Biology subjects

Eltz, T.

Publications and source records attributed to Eltz, T..

4 recordsLinked to original sources

bioRxiv2026

Nanopore sequencing of nested nrDNA barcodes reliably identifies orchid bees (Euglossini, Apidae)

Orchid bees (Euglossini, Apidae) are Neotropical insects whose species-level identification can depend on minute morphological characters, some difficult to see or analyze. In such cases, DNA barcoding may facilitate identification by comparing standardized DNA sequences with reference libraries. The mitochondrial cytochrome c oxidase I (COI) marker widely used in animals does not, however, provide uniform species-level resolution across bee lineages. We developed an adaptive-length nuclear ribosomal DNA (nrDNA) barcoding framework based on overlapping Nanopore-sequenced markers spanning approximately 500 to 5500 bp for 114 Euglossini species. By matching barcode length to specimen quality, material with varied preservation histories was processed within a single analysis. Leave-k-out validation with IDTAXA achieved more than 96% identification success for two longer barcodes, while performance was lower for the shortest. Combining barcode lengths within one reference library maintained high identification success, and confidence filtering reduced overclassification when species were absent from the reference library. For orchid bees, this framework permits affordable high-throughput identification and supports targeted taxonomic verification and revision. Combining adaptive barcode lengths in one analytical framework offers a general design principle for long-read reference-library construction. Its performance must now be tested in other groups.

zoology↗

bioRxiv2024

Non-floral scent sources of orchid bees: observations and significance

Males of the neotropical orchid bees collect environmental volatiles to concoct complex species-specific perfumes that are later used in sexual communication. While perfumes are typically seen as being derived from floral sources, these bees also collect scents from non-floral resources such as decaying wood or tree wounds, even though reports of these sources remain scarce. Here we report observations of male orchid bees collecting scent at 21 different non-floral sources in Central and South America. Male Eufriesea corusca that were marked at one of them, a wounded Protium ravenii secreting odoriferous sap/resin, returned repeatedly over periods of up to 19 days. Chemical analyses of hind-leg contents suggest that this single non-floral source accounted for a substantial fraction (>50%) of the species-specific perfume. This and other findings strengthen the view that non-floral scent sources play a central role in orchid bee perfume biology. Moreover, at the same Protium we also observed female Euglossa spp. harvesting resin for nest construction. The collection of substances by both euglossine male and female bees at the same source strengthens the notion that the evolution of male perfume signaling was promoted by a sensory bias for resinous nest construction materials in females.

ecology↗

bioRxiv2022

The function of environmentally acquired perfume blends in male orchid bees

Perfume making by male orchid bees is a remarkable behavior giving rise to an entire pollination syndrome in the neotropics. Male orchid bees concoct and store perfume mixtures in specialized hind-leg pockets using volatiles acquired from multiple environmental sources, including orchids. However, the precise function and ultimate causes of this behavior have remained elusive. We supplemented male Euglossa dilemma reared from trap-nests with perfume loads harvested from wild conspecifics. In dual-choice experiments, males supplemented with perfumes mated with more females, and sired more offspring, than untreated, equal-aged, control males. Our results demonstrate that male-acquired perfumes function as chemical signals emitted during courtship and received by females when selecting mates. Sexual selection might be a key agent shaping the evolution of perfume signaling. One-Sentence SummaryThe possession of exogenous volatiles increase male mating success and paternity in orchid bees.

evolutionary biology↗

bioRxiv2019

An olfactory receptor gene underlies reproductive isolation in perfume-collecting orchid bees

Speciation is facilitated by the evolution of reproductive barriers that prevent or reduce hybridization among diverging lineages. However, the genetic mechanisms that control the evolution of reproductive barriers remain elusive, particularly in natural populations. We identify a gene associated with divergence in chemical courtship signaling in a pair of nascent orchid bee lineages. Male orchid bees collect perfume compounds from flowers and other sources to subsequently expose during courtship display, thereby conveying information on species identity. We show that these two lineages exhibit differentiated perfume blends and that this change is associated with the rapid evolution of a single odorant receptor gene. Our study suggests that reproductive isolation evolved through divergence of a major barrier gene involved in chemically mediated pre-mating isolation via genetic coupling.

evolutionary biology↗