Bark and Ambrosia Beetle (Curculionidae: Scolytinae) Diversity Found in Agricultural and Fragmented Forests in Piracicaba-SP, Brazil

Abstract

Land use changes and forest fragmentation result in biodiversity loss and displacement, with insects among the most affected groups. Among these, bark beetles (Curculionidae: Scolytinae) occupy a prominent position due to their close ties to food resources, i.e., trees, and importance as primary decomposers in forest ecosystems. Therefore, our study aimed to document scolytine biodiversity associated with landscape components that vary based on their physical or botanical composition. Bark beetle diversity was sampled monthly for 12 mo in an Atlantic forest remnant and five adjacent vegetation plots (mixed Agroforestry System-AFS, of native trees and fruit species; AFS of rubber trees and coffee plants; coffee monoculture; rubber monoculture; and pasture). In total, 1,833 individuals were sampled from 38 species of which 24 (63%) were detected in very low abundance. The remaining 14 species were more abundant and widespread almost in all areas. Hypothenemus hampei (Westwood), Premnobius cavipennis (Eichhoff), Hypothenemus sp1., and Xyleborus volvulus (Fabricius) were the most abundant. The greatest abundance and richness of bark beetles were found in the dry and cold season. The varied microclimatic conditions of the vegetation plots greatly affected the diversity of the Scolytinae. Solar radiation presented a significant negative effect on abundance in almost all the studied areas. The greatest scolytine diversity was found in anthropic areas with tree canopy structure. Open areas (pasture and coffee monocrop) had a lower species diversity. Similarly, a lower abundance and species richness were found for the Atlantic forest remnant.

Coleoborers (Curculionidae: Scolytinae) in native and homogeneous systems of Brazil nut (Bertholletia excelsa bonpl.) in the Southern Amazon, Brazil

“…Muller and Andreive [26] obtained similar results in the number of species collected among the different studied forest formations, where they found 28 species in the area of unaltered dense rainforest, 29 species in the area of altered dense rainforest and 21 species in the planting area homogeneous of Eucalyptus grandis (Hill ex Maiden). Rodriguez, Cognato and Righi [27], in a study of the diversity of Scolytinae in native forests and intercropped and homogeneous forest systems, also found results similar to those of the present study, with little variation between the richness of species in the environments, especially in the anthropized ones, observing 19 species for a native forest fragment, 24 species in the area of agroforestry system and 22 species in a homogeneous rubber plantation (Hevea brasiliensis Willd. Ex A. Juss.…”

“…Similar to the results found in this work, Rodriguez, Cognato and Righi [27], studying the diversity of Scolytinae in native forest areas as well as intercropped and homogeneous forest systems, found that the native forest environments were grouped in greater similarity, and these in dissimilarity in relation to each other to another grouping between homogeneous planting of rubber (Hevea brasiliensis Willd. ex A.…”

“…In general, structurally more complex environments, which present greater dynamics of ecological niches, such as native systems, are characterised by greater diversity. However, it is noteworthy that it is not uncommon in studies of Scolytinae diversity to verify rates for homogeneous or intercropped areas, similar or even higher, to those calculated for native areas [24,27,29]. Scolytinae mainly act in the degradation of plant material that accumulates in environments, their diversity being related, among other environmental factors, to the amount of litter.…”

“…In contrast, Homogeneous Brazil Nut has a homogeneous structure of individuals of Bertholletia excelsa and greater structural simplicity, favouring the occurrence of an expressive number of species of Scolytinae. It can therefore be said that the structural complexity of vegetation and environmental disturbances are the main factors that contribute to Scolytinae diversity patterns [27,46].…”

Spatial distribution of avocado branch dieback and wilting (ABDW) vectored by ambrosia beetles in the Caribbean South America

“…These ambrosia beetles are common inhabitants of forests and agroforestry landscapes of the Neotropics, e.g. forest remnants in Brazil (Sandoval and Ecuador (Zambrano Barcos 2016;Zambrano Morrillo 2016) and plantations of cacao, coffee and several hardwood tree species in Venezuela, Colombia, Ecuador and Brazil (Schabel 2006;Navarro and Liendo 2010;Andersen et al 2012;Martínez et al 2017Martínez et al , 2019Sandoval Rodríguez et al 2017;Atkinson 2018;CABI 2018aCABI , 2018b. Xylosandrus morigerus is native to tropical Southeast Asia and had become established in all tropical regions of the world.…”