What is the name of the anti-predatory norsesquiterpene secreted by whirligig beetles?

What is the name of the anti-predatory norsesquiterpene secreted by whirligig beetles?

• A. Menthol
• B. Limonene
• C. Gyrinidal
• D. Nerolidol

Answer: (C)

Defensive chemistry in beetles often involves terpenoids produced in specialized scent glands. Whirligig beetles specifically secrete a norsesquiterpene called gyrinidal, which acts as an anti-predator repellent to deter attacks from predators like fish. Among the options, gyrinidal is the only compound historically linked to this beetle family’s defensive secretion. Menthol is a mint-derived monoterpene, limonene is a citrus monoterpene, and nerolidol is a sesquiterpene found in various plants and some insects but not the whirligig beetle’s characteristic defense. So gyrinidal best fits the description.

Defensive chemistry in beetles often involves terpenoids produced in specialized scent glands. Whirligig beetles specifically secrete a norsesquiterpene called gyrinidal, which acts as an anti-predator repellent to deter attacks from predators like fish. Among the options, gyrinidal is the only compound historically linked to this beetle family’s defensive secretion. Menthol is a mint-derived monoterpene, limonene is a citrus monoterpene, and nerolidol is a sesquiterpene found in various plants and some insects but not the whirligig beetle’s characteristic defense. So gyrinidal best fits the description.