We explain all you need to know about the lesser-known cousin – brown lacewing, in the article below.
Lacewings are beautiful, golden-eyed insects that have thin wings with intricate vein networks. This gives them a lace-like appearance and, hence, their name. But the name actually includes a large variety of insects.
Taxonomically, all insects under the order of Neuroptera are “lacewings,” which also include Mantidflies and Antlions.
However, when used in regular speech, we only use them to refer to the commonly found brown and green lacewings.
In this article, we will explore the less commonly found brown lacewing. Unlike its green cousin, brown lacewings often get squished because they are confused with other similar-looking bugs.
What Are Brown Lacewings?
Lacewings are tiny insects – only 0.75 inches long that are commonly found in green areas.
They have large, golden eyes, a long segmented body, and thin, transparent veiny wings that are much larger than their body.
Over 5,000 different species exist, though the brown and green lacewings are the two most commonly found ones.
Interestingly both types of lacewings can be green and brown at different stages of their lives – it is hard to differentiate them purely on color. Let’s look at how to tell them apart in the next section.
How To Differentiate Between Brown and Green Lacewings?
Despite their names, one cannot simply distinguish between the brown and green lacewings based on color alone.
This is because an adult green lacewing can have a range of colors – from brown to gray to a reddish hue. Initially green, during fall, the green lacewings take on a brownish color.
One way to separate them as adults is to look at the three segments that make up their bodies.
Brown lacewings will have a longer neck. This is because the first segment of their body is more elongated than the other two, giving them a snakefly-like appearance.
Moreover, brown lacewings are burnt brown in color with papery thin brown wings, while green lacewings have more of a grayish shade of brown. The brown ones are also smaller in size than green lacewings.
Even in the larval stage, the two are virtually indistinguishable – except by behavior.
Both types of larvae move around in circular motions. The green lacewing larva can only move its head forward, but the brown lacewing larva can wiggle theirs from left to right as well.
Where Do They Live?
Lacewings are found across the world but are mainly concentrated in North America and Europe. The US itself boasts 90 different species of lacewings.
Generally, they are found in open, green areas with tall grass and lots of vegetation. They may reside within woody plants, shrubs, crops, and other landscaped spaces.
They avoid the hot and humid summers of the interior mainland and are concentrated near coastal areas. However, in Australia, they are distributed across the continent.
They are attracted to light and quick to take flight if disturbed. You can find them in both urban and rural areas.
What Do They Eat?
Lacewings eat both other insects and plant matter – though they definitely prefer the former. Their larva is found concentrated around the base of trees.
Here, they feed on their smaller invertebrates, spiders, wasps, aphids, and mites. They can also eat decaying vegetable matter, and some, like the sponge-eating lacewing, can feed on freshwater sponges.
Brown lacewing adults also feed on other insects and may occasionally drink nectar as well. Because of their habit of eating smaller parasitic spiders and mites, lacewings are considered generalist predators and are beneficial for crops.
They are commercially bred and released into agricultural gardens for the purpose of biological control of pests. They do not harm crops and plants.
What is the Lifecycle of A Brown Lacewing?
Lacewings lay their eggs in sites that are close to plenty of available food, such as insect-attracting plants and flowers.
Brown lacewing eggs can be distinguished from green lacewing eggs by a short disk present at the end of the eggs. Their eggs look similar to other insect eggs, such as those of syrphids.
Once the eggs hatch, the lacewing larvae start feeding and are active during both day and night time.
The larvae (or nymphs) go through three different instar stages and finally turn into pupa. Pupation generally happens over winter, as the larvae remain safe and warm within tree barks and nooks.
Adults emerge from the pupa and resume their journey to find food and mates. They are most active during the night and are not social.
The whole process lasts around one year. However, this timeline depends on how cold the place is, as, in warm climates, the entire lifecycle can be as short as six weeks with no pupation.
Where Do They Lay Eggs?
Both brown and green lacewing lay eggs along the stalks of green branches or in the topsoil layer of sandy areas. They either lay singular eggs or multiple batches which form large colonies. A colony can contain the eggs of other insects, such as syrphids.
Do They Bite or Sting?
Lacewings cannot bite or sting. But if disturbed, they clamp onto your skin with their jaws, which can lead to skin irritation in some people. They rest on leaves and get easily stunned by sudden movement.
The lacewing larva can also bite, though they do this mostly as a defense mechanism. Their bites are not dangerous and do not usually require medical attention.
Are They Poisonous or Venomous?
