By: Jackie Carroll
Darkling beetles get their name from their habit of hiding during the day and coming out to feed at night. Darkling beetles vary quite a bit in size and appearance. There are over 20,000 species of beetles called darklings, but only about 150 of them are native to the U.S. Darkling beetles damage garden plants by chewing off seedlings at ground level and feeding on leaves. Read on to learn more on how to identify and control these pesky insects.
It’s rare to see a darkling beetle in daylight, although you may occasionally find them running across the ground from one hiding place to another. They like to hide under bits of debris and clods of dirt during the day and come out to feed at night.
Many types of birds, lizards and rodents eat darkling beetle larvae, which are called mealworms. If you feed your pets mealworms, it’s better to buy them from a pet store or mail order source rather than collect them from the wild. Wild mealworms may be contaminated with insecticides or other toxic substances. The species you find in pet stores are bred specifically for animal consumption and have a high nutritional value.
Darklings begin life as small white eggs under the surface of the soil. Once they hatch, the larvae (mealworms) feed for several weeks. They look like rounded worms, cream or light brown in color. The larvae shed their hard skin as many as 20 times as they grow.
After three to four months of feeding, the larvae crawl back into the ground to pupate. They emerge as mature beetles, capable of living 20 years or more if they manage to avoid becoming a meal for other animals.
Darklings range in size from one-twelfth to 1.5 inches (2 mm. to 3.8 cm.) in length. They are solid black or dark brown and never have any colored markings. Their wings are fused together over their back, so they cannot fly. Their shape varies from nearly round to long, narrow and oval.
All darklings have antennae coming from the area near the eye. The antennae have lots of segments, with an enlarged segment at the tip. This sometimes gives the antennae a club-like appearance, or it may look as though it has a knob at the tip.
Insecticides aren’t very effective at getting rid of darkling beetles. You should also be sensitive to the fact that when you try to kill these pests with toxic substances, you may also be poisoning the animals that feed on the beetles and their larvae. The safest method of getting rid of these pests is to eliminate their food sources and hiding places.
Remove decomposing organic matter and plants that have reached the end of their cycle promptly. Although darklings sometimes eat live plant material, most of them prefer decomposing matter. Besides eating garden debris, they also use decaying plants as hiding places.
Keep the garden weed free and remove weeds growing at the edges of the garden. Dense weeds serve as safe havens for darklings seeking shelter during the day. You should also remove stones, dirt clods and bits of wood that may offer shelter.
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Most darkling beetles look similar to ground beetles, black or brown and smooth. They're often found hiding under rocks or leaf litter and will come to light traps. Darkling beetles are primarily scavengers. The larvae are sometimes called false wireworms because they look like click beetle larvae (which are known as wireworms).
Though the Tenebrionidae family is quite large, numbering close to 15,000 species, all darkling beetles share certain characteristics. They have 5 visible abdominal sternites, the first of which is not divided by coxae (as in the ground beetles). The antennae usually have 11 segments and may be filiform or moniliform. Their eyes are notched. The tarsal formula is 5-5-4.
Darkling beetles (also known as litter bugs, dung beetles, tumble bugs, pooh beetles and fece fighters) generally go unnoticed in the yard. Attracted by the scent of animal waste, adult darkling beetles will lay eggs in fecal matter from which larvae will hatch and begin feeding. This activity will happen down under the top of the feces so it’s easy to miss.
Larva are small grub like caterpillars that will develop through several instars before becoming adults. At that time they’ll leave the fecal pile and fly off looking for a mate and some fresh “food”.
“Hey, who’s the odd guy carrying that large net around along the edge of the woods over there?”
“I don’t know, but he sure looks silly doing whatever he’s doing!”
If you have ever seen someone with a net walking along the edge of the woods or along a roadside ditch, it might have been me in search of insects.
As a child, I picked up many insects. In my right hand I have a snack, but in my left hand, I have an insect.
Since I was a child, I have had an interest in finding insects. I can remember picking up cicadas at a family reunion when I was four or five years old, and since then, I was known as the bug boy in my family. Anytime a ‘strange’ looking insect appeared, I was immediately asked, “What is this?” or, “Is this going to sting me?” Once I was a bit older, I was asking the same people, “Can you catch it for me?”
As I grew older, I was introduced to the insect collecting project in 4-H, which is where I discovered my fascination of butterflies and moths. I would try and try to collect tiger swallowtails near my house, but they would fly up into the tree tops when I came running after them with my net. Not only were they difficult to collect, but once collected, they were difficult to properly prepare for my collection. I enjoyed learning to master the techniques with the butterflies so much, that I became attached to them and wanted to learn more and more about the life cycles, taxonomy, and anything else relating to them.
Towards the end of my senior year in high school, I decided to go to the Ohio State University to study entomology. While perusing the Entomology Department websites and other links associated with OSU, I came across the Triplehorn Insect Collection web page. As soon as I saw the web page and knew there was an insect collection, I wanted to be involved with it— especially if there was a chance that I would be working with butterflies and moths!
A drawer of skipper butterflies in the process of being databased.
