Interactions between chilean matorral shrubs and phytophagous insects

Area of Science:

• Plant ecology
• Chemical ecology
• Entomology

Background:

• Lithraea caustica and Colliguaya odorifera are Chilean sclerophyllous shrubs.
• These species often grow together on equator-facing slopes.
• L. caustica experiences significant insect herbivory, while C. odorifera is rarely attacked.

Purpose of the Study:

• To investigate the relationship between leaf phenolic compounds and insect herbivory in L. caustica and C. odorifera.
• To understand the factors influencing differential leaf predation between these closely associated plant species.

Main Methods:

• Correlating leaf growth dynamics, leaf loss, and insect predation with leaf phenolic compounds throughout the year.
• Comparing leaf structural properties (cuticle thickness, density, sclerenchyma, thickness) between the two species.
• Analyzing differences in leaf phenol content.

Main Results:

• Leaf structural properties were similar between L. caustica and C. odorifera.
• Leaf phenol content differed significantly between the two species.
• C. odorifera exhibited higher phenol content compared to L. caustica.

Conclusions:

• Higher leaf phenol content in C. odorifera may reduce leaf palatability to insects.
• This difference in palatability likely explains the lower leaf area loss due to insect damage observed in C. odorifera.
• Phenolic compounds play a crucial role in mediating plant-insect interactions in these Chilean shrubs.