Insects will lay their eggs on the top and underside of plant leaves for protection as well as a food source for the larvae when hatched.
The black eggs found on plant leaves can be the eggs of aphids, lace bugs, wheel bugs, and stink bugs. Once laid, the eggs can pale, changing to a darker color as they age. If allowed to hatch, the larvae will feed on the plant leaves until maturity, which will affect the plant’s overall health.
It can be nerve-wracking to see insect eggs on plant leaves, but proper identification will allow you to make better decisions about whether to leave or take action to remove the eggs from the leaves.
We have covered the different types of insects that lay eggs on leaves and what you can do once you have identified that they are harmful to the plant.
What Insects Lays Eggs on leaves:
Insect eggs vary in shape, size, and color depending on the species. For example, bullet-shaped, keg-shaped, and gelatinous.
Eggs can be laid alone, in clusters, or in large groups that hold on to the leaf with a sticky sap left behind from the female bug. The amount depends on the risk of predation that the larvae are likely to encounter.
Some beetle species lay a few thousand eggs in large batches, as only some will make it past the larval stage.
When hatched, the larvae can attack the plant, feeding on the surrounding structure until they reach a stage of maturity for them to migrate.
At that point, the destruction would have already been done, which in some cases may cause the death of the plant.
List of insects that lay Black Eggs on leaves:
1. Lace Bugs –
If you notice black insect eggs on the underside of leaves that appear to be partially inserted into the leaf tissue, they might be lace bug eggs. Lace bugs are tiny, winged insects that suck sap from the leaves of ornamental plants and trees, causing discoloration.
While lace bug eggs are actually pale in color, many species secrete a dark substance over the eggs.
This substance helps the eggs stick to the leaves, making them black.
2. Aphids –
Aphids tend to attack ornamental plants, such as roses, and cause the growth to be stunted.
Research has shown that these insects lay their eggs on both the lower and upper end of leaves.
3. Stink Bugs –
Stink bug moms lay darker eggs on the top surfaces of leaves than on the undersides of leaves. The darker eggs receive more protection from the sun’s damaging ultraviolet rays.
4. Wheel Bugs –
The egg clusters are glued together and covered with gummy cement and are primarily located on the trunk or branches of trees or shrubs.
The eggs hatch into nymphs that are bright red in color with black markings.
Are Insect Eggs Harmful to Plants?
Insect eggs on leaves are common and can harm plants if not correctly identified and removed. However, some plants can produce a hypersensitive response that protects the plants before the eggs hatch.
For example, some butterfly eggs can trigger a hypersensitive response in plants.
This response is known for the death of cells and plant tissues around the egg and, thus, leads to desiccation or the dropping of the egg.
This is how plants protect themselves by preventing the eggs from hatching on the leaves.
Most plants have a unique first line of defense that helps them protect themselves from enemies before becoming harmful.
In some other cases, plants make themselves more attractive to parasite wasps that help devour harmful eggs.
The effects of eggs on plants are induced by changes in the photosynthetic activity of leaves and the plant’s secondary metabolism and growth.
Examples of egg deposition effects can be the induction of hypersensitive-like plant response, formation of neoplasms, or production of ovicidal plant substances.
In addition, egg deposition can induce a change in the plant’s odor and leaf surface chemistry, which serve as indirect plant defense with the help of antagonists of the insect eggs.
These egg-induced changes lead to the attraction of egg parasitoids and their assistance on a leaf.
Thus egg-induced plant changes and address egg-induced effects on the plant’s transcriptional pattern.
Moreover, biological control through natural enemies of the harmful herbivores and exploitation of the genetic variation in resistance traits among wild relatives are two promising sustainable strategies to reduce pests.
With this, such traits often allow the pest to continue feeding and act when damage already exists.
Killing the insect egg before the pest can hatch and cause harm is an extra attractive option; to do this, we need to study their underlying mechanisms.
How to Prevent Insects from Laying Eggs on Leaves:
Following are the ways to prevent insects from laying eggs on leaves:
- Mist the leaves regularly to keep them moist.
- As eggs are on the surface of the leaves, dusting the leaves often prevents these mites from laying eggs on them.
- Homemade bug spray can be made from water and neem oil for indoor plants.
It has shown positive results in such cases. Moreover, these are natural remedies for preventing pests without any side effects and can be made easily.
- As organic fertilizers are vital for the health of plants, maintaining plant health with organic fertilizers allows plants to outgrow and tolerate pest damage can also be an excellent tactic to keep insects from laying eggs on leaves.
- A natural remedy to boost the immunity of leaves is keeping the soil alive by using compost and other soil amendments to generate a natural immunity of leaves against insects and their eggs.
How to Get Rid of Black Eggs on Leaves:
There are many ways to control black eggs on leaves without using any harmful chemicals. Aphids and other black egg-laying insects and pests have several natural enemies, including other insects, larvae, and birds. Insect eggs are easy to remove by hand or target with sprays.
However, some insects can multiply quickly, so it may take a combination of methods and repeated efforts to control them completely.
Use a Strong Stream of Water
Spray aphids off of plants with a strong stream of water from a garden hose. This method is most effective early on in the season before an infestation has fully taken hold.
Remove by hand
Put on some garden gloves and knock them off of stems, leaves, flower buds, or wherever you see them, and into a bucket of soapy water to kill them.
Soap and water
Apply with a spray bottle directly on aphids and the affected parts of the plant, making sure to soak the undersides of leaves where eggs and larvae like to hide.
The organic compounds in neem oil act as a repellent for aphids and other insects, including mealybugs, cabbage worms, beetles, leafminers, ants, and various types of caterpillars.
Create your own spray mixture with essential oils. Use 4 to 5 drops of each: peppermint, clove, rosemary, and thyme, and mix with water in a small spray bottle. Spray on affected plants to target adult aphids, as well as aphid larvae and eggs.
Sometimes the above-mentioned insects can also lay eggs in the soil which can also be corrected by using the methods described.
The black eggs on leaves cause degradation of the photosynthetic activity of leaves, and dead larva skins on leaves surfaces damage the leaves’ sensitivity and photosynthetic efficiency so exploiting the natural egg-killing capabilities of plants is promising in reducing crop losses in the future.
To retain the sustainability of a plant, some precautionary measures should be taken against black-laying insects and their side effects.
There are many environmentally friendly ways to remove the eggs so one can use them to prevent plants from the damages caused by the black eggs without any chemical destruction i.e, using water, removal by hand, Neem oil, and essential oils.
One can also prevent insects from laying eggs by misting the leaves regularly, Dusting, and cleaning the leaves in order to prevent mites from laying eggs on them.
There are also homemade bug sprays made up of water and neem oil that prevent insects from harming indoor plants.
One can also keep the soil alive by using compost and other soil amendments that act as a natural immune system for leaves.