If you find white and brown squiggles all over the plant leaves in your garden. These lines were formed by tiny larvae which cause the highly destructive complex network of lines by chewing on the interior side of the leaves. The effect on a wide range of plants and causes uncontrolled damage to the plants.
Here in this article, I will tell you about the life miner, their damage, symptoms, life cycle and different control measure.
What is the leaf miner?
Leaf miner is a broad term used to describe the larvae of Lepidoptera, Diptera, and Hymenoptera that used to live inside the plant leaves while feeding and maturing. Most of the growers monitor erratic lines revelation on foliage oftentimes with Fras visible inside the discolored lines. The pattern formed by feeding tunnel is often indicative of particular pests afflicting your plants, but you have to pay close attention to which plants are being targeted as which will be helpful in identifying the pest.
Description of leaf miner:
Leaf miner adults are small in size 0.06 inch to 1.5 mm and in black, the yellow color having a bright yellow scutellum, a triangular spot on the top rear of the thorax within the insect. It is important to differentiate between the leaf miner insect damage and other insect damage, which may occur in the same area. Leaf miner insect is more resistant to insecticides because they usually live inside the leaves which act as a shelter from insecticides. Leaf miner is almost completely surrounded by yellow with only a little portion of black touching the rear of attention. The highest of the thorax of leaf miner is shiny black whereas on L. trifolii is more dark grey colored. The larvae of leaf miners are tiny bright yellow maggots about 2mm long after they emerge from the leaves to pupate. Pupae seem like tiny brown grains of rice. There are often many generations a year.
Female insert the white oval eggs into the leaf tissue puncturing the leaf at the tip and along the perimeters. Numerous punctures are made, but only a little percentage contain eggs the bulk function feeding sites for the adults who imbibe the exudate.
Identification of insect:
Adult insects are about 1/10-inch-long which often present in black to gray flies with yellow stripes and wings. They are similar in appearance to a small hunched back house flies and lay their eggs on the undersides of leaves. Larvae are worm-like maggots that are 1/3 inch in size which are often straw or green in color. They create winding tunnels that are clear aside from the trail of black fecal material left behind as they feed.
Species of leaf miner:
Here are some species of leaf miner which may cause infestation damage to your garden.
Pea leaf miner (Liriomyza huidobrensis): It is also called the American serpentine leaf miner. The larvae infest on the leaves and stems of the peas. It may also affect other a range of vegetables.
Boxwood leaf miner: They feed on the upper and lower parts of plant foliage. The symptoms of boxwood leaf miner infestation include leaves turning yellow and drying making its victim looks extremely unhealthy.
Beet leaf miner: The adult leaf miner fly looks like a daily housefly. The maggots of those insects’ tunnels through the leaves of Swiss chard, spinach beets, and other related plants.
Citrus leaf miner: Small, light-colored moths infest the citrus trees like lemons, limes, oranges, grapefruits, and others. Although it is native to Asia, it currently causes infestation in southern California gardens.
Spinach leaf miner: They usually appear in spring and choose young robins and daffodils as their favorite host plants.
Tomato leaf miner: It is a known serious pest found in tomato plants. The larvae feed voraciously on crops and mines in stalks.
Leaf miner life cycle:
An adult mated female will lay her eggs on or inside an egg’s surface. Inside it, is often through with the female ovipositor, which pierces through the leaf skin to inject the eggs. This could create a little raised spot on the leaf surface. One female may leave about 250 eggs.
In ten days or less, the eggs will begin hatching into a larva. This is often after they are at their most destructive, because the larvae tunnel through the leaf tissue and prey on it, leaving the telltale trails that leaf miners are related to.
This feeding phase will last for 2-3 weeks reckoning on the actual species. Once the larvae are nearing pupation. They will chew through the skin of the leaf and drop onto the bottom below and burrow on it and or two beneath its surface.
At now, if the weather is just too cold for them to survive as adults, the larvae can go dormant and overwinter within the soil beneath the plant. Otherwise, they will form a pupa and start their final transition to adulthood.
It takes approximately fifteen days to transition from pupal form to adult. At that time, the adult moth or fly will dig its way back out of the soil and start the new cycle. They complete several generations in a year.
Habitat of life miner:
They mostly live in hotter climate regions house commercial farms which might suffer major issues.
Not only there is an extensive range of insects are present, but their chosen plant is yet a good range of plants that are subject to leaf miner damage from trees through shrubs. Grasses do not seem to be likely to be consumed but there are also pupa stages beneath grassy oil.
What damage did they cause?
The juicy inner soft tissue of leaves is subject to leaf miner damage, although they like leaf matter that has less cellulose. While they will chew through a leaf vein and promote more leaf on the opposite side. They have an inclination to ignore the veins in favor of sweeter, softer plant tissues.
Particular species of leaf miners have opted to be incredibly selective. They do not cause extensive damage to the tree itself, but they leave open pathways for fungal or bacterial growth on the leaves. For the farmer, this damage can cause portions of or entire crops to become unsellable. As an example, spinach leaf miner damage will make the leaves unpalatable and potentially unsafe to consume. Needless to mention, that may spell disaster for growers.
However, this pest is not limited to edible plants. Leaf miner damage affects the hedging plant. A variety of flowering plants are at risk of the damage further. While in most cases this leaf miner damage would not kill the plant unless it is extremely heavily infested. It will be unsightly and potentially a gateway for fungal or bacterial diseases to urge access to the plant. If the plants are enough healthy, they must survive the leaf miner assault.
How to control leaf miner damage?
