Rice Moth & Angoumois Grain Moth

🦋 Rice Moth / Angoumois Grain Moth

Corcyra cephalonica / Sitotroga cerealella · Lepidoptera: Pyralidae / Gelechiidae

Unlike Indian meal moths (pantry generalists), rice and Angoumois grain moths attack intact whole grains — rice, wheat berries, corn kernels — from the inside out, making early detection nearly impossible.

MothStored ProductGrainLepidopteraInternal FeederRice

🔬

PestControlBasics Editorial Team

Reviewed by Derek Giordano · Updated 2026

Illustrated identification guide — PestControlBasics.com

🔍 Identification

Angoumois grain moth: 12-14mm wingspan; straw-yellow with pointed hindwings. Rice moth: slightly larger; tan with indistinct markings. Both are smaller and less distinctive than Indian meal moth. Key diagnostic: larvae found inside individual grain kernels (you must cut grains open to find them) rather than in webbed masses in open food.

🧬 Biology & Behavior

Females lay eggs on grain surfaces; larvae bore into individual kernels and feed internally. Adults emerge through small round exit holes. Infestations can be extensive before webbing or larvae are visible, because all development occurs within the kernel. Common in bulk stored grains, feed stores, and grain elevators.

⚠️ Damage & Health Risk

Internal destruction of individual grain kernels; significant losses in bulk grain storage; contamination of stored rice, wheat, corn; economic losses in agricultural storage.

🔧 DIY Treatment

Discard infested grain. Freeze new grain purchases at 0°F for 7 days before storage (kills all stages). Store in airtight containers. Clean all cracks and crevices in storage areas. Pheromone traps monitor adult activity.

👷 When to Call a Pro

Phosphine fumigation for large-scale grain storage — requires licensed applicator.

❓ FAQ

How do I know if my rice has grain moths?

Cut individual rice grains in half and look for tiny larvae inside. Alternatively, examine kernels for small round exit holes (where adults emerged). Surface webbing is rare — unlike Indian meal moth, most damage is completely inside the kernel.

Does freezing kill grain moths?

Yes — freezing grain at 0°F for 7 days kills all life stages including eggs inside kernels. This is the most reliable home prevention method for bulk grain purchases.

Factor	Details
U.S. Range	All or most U.S. states
Regional Detail	Distribution varies — consult your local extension service for regional prevalence data.

Factor

Details

U.S. Range

All or most U.S. states

Regional Detail

Distribution varies — consult your local extension service for regional prevalence data.

📅 Treatment Timing Guide

Treating at the right time dramatically improves results. Pest control timed to the life cycle uses less product and achieves better long-term control.

Period	Action
Spring	Inspection and perimeter treatment before pest season starts.
Summer	Active monitoring and targeted treatments as needed.
Fall	Preventive treatment before overwintering pests seek entry.

Period

Action

Spring

Inspection and perimeter treatment before pest season starts.

Summer

Active monitoring and targeted treatments as needed.

Fall

Preventive treatment before overwintering pests seek entry.

💰 Professional Treatment Costs

Service Type	DIY Cost	Professional Cost
Initial inspection	Free (self-inspect)	$75–$150 (often credited to treatment)
One-time treatment	$30–$100 in materials	$150–$500
Annual service contract	N/A	$400–$900/year
Severe infestation	Often ineffective alone	$500–$2,500+

Service Type

DIY Cost

Professional Cost

Initial inspection

Free (self-inspect)

$75–$150 (often credited to treatment)

One-time treatment

$30–$100 in materials

$150–$500

Annual service contract

N/A

$400–$900/year

Severe infestation

Often ineffective alone

$500–$2,500+

Prices vary by region, property size, and infestation severity.

❓ Common Questions About 🦋 Rice Moth / Angoumois Grain Moth

How do I confirm I actually have this pest (not something similar)?

The most reliable confirmation is a physical specimen — capture one and compare to reference images on this page. For cryptic pests (bed bugs, termites), look for secondary signs: frass, shed skins, mud tubes, or bites with a specific pattern. When uncertain, a professional inspection is faster than months of misidentification.

Can I treat this myself or do I need a professional?

DIY is effective for small, accessible infestations caught early. Professionals are worth the cost when: the infestation is inside wall voids or structural elements, multiple rooms are affected, you have health-risk pests (hantavirus, venomous species), or DIY has already failed twice.

How long until the infestation is completely gone?

Expect 3–8 weeks for most infestations with proper treatment. Insects with dormant life stages (pupae, eggs) extend the timeline because those stages are impervious to most insecticides. Follow-up treatments at 2 and 4 weeks catch each new cohort as they emerge.

What's the most common mistake people make treating this pest?

Treating only the visible pest population while ignoring the harborage site, entry point, or breeding location. Killing adults provides temporary relief but the population rebuilds from hidden egg cases, pupae, or new arrivals through unaddressed entry points.