ExploreInsects

Lesser Maple Spanworm Moth

macaria pustularia

The Lesser Maple Spanworm Moth (Macaria pustularia) is a charming and common Geometrid moth native to eastern North America. Named for its caterpillars' favorite food and their characteristic "looping" crawl, this delicate white moth is a frequent visitor to deciduous forests and suburban yards alike. During the summer, it plays an important role in the local ecosystem, serving as a vital food source for nesting birds and acting as a key indicator of forest health. Though small, its abundance makes it a staple of North American woodlands.

Habitat: Found primarily in deciduous and mixed forests, particularly where maple trees are abundant, as well as in wooded suburban parks and gardens.

Appearance

Adults are small, delicate moths with a wingspan of 2 to 3 cm. Their wings are mostly pure, chalky white to light cream, decorated with three distinct orange-yellow or light brownish transverse lines crossing the forewings. A notable diagnostic feature is a tiny, bright orange or brownish spot or smudge located near the middle of the forewing's outer margin. When resting, they hold their wings flat against the surface, showcasing their triangular profile and hiding their light-colored legs beneath.

KingdomAnimaliaPhylumArthropodaClassInsectaOrderLepidopteraFamilyGeometridaeGenusMacaria
Lesser Maple Spanworm Moth
Lesser Maple Spanworm Moth

Category

Insects

Rarity

Common

Danger

1/5 · Very low

Snaps

Be the first to snap!

Interesting facts

Despite their small size, their caterpillars can occasionally experience massive population booms, temporarily defoliating small stands of maples.

The common name 'spanworm' comes from the caterpillar's unique walking pattern, which makes it look as though it is measuring the earth inch by inch.

They are highly attracted to ultraviolet light sources, making them a common subject for backyard moth-watching setups.

Special abilities

Ability

Looping Locomotion

The caterpillar lacks middle prolegs, forcing it to draw its rear up to its front legs to form a loop before extending forward, a highly efficient crawling technique.

Ability

Bark Mimicry

When resting on birch or light-colored tree trunks, the flat, white-and-orange wings of the adult moth blend seamlessly with the bark patterns to avoid detection.

Ability

Selective Feeding

Caterpillars selectively feed on maple leaves with lower tannin levels, maximizing nutrient absorption while minimizing defensive chemical intake.

Measurements & details

Length
1-2 cm
Wingspan
2-3 cm
Weight
0.0001-0.0003 kg
Clutch Size
50-150
Incubation
5-14 days

Diet & Feeding

Caterpillars feed on the foliage of deciduous trees, specifically maples, while adult moths rarely feed, occasionally sipping nectar.

Age differences: Caterpillars feed continuously on leaves, whereas adult moths have reduced mouthparts and feed minimally or not at all.

Primary Foods

  • Red Maple leaves
  • Sugar Maple leaves
  • Silver Maple leaves
  • Boxelder leaves

Foraging Method

  • Grazing

Ecological connections

Traits

No trait badges are assigned for this object yet.

Also known as

No aliases listed yet.

Collections

Collections for this object will appear here as more themes are added.

Safety

Danger

1/5 · Very low

No special safety notes yet.

Frequently Asked Questions

How long is Lesser Maple Spanworm Moth?

1-2 cm

What is Lesser Maple Spanworm Moth's wingspan?

2-3 cm

How much does Lesser Maple Spanworm Moth weigh?

0.0001-0.0003 kg

What does Lesser Maple Spanworm Moth eat?

Caterpillars feed on the foliage of deciduous trees, specifically maples, while adult moths rarely feed, occasionally sipping nectar.

Where is Lesser Maple Spanworm Moth usually found?

Found primarily in deciduous and mixed forests, particularly where maple trees are abundant, as well as in wooded suburban parks and gardens.

How does Lesser Maple Spanworm Moth hunt?

Grazing

How many eggs does Lesser Maple Spanworm Moth lay?

50-150

How long do Lesser Maple Spanworm Moth eggs take to hatch?

5-14 days

Snap Map

Zoom in to split clusters and explore where this object has been snapped.

Loading map…

Recent Snaps

Recent snaps will appear here as new observations are added.

Where to spot

More Insects