Spatio-Temporal Distribution of Bark and Ambrosia Beetles in a Brazilian Tropical Dry Forest

Abstract

Bark and the ambrosia beetles dig into host plants and live most of their lives in concealed tunnels. We assessed beetle community dynamics in tropical dry forest sites in early, intermediate, and late successional stages, evaluating the influence of resource availability and seasonal variations in guild structure. We collected a total of 763 beetles from 23 species, including 14 bark beetle species, and 9 ambrosia beetle species. Local richness of bark and ambrosia beetles was estimated at 31 species. Bark and ambrosia composition was similar over the successional stages gradient, and beta diversity among sites was primarily determined by species turnover, mainly in the bark beetle community. Bark beetle richness and abundance were higher at intermediate stages; availability of wood was the main spatial mechanism. Climate factors were effectively non-seasonal. Ambrosia beetles were not influenced by successional stages, however the increase in wood resulted in increased abundance. We found higher richness at the end of the dry and wet seasons, and abundance increased with air moisture and decreased with higher temperatures and greater rainfall. In summary, bark beetle species accumulation was higher at sites with better wood production, while the needs of fungi (host and air moisture), resulted in a favorable conditions for species accumulation of ambrosia. The overall biological pattern among guilds differed from tropical rain forests, showing patterns similar to dry forest areas.

Positive effects of the catastrophic Hurricane Patricia on insect communities

“…During 2017, the xylophagous guild presented clear seasonal variations, with a high abundance in the transition between the previous wet (2016) and the dry season of 2017. These results are in agreement with a previous study conducted in a Brazilian tropical dry forest, which found a greater abundance of Scolytinae beetles at the beginning of a dry season 15 . In our study, a large portion of the xylophagous guild (90% of the individuals, 50% of species) belongs to the Scolytinae subfamily.…”

“…folivorous and sap-suckers), there is a general reduction in abundance and diversity in the dry season 3 , 6 , 14 . However, this pattern can vary among insect guilds; for example, xylophagous beetles show increased activity at the transition between wet and dry seasons due to favorable abiotic conditions for flight and selection of new hosts 15 . Temporal patterns for some other insect guilds, such as predatory insects, are often unknown in tropical dry forests.…”

How Does Dung Beetle (Coleoptera: Scarabaeidae) Diversity Vary Along a Rainy Season in a Tropical Dry Forest?

“…We believe that the biotic and abiotic conditions are maintained in the first months of the rainy season due to abundant rainfall during this period ( Pezzini et al 2014 ). Ten pre-existing 50 × 20 m plots ( Madeira et al 2009 , Macedo-Reis et al 2016 ) presenting vegetation in advanced stages of secondary succession (over 20 years) were selected, with plots located at least 0.2 km apart ( Fig. 1 ).…”

“…However, this pattern can vary among insect guilds. Ambrosia beetles, e.g., show increased activity at the end of the dry and wet seasons, when the presence of the air moisture in the beginning or end of the rains in association with the water stress on plants favors adult ambrosia beetle emergence to colonize a new host ( Macedo-Reis et al 2016 ).…”

Temperature can limit the invasion range of the ambrosia beetle Euwallacea nr. fornicatus

“…Temperature can affect emergence synchronization and voltinism based on the temperature thresholds required to transition between life stages (Hansen et al ., ; Bentz et al ., ). Consequently, temperature limits dispersal and potential invasive range as a result of the inability to develop in areas that are either too cold or hot (Ungerer et al ., ; Choi, ; Marini et al ., ; Sittichaya et al ., ; Reding et al ., ; Reich et al ., ; Macedo‐Reis et al ., ; Rassati et al ., , b). The relatively consistent response of an insect to temperature can be used to predict life‐history characteristics such as developmental rate and potential distribution (Lantschner et al ., ).…”