Dale L. Forrister

Smithsonian Tropical Research Institute

Over 125 million years of ant-plant interactions have culminated in one of the most intriguing evolutionary outcomes in life history. The myrmecophyte Duroia hirsuta (Rubiaceae) is known for its mutualistic association with the ant Myrmelachista schumanni and several other species, mainly Azteca, in the north-western Amazon. While both ants provide...

Classic theory relates herbivore pressure to the ecology and evolution of plant defenses. Here, we summarize current trends in the study of plant–herbivore interactions and how they shape the evolution of plant chemical defenses, host choice, and community composition and diversity. Inter- and intraspecific variation in defense investment is driven...

The metabolome is the biochemical basis of plant form and function, but we know little about its macroecological variation across the plant kingdom. Here, we used the plant functional trait concept to interpret leaf metabolome variation among 457 tropical and 339 temperate plant species. Distilling metabolite chemistry into five metabolic functiona...

Army ants are keystone predators in the tropics and subtropics. During reproduction, males fly between colonies to mate with unmated, wingless queens. The males of most species are attracted to lights, and thus their presence and the timing of reproduction can be monitored using light traps. Previous studies examined the seasonality of army ant mal...

Plants are widely recognized as chemical factories, with each species producing dozens to hundreds of unique secondary metabolites. These compounds shape the interactions between plants and their natural enemies. We explore the evolutionary patterns and processes by which plants generate chemical diversity, from evolving novel compounds to unique c...

The mushroom genus Psilocybe is best known as the core group of psychoactive mushrooms, yet basic information on their diversity, taxonomy, chemistry, and general biology is still largely lacking. In this study, we reexamined 94 Psilocybe fungarium specimens, representing 18 species, by DNA barcoding, evaluated the stability of psilocybin, psilocin...

In species-rich regions and highly speciose genera, the need for species identification and taxonomic recognition has led to the development of emergent technologies. Here, we combine long-term plot data with untargated metabolomics, and morphological and phylogenetic data to describe a new rare species in the hyperdiverse genus of trees Inga Mill....

In forests, insect herbivores and their host plants are major components of the community. The study of their interactions is essential for understanding the mechanisms promoting and maintaining species diversity and niche differentiation in both trophic levels (Becerra 2015). Theory has long predicted that the evolution of plant anti-herbivore def...

Tropical forests sustain many ant species whose mating events often involve conspicuous flying swarms of winged gynes and males. The success of these reproductive flights depends on environmental variables and determines the maintenance of local ant diversity. However, we lack a strong understanding of the role of environmental variables in shaping...

A major aim of ecology is to upscale attributes of individuals to understand processes at population, community and ecosystem scales. Such attributes are typically described using functional traits, that is, standardised characteristics that impact fitness via effects on survival, growth and/or reproduction. However, commonly used functional traits...

Plants are widely recognized as chemical factories, with each species producing dozens to hundreds of unique secondary metabolites. These compounds shape the interactions between plants and their natural enemies. Here we explore how plants generate chemical diversity, and what evolutionary processes have led to novel compounds and unique chemical p...

The outstanding diversity of Amazonian forests is predicted to be the result of several processes. While tree lineages have dispersed repeatedly across the Amazon, interactions between plants and insects may be the principal mechanism structuring the communities at local scales. Using metabolomic and phylogenetic approaches, we investigated the pat...

Saplings in the shade of the tropical understory face the challenge of acquiring sufficient carbon for growth as well as defence against intense pest pressure. A minor increase in light availability via canopy thinning may allow for increased investment in chemical defence against pests, but it may also necessitate additional biochemical investment...

Herbivores shape tropical forests In tropical forests, high local tree diversity is driven by negative density dependence, a process whereby plant performance is inhibited by closely related neighbors. Negative density dependence could be caused by competition for resources among neighbors or result from shared herbivores and pathogens. Using data...

