Defoliators: Tent Caterpillars Flashcards
What are the three major families of defoliators in the Lepidoptera?
Tent Caterpillars (Lasiocampidae)
Budworms and tortrix moths (Torticidae)
Defoliating moths such as spongy month (Lymantriidae)
15 major spp. of Malacosoma. Common name?
Tent Caterpillers:
Eastern: americanum
Western: californicum
SW: incurvum
FTC: disstria
Minnesota common name for FTC?
“Army worm”
Where is FTC native to?
North America and MN
Outbreaks occur every 5-15 years
Loves aspen but also ash oak and basswood birch or cherry are hosts
Rarely touch sugar maple but happens more going south
Changing host preference by region is unusual
How far can an outbreak of FTC reach?
Millions of acres!
Life Cycle of FTC:
Eggs glued in masses on twigs in fall. Eggs are the overwintering stage. “Egg case” covered in waxy surface (spumaline)
Hardy down to -40
There can be 100-300 eggs/mass. You can use the number of egg masses/acre as an estimate of the next season’s population level.
Eggs hatch into larvae in the early spring at the time of bud break with cool keyhole pattern down their back
ONLY ETC NOT FTC
Messily take silk to tie up a pupal case with whatever is near. The “tent” or silk mats.
FTC don’t make a tent! Will cluster in groups to manage their heat.
Then adults emerge. These are the major defoliators.
Impacts of FTC
Growth loss
Nuisance! (100’s-1,000’s!)
Insecticide use
Tree mortality
Hardwood defoliation
Early season more harmful
Defoliated hardwoods are weaker and more susceptible to secondary pests like root pathogens or boring insects
What do the FTC larvae look like?
Velvety blue coloration with keyhole pattern
ETC has a long white stripe instead of keyhole pattern
Spongy moth look like?
Red dots down body
What terminates a FTC outbreak?
Starvation: running out of food (things to defoliate) 4 million caterpillars per acre!
Predators and pathogens =
Viruses: hang upside down by front legs (droopy)
Fungus: Entomophaga (hang limp full of spores)
Parasites: the friendly fly: Sarcophaga aldrichi (native) female lays eggs on pupal case and then the maggots tunnel in and kill the developing moths
Birds!
