Laboratory and Field Evaluation of Zyrox Fly Granular Bait Against Asian and German Cockroaches (Dictyoptera: Blattellidae)

Abstract

The Asian cockroach (Blattella asahinai Mizukubo) was introduced to Florida in 1986 and has since spread throughout the Southeastern United States. Blattella asahinai is a peridomestic pest and high population densities in residential areas can become a nuisance, especially when adults fly into homes. Few studies to date have been conducted on Asian cockroach control, and we evaluated the efficacy of Zyrox Fly Granular Bait and Maxforce Complete Granular Insect Bait against this species in the laboratory compared with the closely related German cockroach (Blattella germanica (L.)). In no-choice and two-choice assays with both species, Zyrox bait and Maxforce bait achieved nearly 100% mortality within two and five days, respectively. We also tested Zyrox bait against B. asahinai in an invasive field population in North Carolina at the label rate (2 g/m(2)) and at approximately three times the label rate (6.9 g/m(2)), and found that broadcast applications at both rates reduced populations by an average of 64 and 92%, respectively, for 35 d after the initial application. Zyrox Fly Bait appears to be effective against the Asian and German cockroaches, and could be another tool in an integrated pest management program, if its label could be extended or the active ingredient (cyantraniliprole) formulated into a cockroach bait.

Keywords: Blattella asahinai; Blattella germanica; Maxforce Complete Granular Insect Bait; Zyrox Fly Granular Bait; cyantraniliprole.

Fig. 1.

Kaplan–Meier survivorship curves of B. asahinai and B. germanica offered Zyrox Fly Granular Bait, Maxforce Complete Granular Insect Bait, and crushed rat chow in no-choice (A) and two-choice (B) assays. Each curve represents an independent species and treatment combination. Sample size was 50 B. germanica in all assays, 30 B. asahinai in control and Zyrox treatments in all assays, and 23 B. asahinai for Maxforce treatments. (Color online only.)

Fig. 2.

Kaplan–Meier survivorship curves of B. germanica offered Zyrox Fly Granular Bait via ingestion or via contact. Each curve represents an independent treatment. In contact-only assays, insect mouthparts were glued to prevent ingestion. Glue was applied to the head between the eyes as a sham control. Sample size was 30 insects per treatment. (Color online only.)

Fig. 3.

Mean (± SE) B. asahinai found in timed counts in field sites before and after treatment with Zyrox Fly Granular Bait or an untreated control. (A) Plots treated with 2 g/m² Zyrox bait; (B) Plots treated with 6.9 g/m² Zyrox bait. All plots were treated on day 0 following the initial timed count, and bait was re-applied on day 7. In (A) and (B), asterisks denote significant differences between treatments in mean B. asahinai numbers. Sample size was four plots each for Zyrox and control (A), five plots for Zyrox and four plots for control (B). Data were analyzed with a mixed ANOVA.