Earwigs, recognized by their distinctive pincer-like appendages, are insects found globally in diverse environments like gardens, forests, and suburban areas. Despite folklore suggesting they burrow into human ears, this is a misconception, and they pose no such threat. Their life cycle includes egg, nymph, and adult stages, with egg-laying being a central aspect of their reproduction.
Egg Laying and Characteristics
Female earwigs lay eggs, typically beginning in autumn or early spring. They are selective about nesting sites, choosing dark, moist, and protected locations like underground chambers, beneath leaf litter, in soil crevices, or under stones and logs. These burrows can be dug several inches deep to provide a stable environment for the eggs.
The eggs are small, about 1 millimeter long, and are initially oval-shaped and pearly white or cream-colored. As they develop, they may change appearance, sometimes becoming kidney-shaped and turning brownish just before hatching. Clutches range from 20 to 90 eggs, though the number varies by species. Incubation typically occurs within about seven days.
Maternal Care for Earwig Eggs
Earwig reproduction features extensive maternal care by the female, a behavior uncommon among insects. The female remains with her eggs, diligently guarding them against predators and disturbances. She also actively cleans the eggs by licking them, which helps prevent the growth of harmful fungi and mold.
This cleaning behavior contributes to egg survival, as studies show a significantly higher hatching rate when tended by a mother compared to those left unattended. The female repositions her eggs to ensure optimal conditions, adjusting for temperature and humidity within the nest. If scattered, she collects them back into the clutch. This dedicated care continues even after hatching, extending into the early nymphal stages.
The Nymph Stage
After hatching, earwigs emerge as nymphs, miniature adults. These nymphs share the basic body shape of their parents but are typically lighter in color, often appearing pale white, translucent, or light brown. Early nymphs lack fully developed wings, and their pincer-like cerci are usually more slender and straight compared to the adults’ more robust and curved structures.
Earwig nymphs undergo incomplete metamorphosis, growing through instars by molting their exoskeletons. This molting allows them to increase in size and gradually acquire adult features, including wing development and characteristic adult coloration. During initial stages, nymphs may remain dependent on the mother, who can provide food through regurgitation and continued protection, improving their survival rates. As they progress through molts, typically four to six, they become more independent, foraging for a diverse diet that includes decaying plant matter, fungi, algae, and small insects like aphids.