University of Wisconsin–Madison Insect Diagnostic Lab

Late Season Insects: Outdoor Invaders and

other Creatures Around the Yard

PJ Liesch UW Insect Diagnostic Lab

pliesch@wisc.edu

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University of Wisconsin–Madison Insect Diagnostic Lab

Outdoor “Invaders” §  Live outside during warmer months

§  Source varies for each species

§  Seek sheltered overwintering site in the fall §  Rock piles, hollow logs, beneath bark of dead trees §  Homes, sheds, farm buildings, etc.

§  Harmless to people/pets/property §  Won’t bite, don’t spread diseases, don’t damage structures

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University of Wisconsin–Madison Insect Diagnostic Lab

Management of Outdoor “Invaders” §  Important clues:

§  Setting in the landscape §  Case history §  Weather patterns

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University of Wisconsin–Madison Insect Diagnostic Lab

Management of Outdoor “Invaders” §  Exclusion

§  Critical step! §  Seal up cracks on exterior of building

§  Insecticides §  Surface treatment (helps prevent adults from entering)

•  Especially south and west sides of buildings §  Dust insecticides into cracks where adults might enter §  Not worth it for insects that have already snuck in

§  Sanitation §  Best option once insects have gotten indoors §  Vacuum, sweep, etc.

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University of Wisconsin–Madison Insect Diagnostic Lab

True Bugs: Order Hemiptera

§  Simple Metamorphosis §  Often plant feeders

1.  Box Elder Bugs 2.  Brown Marmorated Stink Bugs 3.  Western Conifer Seed Bugs 4.  Hackberry Psyllids 5.  Anthocorids (Pirate Bugs) 6.  Ambush Bugs

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University of Wisconsin–Madison Insect Diagnostic Lab

Box Elder Bugs §  Boisea trivittata §  ~1/2” long §  Red and black body §  Outdoor Invader

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University of Wisconsin–Madison Insect Diagnostic Lab

Box Elder Bugs: Sources §  Outdoor source: boxelders, silver maples §  Two generations per year

§  Invade buildings in the fall; looking for overwintering sites §  Can become active during warm spells; attracted to light at windows §  Can be active on cool days on southern facing walls

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University of Wisconsin–Madison Insect Diagnostic Lab

Brown Marmorated Stink Bug §  Halyomorpha halys §  ~1/2+” long §  Invasive pest from Asia §  Got in to US in mid 90’s

§  Can attack wide variety of plants outdoors

§  Outdoor invader

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University of Wisconsin–Madison Insect Diagnostic Lab

Brown Marmorated Stink Bugs §  First WI Find: 2010

§  2015: 30+ cases §  2016: 30+ cases

§  Can breed in Wisconsin (observed 2016)

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University of Wisconsin–Madison Insect Diagnostic Lab

Western Conifer Seed Bugs §  Leptoglossus occidentalis §  ~3/4” long §  Brownish body, white “zig-zag” on wings §  Outdoor Invader

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University of Wisconsin–Madison Insect Diagnostic Lab

Western Conifer Seed Bugs: Sources §  Outdoor source (Conifers) §  Insignificant damage to trees

§  Invade buildings in the fall; looking for overwintering sites §  Large size makes them easier to exclude

§  Tend to be a minor pest compared to to Asian lady beetles, box elder bugs

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University of Wisconsin–Madison Insect Diagnostic Lab 12

University of Wisconsin–Madison Insect Diagnostic Lab

Kissing Bug

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University of Wisconsin–Madison Insect Diagnostic Lab

Hackyberry Psyllids §  Pachypsylla species §  ~1/8” long §  Grayish body, white banding on wings §  Resemble miniature cicadas §  Outdoor Invader §  Case history & exclusion are key

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University of Wisconsin–Madison Insect Diagnostic Lab

Anthocorids Minute Pirate Bugs (Orius species)

Bites during “Indian Summer”

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University of Wisconsin–Madison Insect Diagnostic Lab

Ambush Bugs §  Jagged Ambush Bugs (Phymata sp.) §  Common on flowers (esp. goldenrod) §  Ambush predators §  ~1/4” long; black and pale colored

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University of Wisconsin–Madison Insect Diagnostic Lab

Beetles in the Fall §  Order Coleoptera

§  Complete metamorphosis §  Some species can fly can show up at homes

Late Season Beetle Pests 1.  Multicolored Asian Lady Beetle 2.  Foreign Grain Beetle 3.  Miscellaneous beetles from firewood

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University of Wisconsin–Madison Insect Diagnostic Lab

Multicolored Asian Lady Beetles

§  Harmonia axyridis §  ~1/4” long §  Usually orange, but highly variable §  Stereotypical “ladybug”

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University of Wisconsin–Madison Insect Diagnostic Lab

MALB Biology

§  Beneficial Insect: §  Biological control §  Predators of aphids & other insects

