Download HERBIVORE LOADS CAN BE HEAVY

HERBIVORE LOADS CAN BE
HEAVY
CLOVER – 200 + SPP.
CORN – 300+ SPP.
APPLES – 400 SPP.
AMERICAN ELM – 600+ SPP.
OAKS – 1500 SPP.
GOLDENROD – 150 SPP.
HERBIVORE LOAD INCLUDES
GENERALISTS AND SPECIALISTS
• 1. MONOPHAGOUS
• 2. OLIGOPHAGOUS
• 3. POLYPHAGOUS
• 4. ALL PLANT PARTS UTILIZED
– DEFOLIATORS VS. SAP SUCKERS
– STEM AND RHIZOME BORERS
– SEED AND FLOWER PREDATORS
INVASIVE SPECIES FREQUENTLY
ESCAPE HERBIVORES
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CANADIAN THISTLE
JAPANESE KNOTWEED
GOATWEED
WATER HYACINTH
JAPANESE HONEYSUCKLE
GARLIC MUSTARD
RAGWEED (INTRO. INTO RUSSIA)
ARE INVASIVE
SPECIES HARMFUL?
FEEDING HABITS
• 1. CHEWING INSECTS
• DEFOLIATORS
• LEAF TIERS AND ROLLERS
• BORERS
• 2. SUCKING INSECTS
• PHLOEM VS. XYLEM FEEDERS
• 3. GALL-MAKING INSECTS
• 800 SPECIES ON VARIOUS S[PECIES OF OAKS
• CANCER-LIKE GROWTH FEEDS AND PROTECTS GALL
MAKER
• DEFOLIATORS
• LEAF TIERS AND ROLLERS
• BORERS
NUTRIENT QUALTY
OF PLANTS IS LOW
1. PLANT TISSUE COMPOSED
LARGELY OF WATER AND POORLY
DIGESTIBLE CELLULOSE
2. POOR NUTRIENT STATE
COMPENSATED BY THE ABUNDANCE
OF PLANTS
3. NITROGEN IS ESPECIALLY LOW
SOME NUTRIENT QUANTITIES
• 1. FRESH WEIGHT OF LEAVES IS 90%
WATER, 1-3% PROTEINS, WITH THE REST
BEING CARBOHYDRATES (MONO-, DI-,
POLYSACCHARIDES)
• 2. SEEDS HAVE LESS WATER AND MORE
PROTEIN (A VALUABLE RESOURCE)
• 3. ACTIVE MERISTEM RELATIVELY HIGH IN
NUTRIENTS, BUT IS LITTLE USED
HYPOTHESES CONCERNING
HOST SELECTION
• 1. THE NUTRIENT SCHOOL
HYPOTHESIS
• 2. THE SECONDARY PLANT
SUBSTANCE HYPOTHESIS
MANY SECONDARY
PLANT CHEMICALS
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1. GLUCOSIDES (E.G., MUSTARD OILS)
2. ALKALOIDS (E.G., NICOTINE)
3. PHENOLS
4. TERPENES (E.G., TURPENTINE)
5. TANNINS
6. SAPONINS
7. PYRETHRUMS
8. HORMONES (E.G., PHYTOECDYSONE)
PLANT DEFENSES
• 1. NON-CHEMICAL DEFENSES
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ESCAPE IN SPACE
ESCAPE IN TIME
USE SATIATION
STRUCTURAL DEFENSES (COLOR SHIFTS,
HARDEN TISSUES, ACQUIRE TRICHOMES,
SPINES, BRISTLES OR SPURS, HAVE SILICA
OR WAXES)
• 2. CHEMICAL DEFENSES
• USE A VARIETY OF SECONDARY PLANT
SUBSTANCES
GARLIC MUSTARD
CANADIAN THISTLE
JAPANESE KNOTWEED
EMERALD ASH BORER