated with animal waste and dead tissue. The aim of this study was to evaluate insect activity associated with composted and exposed beef cadavers, specifically filth flies that can serve as mechanical vectors of important human pathogens such as E. coli 0157:H7. Greater numbers of all types of arthropods were trapped overall at the exposed animal site than the composted animal site. Most importantly, the number of filth flies was significantly lower at the composted site (P ¼ 0.0009). Laboratory analysis of volatile organic compounds from composted and noncomposted rats indi- cated that known fly attractants such as dimethyl disulfide may be inhibited by the composting process. Implementing composting programs at livestock facilities could reduce the risk of flies spreading harmful pathogens to surrounding areas, including farms that grow fresh produce. Key words: bovine cadaver, decomposition, carcass disposal, Calliphoridae, Muscidae Filth flies are well-known pests that are directly associated with live- stock operations. They develop in various types of decaying organic matter including animal manure and decomposing animal tissue; therefore, animal production facilities create ideal conditions for their development. Commercial livestock facilities are challenged with regular disposal of substantial amounts of manure and animal carcasses. In the United States, this can amount to millions of cattle carcasses annually (USDA, National Agricultural Statistics Service 2011). Catastrophic events such as disease outbreaks and natural di- sasters can dramatically increase the number of livestock mortalities, and these circumstances require a safe and effective means of carcass disposal. Exposed livestock cadavers can contain harmful zoonotic pathogens that can be transmitted to other livestock animals (Lloyd- Smith et al. 2009), and many filth flies are competent mechanical vectors of pathogenic microorganisms that can be acquired from an- imal manure and animal carcasses (Greenberg 1973, Graczyk et al. 2001). Filth flies have also been implicated in the transmission of antibiotic-resistant bacteria (Zurek and Ghosh 2014). Livestock op- erations have been suspected of creating selection pressure for anti- biotic resistance owing to their widespread use of antibiotics, and filth flies can easily spread these organisms from animal facilities di- rectly to urban environments (Zurek and Ghosh 2014). Filth flies are potential vectors for contaminating produce on-farm, and there- fore their control is an essential component of food safety (Talley et al. 2009, Wasala et al. 2013). Some alternative methods of carcass disposal may leave the area more accessible to flies. Abandonment is illegal, although many pro- ducers still leave exposed carcasses to decompose on their property. Above-ground burial has proven to be an ineffective means of ca- daver disposal and does not reduce insect activity or pathogen sur- vival (Eamens et al. 2011). Incineration and rendering are additional options for carcass disposal, and although both methods are accept- able, the biosecurity of transporting and preparing the dead animals for these methods can be problematic and expensive for producers VC The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com 1299 Journal of Medical Entomology, 54(5), 2017, 1299–1304 doi: 10.1093/jme/tjx073 Advance Access Publication Date: 8 April 2017 Research article Downloaded from https://academic.oup.com/jme/article/54/5/1299/3192379 by guest on 05 February 2023