The foreign grain beetle is a common household pest that can be found in a variety of settings, particularly where damp, moldy grain and other materials are present. Being a small and flattened insect, it has a reddish-brown color and measures about 1/12 inch long. Under magnification, you will notice two peg-like projections behind its head which help differentiate these beetles from similar insects like fruit flies or gnats UMN Extension.
These beetles are known to be strong fliers, typically becoming more abundant during late summer and fall. Their diet mainly consists of molds and fungi that grow on damp grain and grain products Plant & Pest Diagnostics. In addition, they are often found in close proximity to grain processing facilities where damp, moldy grain tends to accumulate.
Foreign Grain Beetle: An Overview
Identification and Characteristics
The foreign grain beetle (Ahasverus advena) is a small, flattened insect. Its key features include:
- Color: Reddish-brown
- Size: About 1/12 inch long
- Two peg-like projections on the thorax
These beetles can be confused with fruit flies or gnats due to their size and strong flying abilities. However, their hard shell sets them apart from flies.
Biology and Life Cycle
The life cycle of foreign grain beetles consists of four stages: egg, larva, pupa, and adult. They primarily feed on molds and fungi, particularly on damp grain, grain products, and other materials.
Habitat and Distribution
Foreign grain beetles have a global distribution. They are commonly found around grain processing facilities where damp, moldy grain accumulates. Their habitat preferences include:
- High humidity environments
- Locations with damp, moldy grain
By understanding their identification, biology, and habitat, we can better manage and prevent foreign grain beetle infestations.
Infestations and Impact
Foreign Grain Beetles in Homes
Foreign grain beetles (Ahasverus advena) are small, reddish-brown insects, which can infest homes, typically in areas with high humidity and moisture like basements and kitchens. These pests can enter through:
- Cracks and crevices in walls
- Open windows and doors
In new homes, they are attracted to moisture in wood and wet building materials. However, their presence is harmless to humans and pets.
Characteristics of foreign grain beetles:
- About 1/12 inch long
- Reddish-brown color
- Hard shell
- Two peg-like projections behind the head
- Strong fliers
Damage Caused in Grain Storage Facilities
Foreign grain beetles are known for infesting grain storage facilities. They cause damage by feeding on molds and fungi growing on damp grain and grain products. The infestation can lead to spoiled grain, resulting in financial losses for facility owners.
Examples of damage:
- Reduced grain quality
- Grain contamination
- Spoilage
Nuisance and Harmlessness
Though foreign grain beetles are pests, they are harmless to humans and pets. They do not bite, sting, or transmit diseases, but their presence can cause discomfort and annoyance by flying around living spaces.
Nuisance factors:
- Can be confused with fruit flies or gnats
- Presence in rooms and living areas
- Annoying flying behavior
Harmless factors:
- Do not bite or sting
- Do not transmit diseases
| Comparison | Foreign Grain Beetles | Fruit Flies | Gnats |
|---|---|---|---|
| Appearance | Reddish-brown | Brownish-yellow | Dark-colored |
| Size | About 1/12 inch | 1/8 inch | 1/16-1/8 inch |
| Infestation areas | Homes, grain storage facilities | Kitchens, near fruits | Near moist areas |
| Harmfulness | Harmless | Harmless | Varies |
In conclusion, it is essential to be aware of the infestations and impacts of foreign grain beetles to take preventive measures and maintain a hygienic living environment.
Signs of Foreign Grain Beetle Presence
Moldy Conditions
Foreign grain beetles thrive in moldy and damp conditions. They primarily feed on molds and fungi growing on damp grain, grain products, and other materials1. Watch out for:
- Dampness in storage areas
- Signs of mold or fungus on grains, cereals, oilseeds, and dried fruits
Appearance of Larvae
Another sign of foreign grain beetle presence is the appearance of their larvae in the infested area. These larvae are usually:
- Yellowish-white in color
- With a brown head
- Less than 1/8 inch long when mature2
Infested Food Products
Foreign grain beetles infest a variety of moldy food products. Keep an eye on:
- Cereals
- Grains
- Oilseeds
- Dried fruits
Prevention and Control Measures
Moisture Management and Ventilation
Proper moisture management is crucial in preventing foreign grain beetle infestations. Some ways to achieve this are:
- Using a dehumidifier to maintain relative humidity below 60%
- Properly ventilating spaces, especially in crawlspaces and basements
- Fixing leaks and addressing water intrusion promptly
For example, in a new home constructed during the rainy season, it’s essential to take measures to prevent excess moisture buildup.
