Manual E, Chapter 3: Insects and their relatives Dr. Vera Krischik, Department of Entomology, University of Minnesota

Manual E, Chapter 3: Insects and their relatives Learning objectives Why insects are beneficial Pest damage Understand basic insect biology Common insect pests attacking turf/ornamentals Continue professional development

Manual E, Chapter 3: Insects and their relatives Terms to know vectorInsects that transmit disease causing microbes from plant to plant arthropodScientific name for all insects and relatives entomologistScientist who studies insects and mites

Manual E, Chapter 3: Insects and their relatives Introduction Not all insects pests 1,000,000 species/ total 2 million 10,000 insects considered pests Must know the difference between the two

Manual E, Chapter 3: Insects and their relatives Beneficial insects BC Beneficial insects ladybird beetles lacewings Trichogramma parasitic wasps Sold by companies for augmentation

Manual E, Chapter 3: Insects and their relatives Damage caused by insects Chewing on leaves, fruits, seeds, roots Tunneling or living in stems, leaves, roots Sucking plant juices from leaves, stems, roots, fruits, flowers Causing galls and other malformations on plants Transmitting plant disease

Manual E, Chapter 3: Insects and their relatives The biology of insects: form and function Arthropods, jointed legs Invertebrates, no backbone, segmented Class Insects; Class Arachnida Wings: 2pairs, some orders 1, 0 wings Head with eyes, antennae, mouthparts

Manual E, Chapter 3: Insects and their relatives The biology of insects: form and function Insects chewing mouthparts: Grasshoppers, beetles, caterpillars Insects piercing-sucking mouthparts: siphon-like sucking; needle-like penetrating issue bugs, aphids, scales, leafhoppers, thrips mosquitoes, lice, arachnids,ticks

Manual E, Chapter 3: Insects and their relatives The biology of insects: insect development Insect development: change plant tissue into insect biomass Incomplete metamorphosis: egg, nymph, adults examples: grasshoppers, true bugs, aphids, leafhoppers Complete metamorphosis: Egg, larvae (caterpillars, grubs, maggots), pupae, adult exp: beetle, moths, butterflies, flies, bees, ants

Manual E, Chapter 3: Insects and their relatives Major insect orders: Class Insecta Orthoptera Incomplete metamorphosis, nymphs resemble adults Chewing mouthparts Grasshoppers, crickets, katydids

Manual E, Chapter 3: Insects and their relatives Major insect orders: Class Insecta Hemiptera, true bugs Incomplete metamorphosis: nymphs resemble adults; egg, nymph, adult Piercing-Sucking mouthparts Bed bugs, plant bugs, damsel bugs, assassin bugs Inject toxins into hosts, wilting Transmit diseases

Manual E, Chapter 3: Insects and their relatives Major insect orders: Class Insecta Homoptera, aphids, scales, winged/wingless Incomplete metamorphosis: nymphs resemble adults; egg, nymph, adult Piercing-sucking mouthparts Aphids, psyllids, scales, mealybugs, leafhoppers, spittlebugs Suck juices, wilting, Transmit diseases

Manual E, Chapter 3: Insects and their relatives Major insect orders: Class Insecta Thysanoptera, thrips, winged/wingless Incomplete metamorphosis: nymphs resemble adults; egg, nymph, adult Piercing- sucking mouthparts Aphids, psyllids, scales, mealybugs, leafhoppers, apittlebugs Suck juices, wilting Transmit diseases

Manual E, Chapter 3: Insects and their relatives Major insect orders: Class Insecta Coleoptera, beetles, weevils Complete metamorphosis: egg, larvae, pupae, adult Chewing mouthparts in larvae and adults Adults with first pair of wings hardened into elytra Range from pinhead size to several inches long Grubs in turf, lady beetles, leaf beetles, borers

Manual E, Chapter 3: Insects and their relatives Major insect orders: Class Insecta Lepidoptera, moths, butterflies Complete metamorphosis: egg, larvae, pupae, adult Chewing mouthparts in larvae; adults no mouthparts or coiled for nectar feeding Two pairs of wings Moth antennae feathery; butterfly clubbed Moth nocturnal; butterfly diurnal

Manual E, Chapter 3: Insects and their relatives Major insect orders: Class Insecta Diptera, flies Complete metamorphosis: egg, larvae, pupae, adult Chewing mouthparts in larvae; adults piercing/sucking/lapping/biting mouthparts One wings; second pair halteres, club-like organs Flies, mosquitoes, gnats, midges Transmit disease, as soft rot

