The locust borer beetle is a type of long-horned beetle, known for its distinctive yellow and black markings, as well as its infestations in black locust trees. While these beetles have a striking appearance, many people might wonder if their bite is something to be concerned about.
Although the adult locust borer beetle closely resembles wasps or hornets because of its bright yellow markings, it is not poisonous or capable of stinging. In fact, these beetles are mostly harmless to humans, focusing primarily on feeding on the pollen and nectar of goldenrod plants. So, there is no need to worry about any adverse effects or dangers related to their bite.
It’s worth noting that locust borer beetles do pose a danger to black locust trees, as their larvae tunnel into the tree trunks, causing significant damage. Management of infestations typically requires pruning infested branches and applying appropriate insecticides, to maintain the overall health of the trees.
Locust Borer Beetle Bite: Is it Poisonous?
The Locust Borer (Megacyllene robiniae) is a type of long-horned beetle. As adult locust borers feed mostly on the nectar and pollen of goldenrod plants, they aren’t known to be harmful toward humans1. Their larvae, however, can cause damage to locust trees2.
Some key features of the locust borer beetle include:
- Adults are about one inch long with reddish legs1
- Distinct yellow and black bars found on their heads, pronotums, and elytra2
When discussing whether a locust borer beetle bite is poisonous, it’s important to note that:
- There’s no information suggesting that a locust borer bite contains any venom or toxins
- Bites from locust borers are rare, as they primarily consume plant material1
In comparison to other beetle species, locust borers have some notable differences:
Characteristic | Locust Borer | Other Beetle Species |
---|---|---|
Coloration | Yellow & black bars1 | Varies widely |
Habitat | Goldenrod plants1 | Various locations |
Effect on humans | Not poisonous | Some species can deliver harmful bites |
In summary, locust borer beetles do not possess a poisonous bite, nor do they pose a significant threat to humans. Their primary focus lies in plant consumption, more specifically on goldenrod plants.
Classification and Identification
The Locust Borer Beetle (Megacyllene robiniae) is a species of longhorn beetle belonging to the Cerambycidae family within the order Coleoptera. It is primarily known for infesting black locust trees (Robinia pseudoacacia). The adult beetle can be identified by its distinctive features:
- Black and yellow markings mimicking stinging insects
- Yellow “W” shape across the elytra or wing covers
- Reddish legs
- Antennae that are about as long as their body
These beetles are not known to be poisonous and do not possess any venom. In comparison to other beetles, the locust borer has some unique features:
Feature | Locust Borer Beetle | Other Beetles |
---|---|---|
Body Markings | Yellow and black | Various colors |
Leg Color | Reddish | Various colors |
Antennae Length | As long as body | Varies, often short |
When it comes to identifying the locust borer, remember these key points:
- It belongs to the Cerambycidae family
- Mimicking pattern helps protect from predators
- Infests black locust trees specifically
- Not venomous or dangerous to humans
Habitat and Life Cycle
The locust borer beetle (Megacyllene robiniae) is native to North America, specifically in the eastern part of the continent1. In the early 1900s, they spread to Canada2. These beetles prefer habitats such as:
- Uncultivated fields
- Meadows
Locust borers rely on plants like goldenrod (Solidago) for nectar and pollen3. Their life cycle consists of three main stages4:
- Larvae
- Pupa
- Adult
During winter, the beetle larvae hibernate within the tree bark5. In spring and summer, they feed on the tree’s heartwood, causing structural damage6. Eventually, the larvae pupate and transform into adults7.
Populations of locust borer beetles can vary depending on factors like geography, climate, and food availability.
Comparison Table
Locust Borer Beetle Stage | Characteristics |
---|---|
Larvae | Legless, white, tunneling |
Pupa | Protected, metamorphosis |
Adult | Black, yellow markings |
Host Plants and Damage
The locust borer beetle is known to infest and damage black locust trees and its cultivars, such as the purple robe locust1. Feeding primarily on tree xylem1, these pests can weaken branches or trunks through extensive tunneling in the wood1.
Infestations can leave trees more susceptible to wind damage, hinder the flow of nutrients, and allow entry points for pathogens2. Both the larvae and adult beetles can cause harm to trees, with the life cycle disrupting the tree’s health and growth1.
