Leafhoppers
Cicadellidae
also called Potato leafhopper, Rose leafhopper
Wedge-shaped hoppers that run sideways and jump when disturbed, stippling leaves pale and carrying aster yellows between plants. Reflective mulch and mesh keep them off.
How to know it
A slender wedge 3–6 mm long, green, brown or boldly marked depending on the species, that scuttles sideways around a stem before it jumps. The nymphs are wingless miniatures doing the same sideways run. Cast white skins stay stuck to the leaf undersides after each molt.
What you'll see
- Fine white or yellow stippling across the upper leaf, coarser than spider-mite damage and with no webbing.
- Leaf edges of beans and potatoes yellowing then browning in a V from the tip — hopperburn.
- Insects springing off in all directions when you brush the foliage.
- Empty white cast skins littering the leaf undersides.
- Stunted, oddly yellow plants in a border, with green sterile flowers — a sign the hopper has left aster yellows behind.
Where it comes from
Some species overwinter as eggs in woody stems; the potato leafhopper cannot survive frost at all and rides the spring storm fronts north each year, which is why hopperburn appears suddenly in June with no build-up. Two to five generations a season, eggs inserted into leaf veins and stems.
Hot, dry summers favor them, and so does a still, sheltered garden. Damage on beans and potatoes builds through July and August; the disease they carry matters far more in perennial borders and lettuce than the feeding does.
Dealing with it
- Hose the foliage hard in the morning; the nymphs cannot fly and many do not get back up.
- Use insecticidal soap on the leaf undersides in the evening, repeating after a week — it reaches nymphs, not adults.
- Pull and bin any plant showing the yellowed, deformed, green-flowered look of aster yellows; it will not recover and it is now a reservoir.
- Lay reflective silver mulch under beans and lettuce, which genuinely confuses incoming adults.
- Accept late-season stippling on ornamentals — the leaf is nearly finished with its year anyway.
Keeping it out
- Cover lettuce, carrots and young beans with fine mesh through the main flight.
- Clear perennial weeds at the garden edge — plantain, thistle, dandelion — which host both the hopper and the phytoplasma.
- Grow flowering umbels to keep the tiny egg parasitoids and the minute pirate bugs resident.
- Water beans and potatoes through dry spells; a well-watered plant carries hopperburn far better.
- Choose leafhopper-tolerant bean cultivars where hopperburn is an annual event.
What it goes for
Beans, potatoes, grapes, apples, roses, dahlias, echinacea, carrots and lettuce.
Trouble it brings with it
Who hunts it for you
- Assassin bugReduviidae A patient ambusher with a curved beak it drives into whatever it catches — caterpillars, beetles, bugs, and the occasional bee, so count it a generalist rather than a specialist. It will jab a careless finger too, so admire it and leave it be. Grow to recruit it: Dill,Fennel,Goldenrod,Sweet alyssum,Tansy,Yarrow
- Big-eyed bugGeocoris spp. A stubby 3 mm bug with enormous wrap-around eyes, working the soil surface and the low foliage for aphids, mites, thrips and insect eggs. It is the main natural check on chinch bugs in a lawn and it is killed outright by insecticide. Grow to recruit it: Calendula,Clover,Cosmos,Goldenrod,Sweet alyssum
- Damsel bugNabidae A slender, mantis-armed bug that grabs aphids, small caterpillars, and thrips in low crops and meadowy edges. Leave a strip of unmown grasses and flowers for it to overwinter in. Grow to recruit it: Fennel,Sweet alyssum,Yarrow
- SpidersAraneae Webs, ambushes, and night patrols make spiders the garden’s steadiest generalist predators, taking whatever flies or crawls past. Mulch, ground cover, and undisturbed corners keep the population dense. Grow to recruit it: Lavender,Thyme
See also
The Cottage Garden Companion — the gardener's bestiary at cottagegardencompanion.com