There are many ways to control leaf miner damage.
The first step in the management of any pest in defined monitoring in which you identify the right stage of the pest development. There are the following stages you can monitor while seeing an infected plant.
The easiest and most accurate way to control leaf miners is to seeming for its damage to host plants. The larvae feed within the plants’ leaves or needles. They produce either large blotches or tunnels that wander under the surface of the leaf. You can easily notice the symptoms of damage.
Leaf miner larvae are very flat, a trait that allows them to adapt to feeding inside a leaf. Feeding larvae eat the green tissue inside the leaf and leave a meandering trail that is covered by a skinny case or cover. If there are many larvae feeding on one leaf, their tunnels may join and provides the looks of huge blemishes or spots.
The precise monitoring gives you a full overview of the damage level and the idea of an overall population of insect which attacks the plants.
Control the damage level:
After precisely estimating the insect population and the damage level, the next step is to adopt an appropriate method to control the leaf miner attack.
First of all, adopt a precautionary measure to control the insect attack because protection is always better than cure. Here are two precautionary measures you have to adopt to protect your crop.
For protection, you have to choose those cultivars which are more resistant to leaf miner. Most of the American cultivar is more susceptible to attack, while the English varieties are more resistant to leaf miner. Here are some resistant cultivars: Buxus sempervirens, pendula, suffruticose, Handworthiensis, Pyramidalis, Argenteo- varigata and Varder valley.
If the plants are damaged by the insect attack. They mostly damage the branches and leaves of the plant. You can protect the plants by pruning the affected branches.
Prons of adopting precautionary measure:
You can protect your garden at the right time. It is also economical because the cost of pesticides is reducing moreover it is also an environmentally friendly method to control the pest population, it does not have any verse effect over the environment.
Cons of adopting precautionary measure:
This technique is only effective if the insect not attacks on the plant. If the insect attack on the plant in epidemic form. It is only a remedy against the plant not the control against the insect attack.
Here is some cultural technique in which you have to opt to protect your garden.
- By adopting good field sanitation properties, you can also control the epidemic outbreak of leaf miner insects.
- The healthier the plant, then there are fewer chances of leaf miner attack. You have to maintain the health of the plant by applying organic fertilizers and proper irrigation which allow the outgrowth of the plant and also provide resistance against pest damage.
- Always use harvest-guard which prevents the adult insects from laying eggs on the leaves.
- You can also use a yellow or blue sticky trap to catch the egg-laying adults. Always cover soil under infested plants with plastic mulches to prevent the larvae from reaching the ground and pupating.
Benefits of cultural control:
Through cultural control, you made alive your soil by adding compost to the soil and by soil amendment practices which ultimately enhance the fertility of the soil.
By improving cultural practices also improve the soil texture and moisture level in soil which is good for plant growth.
The disadvantage of cultural control:
It is not last lasting means to control the leaf miner attack and it is not completely eradicating the leaf miner from the garden.
Here are few biological means which are used to control leaf miner insect. These ways are also environment-friendly and had no certain damage to the environment.
- Always use beneficial insects against the leaf miners, they act as prey for the insects. The parasitic wasp Diglyphus isaea is a commercially available beneficial organism that will kill leaf miner insect lives in mines. The wasp is especially beneficial to indoor growers of ornamentals and vegetables.
- You should always prefer Bio Neem contains azadirachtin which is the key insecticidal ingredient found in neem oil. The concentrated spray will disrupt the growth and development of pest insects and has repellent and antifeedant properties.
- You have to choose fast-acting botanical insecticides which should be used as last resort. They are derived from plants that had insecticidal properties.
- You can also use trap crop lamb quarters, columbine and velvetleaf. If you have dealt with leaf miners in the past growing season. They serve as a more inviting alternative for the leaf miners and direct them away from the crops being protected.
- Application of Bacillus thurigiensis also known as BT which can help with some larval issues in addition they are available as garden dust or in spray form known as Monterey Bt. These bacteria will act as poison for leaf miner larvae if they come in contact with the insect.
- In the worst cases of infestation, a spinosad-based product like Monterey Garden insect spray could also be used. Once it is soaked through the leaf surface, the spinosad will poison leaf miner larvae inside. However, like all of those, it is going to take multiple applications.
Advantages of biological control:
- It is a safer and environmentally friendly technique.
- It is also non-toxic for beneficial insects like honey bees.
- They are easily breakdown into simple chemicals and less harmful to the environment as most of the insecticides had their properties.
The disadvantage of biological control:
The only set back of this system is the natural predator of leaf miner sometimes become a pest of other plant and create massive damage to other plants.
This insect mostly lives inside the leaf and protect themselves from the insecticidal spray. To kill these insects always use a systemic insecticide because it is absorbed by the plant and ultimately kills the harmful leaf miner insects.
If you notice leaf miner damage on foliage by thoroughly apply spinosad which is Monterey garden insect spray to all plant surfaces. Once ingested spinosad stops larvae from feeding and that they will die within 24-48 hours. Repeat the applications 2-3 times throughout the season if damage persists.
Merits of chemical control:
They are fast means to control the leaf miner insects. They are normally used to control large populations of insects.
Demerits of chemical control:
They had a harmful effect on the health of human beings and also had affected the other beneficial insects. The excessive use of pesticides will ultimately produce resistance in the leaf miner insects which rather made control the insect population more difficult.
Here I tell you all means to control leaf miner insects with their merits and demerits, now it is up to you which method you adopt to save your garden from leaf miner damage.
Like This Article? Pin it on Pinterest