Manual E, Chapter 3: Insects and their relatives Major insect orders: Class Insecta Arachnida: Acarina, mites Four pairs of legs Chelicerae, fangs/sucking mouthparts that inject toxins into tissue No wings, tiny

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: 26 artificial groups in five categories Leaf-chewing Leaf-chewing Sucking insects and mites Sucking insects and mites Stem, shoot, and trunk borers Stem, shoot, and trunk borers Gall-forming insects and mites Gall-forming insects and mites Root-feeding insects Root-feeding insects

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing Removes leaf area. Cutworm caterpillars Sawflies Elm leaf beetle Birch leafminer Cankerwoms Casebearers Webworms Tent caterpillars

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing Common name: Cutworms Hosts: Grass and seedlings Larvae: Fat, thick, curl when touched, 1-2 inches Adults: Dull colored moths Overwinter: Larvae or pupae

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing No. of generations: One Feeding: Feed, lay eggs at night Damage: Cutting off stems at soil surface Control: Cut grass in early morning to kill foraging larvae

Ornamental plant pests: Leaf-chewing

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing Common name: Cankerworms, inchworms Two species: Fall cankerworm lays eggs in fall on twigs and spring cankerworm lays eggs in spring on bark Hosts: Elm, apple, basswood, oak, boxelder, ash, maple Larvae: Inch along, balloon on silk Adults: Gray brown colored moths Overwinter: Eggs or pupae

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing No of generations: One Feeding: On leaves Damage: Holes in buds and leaves Control: Early in spring when noticed

Sawflies

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing Common name: Sawflies, caterpillar-like Hosts: Conifers, rose, mountain ash, pear Larvae: More than 6 prolegs (caterpillars have 2-5 legs) Adults: Look like flies, but antennae are plumose; two pairs of wings; eyes not like flies Overwinter: Pupae in cocoons in soil, eggs

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing No of generations: One/several depends species Feeding: Feed in groups Damage: Removes terminals or basal ends of shoos depending on the species in conifers; entire shoot in Rose family Control: Early in spring when noticed before defoliation is too high. Pesticides: Not Bacillus thuringiensis var. kurstaki (BT), Dipel, Thuricide; Orthene, Malathion, Sevin

Ornamental plant pests: Leaf-chewing

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing Common name: Elm leaf beetle, two generations Hosts:All species of elms Larvae: Small yellow and black stripes.1/2 in Adults: Brownish yellow, 1/4 in Pupae: On top of mulch, soil under the tree Overwinter: Adults in houses, under bark

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing No of generations: Two Feeding: Larvae feed on underside of leaf, skeletonizing; females feed for one month laying eggs every few days Damage: Larvae skeletonizing; adults chew holes Control: Time to spray in May for gen one and July for gen two

Ornamental plant pests: Leaf-chewing

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing Common name: Birch leaf miner Hosts: Gray, Paper; European white birch Larvae: In mines, inside the leaves, blotch not serpentine mines Adults: Look like flies, but antennae are plumose; two pairs of wings; eyes not like flies Overwinter: In soil as pupae.

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Leaf-chewing No of generations: Two Feeding: Only larvae in mines Damage: Brown blotch mines In dry years or heavy infestation can kill trees Control: Time to spray in May for ggemone and mid-June for gen two, only if tree is severely defoliated. Degree day is 310 days (around May 15) for gen 1 Pesticides: Dimethoate or acephate are systemic insecticides, not residual. Metasystox-R2 in soil with Kiornitz injection system

Ornamental plant pests: Sucking insects and mites Sucking insects remove pholem or xylem from the plant, causing wilting, brown discoloration, and possible leaf death. Sooty mold often grows on the liquid feces, causing loss of photosynthate. Spider mite Mites Leafhoppers Plant bugs Ash/ honeylocust plant bug

Ornamental plant pests: Sucking insects and mites

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Common name: Spider mites, galls, free-roaming Hosts: Many plants Larvae: Six legs Adults: Tiny round relatives to insects; red, green, brown, yellow, w/ or w/o spots. Eight legs, two body regions. Most destructive in hot, dry weather Overwinter: Eggs or adults

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Feeding: Use chelicerae or fangs to inject toxins into leaves. Damage: Discoloration, distortion, webbing, galls, russeting Control: Use a miticide, spray plants to dislodge mites. Biological control: Many natural enemies such as green lacewings, ladybugs, damsel bugs

Ornamental plant pests: Sucking insects and mites

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Common name: Aphids, approx 50 species Hosts: Many plants Nymphs: Young resemble adults, except for size Adults:Small 1/16 to 1/18 in; females give birth to live young, wingless; wings produce in fall and when food quality decreases. Long antennae, tubercles on the rear of abdomen. Overwinter: Eggs or adults

