Table 1.
Summary of studies that quantified fipronil resistance in field-collected B. germanica
| Year | Authors | RRa range | No. of strains | Collection years | Location | Type of treatment | Assay used | Time of mortality assessment |
|---|---|---|---|---|---|---|---|---|
| 1997 | Scott and Wen | 1.0–1.8, (1.8–7.7)b | 7 | 1990–1992 | United States | Topical | Dose-response | 4 d |
| 1997 | Valles et al. | 1.0–1.3 | 3 | 1989–1996 | United States | Topical | Dose-response | 1 d |
| 2003 | Holbrook et al. | 1.2–>17c | 20 | 1997–1998 | United States | Topical | Discriminating doses | 3 d |
| 2004 | Wang et al.d | 8.7–9.3 | 3 | 2003 | United States | Topical | Dose-response | 3 d |
| 2005 | Kristensen et al. | 1–15 | 7 | 1996–2002 | Denmark | Topical | Dose-response | 3 d |
| 2006 | Nasirian et al. | 1–2.6 | 11 | Unknown | Iran | Topical | Dose-response | 3 d |
| 2010 | Chai and Lee | 1.0–10.0 | 22 | 2005 | Singapore | Topical | Dose-response | 2 d |
| 2012 | Gondhalekar et al. | 37.9 | 1 | 2006 | United States | Topical | Dose-response | 3 d |
| 2013 | Ang et al. | 1.2–3.0 (10.8–25.8)b | 6e | 2005 | Singapore | Topical | Dose-response | 2 d |
| 2016 | Ko et al. | 5.6 (15.9)b | 1 | 2012 | Puerto Rico | Topical | Dose-response | 2 d |
| 2017 | Liang et al. | 0.9–1.4 (2.5–25.0)b | 3 | 1999–2004 | United States | Topical | Dose-response | 5 d |
| 2017 | Wu and Appel | 2.0–8.7 | 6 | 2011–2012 | United States | Topical | Dose-response | 3 d |
| 2019b | DeVries et al. | 6–23 | 7 | 2011–2014 | United States | Topical | Dose-response | 2 d |
| 2020 | Hu et al. | 1.5–3.8 | 24 | 2017–2018 | Taiwan | Surface contact | Time-course (LT50) | 7 d |
| 2022a | Lee et al. | ~27.7f | 5 | 2018-2020 | United States | Ingestion | Discriminating doses | 3 d |
| 2022 | Present paper | 22.4–37.2 | 5 | 2018–2019 | United States | Topical | Dose-response | 4 d |
RR is the resistance ratio, calculated as LD50 (or LT50) of field-collected strain/ LD50 (or LT50) of a reference susceptible strain.
Artificially selected population(s)
RR >17 is based on the observation that the LD50 of the susceptible strain was 2 ng, and 34.5 ng (10-fold the LD99) failed to kill 50% of the cockroaches.
One of the strains (Cincy) also was used by Wang et al. (2004) and had an RR = 8.6.
The same 6 populations were examined by Chai and Lee (2010) and Ang and Lee (2011).
RR >27.7 is based on the observation that the LD50 of the susceptible strain was 1.3 ng, and 36 ng (10-fold the LD95) killed 20–70% of the cockroaches.