With the warmer seasons comes the added pressure of garden pests. As more people turn to growing food for themselves or their families, so too does the need for pest prevention.
Potatoes are one crop that many of us add to our gardens. Not only are they versatile in the kitchen, but they can also provide a bounty at harvest time with minimum effort.
Let’s discuss a pest that can impact this marvelous plant, alongside some other staples: the potato leafhopper.
What Are Potato Leafhoppers?
Scientifically known as Empoasca fabae, potato leafhoppers are a common pest that poses a threat to a wide variety of crops, particularly potatoes, beans, strawberries, eggplants, clover, and apples.
Alfalfa, in particular, suffers from huge economic losses and is a major concern for commercial growers. In North America, the potato leafhopper is also considered an agricultural threat to the commercial production of potatoes.
Potato leafhoppers emerge as adults at the beginning of spring from their overwintering sites, which are typically grass, weeds, and plant debris.
They are small and measure about one-eighth inches long at the adult stage. They have pale green to vibrant yellow heads and legs. They are wider at the head and angle into a wedge shape at the end.
Fully mature adults have about eight pure white dots on their prothorax, the first segment of the body and containing the first pair of legs.
The potato leafhopper’s most identifiable trait is its hopping and jumping ability. With those extraordinarily powerful back legs, it can easily move from plant to plant.
Once adults emerge from their hiding spot, they begin to feed on plant tissues via a sucking motion.
By sucking on plants, they draw out the vital plant sap using needle-like mouthparts. This causes significant damage to crops and weakens the attacked plant. The potato leafhopper has a voracious feeding habit and will easily drain its victim of nutrients and energy.
Potato Leafhopper Lifecycle
Understanding the lifecycle of the potato leafhopper is crucial for the effective pest management strategy of home and commercial growers alike. The potato leafhopper transitions from egg to adult in three stages that take about two to three weeks.
When conditions suit, this pest can produce, on average, three to five generations each growing season.
1. Egg Stage
Laid by adult females in the leaf veins of host plants. Eggs are tiny in scale and pale in color, making them hard to spot. Hatching generally occurs within 7 to 10 days of being laid.
2. Nymph Stage
When the nymphs emerge from the eggs, they’re miniatures of their adult form. The main difference is that they are wingless at this point. Instead of flying, they crawl. Nymphs have toxic saliva, which cross-contaminates plants as they suck out the sap.
In order to transform into winged, reproductive, adult potato leafhoppers, nymphs must undergo five instar changes. In these change phases, the nymphs shed their skin and grow larger. On the fifth instar change, they develop their wings.
The ideal temperature for nymph development is 55-88°F.
3. Adult Stage
As this pest feeds, it further infests the plant. Females deposit their eggs inside the plant tissues on the underside of their leaves, utilizing the protection of the foliage.
Each female lays one to six eggs at a time. Females live for around 30 days and can lay each day. A female can lay hundreds of eggs, up to 300, during her lifetime.
Characteristics and Habitat
One of the potato leafhopper’s key characteristics is its ability to reproduce rapidly. It’s most active during warm, dry weather and tends to congregate in large numbers on the underside of leaves.
Because they rely on warm weather conditions, this pest favors southern winters and northern summers. They are migrating insects, as they are unable to withstand low temperatures.
In order to migrate, they utilize wind and their wings to travel, but they also can move via human help in plant debris, potted-up plants, and the transfer of vegetation.
Research indicates that alfalfa plants are at higher risk following the second and third rounds of harvesting, possibly due to the plant’s chemical response to the cutting process.
June through mid-July are high-risk times for those near or with alfalfa fields. At harvest time, any established adults are displaced and forced to spread further afar to find new hosts.
Signs of a Potato Leafhopper Infestation
This pest feeds via its sucking mouthparts during the nymph to adult stages, so there is plenty of draining of the host plant’s resources.
In order to prevent coagulation of sap in response to injury by the plant the potato leafhopper uses it’s toxic saliva to keep the wound open.
This can significantly weaken the attacked plant, and even after the potato leafhopper has finished its feed other diseases can set in.
Damage associated with the potato leafhopper can be more dramatic at times of drought as the plant is under numerous stresses at once.
Foliage Discoloration
Caused by the draining of the nutrients by the potato leafhopper.
Scorched-like burn marks and browning of the leaf layers can appear shortly after an infestation takes hold. Known as ‘hopperburn’.
The outer tips of the leaf can start to turn yellow and the main veins feeding the foliage collapse in response to the toxins released into the bite marks by both nymph and adult.
Pest Presence
A clear indication that your plants have a potato leafhopper issue is when they are literally partying on them. These pests are highly sociable insects at nymph and adult phases. The more you see, the bigger your problem.
Distorted Foliage
This sign should set alarms going. It normally follows other symptoms as the host plant loses vital nutrients. Without the ability to photosynthesize, the leaves curl and eventually die.
However, the toxin is rarely systemic, and damage signifies the level of infestation. The more signs visible, the worse the numbers involved.
Such damage can affect the overall vitality of the entire plant and yield.
7-Step Management of Potato Leafhoppers
Potato leafhoppers are experts at increasing their populations rapidly and moving from host plants to new plants, so it is vital to take prompt action at the first sign of an infestation.
A combination of approaches may be required as this pest quickly transitions through its lifecycle to reproductive age.
Step 1 – Monitor
From early spring until mid-fall, regularly inspect your plants as soon as foliage appears. This is particularly important for those in regions with warmer fall temperatures. At the first signs of potato leafhopper eggs or adults, it’s time to act.
Step 2 – Protect
When growing crops that are susceptible to potato leafhoppers, consider using physical barriers in order to block deter them. Floating row covers are the gold standard in protecting plants from pests. Cloches can protect small plants.
Cold frames can provide some protection, but the plants will be exposed if you open the frame to air it out on hot or nice days.
Step 3 – Hygiene
Good garden hygiene is important in controlling all pests. Remove all decaying or dead plant debris from around the garden throughout the year. Weeding is a must, as well, in order to reduce over-wintering and deny leafhoppers a place to hide.
If you are moving potentially infested plants with eggs across the garden, be vigilant and treat them prior to relocation.
Step 4 – Chemical Treatment
Always consider natural treatments first. When you resort to chemicals, you run the risk of harming beneficial insects and upsetting the balance of your garden.
Use preventative treatments like neem oil and diatomaceous earth. Both of these will kill and dry out any potato leafhoppers that arrive.
If you don’t detect the problem early on and it escalates, you might need to resort to insecticidal sprays. Sevin, insecticidal soap, neem oil, and pyrethrins are effective. Be sure to spray the underside and stems of the plant so there are no hiding places.
Step 5 – Crop Rotation
Crop rotation is always a good idea, especially where potatoes are concerned. Avoid replanting in that same spot on a regular basis. This goes for all plant species that attract leafhoppers.
Breaking the lifecycle of the potato leafhopper will assist in curbing its bi-generational hold on your crops.
Step 6 – Biological Control
A natural and effective way to reduce and limit potato leafhoppers’ spread is by encouraging its natural predators like birds, spiders, and parasitic wasps. You can also purchase and introduce predators, like lacewings, ladybugs, and minute pirate bugs.
Step 7 – Plant Care
Healthy plants are less inclined to fall foul of insect infestations. Be sure to provide your plants with adequate water and nutrients to keep them strong.
Always follow growing guides, seasonal growing recommendations, and care information for susceptible plants.
