What are the environmental safety considerations when applying larvivores like Bti?

• A. Bti can be applied anywhere without risk.
• B. Label rates are optional.
• C. Non-target impacts minimal; maintain aquatic ecosystem safety; avoid runoff; follow label rates; ensure proper application in standing water.
• D. Bti is always toxic to fish.

Answer: (C)

Environmental safety when applying larvivores like Bti focuses on using the product precisely as labeled to protect non-target aquatic life and water quality. Bti is a biological larvicide that targets mosquito and some related Diptera larvae, so it’s relatively specific, and its toxins work in the larval gut. Because of that specificity, the risk to fish and most aquatic organisms is low when you follow proper procedures, but there are still important precautions. Use the exact label rates to avoid overdosing, which can increase exposure to non-target organisms and waste resources. Apply only to standing water where mosquito larvae are present—flowing water can dilute or wash away the product and reduce its effectiveness while spreading it beyond the intended area. Avoid runoff into connected water bodies and protect drinking-water sources or sensitive habitats. In short, apply Bti thoughtfully: follow the label, prevent runoff, and target treatments to standing water with larvae present.