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Common name: Aphids, approx 50 species Hosts: Many plants Nymphs: Young resemble adults, except for size Adults:Small 1/16 to 1/18 in; females give birth to live young, wingless; wings produce in fall and when food quality decreases. Long antennae, tubercles on the rear of abdomen. Overwinter: Eggs or adults

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Feeding: Sucking mouthparts;suck sap on underside of leaf, leaf curl around them. Suck juices from leaves, stems, buds Damage: Produce honeydew on which sooty mold grows. Cause plants to stunt, do poorly. On bark aphids do little damage. Disease: Carry pathogens, virus Control: Spray water Pesticides: Orthene, Cygon, Malathion, insecticidal soap Biological control: Green lacewings, ladybugs, damsel bugs, syrphid flies

Ornamental plant pests: Sucking insects and mites

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Common name: Leafhopper Hosts: Maple, sycamore, hawthorn, azalea Nymphs: Similar to adult without wings Adults: Small green, wedge shaped, 1/4 to 1/3 in; wings roof-like over head; numerous,rise like a cloud of dust Overwinter: Eggs or adults.

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Feeding: Suck juices from leaves, stems, buds Damage: Irregular patches where leaves are bleached. Can be common in turf. Control: Not usual, spray foliage with insecticidal soap

Ornamental plant pests: Sucking insects and mites

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Common name: Plant bugs; ash plant bug, honeylocust plant bug Hosts: Ash, honeylocust Nymphs: Look like adults, wingless Adults:Oval green, brown 1/16 to 1/4 in ash plant bug (pale brown w/ yellow markings), honeylocust plant bug (pale green) Overwinter: Eggs

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Feeding: Underside of leaves Damage: Brown, puncture wounds from mouthparts; leaves run yellow or brown w/ stippling, brown excrement on underside of leaves. Honeylocust plant bug can damage buds and young leaves. Control:Honeylocust in sun/ yellow leaf cultivars more more attract to honeylocust plant bug. Spray week after bud break. Pesticides: Acephate, carbaryl, malathion, soap

Ornamental plant pests: Sucking insects and mites

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Common name: Scales Hosts: Many plants Crawlers: Small white, yellow, orange, w/ legs. Adults: Lack wings, antennae, eyes; round, waxy protective shells/covers or wool-like filaments; all colors Overwinter: Eggs, immature females, adult females

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Sucking insects and mites Feeding: Remove sap Damage:Stresses plant, dieback on twigs, leaves; Honeydew promotes black sooty mold. Control: Time pesticide application to when crawlers have emerged. Dormant oils in late winter may work on some scales.

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Shoot, stem, trunk borers Borers can attack trunk, branches, roots. In general, the adult borer emerges in the spring and lays an egg that hatches and chew into the bark. Larvae pupate inside the host and chew an exit hole to emerge. Feeding interferes with the movement of water and nutrients, permits the invasion of damaging microorganisms; Plants will grow poorly, have irregular form, die, or be easily damaged by weather.

iris borer Ornamental plant pests: Shoot, stem, trunk borers

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Shoot, stem, trunk borers Common name: Iris borer Hosts: Iris Larvae: White Adults: Drab moth in Fall when it lays eggs on leaves. Overwinter: Eggs on leaves

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Shoot, stem, trunk borers Feeding: Larvae feed on blade, then rhizome Damage:Brown water soaked leaves. Rotting of the rhizome Control: Spray leaves in early spring Pesticides: Dimethoate (Cygon)

Ornamental plant pests: Shoot, stem, trunk borers

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Shoot, stem, trunk borers Common name: Bronze birch borer Hosts: Birch, white birch Larvae: White, flatheaded larvae Adults: Metallic wood boring beetles leave D-shaped exit holes in bark Overwinter: Larvae in trunk

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Shoot, stem, trunk borers Feeding: Larva feed in cambium, but can move into heartwood to pupate; tunnels packed with frass Damage: Interfer with movement of fluids; calluses from feeding in tunnels appear as ridges on the bark Control: Red or river birch more resistant; Borers prefer to lay eggs I sun, birches prefer cool understory, not exposed sites due to shallow roots Pesticides: Repeated application of chlorpyrifos(Dursban) or bendioarb (Turcam, Dycarb) to trunk

Ornamental plant pests: Gall-forming insects /mites gall-formers

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Gall-forming insects /mites Common name: Oak cynipid gall, hackberry nipple gall, maple spindle gall, maple velvet gall Hosts: Oaks, hackberry, maple Larvae: Inside galls Adults: Short-lived, lay eggs Overwinter: in galls

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Gall-forming insects /mites Feeding: Inside gall Damage: Only disfigures leaf, stem, rarely kills Control: Must be before budbreak; once gall is formed can not control

Ornamental plant pests: Root-feeding insects black vine weevil

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Root-feeding insects Common name: Black vine weevil Hosts: Yews, azaleas, many plants Larvae: On roots, white, plump, legless Adults: Black, long snout, live 1 year Overwinter: As larvae or adults in soil.

