Has your effort to grow a bunch of beautiful eggplants flopped because of flea beetles infestation?
I know that feeling when things are going well in your vegetable garden, and everything looks great. Until one day you notice small holes on the leaves of your eggplant.
Looking closely, you spot black little insects at the base of your plant and some on the foliage surface.
They are the notorious flea beetles!
You panic and rightly so.
Because let’s face it, flea beetles can severely hinder growth and stunt young plants and where the pest pressure is high, their feeding activity can result in unimaginable plant loss.
In this article, I am going to discuss 9 effective ways to get rid of the notorious bug naturally.
Flea Beetle Damage
Most damage is caused by the adults feeding on the cotyledons, stems and young leaves leaving characteristic pits and small holes (shot-holing). The larvae feed in 'mines' within the plant tissue and some sometimes, the larvae also feed on the plant roots.
In a recent research published in the Journal of Economic Entomology, eggplant flea beetle (Epitrix fuscula) can cause up to 60% leaf damage with an equivalent of 40 – 60% loss in yield.
That’s massive if you ask me!
This happens when flea beetles injure your eggplant leaves by chewing small shot holes in them, which reduces the photosynthetic capability of the plant, which, in turn, can reduce the size, weight, and overall yield.
This injury can also stunt the growth of the plant or even kill seedlings.
But even worse, flea beetles have been known to transmit viral and bacterial infections. And this possess a much bigger risk to your plants.
This article focuses primarily on various ways you can control eggplant flea beetles without harsh using harsh substances. But before then, you need to have a proper diagnosis before prescribing control measures.
Let’s start by diagnosis:
How to identify flea beetles on your eggplant
Eggplant flea beetles are very small organisms ranging from 1/6 to 1/8 inches long. But as small as they are, you can see them using a naked eye.
They have a wide range of colour but those that attack eggplants are mostly black.
In general, flea beetles have large back legs which they use for jumping, especially when disturbed. They are able to travel up to a kilometer in search of a suitable feeding and breeding ground.
If you notice shallow pits and small rounded, irregular holes (usually less than 1/8th inch) in the leaves, it is almost always a sure sign that your plants have been infested by flea beetles.
Flea Beetle life cycle – Epitrix fuscula (Crotch)
An eggplant flea beetle has at least two generations per year, and can complete its life cycle from the egg to adult in 30–45 days.
They lay their eggs at the base of solanaceous plants, typically the same plants the adults are feeding on. The eggs are laid in the spring as soon as the adults emerge from overwintering and are laid throughout the season.
The eggs require 6 to 8 days to hatch. After hatching, the larva burrow into the ground and feed on root hairs. The larva will last for about 20 days while the pupal stage lasts 1-4 days.
The adults emerge from the soil after pupation and seek host plants. Eggplant flea beetles overwinter as adults in leaf litter, soil, or debris near their host plants.
During the season, they will be often found feeding together on the same host plants.
How to Control Flea Beetles on your Eggplant
1. Start by monitoring using sticky traps
Place yellow sticky traps in your garden to see if you have flea beetles. And if so what’s the threshold. A few beetles are no match for a vigorously growing plant. Therefore, only take action when there’s an increase in number of beetles in your sticky traps.
2. Keep the weeds under control
Control weeds in and around planting sites to limit food sources for flea beetles. This is especially important for those weeds in the solanecious family such as jimson weed, henbane, bittersweet nightshade, and violet nightshade.
3. Use screens when the seedlings are growing
Screening can help in keeping the flea beetles away from your young plants.
4. Use a decoy crop such as radish to attract them (Pull strategy)
Flea beetles are naturally attracted to tall growing plants. Especially if those plants are radishes. You can plant some radish earlier than your eggplant. It is easier to control the beetles when on radish than the eggplant
5. Plant mint next to your eggplant (Push strategy)
A flea beetle has an allergy for mint! This means if you plant mint next to crops that attracted flea beetle. They will be repelled like magic. If you’re worried that mint could turn invasive and get out of hand, consider growing them in pots. That way you have more control. You can also use talcum powder – its great smell repels beetles.
6. Use a mulching fabric as much as possible
This is not as effective but it helps to reduce reproduction. As we have already seen, adults lay eggs in the soil or debris around the host plant. If you cover the soil with a mulching fabric, they’ll have no room to lay their eggs.
7. Plant your eggplant at the right time
Eggplant is a hot weather crop. If you put them in too early you are asking for problems. You should wait until the soil temperature is at least 70F. This will give them a head start. Before they are attacked, they are already too strong and can withstand minor damage.
8. Biological control of flea beetle using natural enemies
Microctonus vittatae is a native braconid wasp. This wasp kills the adult flea beetle.
The female wasp uses her ovipositor to lay eggs just under the skin of an unlucky flea beetle.
As the eggs hatch, the larvae feed on the beetle viscera literally eating a flea beetle alive. Larvae chew their way out through the host’s skin when they mature.
Once outside, the future wasps pupate, spinning tiny oval cocoons that look like insect eggs along the external back and sides of the beetle.
These fellows and ladies are not just innocently hitching a ride. When the adult wasps emerge from the cocoons, the already weakened beetle will soon die, thus preventing any further damage on your eggplants.
But how do you attract braconid wasp to your garden?
Plant white sweet alyssum (Lobularia maritima) around your eggplants. These beneficial bugs have a liking for this type of plant and in no time, they will be plenty in your garden.
I have written a comprehensive article that explains in detailing which plants attract which beneficial bugs. You can find it here - 12 Plants That Attract Ruthless Good Bugs
9. Spray with spinosad based pesticide (Most effective)
If all else fail, directly spray your eggplant every 5 days with spinosad for 3 weeks.
My best recommendation is Monterey’s Garden Insect Spray which contains Spinosad as an active ingredient.
Spinosad is a natural substance made by a soil bacterium that can be toxic to insects. It is a mixture of two chemicals called spinosyn A and spinosyn D. It is used to control a wide variety of pests.
Spinosad affects the nervous system of flea beetles that eat or touch it. It causes their muscles to flex uncontrollably. This leads to paralysis and ultimately their death, typically within 1-2 days.
You don’t have to worry about the environmental impact because spinosad is broken down rapidly by sunlight. When applied to leaves, some spinosad can be absorbed. However, it does not readily spread from leaves to the rest of the plant.
Spinosad is practically non-toxic to moderately toxic to fish depending on the species. But most importantly, evidence suggests that spinosad has little or no effect on honey bees and other beneficial insects after sprays have dried.
For double effect, drench the soil at base of the plant with Neem Oil.
There you have it.
9 effective ways you can use to get rid of flea beetles in your eggplant garden without hurting the environment.
Which ones will you choose?
Back to you.
And as always, don’t forget to leave a comment.