Lacewings are not poisonous to humans, and the bites of both larvae and adults are harmless.
It is rare to get a lacewing bite. Bites are usually a result of them perceiving you as a threat.
Lacewing bites are not dangerous as they do not infect humans with pathogens. But a large infestation could be bad for your crops as they sometimes do carry plant-based diseases.
Are They Harmful to Humans as Pests?
Lacewings are not considered pests. In fact, they are beneficial for getting rid of pests and keeping the mite and spider populations in your garden under control.
However, if you see them in large numbers, it could spell trouble. While they don’t harm plants, they might carry hosts for plant-based diseases, which could make your crops sick.
A commonly found bacteria that uses lacewings as a host is Rickettsia which can affect plants like clover and grapevine.
Are They Beneficial?
Lacewings are generalist predators. This means that they do not have a special diet but instead prey on any and all smaller invertebrates they see.
The list includes mealybugs, mites, parasitic spiders, caterpillars, aphids, whiteflies, and many more. Some adults also drink nectar, but they don’t harm or feed on plants.
This makes lacewings a great ally to have in gardens. They are a natural way to get rid of smaller pests without insecticide.
Can They Come Inside Homes?
It is possible that an adult lacewing can enter your home. In this case, the lacewing is probably attracted by the light, or it is looking for a warm and dry place to hibernate for the winter.
They are not harmful, and you can simply sweep, vacuum, or brush them out. If there are large numbers of them, it might be best to call pest control.
What Are Brown Lacewings Attracted To?
Brown lacewings are active at night. They are usually attracted to light. During mating season, males are attracted to pheromones.
You can attract them to your garden by having a good mix of pollen-producing plants that are the food source of lacewings.
How To Get Rid of Them?
Generally, lacewings in the garden are a good sign and do not need to be treated.
However, if you have them in large numbers to the point where they are a hindrance while gardening – you can get rid of them.
A simple way to get rid of lacewings is to target their food source. Their food source mainly consists of smaller invertebrates that are highly susceptible to insecticides.
You can get a systemic insecticide and spray it on your plants. This will kill smaller mites and aphids. With no food source, the lacewings will move on to greener pastures.
Interesting Facts About Brown Lacewings
- Lacewing larvae have an alligator-like appearance.
- The first larval or instar stages are highly active and mobile. They exhibit different types of head movements. However, later instar stages are less and less mobile.
- During courtship, to attract a mate, lacewings can create low-frequency vibrations using their abdomen. Consequently, the stalk on which the lacewing is resting can also vibrate.
- A single lacewing can eat more than 200 aphids or invertebrates in a week.
Frequently Asked Questions
Why do lacewings bite humans?
Lacewings do not generally bite humans. However, if mishandled or upon sensing danger, they will clamp their jaws onto the skin of the human, which can resemble a bite. This is not painful or toxic. Larvae are more likely to bite humans than adults.
Are lacewings better than ladybugs?
While ladybugs have long been the poster child of good pest-control insects, lacewings are actually better than them.
Lacewings consume smaller, soft-bodied insects at a 20 times faster rate than ladybugs. Mantises are also similarly helpful but not as popular.
Where can I buy brown lacewing larvae?
You can connect online with suppliers who specifically breed certain insects for biological pest control.
Brown lacewing larvae will keep your plants free of mites and, as adults, will be food for their natural enemies, such as dragonflies. All of these insects are equally important for a healthy garden ecosystem.
What is Brown lacewing’s scientific name?
The brown lacewing larvae are known as Hemerobiidae. The name Hemerobiidae encapsulates the entire range of brown lacewings species – all of whom have thin, veiny wings and small, long bodies. The green lacewing, on the other hand, is known as Chrysopidae.
Wrap Up
Lacewings are friends, not foes. There is not much to fear from. These golden-eyed insects can greatly help crops by keeping a balanced ecosystem.
Though those engaging in gardening among tall grasses may find them to be an irritant as they mistakenly attack humans – they are best retained as a natural pest control agent.
Thank you for reading!
4 Comments. Leave new
I am dealing with a large number of these indoors, I don’t have any houseplants. I am trying to figure out how to keep them outside as opposed to inside, any suggestions?
How can I send a photo to your website as I believe I have come in contact with a Brown Lacewing larva. Thought you could add it to your gallery.
Respectfully,
Gary
You may submit images to our site using the Ask What’s That Bug? link on our site.
How can I send a photo to your website as I believe I have come in contact with a Brown Lacewing larva. Thought you could add it to your gallery.
Respectfully,
Gary