Fipronil and ivermectin treatment of cattle reduced the survival and ovarian development of field-collected Anopheles albimanus in a pilot trial conducted in northern Belize

Table 1 Proportion (± 95% confidence interval) of wild-caught Anopheles albimanus that ingested blood when exposed to treated and untreated heifers (Belize, 2018)

Treatment	Number of heifers	Pre-treatment	Day after treatment
Treatment	Number of heifers	Pre-treatment	Day 2	Day 5	Day 7	Day 14
Control	2	43 ± 9% N = 108/n₁ = 48, n₂ = 60	54 ± 10% N = 100/n₁ = 50, n₂ = 50	62 ± 9% N = 120/n₁ = 60, n₂ = 60	68 ± 11% N = 71/n₁ = 36, n₂ = 35	79 ± 6% N = 192/n₁ = 96, n₂ = 96
Fipronil	3	51 ± 8% N = 144/n₁ = 48, n₂ = 48, n₃ = 48	47 ± 8% N = 150/n₁ = 50, n₂ = 50, n₃ = 50	65 ± 7% N = 176/n₁ = 58, n₂ = 58, n₃ = 60	71 ± 9% N = 102/n₁ = 34, n₂ = 34, n₃ = 34	74 ± 5% N = 288/n₁ = 96, n₂ = 96, n₃ = 96
Ivermectin	1	37% N = 48	24% N = 50	40% N = 57	51% N = 33	85% N = 96
Statistical comparisons	Control vs. fipronil	χ² = 1.91 p = 0.17	χ² = 1.07 p = 0.30	χ² = 0.25 p = 0.62	χ² = 0.18 p = 0.67	χ² = 1.38 p = 0.24
Statistical comparisons	Control vs ivermectin	χ² = 0.36 p = 0.60	χ² = 12.2 p = 0.0005	χ² = 7.7 p = 0.006	χ² = 2.49 p = 0.11	χ² = 1.90 p = 0.17

N total number of mosquitoes exposed to a treatment group; n number of mosquitoes exposed per heifer within a treatment group

ISSN: 1475-2875