Plant-insect interactions and beta-diversity of Amazonian tree lineages

A major new axis of research in our laboratory includes characterization of phytophagous insect community structure across geographic and environmental gradients. This work is being led by PhD student Greg P.A. Lamarre.

I am a tropical ecologist working on plant-insect interaction in the Tropics. I am also entomologist, member of SEAG network, working on moths and butterflies. My research focuses on understanding how herbivorous insect communities could promote tropical plant diversity by exerting different pressures on plants across gradients of resource availability. Across habitats that differ in resource availability, herbivores are predicted to reinforce convergence within habitats and divergence among habitats in allocation strategies of growth vs. defense investment. Herbivores can therefore promote habitat specialization and beta-diversity in plants.

First, we are charactarizing insect community structure across wide gradients of soil resource availability in the Amazon Basin, using a suite of insect trapping methods. Second, we are monitoring leaf production and herbivory rates on common species and focal tree genera across this same gradient. Finally, we have established a reciprocal transplant experiment across habitats and countries that includes an herbivore exclusion treatment to conduct a controlled test of herbivory rates and their consequences for plant performance across the geographic and environmental gradient.

Experimental design to characterize composition and abundance

Approximately half of the estimated 2 million eukaryotic species on Earth are thought to be Arthropods, most of these insects. Recent models suggest that two-thirds of this diversity remains to be discovered, and the actual number of insect species is more on the order of 3 million. Tropical forests are expected to house most of this diversity, but very few studies have been conducted to characterize insect communities in tropical forests. We are developing a suite of complementary trapping techniques to characterize insect communities using replicable methods that permit quantitative estimations of relative abundance and species composition.

We conduct a multi-approach sampling using six different types of insect sampling methods within tropical forests of French Guiana (2010) and Peru (2011). We combine the use of three complementary strategies of trapping that target different groups: ‘Attractive sampling’ methods, ‘Flight trajectories’ sampling and ‘By-Hands’ sampling methods. To date, our study represents one of the major insect sampling efforts in Neotropical rain forest, with nearly 300,000 insects collected representing more than 10 arthropod orders.

Collaborators and Specialists

An important collaborator in this research is the Société Entomologique Antilles-Guyane (SEAG). Composed of 20 entomologists in French Guiana, SEAG works in collaboration with 120 taxonomic specialists worldwide. We thank all those specialists who are contributing to advance this important work. Colloboration on tropical forest ecology also included various scientists in UC Berkeley (P. Fine), University of Florida (A. Kawahara) and Smithsonian (T. Erwin).

Publications and conferences

4 - Lamarre, G., C. Baraloto, C. Fortunel, N. Davila Cardozo, I. Mesones, J. Grandez Rios, M. Rios, E. Valderrama, and P. V. A. Fine. in PRESS. Herbivory, growth strategies and habitat specialization in tropical tree lineages: implications for Amazonian beta-diversity. Ecology Special Issue in Phylogenetic Ecology.

3 - Lamarre, G., P.V.A. Fine and C. Baraloto.  2011.  Abondance relative des Coleopteres dans trois types d’habitats forestiers de la foret tropicale de Guyane Francaise: relations avec la structure et la diversite de la communaute de plantes ligneuses. In: Touroult J., 2011. Coleopteres de Guyane. ACOREP-France pp 3-9.

2 - Vedel, V., Camus, D. and Lamarre, G. 2011. Malaise and glass traps: useful means of catching canopy-dwelling spiders? Newsl. Br. arachnol. Soc. 122: 12-15.

1 - Lamarre, G. and Bénéluz, F., 2009. A non-destructive method for species identification (Insecta : Lepidoptera) in the ecological park Nueva Juventud, San Andrés, Petén, Northern Guatemala. Lambillionea, CXI, 3 : 348-352.

Conferences

Lamarre G., Christopher Baraloto and Paul V.A. Fine., 2011. Arthropod abundance and community structure in contrasting Amazonian forests. Entomological Society of America: ESA. Reno, Nevada (USA). 13-16 November, 2011. (lecture)

Lamarre G., Fine Paul., Brûlé Stéphane and Baraloto Christopher. 2010. Turnover in Phytophagous insect communities in contrasting tropical forest habitats : Amazon basin. Association for Tropical Biology and Conservation : ATBC. Bali, (Indonesia). 19-23 July, 2010. (poster)