Stratification in French Guiana: Cerambycid Beetles Go Up When Rains Come Down

Ecological patterns and processes in the vertical dimension of terrestrial ecosystems

Climatic gradients such as latitude and elevation are considered primary drivers of global biogeography. Yet, alongside these macro-gradients, the vertical space and structure generated by terrestrial plants form comparable climatic gradients but at a fraction of the distance. These vertical gradients provide a spectrum of ecological space for species to occur and coexist, increasing biodiversity. Furthermore, vertical gradients can serve as pathways for evolutionary adaptation of species traits, leading to a range of ecological specialisations. In this review, we explore the ecological evidence supporting the proposition that the vertical gradient serves as an engine driving the ecology and evolution of species and shaping larger biogeographical patterns in space and time akin to elevation and latitude. Focusing on vertebrate and invertebrate taxa, we synthesised how ecological patterns within the vertical dimension shape species composition, distribution and biotic interactions. We identify three key ecological mechanisms associated with species traits that facilitate persistence within the vertical environment and draw on empirical examples from the literature to explore these processes. Looking forward, we propose that the vertical dimension provides an excellent study template to explore timely ecological and evolutionary questions. We encourage future research to also consider how the vertical dimension will influence the resilience and response of animal taxa to global change.

Xylotrechus arvicola (Coleoptera: Cerambycidae) capture in vineyards in relation to climatic factors

BACKGROUND

Captures and seasonal abundance of Xylotrechus arvicola (Coleoptera: Cerambycidae) in relation to climatic factors were studied in vineyards between the years 2013 and 2020. Insects captures from vine wood in two Vitis vinifera varieties were evaluated every year by counting the number of insects captured with CROSSTRAP®. The captured insects were grouped (by sex and total) into ranges of 10 days and compared to climatic data (daily average, temperature and rainfall) for each cultivar and year.

RESULTS

The capture periods spanned from 1 June and 31 July, with the period from 1 to 30 June having the greatest number of insect captures, as long as weather conditions were favourable, i.e. temperature above 20.00 °C and accumulated rainfall in 10 days lower than 0.40 mm, verified through the analysis of parameter estimates, in which, only the temperature parameter was significantly.

CONCLUSIONS

The study provided useful information for the integrated pest management of X. arvicola through mass trapping in vineyards when temperature exceeds 20.00 °C and the accumulated rainfall is less than 0.40 mm in 10 days to obtain peak captures. This is the first quantitative study of X. arvicola control associated with temperature and rainfall in Vitis vinifera. © 2022 Society of Chemical Industry.

Anadenanthera colubrina (Fabaceae) logs in the Atlantic Forest biome: first host plant for Thoracibidion lineatocolle (Col.: Cerambycidae) and a new host for Temnopis megacephala (Col.: Cerambycidae)

Wood-boring beetles develop in live trees and dead wood, performing ecological services such as decomposition and regulation of forest resources. Species of the Cerambycidae family, widely distributed in the world, bore into the trunks of trees and dead wood in native and cultivated areas. The objective is to report the first host plant for Thoracibidion lineatocolle (Thomson, 1865) (Coleoptera: Cerambycidae) and a new host plant for Temnopis megacephala (Germar, 1824) (Coleoptera: Cerambycidae) in the Brazilian Atlantic Forest biome. Three logs, with one-meter-long by 20 cm in diameter, were cut from the trunk of a healthy Anadenanthera colubrina (Fabaceae) tree in October 2013 and tied in the understory at 1.5m high in the Rio Doce State Park, Minas Gerais State, Brazil. The logs, exposed in the forest, were each removed after 40, 80 and 120 days and stored individually in a cardboard box in the "Laboratório de Campo do Projeto de Ecologia de Longa Duração (PELD-CNPq)" in the Rio Doce State Park. A total of 94 individuals of T. lineatocolle and 228 of T. megacephala emerged from the A. colubrina logs. This is the first report of a host plant for T. lineatocolle and a new host plant for T. megacephala.

Spatio-temporal variation of Cerambycidae-host tree interaction networks

Despite its high ecological importance, the commensal interactions at community level are poorly studied. In tropical dry forests (TDF) there is a great diversity of species adapted to the high seasonality that characterizes them; however, little is known regarding how the spatial and temporal availability of resources generates changes in the pattern of commensal interactions. We experimentally studied changes in the diversity, composition, and pattern of interactions in spatio-temporal associations between the saproxylophagous beetles and their host trees in a TDF in Morelos, Mexico. A total of 65 host tree species were selected, from which 16 wood sections were obtained per species. These sections were exposed in the field to allow oviposition by the cerambycids under four different (spatio-temporal) treatments. We analyzed the network structure and generated indices at species level (i.e., specialization, species strength, and effective partners) and those related to physical characteristics of the wood (hardness and degradation rate) and the cerambycids (body size). In total, 1,323 individuals of 57 species of cerambycids emerged. Our results showed that, independently of the space and time, the network presented a nested and modular structure, with a high specialization degree and a high turnover of cerambycid species and their interactions. In general, we found that the cerambycids are mostly associated with softwood species with a lower decomposition rate of wood, as well as with the most abundant host species. The commensalistic interactions between the cerambycids and their host trees are highly specialized but are not spatio-temporally static. The high turnover in the interactions is caused by the emergence patterns of cerambycids, which seem to restrict their use to certain species. The knowledge of the spatio-temporal variation in Cerambycidae-host tree interactions allows us to predict how environmental and structural changes in the habitat can modify the species ensemble, and therefore its interactions.

Seasonal diversity of Cerambycidae (Coleoptera) is more complex than thought: evidence from a tropical dry forest of Mexico

Global climate change is expected to affect temperature and precipitation patterns worldwide, which in turn is likely to affect insect phenology, distribution and diversity. To improve our understanding of such processes, it is important to understand how insects may respond to changes in seasonality, and how these affect their activity, patterns of distribution and species richness. The tropical dry forest (TDF) is a highly seasonal ecosystem, for which two seasons are commonly described (rainy and dry) and there is a lack of information on the combined effect of both precipitation and temperature on the insect communities. In order to evaluate the seasonal patterns in the community of Cerambycidae in a TDF, historical climatic variables were obtained, and an annual sampling of the family was carried out, using three collection techniques. We found that the Cerambycidae family showed a more complex response to climate, than simply the rainy and dry season of the year. The relationship between diversity and composition of cerambycids with changes in temperature and precipitation showed four seasonal communities which were synchronized with phenological processes of the TDF. Climate change could reduce biodiversity, causing seasonal patterns to lose complexity, either because the climatic characteristics of a season disappear and/or because the duration of a season expands, these changes will modify the ecological processes of the TDF, since they would generate changes in the flora and fauna associated with the different seasons.