Pervasive Resistance to Pyrethroids in German Cockroaches (Blattodea: Ectobiidae) Related to Lack of Efficacy of Total Release Foggers

Zachary C. Devries, Richard G. Santangelo, Jonathan Crissman, Alonso Suazo, Madhavi L. Kakumanu, Coby Schal, Michael Rust

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


Despite limited efficacy data, do-it-yourself (DIY) insecticide products often promise low-cost alternatives to professional pest control. Total release foggers (TRFs, 'bug bombs'), which are prominent DIY products, were recently shown to be ineffective at reducing German cockroach (Blattella germanica L.) infestations, in contrast to highly effective baits. However, the reason(s) for TRF failure remain unknown. Therefore, we investigated insecticide resistance of apartment-collected cockroaches from homes where TRFs failed. In topical (direct) application assays, resistance to cypermethrin (a common active ingredient in TRFs) was 202 ± 33 times that of a laboratory insecticide-susceptible population (based on LD50 ratios), while resistance to fipronil, a common bait active ingredient, was considerably lower at 14 ± 2 times that of the laboratory insecticide-susceptible population. The addition of PBO, a P450 inhibitor that synergizes pyrethroids, enhanced the efficacy of cypermethrin, but only at high doses of cypermethrin. Additionally, >96% of screened cockroaches possessed at least one copy of the L993F mutation in the voltage-gated sodium channel, known to confer resistance to pyrethroids (knockdown resistance, kdr). Because TRF treatments killed insecticide-susceptible sentinel cockroaches but failed to kill apartment-collected cockroaches, these results suggest that pyrethroid resistance is a major factor contributing to the failure of TRFs. Multiple mechanisms of resistance, including metabolic detoxification of the pyrethroids and kdr mutations that confer target-site insensitivity, suggest that TRFs would lack efficacy against German cockroaches in residential settings, where high levels of pyrethroid resistance have been documented globally.

Original languageEnglish
Pages (from-to)2295-2301
Number of pages7
JournalJournal of Economic Entomology
Issue number5
StatePublished - Sep 23 2019

Bibliographical note

Funding Information:
We thank residents of several housing communities in Raleigh, NC who participated in this study; this study would not have been possible without their support and partnership. Funding for this study was provided by the Blanton J. Whitmire Endowment at North Carolina State University, the U.S. Department of Housing and Urban Development Healthy Homes program (NCHHU0017-11), the U.S. Environmental Protection Agency Pesticide Environmental Stewardship Program (PESP, PE-95450709), and a National Institute of Environmental Health Sciences grant to the Center for Human Health and the Environment (CHHE, P30ES025128). Z.C.D. was support in part by the David R. Nimocks Jr. Fellowship and scholarship awards from the Foundation for Agromedicine and Toxicology, Pi Chi Omega, and the Entomological Society of America (Monsanto Research Grant Award, MUVE Scholarship).

Publisher Copyright:
© 2019 The Author(s). Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved.


  • cypermethrin
  • do-it-yourself pest control
  • kdr
  • topical application

ASJC Scopus subject areas

  • Ecology
  • Insect Science


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