The residents of the US & Canada, and especially from Georgia surely would know about these green Beetles.
This write-up will have a brief description of these Green Beetles that includes their physical aspects, life cycle, behavior, the damage these green beetles can potentially cause, and how to curb their growth.
Green June Beetles: Brief Description
With a very common name, Green June Beetles are also known by their scientific name Cotinis nitida. In the layman language, it is usually called June Beetles. These green beetles are green in color, thus called Green June Beetles.
They can have colorful stripes over their body or wing covers. Usually, they have the color rusty brown, slightly golden, or bright orange. These green beetles are hardly an inch long. Smaller ones can be of the size around half an inch.
Many times, people get confused between the Japanese beetle & the green June beetle. The Japanese beetle is also green in color with brownish color wing covers.
The Japanese beetle differs from the green June beetle and can be easily identified by its size. Japanese beetles are smaller in size.
These green beetles are also confused with the bumble flower beetles, as both the species crawl on their backs. Though the bumble flower beetles do not cause much damage.
Why Are These Green Beetles Called June Beetles?
These green beetles start their flight around the later phase of June, and hence the name of June’s beetles. They are also known as June bug or June beetle grubs. The fully grown adult Green June Beetles are also called Grub worms.
These grubs are very common in the soil. These green beetles usually prefer soil with plenty of organic matter. Green June’s beetles usually prefer sandy soil.
Lifecycle of Green June Beetles:
The lifecycle of these green beetles are eggs, larvae, pupae & ultimately as adult green beetle. Ultimately, fully grown adult green beetles (grub worms) usually resides in loamy soils. The life cycle of these green beetles is one year.
Once the mating process between the male & female is completed, the female makes a burrow in the soil and places around 50 to 75 eggs. The eggs have a hatching period of 2 weeks.
The eggs are white in color & elliptical in shape. After the period of 2 weeks, these eggs start becoming spherical in shape & eggs hatch into larvae.
In the larval stage, these insects are initially white in color and can grow up to 1.5 inches. Slowly, they start developing a head & spiracles that brown in color. During the stage of larvae, the color slowly changes to green.
The larva ultimately develops a brown head & three pairs of legs. They crawl on their backs. The legs have no particular use in crawling and are in the air. This is a unique distinction of the green June beetle larvae.
Larva feeds on manure, organic matter, mold, compost & humus. Larvae mainly damage the roots of the plants. Particularly, the larva damages the plants that have been raised over fertilizers & mulch.
The larval stage of the green June beetle is more dangerous than the adult green beetle.
The stage of the pupa is for 18 days until it becomes an adult green beetle. The pupa is in the form of a cocoon. The cocoon is produced during the larval stage when the larva produces a thick viscous fluid. A cocoon is built by dirt, dust & soil particles.
The viscous fluid helps in the formation of the cocoon. The shape of the cocoon is oval. When the pupa is converting into an adult beetle, it slowly develops green color.
Adult Green Beetle
Adult Green Beetles shrink in length when compared to their larva. They are around half an inch to an inch in length & around half an inch in width.
Now, the insect fully justifies its name of green beetle. Adult green beetles usually eat rotten fruits. These fruits are grapes, oranges, berries, apples, apricots, plums, pears, and many more.
These green beetles can be very notorious as they can feed over the sap of maple, oak, and other trees. The adult green beetle starts their flight in late May & continues till early August with the most time of flight occurring in the months of June & July.
Damaging Stage & Time:
Larva & Adult green beetles usually cause the damage. The damages by larval stage are during the late summer till the fall & again in the spring. These insects become more & more dangerous when the temperature rises beyond 22°C or around 70° F.
During the warm winters, these grub worms come out of the soil leaving their trail. Also, apart from the trails of tunnels, they also form mounds of soil. These indications increase during the spring.
After their feast is done, the mature lava enters the soil again, and in the late spring, starts to pupate. They arise as adult beetles in mid to late June & live until late August & early October. The size of the tunnels can be around the size of one’s finger.
Mating & Hatching
Female green beetles travel & settle near the grass surfaces. These female green beetles release some chemicals which attract the male green beetles. The male beetles track these chemicals & reach the female green beetles.
The female green beetle comforts itself at a safe place & mating occurs. Once, the mating occurs female green beetle finds a comfortable grassy & moist area. It selects a place where the soil contains high amounts of organic matter.
The female green beetle then digs a hole in the soil & prepares a small ball of soil from it. It then lays its eggs in this small ball of soil. The ball of soil is burrowed around 7 inches deep into the soil.
The hatching period of the eggs is around 2 weeks. A female green beetle has the capability of laying around 60-75 eggs after mating. Once the eggs break open, the young larvae start digging in search of organic matter.
Tunnelling & Mounds by the Green June Beetles
It is noted by the experts that limited tunnelling can be beneficial whereas excess can hamper the soil quality. Soil is aerated due to the tunnelling by these green beetles. Excess of it can loosen the soil & damages the plant roots. These green beetles also have a knack for leaving small mounds of soil near the tunnel. In the process of tunnelling, they also leave their trail.
There are two types of predators, namely: Insects & Vertebrates.
There are several predators of the larval stage as well as of the grub worms. Scolia dubia, a type of wasp, particularly known as the digger wasp is a well-known predator of larval stage & adult green June beetle.
Digger wasp digs the burrows & finds out a female green June beetle. It then paralyzes it & then lays her eggs on it. The larvae of the wasps consume the body of the green beetle.
Flesh fly is another well-known predator that feats on both the larval stage & the adult green June beetle. The larval stage of the flesh fly sticks to the adult green June beetle & sucks its nutrition, thus acting as a parasite.
The larval stages are preyed on by many vertebrates like raccoons, chipmunks & moles. Also, birds like crow & jay are known as predators of the adult green June beetles.
Management of Green June Beetles
See the extent of the damage by these green beetles. If the tunnelling & molds are not severe then they will not be an issue.
Instead, they aerate the soil. But if you feel that these green beetles are a nuisance then the following insecticides can be used:
(Suggested by Georgia Pest Management Handbook)
- The best time for the control application would be around August to October.
- The soil must be irrigated (if it is dry).
- Use pyrethroids & sevin. Apply them late in the day. They work very well at the adult green June beetles.
- Remove the dead beetles & mark the area as an infected area.