Figeater beetles, belonging to the Scarab family, are known for their striking green color and attraction to ripe fruit, particularly figs.
While these insects play a crucial role in our ecosystem, a common question arises: are figeater beetles blind?
The answer lies in their ability to perceive light and locate food sources. Although figeater beetles may not have the sharpest vision compared to other insects, they are not entirely blind.
They rely on their sense of smell to locate the ripe fruits that they feed on. Understanding the sensory abilities of figeater beetles is essential, as this knowledge helps us appreciate their contribution to the ecosystem.
Understanding Figeater Beetles
Figeater beetles (Cotinis mutabilis) are a species of scarab beetles that belong to the family Scarabaeidae. They are also called green fruit beetles or western green June beetles.
These beetles have an iridescent green color, making them visually striking. Some key features of figeater beetles include:
- Oval shape
- Stout body
- Clubbed antennae with segments that press tightly together
Habitat and Distribution
Figeater beetles are predominantly found in the southwest region of the United States, including California. They are also present in Mexico and other parts of the southwestern United States. These beetles tend to inhabit areas with:
- Desert trees
- Ripe fruits
- Decaying organic matter
They are active from late spring through early fall and overwinter as larvae, going through one generation per year. During this time, they may occasionally be a pest for ripe fruits.
Comparison of Figeater Beetles and Red/Confused Flour Beetles:
|Red/Confused Flour Beetle
|Tribolium castaneum / Tribolium confusum
|Clubbed, segments tightly together
|Club-like, three-segmented (red) or four-segmented (confused)
|Rust-red (red) or dark brown (confused)
|Southwest United States, Mexico
|Flour mills, grain storage facilities
|Activity and Distribution
|Late spring through early fall
|Throughout the year
|Occasional pest of ripe fruits
|Pest of stored grain and flour products
Life Cycle and Behavior
Diet and Feeding Habits
Figeater beetles are known for their fondness for ripe fruit, especially soft ones like figs. They also consume nectar, pollen, and petals from flowers, helping to diversify their diet.
Examples of their preferred fruits include:
Reproduction and Egg Laying
Figeater beetles mate in spring, primarily during late spring. They lay their eggs in decomposing organic matter, providing nourishment for the larvae once they hatch.
The larval stage of figeater beetles is sometimes referred to as “crawly backs”. These larvae primarily feed on rotting plant material, aiding decomposition. At times, they may also consume small insects.
Figeater beetles undergo a pupal stage in their life cycle, during which they transform from larvae to adult beetles. This process occurs within underground chambers made by the larvae.
Upon emerging as adults, figeater beetles continue their diet of ripe fruit and floral resources. Birds and chickens can occasionally prey on these beetles, affecting their population.
|Larva (Crawly back)
|Rotting plant material, occasional small insects
|Does not feed
|Ripe fruit (figs, peaches, apricots, and grapes), nectar, pollen, and flower petals
Figeater Beetles and Gardens
Fruits and Vegetables at Risk
Figeater beetles, also known as green fruit beetles or Cotinis mutabilis, mainly target soft-skinned fruits in gardens and orchards. Some examples of their preferred fruits are:
Damage Caused by Figeater Beetles
These beetles cause damage by feeding on the fruits, leaving behind irregular holes and rotting fruit tissue.
- Figeater beetles: Create superficial damage to fruits, making them unappetizing.
- Japanese beetles: Cause more severe damage, defoliating plants and destroying leaves, leaving a lace-like appearance.
|Damage to Fruits
|Damage to Leaves
|Holes in fruits
Preventing Figeater Beetle Infestations
Here are some tips to prevent or minimize figeater beetle infestations in home gardens:
- Remove ripe and overripe fruits promptly.
- Maintain clean and tidy compost piles.
- Apply organic mulch to reduce beetle breeding sites.
- Monitor plant roots for beetle larvae and remove them as needed.
Figeater Beetle vs Green June Beetle
Figeater beetles (Cotinis mutabilis) and green June beetles (Cotinis nitida) are often confused due to their similar appearance. However, there are some key differences between these species.
