Plant-Insect Interactions

Question 1

What are the three types of phytophagy (herbivory)?

Answer 1

• Monophages: feed on a unique pant taxon
• Oligophages: feed on a few taxa
• Polyphages: feed on many taxa

Question 2

What are the two types of plant defences against phytophagy?

Answer 2

• Physical defences (constitutive = always there): spines, silica in the leaf tissue
• Chemical defences (constitutive or induced = turned on): plants produce secondary compounds for defence (although “defensive” compounds may sometimes simply be metabolic waste products)

Question 3

What is an indirect induced defence?

Answer 3

• Systemic acquired resistance in the plant defence response to phytophagy/pathogen exposure
• Undamaged plants can detect early warnings of phytophagy by detecting volatile compounds released by their damaged neighbours
• Systemic acquired resistance is therefore indirectly activated in other plants

Question 4

What are leaf chewers and which orders is this phytophagy common in?

Answer 4

• It’s in the name, they chew leaves and hold an important role in ecosystems.
• Common in Lepidoptera, Coleoptera, Phasmatodea and Orthoptera.