Predicting tropical insect herbivore abundance from host plant traits and phylogeny

Abstract

Abstract. Phylogenetic ecology has identified patterns of diversity in communities that may find explanation in trophic interactions, and yet there have been few attempts to directly relate such patterns among trophic levels. Density-dependent processes involving pests and pathogens, for example, have been invoked to account for plant community phylogenetic patterns, but relatively little is known about how plant relatedness might affect community structure at other trophic levels. We examined the degree to which the abundance of herbivores in a rain forest community is explained by the phylogeny and functional traits of host plants. We destructively sampled all stems !5 cm diameter in two 1-ha plots of New Guinea primary and secondary lowland forest to test predicted relationships between herbivore abundance and plant resources. We analyzed per-tree caterpillar and leaf miner abundance, total leaf biomass (kg), percentage of immature foliage, specific leaf area (cm 2 /g), leaf nitrogen content (percentage of dry mass), and presence of exudates in the context of a plant community phylogeny estimated from DNA barcodes.Apart from nitrogen content and exudates, neither plant resources nor herbivore abundance showed evidence of phylogenetic signal in our community sample. The plant traits we measured could account for only 30% and 16% of variation in caterpillar and leaf miner abundance, respectively, among individual trees. Leaf biomass was a stronger predictor of herbivore abundance than either resource quality (leaf nitrogen content) or palatability (percentage of immature foliage, specific leaf area). The primary importance of resource quantity was also observed at the plant species level in analyses of species means and phylogenetic generalized least-squares regression. Plant relatedness did not account for much variation in herbivore abundance, but significant effects of exudates and leaf nitrogen content on caterpillar abundance illustrate how conserved traits at one trophic level may influence community-wide patterns at another.

Influence of plant resistance traits in selectiveness and species strength in a tropical plant‐herbivore network

“…Th e strength of host species interacting with herbivores can be infl uenced by density-dependent processes. Th e most abundant plant species (i.e., those with most biomass or cover) tend to be related to a greater number of herbivore species ( Basset, 1991 ;Marques et al, 2000 ;Whitfeld et al, 2012 ) simply by having a greater probability of being found, that is, a greater apparency ( Feeny, 1976 ). However, in the particular case of tropical systems, where herbivorous insects are highly specialized to their host plants ( Novotny et al, 2002 ;Novotny and Basset, 2005 ;Ødegaard et al, 2005 ;Weiblen et al, 2006 ;Forister et al, 2012Forister et al, , 2015, it is likely that species strength is independent from the host plants biomass or abundance.…”

DNA Barcodes of Lepidoptera Reared from Yawan, Papua New Guinea

“…Field methods were similar to our previous study at Wanang (Miller et al 2013, Whitfeld et al 2012. Ten 45 x 45 m (0.2025 ha) plots were surveyed for woody stems with a diameter at breast height (DBH) ³ 5 cm, along with woody epiphytes with stems ³ 1 cm.…”

“…This paper provides metadata for DNA barcodes (cytochrome coxidase I sequences, COI) in GenBank for a collection of specimens from ecological studies in Yawan, Morobe Province, Papua New Guinea (PNG), sampled as part of long term research on the ecology and taxonomy of herbivorous insects in PNG (Miller et al 2003, Whitfeld et al 2012). This paper aims to make DNA barcode data available to document ongoing research, to contribute to the International Barcode of Life (iBOL; www.ibol.org) project, and to encourage enhancement in species identification, in line with the concept of DNA barcode data release papers and the Fort Lauderdale principles for genetic data (Schindel et al 2011).…”

Tree Cavity-Using Wildlife and the Potential of Artificial Nest Boxes for Wildlife Management in New Guinea

“…The NGBRC established two one-ha research forest plots, one in primary forest and one in secondary forest, and all trees >5 cm DBH were identified, tagged and mapped. The NGBRC study involved the felling of all trees and lianas in the two plots [46]. D. Warakai carried out cavity census of all trees >5 cm DBH on these two forest plots, from 18 February 2006 to 3 March 2006, before the trees were felled.…”