Sanitation and Cleanliness
Maintaining cleanliness is an effective way to prevent foreign grain beetles. Key steps include:
- Regularly inspecting food products for pests
- Storing foods in sealed containers
- Discarding infested items in sealed plastic bags
- Cleaning up spills and crumbs immediately
- Vacuuming regularly to remove beetles and their food sources
Chemical and Non-Chemical Treatments
When it comes to treating foreign grain beetle infestations, both chemical and non-chemical options are available. Below is a comparison of some common methods:
| Method | Pros | Cons |
|---|---|---|
| Insecticides | Quick and effective | May require professional application |
| Desiccant dust | Non-toxic | Could be messy |
| Pheromone traps | Environmentally friendly | May not eliminate the entire problem |
Insecticides should be used as a last resort, and it is advisable to consult a pest management professional before application. Non-chemical options like desiccant dust and pheromone traps can be used for minor infestations.
By following these prevention and control measures, it’s possible to keep foreign grain beetles at bay and protect your property from infestations.
Bug Control Recommendation Tool
Comparison with Other Beetles
Sawtoothed Grain Beetle
The Sawtoothed Grain Beetle (Oryzaephilus surinamensis) is often found infesting stored food products. It is a small, narrow and flat beetle that is dark brown in color.
- Feeding: These beetles feed on a wide range of products such as cereals, dried fruits, nuts, and spices.
- Damage: They can cause considerable damage to food products, making them unsuitable for consumption.
- Excess moisture: Sawtoothed grain beetles thrive in environments with excess moisture.
Flour Beetle
Flour Beetles include two species: the Confused Flour Beetle (Tribolium confusum) and the Red Flour Beetle (Tribolium castaneum). Both of these beetles infest stored food products, especially flour.
- Nuisance: Although they don’t bite or sting, they can cause significant damage to stored food products.
- Spices: Their presence can alter the taste of spices and baked goods.
- Biology & Reproduction: These beetles reproduce quickly and adapt to various environments.
Flour Beetle description provides more information on their appearance and behavior.
Fungus Beetle
Fungus Beetle, like the Foreign Grain Beetle (Ahasverus advena), primarily feeds on molds and fungi growing on damp grain, grain products, and other materials.
- Dead insects: It can be found in areas where dead insects are present, as they also feed on them.
Comparison Table
| Sawtoothed Grain Beetle | Flour Beetle | Fungus Beetle (Foreign Grain Beetle) | |
|---|---|---|---|
| Preferred Food | Cereals, dried fruits | Flour | Molds, fungi, damp grain |
| Damage to Stored Goods | Yes | Yes | Yes |
| Reproduction | Fast | Fast | Unknown |
These comparisons provide a brief overview of the differences and similarities between the foreign grain beetle and other common beetles found infesting stored food products.
Other Interesting Facts and Behavior
Migration and Strong Fliers
Foreign grain beetles are known to be strong fliers, which allows them to travel significant distances and, as a result, can infest new homes or older ones. These beetles can easily be confused with fruit flies or gnats due to their small size and strong flying abilities.
Foreign Grain Beetles in Older Homes
Older homes may experience a foreign grain beetle infestation if they provide suitable conditions, such as:
- Damp environments, like humid bathrooms
- Presence of mold or fungi
- Stored products with high moisture content
Foreign grain beetles are attracted to older homes because they often have damp spaces like wall voids and crawlspaces where mold can grow on building materials, which is their primary food source.
Quick Facts:
- Family: Silvanidae
- Body color: Reddish-brown
- Pronotum: Two peg-like projections behind the head
- Larva stage: Pupa
- Habitat: Stored products, damp spaces, and moldy grain
Homeowners can prevent and control foreign grain beetle infestations by maintaining proper moisture levels, conducting regular pest control inspections, and storing products in sealed containers.
| Foreign Grain Beetle | Fruit Fly |
|---|---|
| Reddish-brown | Black |
| 1/12 inch long | 1/8 inch long |
| Strong fliers, can be mistaken for fruit flies | Attracted to ripening fruit and decaying organic matter |
To sum it up, foreign grain beetles are small and robust fliers that can migrate to new or older homes, and they can be confused with fruit flies. They are attracted to humid environments and moldy materials, which makes older homes with damp spaces and stored products more prone to an infestation.
Footnotes
19 Comments. Leave new
I have these exact same tiny bugs all through my laundry room and bedroom. I have sprayed and vacuumed and sprayed to no avail. I noticed them after we came back from camping almost 5 months ago. I am at my wits end. We have animals so to fumigate the house would be hard. Is there any other solution?? Please help.
I think they are red floor beetles or confused beetles.
