Moths can be tricky to identify correctly for several reasons. There are over 160,000 species of moths worldwide, so telling them apart is no easy task. Many moths resemble butterflies, while some moths mimic other insects or objects to avoid predators. Moth identification requires a close look at some key characteristics to distinguish them from other insects.
How to Identify Moths
Here are some tips for deciphering moths from butterflies and identifying the type of moth you see:
- Check the antennae – Moth antennae are feathery or saw-edged while butterfly antennae have knobs on the ends.
- Note the body shape – Moths tend to have stout, hairy bodies while butterflies have slender abdomens.
- Look at resting posture – Butterflies rest with wings folded vertically together above the body. Moths rest with wings open flat or in a tent-like fashion.
- Examine the wings – Most moths have plain wings lacking the bright colors and distinctive patterns seen on butterfly wings.
- Pay attention to activity – Butterflies are active during the day while most moths fly at night.
Using these identification tips and paying close attention to features can help you decipher whether you are looking at a moth or some other insect. If it is indeed a moth, a few more clues can help narrow down its family and species.
Key Features of Moth Families
There are over 30 families of moths that all have some distinguishing traits. Here are features to look for in some of the most common moth families:
Saturniidae (Giant Silkmoths)
- Very large wingspans from 1.5 – 6 inches
- Thick bodies covered in hair-like scales
- Feathery antennae
- Dull colored wings in shades of brown, gray, yellow, or green
Sphingidae (Hawk Moths, Sphinx Moths)
- Narrow and thick abdomens
- Long, narrow forewings and shorter hindwings
- Streamlined appearance for fast, sustained flying
- Drab coloration in browns, grays, and muted greens
- Larvae have a distinct horn on the hind end
Noctuidae (Owlet Moths)
- Robust, hairy bodies
- Thick antennae
- Front wings often brown, gray, or reddish with dark markings
- Hind wings are paler or white
- At rest, wings are rolled around the abdomen
Geometridae (Geometer Moths)
- Slender bodies and broad wings
- Wings angular with lines and spots creating geometric patterns
- Caterpillars move in a looping fashion rather than crawling
- At rest, wings are outstretched and flat
- Cryptically colored in shades of brown, gray, or green
Arctiidae (Tiger, Lichen, and Wasp Moths)
- Medium to large sized moths
- Hairy bodies and legs
- Brightly colored bands or spots on wings
- Tiger moths are orange/black, lichen moths are brown/white, and wasp moths mimic paper wasps
- At rest, wings are folded roof-like over body
Once you have identified the moth family, examine field guides or online insect databases to match the characteristics to a species.
Distinguishing Moth Larvae
In addition to adult moths, caterpillars are often indicators of moth presence. Here are ways to identify some common moth larvae:
- Tent Caterpillars – Hairy with blue, white, black, and orange stripes. Build large spun silk nests in trees.
- Tomato Hornworms – Large and green with 7 white V-shaped markings on sides. Horn on rear end.
- Codling Moth Larvae – Pinkish-white caterpillars with brown heads that bore into apples and pears.
- Cutworms – Plump, soft-bodied caterpillars that curl up when disturbed and damage seedlings.
- Gypsy Moth Caterpillars – Hairy with 5 pairs of blue spots and 6 pairs of red spots running along their backs.
Paying attention to the distinct characteristics of moth larvae can help identify the species and potential damage to plants.
Conclusion
Identifying moths accurately involves careful observation of details. Compare antennae, wing shape, colors, patterns, resting posture, and larvae features to distinguish moths from butterflies and determine the moth species. Use field guides, online insect resources, and these identification tips to decipher the many moths you may encounter.
Moth Identification Chart
Here is a chart summarizing some of the main features to look for when identifying common moths:
| Moth Family | Antennae | Wings | Body | Resting Position | Colors |
|---|---|---|---|---|---|
| Saturniidae | Feathery | Large, dull shades | Thick, hairy | Flat, open | Browns, grays |
| Sphingidae | Thick | Elongated | Robust | Flat, open | Cryptic hues |
| Noctuidae | Thick | Brown/gray with markings | Hairy | Roof-like over body | Browns, grays |
| Geometridae | Slender | Broad, angular | Slender | Outstretched, flat | Browns, grays |
| Arctiidae | Varies | Hairy scales, bright bands | Hairy | Roof-like over body | Oranges, blacks, whites |
This table summarizes key identification features like antennae type, wing characteristics, body shape and hairiness, resting postures, and coloring for 5 common moth families. Comparing moths to these features will aid in pinpointing the family and species.
Identifying Moth Damage
In addition to visual identification, moths can be recognized by the type of damage they cause. Here are some common signs of moth damage:
- Holes in sweaters, carpets, and other fabrics from clothes moths
- Grain, cereals, and spices clumped with webbing from pantry moths
- Tunnels and holes in tree bark from bark mining moths
- Defoliation of tree leaves from larvae like tent caterpillars and gypsy moths
- Chewed leaves, stems, and fruits on crops like cabbage and apples from cutworms and corn earworms
- Signs of leafmining where larvae burrow between leaf surfaces
Take note of the location and type of damage to determine if moths are the cause. Compare to moth feeding habits and larval characteristics to identify suspect moth species.
When to See Moths
Moth activity fluctuates throughout the year with many emerging at specific times. Here is an overview of when different moth types are most likely to be spotted:
| Months | Moth Type |
|---|---|
| February – October | Gypsy Moths |
| May – August | Luna Moths |
| June – September | Tomato Hornworm Moths |
| April – November | Pantry Moths |
| July – September | Hummingbird Moths |
This table outlines when common moth species are most active as adults based on their life cycles and development. Focus moth watching and monitoring during these peak times to spot different moth types.
Attracting Moths for Observation
To draw moths for easier observation and study, try these tips:
- Use bright lights such as mercury vapor lamps at night
- Leave windows or porch lights on at night
- Plant night-blooming flowers like jasmine, petunias, and silene
- Use sugary bait mixtures on trees or posts
- Hang fruit slices or pieces of stale beer, wine, syrup, etc.
- Install moth pheromone traps
- Leave natural fabric items outside at night to attract clothes moths
Creating light sources at night with both artificial and night-blooming flowers will help attract moths. Sugary baits, fruit, and fermented items will also draw hungry moths. Pheromone traps contain species-specific moth pheromones to attract certain types of moths.
Deterring Moths
To discourage moths from becoming a nuisance around homes and gardens, consider these deterrents:
- Seal any openings where pantry moths can enter pantries and cupboards
- Use tight-fitting lids on food containers
- Store fabrics like wool in airtight containers
- Use cedar in storage areas as a natural moth repellent
- Freeze fabrics or heat items to high temperatures to kill moth larvae and eggs
- Clean up food spills quickly to remove sources of attraction
- Use pheromone traps to capture male moths and prevent mating and reproduction
- Employ parasitic wasps or Bacillus thuringiensis (Bt) to kill larvae
Eliminating access, thoroughly cleaning areas, using pheromones and organic controls, and freezing or heating items helps control pest moth populations. Always identify moths correctly before treating infestations.
Conclusion
Moth identification involves close inspection of wings, antennae, bodies, colors, behaviors, larvae, and damage. Compare unknown moths to characteristics of common moth families and species to distinguish from butterflies. Focus moth watching during peak activity times. Attract moths with lights, flowers, and bait for easier observation. Deter problematic moths through sanitation, storage, organic treatments, traps, and temperature controls. Accurate moth identification allows appropriate control and prevention methods.