Some damage signs include:
- Holes in the bark
- Reddish frass in bark crevices or around the base of the tree2
Insecticides can provide some control, but proper tree care and maintenance are also essential to prevent infestations3.
Comparison of infested vs. healthy trees:
Infested Trees | Healthy Trees |
---|---|
Holes in the bark | Intact bark |
Reddish frass | No visible frass |
Weakened branches | Strong branches |
Prone to wind damage | Resistant to wind |
Nutrient flow hindered | Nutrient flow maintained |
Prevention and Management
Locust borers are a type of long-horned beetle that can cause damage to trees, especially black locust trees. Although they are not known to be poisonous, it’s essential to manage them to maintain the health of your trees.
To prevent locust borer infestations, focus on maintaining the overall health of your trees. Ensure they receive adequate water, especially during drought periods. Also, prune any infested branches and either chip or burn them to eliminate the pests.
When choosing insecticides, opt for carbaryl (also known as Sevin) or pyrethroid-based treatments. Apply these insecticides as a residual surface application on the bark of the trunk and large scaffold branches during late July or early August, before egg-laying begins.
Some pros and cons of using insecticides include:
Pros:
- Effective at reducing borer populations
- Can stop an infestation from spreading
Cons:
- May impact non-target species
- Can be harmful if not used correctly
It’s essential to monitor for locust borer activity regularly. Examples of signs of infestation include frass (sawdust-like material) near the tree base, blistered bark, and exit holes on the trunk.
To recap, the key elements for locust borer management are:
- Maintain healthy trees with proper watering and pruning
- Apply appropriate insecticides before egg-laying
- Monitor for signs of infestation
By following these steps, you can prevent or manage locust borer infestations and maintain the health of your trees.
Bug Control Recommendation Tool
Footnotes
- Locust Borer – Home and Garden IPM from Cooperative Extension ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10
- Locust Borer – Department of Entomology ↩ ↩2 ↩3 ↩4 ↩5
- https://extension.umaine.edu/home-and-garden-ipm/fact-sheets/common-name-listing/locust-borer/ ↩ ↩2
- https://extension.usu.edu/pests/ipm/ornamental-pest-guide/arthopods/wood-borers/locust-borer ↩
- https://extension.usu.edu/pests/ipm/ornamental-pest-guide/arthopods/wood-borers/locust-borer ↩
- https://extension.usu.edu/pests/ipm/ornamental-pest-guide/arthopods/wood-borers/locust-borer ↩
- https://mdc.mo.gov/discover-nature/field-guide/locust-borer ↩
4 Comments. Leave new
I found 2 locusts in my yard today I haven’t seen these in 35 years and when I did see them I lived in AZ… this has come as a big surprise as I have been in oregon for 35 years and have never came across one until today. Does anyone know how we can all of a sudden find locusts here?
Locusts are Grasshoppers, and this Locust Borer is a beetle that feeds on BlackLocust Trees, hence the name. According to BugGuide, the Locust Borer, is reported from Oregon bug NOT Arizona, but Oregon and the Pacific Northwest is not the native range of the species because according to BugGuide: “Previously confined to the native range of Black Locust in the northeast, it has spread with the trees throughout the US and parts of Canada.” We suspect you saw the similar looking Mesquite Borer in Arizona, and according to BugGuide: “Adults are active day and night, running rapidly along freshly cut branches of their host plants and feeding on the blossoms of Koeberlinia, Acacia, Baccharis, Bumelia, Clematis, and Solidago.”
Hi folks well all I can say is yes the Locust borer beetles are definitely here and I’m in Washington right across the river from Portland Oregon in Vancouver Washington..
We have LOTS of locust trees here, and the beetles too. If they are chewing up the trees, no wonder so many branches come crashing down during a wind storm! I have seen several of these beetles this summer, but never seen them before. Colorful bugs for sure!
Hi folks well all I can say is yes the Locust borer beetles are definitely here and I’m in Washington right across the river from Portland Oregon in Vancouver Washington..
We have LOTS of locust trees here, and the beetles too. If they are chewing up the trees, no wonder so many branches come crashing down during a wind storm! I have seen several of these beetles this summer, but never seen them before. Colorful bugs for sure!