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Root-feeding insects Feeding: Adults leaves, grubs roots Damage: Adults notch leaves, grubs on roots, grubs can spread disease Control: Spray foliage and drench soil

Ornamental plant pests: Turf / Leaf-chewing insects Grubs: Birds, skunk damage, turf pulls from roots Sod webworm: Moths flying above turf Billbugs: Yellowing, browning Chinch bugs, Aphids: brown patches

Ornamental plant pests: Turf/ Root-feeding insects May, June beetles: root- feeders

Ornamental plant pests: Turf/ Root-feeding insects May, June beetles: root- feeders

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf/ Root-feeding insects Common name: May, June beetles Hosts: Turf grasses Grubs: C-shaped in soil feeding on roots Adults: Large June beetles have 3 year life cycle Overwinter: Grubs in soil

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf/ Root-feeding insects Feeding: grubs on roots; adults on Norway maple, grapes,linden Damage: Remove roots, leaves Control: 2 or more grubs per sg ft Treat in year two, treat in June, not fall as grubs move down into the soil to overwinter

Ornamental plant pests: Leaf-chewing insects

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf / Leaf-chewing insects Common name: Sod webworms, lawn moths Hosts: Turf grass Larvae: Dirty white w/ dark boxy spots; rest in silken tunnels; glisten in dew Adults: Narrow appearance due to folded wings, darting flight above turf grass; two gen June, Aug Overwinter: Larvae in soil in tunnels

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf / Leaf-chewing insects Feeding: Remove leaf blade Damage: Small brown areas; not common Control: 15 worms/sg yd Pesticides: nematodes Steinernema carpocapsae, Beauveria bassiana fungus, Bacillus thuringiensis var. kurstaki Btk, insecticdal soaps

Ornamental plant pests: Turf / Leaf-sucking insects

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf / Leaf-sucking insects Common name: Greenbugs, aphids, approx 50 species Hosts: Many plants Nymphs: Young resemble adults, except for size Adults:Small 1/16 to 1/18 in; females give birth to live young, wingless; wings produce in fall and when food quality decreases. Long antennae, tubercles on the rear of abdomen. Overwinter: Eggs or adults

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf / Leaf-sucking insects Feeding: Sucking mouthparts;suck sap on underside of leaf, leaf curl around them. Suck juices from leaves, stems, buds Damage: Produce honeydew on which sooty mold grows. Cause plants to stunt, do poorly. On bark aphids do little damage. Disease: Carry pathogens, virus Control: Spray water Pesticides: Orthene, Cygon, Malathion, insecticidal soap Biological control: Green lacewings, ladybugs, damsel bugs, syrphid flies

Ornamental plant pests: Turf / Leaf-sucking insects

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf / Leaf-sucking insects Common name: Chinch bug Hosts: Turf grass Nymphs: Look like adults w/o wings; red become dark as mature Adults: Head narrower than shoulders; light colored forewings with black triangle.Females lay 200 eggs in 3 to 5 weeks OOver winter Adults

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf / Leaf-sucking insects Feeding: Adults and nymphs suck juices and inject toxins Damage:browning blades; feed along margin of dead and green grass Control: Pesticides: nematodes Steinernema carpocapsae, Beauveria bassiana fungus, insecticdal soaps Biological control: Bigeyed bugs

Ornamental plant pests: Turf / Leaf-chewing insects

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf / Leaf-chewing insects Common name: billbug Hosts: Turf grass Larvae:Legless, chew blades, then make nest in crown. Adults: Dark long snout, walk on edges of hard surfaces in spring Overwinter: Adults

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf / Leaf-chewing insects Feeding: Adults and larvae chew blades Damage: Brown, irregular shaped areas in lawn. 10 larvae/sg ft need control Control: May adults; larvae when small

Ornamental plant pests: Turf / Leaf-sucking insects

Manual E, Chapter 3: Insects and their relatives Ornamental plant pests: Turf / Leaf-chewing insects False chinch bug: Does not have black triangle in wings, head is same size as thorax; do not need to control. Big-eyed bugs: Large eyes, head same size as thorax and are predators Night Crawlers: Do not control Ants: Do not control