Moths range from tiny micro-moths measuring only a few millimeters to giants with wingspans comparable to a dinner plate. The family Lepidoptera contains some of the largest flying organisms in the world. Determining the largest moth requires looking beyond a single metric, as the species with the greatest width is often not the species with the greatest overall body mass.
Defining Moth Size Metrics
Entomologists use two distinct primary measurements to classify the size of a moth, separating the longest from the bulkiest. The most common metric is wingspan, which is the maximum distance from one wingtip to the other when the wings are fully spread, providing the dimension of sheer width. The second metric focuses on body size, including body length, volume, and overall mass or weight. A moth with a massive wingspan often possesses long, slender wings attached to a relatively small body. Conversely, a moth with a slightly smaller wingspan might have thick, heavy wings and a bulkier abdomen, resulting in a higher total body mass.
The Widest Moths (Record Holders by Wingspan)
The title for the widest moth belongs definitively to the White Witch Moth (Thysania agrippina). This insect holds the record for the greatest wingspan of any lepidopteran and any insect globally. A specimen collected in Brazil holds the documented record, measuring up to 12 inches (approximately 30 centimeters).
The massive wings of the White Witch Moth are long and narrow, featuring a pattern of dark lines on a pale gray or white background that aids in camouflage against tree bark. This species is native to the Neotropics, ranging from Mexico through Central America and deep into South America. While it primarily inhabits tropical forests, it sometimes appears as a stray as far north as Texas. Other species, like the Asian Atlas Moth (Attacus atlas), are often cited for impressive width, but the White Witch Moth is consistently recognized for having the longest wingtip-to-wingtip measurement.
The Heaviest Moths (Record Holders by Body Mass and Length)
While the White Witch Moth wins in linear width, the heaviest moth is the Hercules Moth (Coscinocera hercules). Native to New Guinea and northern Australia, this moth competes for the title of “largest” based on its physical bulk. The Hercules Moth possesses the largest documented wing surface area of any living insect, covering approximately 300 square centimeters.
Although its wingspan is typically 27 to 30 centimeters, one exceptional female specimen was recorded with a wingspan of 36 centimeters. The species’ impressive weight is better demonstrated in its larval stage. The caterpillars grow up to 14.5 centimeters in length and can weigh as much as 45 to 54 grams. This stored energy sustains the adult moth, which lives for a short period without feeding because it lacks functional mouthparts. The Atlas Moth is also a contender for bulk, as its wide, heavy wings give it a greater wing area and body mass than the slender White Witch Moth. Female Atlas Moths are noticeably larger and heavier than males, which is typical for silk moths.