§  Pest §  Give other lady beetles a bad name §  Invade in large numbers in fall; nuisance factor §  Capable of biting §  Reflex bleeding; staining §  Potential to disrupt ventilation

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University of Wisconsin–Madison Insect Diagnostic Lab

MALB

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University of Wisconsin–Madison Insect Diagnostic Lab

Foreign Grain Beetles (and other Fungus Beetles)

§  Ahasverus advena §  ~1/16” long §  Small brownish beetle §  Two bumps behind head

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University of Wisconsin–Madison Insect Diagnostic Lab

Foreign Grain Beetles §  Fungal feeders §  Can be a pest of stored grains (i.e., musty grains)

§  “Suddenly” appear in newly-constructed homes §  Moisture on framing causes a small amount of fungal growth §  If in an older house, could indicate a moisture issue

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University of Wisconsin–Madison Insect Diagnostic Lab

Foreign Grain Beetles: Management §  No fungus No fungus beetles

§  Tend to clear up on their own over time §  Drier air, use of furnace in fall and winter dry out wall voids §  AC/Dehumidifier may hasten the drying-out process

§  If heavy/persistent infestation: dust formulation for wall voids

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University of Wisconsin–Madison Insect Diagnostic Lab

Firewood Insects Longhorned

Beetles

Wood Wasps

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University of Wisconsin–Madison Insect Diagnostic Lab

§  1 pairs wings (adults)

§  Complete Metamorphosis

Late Season Fly Pests

1.  Cluster Flies 2.  Face Flies 3.  Fungus Gnats (Occasional)

True Flies: Order Diptera

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University of Wisconsin–Madison Insect Diagnostic Lab

Cluster Flies §  Pollenia rudis §  ~1/4” long §  Dark gray body §  Thorax covered in fine, golden hairs §  Red Eyes

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University of Wisconsin–Madison Insect Diagnostic Lab

Cluster Flies: Sources §  Outdoor source §  Larvae are parasites of earthworms

§  Invade buildings in the fall (September); looking for overwintering sites §  Can become active during warm spells; attracted to light at windows §  Attics and upper floors

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University of Wisconsin–Madison Insect Diagnostic Lab

Face Flies §  Musca autumnalis §  ~1/4” long §  Very similar to house fly (Musca domestica) §  Dark gray body, yellowish abdomen (♂) §  4 dark stripes on thorax §  Red Eyes

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University of Wisconsin–Madison Insect Diagnostic Lab

Face Flies: Sources §  Outdoor source (primarily rural areas) §  Larvae only develop in fresh manure (manure management?)

§  Invade buildings in late summer/fall; looking for overwintering sites §  Can become active during warm spells; attracted to light at windows §  Attics and upper floors

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University of Wisconsin–Madison Insect Diagnostic Lab

Fungus Gnats §  ~1/8” long §  Variable coloration (often dark) §  Wing veins unique §  Long antennae §  Delicate-looking

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University of Wisconsin–Madison Insect Diagnostic Lab

Fungus Gnats: Sources §  Indoor or outdoor sources

§  Seen in fall when potted plants brought indoors §  Fungus feeders §  Require moisture + organic material

§  Top Locations: §  Indoor plants (overwatering!) §  Plumbing leak §  Bird feces §  New homes (residual moisture; similar to foreign grain beetle)

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University of Wisconsin–Madison Insect Diagnostic Lab

Yellowjackets, Hornets, Paper Wasps §  Yellowjackets: Vespula sp. §  Bald-Faced Hornet: Dolichovespula maculata §  Paper Wasps: Polistes sp.

§  ~1/2” - 3/4” long §  Black & yellow or black & white §  Typical “wasp” appearance §  Shape and location of nest helps with identification

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University of Wisconsin–Madison Insect Diagnostic Lab

Yellowjackets

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University of Wisconsin–Madison Insect Diagnostic Lab

Bald Faced Hornets

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University of Wisconsin–Madison Insect Diagnostic Lab

Paper Wasps

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University of Wisconsin–Madison Insect Diagnostic Lab

Wasp : Management §  Annual colonies; don’t reuse nest from year-to-year §  Colonies typically die out on their own in October

§  Avoidance: possible to avoid area until colony dies out?

§  Exclusion: useful for preventing nesting activity next year

§  Insecticides: §  Aerosols/liquids for exposed nests §  Dusts for inaccessible nests (ground, wall void, soffit, etc.)

www.extension.umn.edu/garden/insects/find/wasp-and-bee-control/

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University of Wisconsin–Madison Insect Diagnostic Lab

Orb-Weaver Spiders §  Cross Orb Weaver §  Marbled Orb Weaver §  Shamrock Orb Weaver

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University of Wisconsin–Madison Insect Diagnostic Lab

Questions?

Patrick (PJ) Liesch pliesch@wisc.edu

IDL Website: labs.russell.wisc.edu/insectlab/

Blog Website: labs.russell.wisc.edu/insectlab/blog/

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