Architectural diversity and galling insects on Caryocar brasiliense trees

Area of Science:

• Ecology
• Entomology
• Plant-insect interactions

Background:

• Galling insects are specialized herbivores impacting plant communities.
• Caryocar brasiliense is economically important, supporting local communities.
• Understanding insect-herbivore dynamics is crucial for ecosystem health.

Purpose of the Study:

• To investigate the relationship between Caryocar brasiliense tree architectural diversity and galling insect community.
• To quantify the impact of canopy structure on insect abundance, diversity, and natural enemies.

Main Methods:

• Field study measuring tree canopy dimensions (height/width ratio - RHW).
• Quantified abundance of adult galling insects and galled leaves.
• Assessed gall parasitoid richness and predator (Zelus armillatus, ants) abundance.

Main Results:

• Higher RHW (canopy height/width ratio) correlated with increased adult insect abundance (7x) and galled leaves (1.6x).
• Gall parasitoid richness was 1.8 times higher in trees with greater RHW.
• Predator abundance varied, with Zelus armillatus higher on largest RHW trees and ants on smallest RHW trees.

Conclusions:

• Complex plant architectures, indicated by higher RHW, promote greater species diversity for galling insects and their natural enemies.
• First observation of interspecific competition and 'prudence strategy' in galling insects within the Brazilian Cerrado.
• Tree architectural diversity is a key factor shaping galling insect communities.