Coevolutionary theory has long predicted that the arms race between plants and herbivores is a major driver of host selection and diversification. At a local scale, plant defenses contribute significantly to the structure of herbivore assemblages and the high alpha diversity of plants in tropical rain forests. However, the general importance of pla...

MrBayes majority-rule consensus tree for the nuclear locus wingless, sequenced for exemplars of each of the selected 41 jMOTU 1.5% COI MOTUs. Numbers above nodes indicate posterior probabilities. Taxon labels are colored to indicate membership of different MOTUs.

List of compounds putatively identified through matches to reference MSMS spectra on the Global Natural Products Social Molecular Networking database (https://gnps.ucsd.edu/ProteoSAFe/static/gnps-splash.jsp). The cosine score is a measure of the similarity of MS/MS-derived fragments between two compounds.

Detailed chemical methods for construction of a chemical similarity matrix.

MrBayes majority-rule consensus tree for the mitochondrial COI DNA barcode fragment. Numbers above nodes indicate posterior probabilities. Taxon label colors indicate membership of 1.5% sequence divergence jMOTU taxa, indicated by the labels at right.

MrBayes majority-rule consensus tree for the nuclear locus ITS2, sequenced for exemplars of each of the selected 41 jMOTU 1.5% COI MOTUs. Numbers above nodes indicate posterior probabilities. Taxon labels are colored to indicate membership of different MOTUs.

Phylogenetic relationships for the gene CO1 among the Inga-feeding sawfly MOTUs and a panel of voucher sequences for sawflies in the families Argidae, Pergidae (sister group to Argidae; Malm and Nyman, 2015) and Tenthredinidae. The tree shown is a majority-rule consensus tree constructed in MrBayes, using substitutions modeled as GTR+I+G for each o...

Metadata for additional reference sawfly sequences, with species name, country of origin, Genbank accession numbers for COI and PGD gene fragments, and source reference.

Information on the ten sequence loci used for construction of the Inga species tree. Locus number, reference transcript, functional annotation and the substitution model used in phylogenetic analyses all refer to Nicholls et al. (2015).

Results of MOTU identification analyses of Inga- and Zygia-feeding sawflies, using a 645 bp fragment of the mitochondrial COI DNA barcoding region for (a) jMOTU and (b) ABGD.

Parafit analysis output for sawfly and Inga phylogenies, for sawfly MOTUs in the family Argidae. (B) Parafit analysis of concordance between sawfly phylogeny and Inga chemogram. In (A) and (B) herbivore-Inga associations that are identified as individually significant are highlighted in yellow.

Sawfly MOTU accumulation curves when sampling over Inga host plant taxa, and when sampling over individuals. For each curve, the mean estimate is shown as a dark blue line and the standard deviation as a pale blue shaded region either side. The total numbers of Inga taxa and sawfly specimens in these analyses were 34 and 1286, respectively.

Metadata for all sawfly specimens collected in this study, including host plant and collection location, MOTU allocation (1.5% jMOTU taxa), and Genbank accession numbers for all sequenced gene fragments. Note that in our sampling system, each study site has independent collection numbers. Thus, it is possible for two Inga plants to have the same ho...

Molecular methods for PCR amplification of sawfly sequences.

The need for species identification and taxonomic discovery has led to the development of innovative technologies for large‐scale plant identification. DNA barcoding has been useful, but fails to distinguish among many species in species‐rich plant genera, particularly in tropical regions. Here, we show that chemical fingerprinting, or ‘chemocoding...

Selective pressures imposed by herbivores are often positively correlated with investments that plants make in defense. Research based on the framework of an evolutionary arms race has improved our understanding of why the amount and types of defenses differ between plant species. However, plant species are exposed to different selective pressures...

Appendix S1. Details of leaf sample collections from the field (collection sites are presented in Appendix S2). Appendix S2. Map of collection sites at the Tiputini Biodiversity Station in Ecuador. Appendix S3. Distances between trees of Inga species that were sampled for expanding and mature leaves. Appendix S4. Chlorophyll content in expanding...