- Size: Figeater beetles are larger, ranging from 0.78-1.18 inches in length, while green June beetles are smaller, reaching only 0.59-0.86 inches in length.
- Color: Both have green, iridescent exoskeletons, but figeater beetles have a more uniform green color, while green June beetles may exhibit variations with more brown or bronze shades.
Example: In the garden, you might spot a green June beetle near compost piles, whereas a figeater beetle might be found buzzing around ripening fruit.
|Green June Beetle
|Green, brown, or bronze
Figeater Beetle vs Japanese Beetle
Figeater beetles and Japanese beetles (Popillia japonica) are quite different in terms of appearance and habits.
- Size: 20-30mm.
- Color: Iridescent green.
- Habits: Active during daylight hours, feeds on ripe fruits.
- Size: 8-11mm.
- Color: Green and metallic bronze.
- Habits: Active in the early morning and late afternoon, feeds on the foliage of more than 300 plant species.
For example, a Japanese beetle might be seen causing significant damage to roses or grapevines, while a figeater beetle would usually be found on soft, overripe fruits.
|Green, metallic bronze
|Early morning, late afternoon
|The foliage of over 300 plant species
Interactions with Humans and Other Species
Are They Blind?
Figeater beetles have weak eyesight, but they are not entirely blind. People often consider them blind as they have poor navigation skills and often tend to crash into things while flying.
Flight and Movement Patterns
Figeater beetles have a clumsy and loud flight, which often brings them into contact with humans. These beetles are known for their buzzing sound, often compared to bees, while flying.
As mentioned above, they are not great at navigating, so they might bump into people or objects, but they’re harmless to humans.
Their flight patterns include zigzagging and making sudden turns, which enable them to evade birds and other predators.
Although figeater beetles can be destructive to fruit crops, they generally do not pose a significant threat to humans or their property.
Predators and Natural Controls
Figeater beetles face several predators in their natural habitat, such as:
- Birds: Various species of birds prey on figeater beetles, particularly when the beetles are flying.
- Lizards: Some lizards, like geckos, actively hunt for figeater beetles.
Natural controls for figeater beetles include:
- Parasitic wasps: These wasps attack and consume figeater beetle larvae, reducing the beetle population.
- Nematodes: Nematodes are microscopic worms that can infiltrate the soil and attack the larvae of the figeater beetles.
Comparison between figeater beetles and bees:
|Buzzing similar to bees
|Clumsy, zigzagging, sudden turns
|Straight, more controlled
|Destructive to fruits
In conclusion, figeater beetles might exhibit erratic flight patterns and collisions with objects, but they are not blind; they possess limited eyesight. Therefore they keep colliding with objects.
While their vision might not be the best, but they have a strong sense of smell. They rely on their keen sense of smell to locate ripe fruits for feeding.
These beetles play an essential role in the ecosystem by aiding in decomposition. Also they are decent and pollinators. However, they cause damage to fruits.
Understanding their behavior and interactions with their environment helps us appreciate their unique characteristics and ecological significance.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Crawly Back: Figeater Larva
Are these figeaters that we have in the compost pile?
January 10, 2010
We found A LOT of these grubs in our compost pile. Is our compost pile considered “infested” now and shouldn’t be used? Are they crawly backs or figeaters?
Though I never saw it crawl on its back. Do I pick them out? If they are figeaters does that mean the figs in my fig tree will be subject to attack? 🙂
San Jose, CA
You are absolutely correct. These are Crawly Backs, the larvae of the Green Fruit Beetle or Figeater, Cotinis mutabilis. The idea of a compost pile is that organic material is broken down by decomposition and the action of insects and worms.
The Crawly Backs are assisting in the composting process. The beautiful adult beetles will eat fruit, but unless they are extremely plentiful, they will probably not significantly damage your fig crop.
We expect birds and squirrels will eat more figs than the Figeaters. We would leave the Crawly Backs in the compost pile. We could not locate many images of Crawly Backs online, but we have our own posting from 2008 and Ask.Com has a nice image and some information.