During my freshman year in college, I began working in the Triplehorn Insect Collection learning the basics while slowly being introduced to the butterflies and moths of the collection. During my sophomore year, I started working on the skipper butterflies. Not only do I work with skipper species from Ohio, but I work with the entire skipper collection. The broad goal of my project is to curate and database the entire skipper collection while focusing on a few Ohio species. During this project, I have gained experience with insect taxonomy, different computer software, and most of all, I felt a sense of accomplishment, knowing that I had been entrusted to work on an entire section of the collection.
Riley identifying a moth under a microscope.
This past summer, I was able to stay in Columbus, and I knew that I wanted to work in the insect collection. As a result, this was the perfect opportunity to meet the internship requirement for my entomology major and thus, I became an intern with the Triplehorn Insect Collection for the summer.
During my internship in the collection, I had three main areas of focus. The first focus was continuing the work with the skipper butterflies in the collection. My second focus was to learn the morphology of butterflies and moths with Dr. Steven Passoa, a National Lepidoptera Specialist with USDA/APHIS/PPQ. The third focus of my internship involved the databasing the darkling beetle collection, as part of a specimen data digitization project funded by the National Science Foundation.
Working with Dr. Passoa was one of the most enjoyable parts of my summer. He presented new techniques and ideas to me on a weekly basis that I could then apply to my work with the skipper butterflies and other areas of the butterfly and moth collection. His excitement for butterflies and moths fueled my own excitement for this group as I continued to work with him.
The specimen is being moved down the pin so glue can be applied to the pin at the proper spot.
With the darkling beetle portion of my time this summer, I was able to apply many of the same techniques used with butterfly curation and databasing for the darkling beetles, but I also learned how to fix beetle specimens known as spinners – ones that swivel around their pin freely. I enjoyed being able to apply knowledge from other areas of the collection to the beetle collection this summer and learning new techniques with the beetles. Although I spent a large portion of my summer working closely with beetles, my heart did not sway away from butterflies and moths.
After the “spinner” specimen has been glued to the pin, the labels are placed back onto the specimen using forceps, a pinning block, and a steady hand.
It is safe to say after working with other groups of insects that my true interest is working with butterflies and moths. Whether carrying a net along the edge of a forest in search of new specimens, or sitting at a microscope identifying butterflies and moths, I am enjoying what I am involved with at the Triplehorn Insect Collection and I am learning a lot.
About the Author : Riley Gott is an Undergraduate Curatorial Assistant at the Triplehorn Insect Collection. He is majoring in Entomology (Class of 2017) and he loves butterflies.
There are lots of reasons to grow your own mealworms. Mealworms are an excellent, high protein treat for chickens. They are a staple in the Bluebird diet, but many wild birds enjoy them.
Other pets like lizards, hedgehogs, and fish love to eat mealworms.
Mealworms make a great fishing bait.
And people even eat mealworms. Eating bugs (called entomophagy) is a normal way of life in Africa, Asia, and Latin America. Cooked mealworms are reported to have almost flavor, but when roasted they have a nutty flavor.
Mealworms make an excellent treat for chickens.
Mealworms can be used to train chickens to come when called or as a reward for going into the coop at night.
Mealworms are also an excellent supplement when your chickens are molting. Feathers are almost entirely made of protein. Adding some extra protein into your chickens diet helps them grow new feathers quickly.
“The nutritional value of live mealworm is composed of 20% protein, 13% fat, 2% fiber, and 62% moisture, while the dried mealworm’s nutritional value is composed of 53% protein, 28% fat, 6% fiber, and 5% moisture.”
Yes, chicks can eat mealworms starting around 1-2 weeks old. Mealworms are great for a baby chickens growth and development, and it’s just fun to watch them get excited about a wiggly worm.
If you decide to give baby chicks treats, they will need a dish of chick grit to help them digest the new foods. They don’t need grit if they are only eating chick starter feed.
Examine your lettuce plants regularly to detect insects before they begin eating the plants. Look at the base of the lettuce where it touches the ground, as well as the tops and bottoms of leaves. Most destructive lettuce pests are easily controlled with a combination of removing the insects by hand and cultural control. Many lettuce pests are attracted to rotting vegetation, so keep the garden bed clean of plant debris. Insecticides are not a good option for dealing with insects that eat lettuce plants not only are insecticides not very effective on adult caterpillars, but insecticides may kill beneficial insects that keep other garden pests under control.
Drue Tibbits is a writer based in Central Florida, where she attended Florida Southern College. Her articles have appeared in Entrepreneur and Your Home magazines. She has also been profiled in the Florida Today newspaper and the Writer's Digest magazine. In addition to writing brochure copy for local businesses, she helps new start-up companies develop a local image presence.
There are some types of true beetles that many people tend to associate with other types of flying insects.
Ladybugs are red and black beetles that include different types
Although commonly called ‘ladybugs,’ these delightful winged insects are a type of beetle in the family Coccinellidae. The term ‘lady beetles’ is the more correct name for these red beetles with black spots. Species of ladybugs (or, ladybirds) are beneficial beetles that are good for controlling aphid populations.
Learn more about the many different types of ladybugs that inhabit gardens and grasslands in the summer.
Fireflies are nocturnal beetles that glow in the dark
Even though they are called fireflies, these interesting insects are a member of the beetle family Lampyridae. The most fascinating of the species are the nocturnal fireflies that glow in the dark. For this reason, they are also called glowworms in some countries.
Fireflies grow up to 1” (2.5 cm) long and they use chemical lights to attract prey and mates.