This is the first posting I have found that match the bug… it doesn’t look like any other weevil on the web. Please help. email me at nikakoda66@gmail.com
I think we have the same thing in our house! they are everywhere. our grain products.. and also everywhere else – bedrooms, bathrooms, etc etc
any luck with getting rid of them? any tips?
I think we have the same thing in our house! they are everywhere. our grain products.. and also everywhere else – bedrooms, bathrooms, etc etc
any luck with getting rid of them? any tips?
I’ve been searching the Internet like crazy to find out what this big is called and how to get rid of it..I have some in the washroom, bedroom, kitchen…the exact same one on the picture…did anyone find out what type of beetle this is? I found one on my bed sheet…
I know this is a dead thread but for anyone else looking it looks to me like some kind of grain beetle. Not a sawtooth or merchant, too smooth for that, doesn’t really look like a grain weevil either.
I’d approach their removal the same as other gain beetles.
Thanks for the comment Craig. The beauty of our archive is that though there may not be recent activity, our threads never really die.
I know this is a dead thread but for anyone else looking it looks to me like some kind of grain beetle. Not a sawtooth or merchant, too smooth for that, doesn’t really look like a grain weevil either.
I’d approach their removal the same as other gain beetles.
does the beetle type in that photo have a mint-like smell to them when they are picked up or squished? Beetles just like that pester me in groups in my pen containers. I also see them in my room. Each year is worse.
I’m no expert but I’ve experienced an outbreak of a similar looking beetle and have been searching the web non-stop in the last couple days so I’ve seen a large number recently. I believe that the one in this post is the either the red flour beetle, or the confused flour beetle.
Source: http://entnemdept.ufl.edu/creatures/urban/beetles/red_flour_beetle.htm
Thanks for the information and link.
I’m no expert but I’ve experienced an outbreak of a similar looking beetle and have been searching the web non-stop in the last couple days so I’ve seen a large number recently. I believe that the one in this post is the either the red flour beetle, or the confused flour beetle.
Source: http://entnemdept.ufl.edu/creatures/urban/beetles/red_flour_beetle.htm
I think I have this same bug, but it is bigger then a grain beetle. Notice it jumps after I squish it. Can’t find anything online.
Found the same little brown beetles in my bed. They can fly. Size is from 1 to 5 mm. Fine striations are visible on their back when looked at with magnifying glass.
After a bit of research, I’ve concluded that these are the “lesser mealworm” beetle. Latin name is Alphitobius Diaperinus”. This species of beetle is parasitic to birds, both domestic and wild, and even mammals. It is known to feed on live animals. It is spread world-wide. It carries & can transmit other parasites.
Here’s why I concluded these are A.D beetles. Since 2 months ago, when the migratory swallows came back in their nests in the inner roof above my apartment’s ceiling, we’ve been finding these little brown beetles all over the apartment building. That’s the connection to birds. These migratory swallows winter in southern USA, and the little beetles could be hitchhiking a ride on the birds on their way north.
Another tenant has also found them in their bed. If these were grain beetles, they would be in the food, but we did not see them in foodstuff at all. I’ve gotten bitten at night. These beetles seem to like body heat and seem to be carnivorous.
I found their nest under my mattress and in my sofa, had to throw that stuff away. We’ve put sticky traps in many places, and that little brown beetle is the only bug found in the trap.
I’ve started spraying my apartment with solutions of cedarwood & eucalyptus essential oils. I got rid of clutter. Am now spraying belongings and packing in air-tight containers, to be stored for a while.
Since you didn’t include a pic, nobody can back up your conclusion but it sounds like bed bugs to me. You might want to double check.
I know this is old but given that they are everywhere (for commenters too) and not just in food (or the kitchen) then perhaps this is one of the Powder Post Beetles (Lyctinae) that infest wood and are in the same superfamily as many of the Carpet (and Deathwatch) Beetles.
https://en.wikipedia.org/wiki/Powderpost_beetle
http://bugguide.net/node/view/59616
This page explain a lot about them:
http://www.powderpostbeetles.com/powderpost-beetle-control.html
I know this is old but given that they are everywhere (for commenters too) and not just in food (or the kitchen) then perhaps this is one of the Powder Post Beetles (Lyctinae) that infest wood and are in the same superfamily as many of the Carpet (and Deathwatch) Beetles.
https://en.wikipedia.org/wiki/Powderpost_beetle
http://bugguide.net/node/view/59616
This page explain a lot about them:
http://www.powderpostbeetles.com/powderpost-beetle-control.html
I came across this thread when I too found these in my bedroom drawers,, bathroom and all my purses! They are horribly annoying. I emptied out my dresssr tonight and I washed everything down with apple cider vinegar. I don’t know if it will help. Has anyone gotten rid of them?