Do Lecythidaceae Specialists (Coleoptera, Cerambycidae) Shun Fetid Tree Species?¹

Abstract

Characteristic secondary metabolites are currently acknowledged to play a pivotal role in the circumscription of a plant's insect fauna. A newly discovered association between wood–boring longicorn beetles (Cerambycidae) and their host trees belonging to the Brazil nut family (Lecythidaceae) inspired a yearlong rearing project in the lowland Neotropical rain forest of central French Guiana. Branches severed from five species of Lecythidaceae yielded 1813 cerambycids belonging to 37 species. Two of the five tree species, Couratari stellata and Gustavia hexapetala, yielded impoverished complements of cerambycids that included large percentages of generalists. Both tree species are characterized by fetid odors. Wood samples collected from the malodorous C. stellata, as well as from two well–colonized species, Lecythis poiteaui and Eschweilera coriacea, were analyzed for their volatile components. Sulfur compounds accounted for almost 15 percent of the volatiles detected from C. stellata, while they were at most minor components of the two well–colonized tree species. S–methylmethionine, isolated from a C. stellata wood sample, appeared to be the major sulfur compound contributing to the distinctive smell. We hypothesize that this foul odor is a deterrent to specialist cerambycids seeking oviposition sites.

Volatile phytochemicals as mosquito semiochemicals

“…These compounds serve a variety of functions for the plants such as pollinator attraction, direct and indirect self-defense against herbivores, and for their own metabolic processes (Paré and Tumlinson, 1999; Berkov et al, 2000; Schiestl et al, 2000; Loreto and Velikova, 2001; Schiestl and Ayasse, 2001; Sharkey et al, 2001; Van Poecke et al, 2001). In an evolutionary arms race, herbivorous insects have adapted mechanisms to identify suitable host plants and to evade non-host plants using their floral scents (Visser, 1986).…”

Interactions between Oncideres humeralis Thomson (Coleoptera: Cerambycidae) and Melastomataceae: host-plant selection and patterns of host use in south-east Brazil

“…Host-plants of various Cerambycidae species and frequencies with which they were reared from hosts or observed on hosts in the field. (Buck 1957, Hovore & Penrose 1982, Rice 1989, 1995, Di Iorio 1996, Berkov et al 2000. In the present study, O. impluviata and O. saga used two plant families, and shared one Fabaceae species (Inga sp).…”

“…O. humeralis larvae reach the central region of the Melastomataceae trunk through the bifurcations of the secondary branches (Paulino Neto 2003), which are rich in soft parenchymatic cells. Adaptation to intra-xylematic phloem may explain oligophagy in other cerambycid species (Papp & Samuelson 1981, Hanks et al 1993a, Berkov et al 2000.…”

Neotropical soldier flies (Stratiomyidae) reared from Lecythis poiteaui in French Guiana: Do bat-pollinated flowers attract saprophiles?

“…N-methylpyrrole, a mutagen that binds to the minor groove of DNA molecules (Cho et al 1995), probably makes a minor contribution. It is also formed in senescing L. poiteaui wood (Berkov et al 2000). Sulfur compounds (dimethyl sulfide and dimethyl trisulfide) undoubtedly make a much greater contribution.…”

“…Sulfur compounds impart an unpleasant aroma to some Lecythidaceae, and may deter wood-boring beetles seeking oviposition sites in senescent trees and branches (Berkov et al 2000). They also contribute to the infamously unpleasant aroma of the cannonball or ''abricó -de-macaco'' fruit, Couroupita guianensis Aubl., and may attract diverse mammalian fruit visitors (Berkov and Purzycki 2004, Leite Pitman, unpubl.…”