“Bugs” & Aphids On Perennials Fourlined plant bug - one generation. Most damage in May & early June. Prefers mint family. Aphids – many species, several generations per season. Look for predators – be patient! Syringe (hose off with water).
Fourlined plant bug (damage above), late instar nymph (above right), and adult (right).
Tarnished plant bugs also damage various perennials as well as several shrubs. Tarnished plant bug nymph (above), and adult (right).
Other Miscellaneous Bugs Many stink bug species feed on seeds and flowers. Chrysanthemum lace bugs are unique in that they prefer leaf upper surfaces!
Other sucking insects that attack perennials include tree hoppers (left) and leafhoppers (below). The painted sharpshooters (a kind of leafhopper) cause puckering of leaves. The nymphs (below) run sideways.
Rudbeckia psyllids cause disease like purple blotches on the leaves of host plants. The psyllid nymphs and pupae look like scales.
Most perennials have one or two species of aphids that may feed on them. The goldenrod aphid (above) feeds on a variety of daisy and composite flowers. The milkweed aphid (right) feeds exclusively on plants in the milkweed family.
Generalized diagram of an aphid life cycle showing a species that alternates asexual and sexual forms along with alternation of hosts.
Plant Bug & Aphid Control (for homeowners) Traditional Diazinon Dursban Sevin Orthene Malathion DiSyston Still/Now Available Pyrethroids (permethrin, resmethrin, esfenvalerate, bifenthrin, cyfluthrin) Soaps & Oils Sevin, Malathion X X ? X
Sawflies & Caterpillars On Perennials Columbine sawfly – one generation (May to June). Hollyhock sawfly – 3-4 generations. “Generalist” caterpillars – cabbage looper, European corn borer, green fruitworm. Stalk Borer & Iris Borer – not much you can do other than remove!
Columbine sawflies can completely defoliate plants by the time they are ready to flower. Columbine sawflies hide on the undersides of host leaves during the day. Though the larvae look like caterpillars, they have more than 5 pairs of prolegs on the abdomen – a sawfly characteristic.
Hollyhock sawfly larvae skeletonize leaves and the damage is often mistaken for Japanese beetle damage. Larva (below) Adults look like small wasps or flies.
The violet sawfly produces damage that often looks like slug damage – look on leaf undersurfaces to determine if the sawfly larvae are hiding there. Lysimachia sawfly larvae are covered with a white powdery material.
The cabbage looper may be found on a variety of annual or perennial flowers as well as vegetable crops. Fruitworms usually attack fruit tree foliage, but they may be found on roses and perennials.
The milkweed tiger moth has a striking caterpillar that feed on all plants in the milkweed family. American painted lady caterpillar feeding on perennial.
Sawfly Insecticides (for homeowners) Traditional Dursban Diazinon Sevin Orthene Still/Now Available Pyrethroids (permethrin, resmethrin, esfenvalerate, bifenthrin, cyfluthrin) Merit Sevin Soaps or Oils X X X
Caterpillar Insecticides (for homeowners) Traditional Dursban Sevin Orthene Malathion Still/Now Available Sevin Pyrethroids (permethrin, resmethrin, esfenvalerate, bifenthrin, cyfluthrin) Merit (imidachloprid) Bt Soaps or Oils X X
The iris borer overwinters in the egg stage attached to old leaves. The eggs hatch in spring and the larvae burrow down the leaves to the rhizomes. They continue feeding all summer, nearly eating all the rhizome internal tissues. The larvae drop out in August, pupate in the soil and the adult moths emerge in October into November.
Iris Borer Insecticides (for homeowners) Traditional Dursban Lindane Cygon (dimethoate) DiSyston Still/Now Available ??? X X X X
Twospotted Spider Mite On Perennials Prefer hot-dry conditions. Females overwinter in mulch & protected areas OFF THE PLANT. Often “reinstalled” on new bedding plants. Often resistant to common miticides.
Twospotted spider mites can completely web over the foliage of their hosts. Twospotted spider mite eggs, nymphs and adults generally reside on leaf undersurfaces unless they have completely covered their host foliage.
Miticides (for homeowners) Traditional Kelthane Cygon Soaps & Oils Orthene ? Still/Now Available Pyrethroids?? Soaps or Oils DiSyston (Rose Systemic Granules) ? Conserve (=Naturalite) ?? X X X X
Coneflower flowergall mites are eriophyids. Eriophyids are often not susceptible to regular miticides.
Leafminers on Perennials Columbine leafminer(s) – several species with multiple generations per year - dipterous. Serpentine leafminers – several species that attack Phlox, hollyhocks and others - dipterous.
Columbine leafminer adults (above left) feed by making “pinholes” in leaves (left). Eggs are inserted into leaves and the larval maggots make winding mines which may end in a large blotch.
Leafminer Insecticides (for homeowners) Traditional Dursban Lindane Cygon (dimethoate) DiSyston Orthene Neem (azadirachtin) Still/Now Available Pyrethroids (permethrin, resmethrin, esfenvalerate, bifenthrin, cyfluthrin) Merit ? Neem ? Conserve ? DiSyston ? X ? X X X
A half dozen species of slugs can be found in Ohio landscapes and most will feed on the leaves of plants while others specialize on feeding on fungi. Garden snails are not common in Ohio, but they occasionally become established through recent plantings of new plants. Most can’t survive Ohio winters.
Molluscicides (for homeowners) Traditional Metaldehyde Methiocarb Still/Now Available Iron Phosphate (Sluggo) Metaldehyde (Deadline) X
Black Vine Weevil On Perennials Not a common landscape pest of perennials, mainly in container production areas. One generation per year, females lay eggs over long period of June & July. Larvae overwinter in soil or pots.
Black vine weevils are commonly called the Taxus Weevil because this is one of their favorite hosts. Black vine weevil larvae look like scarab white grubs, but weevil larvae have no obvious legs (right).
Black Vine Weevil (adults only) (for homeowners) Traditional Dursban Turcam (professionals only) Orthene Still/Now Available Pyrethroids (cyfluthrin, resmethrin, bifenthrin)??? Cygon & DiSyston? X X X
NEW! Black Vine Weevil Management Merit! (home owner product available, apply to soil for larval control, NOT mulch, not for adults!)