Letter 2 – Crawly Backs
Subject: Green June Beetle Grubs
Location: Rose Hills
January 27, 2014, 12:21 pm
Happy New Year Daniel,
I hope all is well on the other side of the hill.
I wanted to share & get your thoughts on my morning find. I lifted a board in the backyard known to harbor a variety of chicken treats and much to my shock founds grubs the size of fingers!
I diligently fought off 5 chickens & saved them for their photo shoot.
A little internet research tells me they are Green June Beetle Larvae. (I used this site: http://blog.growingwithscience.com/2008/10/bug-of-the-week-green-june-beetle/)
One telltale trademark is that they flip over onto their back to crawl away. They are pretty fast at doing that too. Gave me a hard time photographing them.
I am pretty sure this is what I have.
My conundrum is, now what do I do with them? I imagine I should just put them back and make the girls wait for when they emerge to fly and they can chase them around the yard.
We had a lot last year and a repeat would be nice… for the chickens. I’m just not sure how much of a pest they really are in greater Los Angeles nor do I feel right intervening in the circle of life.
Here are the photos I managed to get.
Signature: joAnn Ortiz
Crawly Back is a reference to the manner in which the larvae move through substrate, which you noted in your letter. Our initial inspection of the link you provided did not indicate the home base for the blogger, and there are other Green June Beetles in the genus, but our western species is Cotinis mutabilis.
In our opinion, Crawly Backs are beneficial as they help to break down materials in the compost pile, and though your letter did not mention a compost pile, we suspect that if you have chickens, you also have a compost pile.
We would release the Crawly Backs into the compost pile.
Letter 3 – Crawly-Back
Can you identify this grub?
Mon, Oct 6, 2008 at 2:53 PM
I found about 10 grubs at the bottom of my compost pile while turning it the other day. At first I thought I saw a shrimp and thought: “We don’t eat shrimp, how’d that get there?” Then I realized there were many more and they were all burrowing away from the light.
The largest was about as big as my thumb but I let it get away as I looked on in stunned amazement. This one pictured is about as thick as my index finger and an inch and a half or so long.
It was difficult to take a picture of the top of it because it wanted arch it’s back and burrow back down into the earth.
Can you help? I’d like to post your response on my blog www.ramshacklesolid.com
Los Angeles, CA
Congratulations. You have Crawly-Backs. Charles Hogue indicates in his wonderful book, Insects of the Los Angeles Basin, that the grubs of the Green Fruit Beetle or Figeater, are called Crawly-Backs. He writes:
“The adults are active from late summer to early fall and, during this period, lay their eggs in compost piles and other accumulations of decomposing plant litter. The larvae are fairly large (2 in., or 50 mm, long) and C-shaped; the body is pale translucent white, and the head is dark brown.
The first two molts are completed in the fall, the third the following spring. Larvae move forward on their backs with an undulating motion of the entire body. They obtain purchase on the substratum with transverse rows of stiff short stout bristles on the back of the thorax. Because of the peculiar manner of locomotion, they are known as ‘crawly-backs.'”
The adults are beautiful metallic green beetles that have a loud buzzing flight.
Letter 4 – Crawly-Back
six-legged worm thing?
February 2, 2010
Im not sure what this thing is it was found in my back yard and it’s a little over 2 inches long and fairly thick it has fuzz on it and it must burrow because when i put it in the grass again it starts moving down.
When it’s flipped right side up it rolls onto its back and begins to wiggle normally. it has a dark-colored head not sure if it’s dark red but it does have pincers and there’s something inside its tail maybe a sack it’s black and white.
I’m not too fond of insects but I’d like to know what this is because I’ve never seen one before.
Los Angeles California
This is the larva of a Green Fruit Beetle, Cotinus mutabilis. They are often found in compost piles and they are known as Crawly-Backs. The beautiful green adults fly in August, and because they feed on fruit, they are sometimes called Figeaters.