Open vegetation formations (grasslands and savannahs) support a higher diversity of Cetoniidae (Insecta: Coleoptera) than forest formations in the brazilian Cerrado

Brazil has 22 genera and 75 species of Cetoniidae, with the Cerrado hosting the greatest diversity among Brazilian biomes. However, the diversity of groups among the different phytophysiognomies of the biome is not known. The objectives of this study are to assess Cetoniidae diversity and to verify the seasonality of these beetles in three Cerrado phytophysiognomies (gallery forest, cerrado sensu stricto, and campo sujo) located in three conservation units in Brasilia, Distrito Federal, Brazil. We collected adults monthly (October/2016 to September/2018) using 180 traps baited with bananas fermented with sugarcane juice, totaling 1,574 specimens, 8 genera, and 17 species. Cetoniidae diversity was higher in the phytophysiognomies with lower tree density (campo sujo and cerrado sensu stricto) than in gallery forests (forest formation), confirming our hypothesis that more open areas favor the dispersal of these insects due to their diurnal long-flying behavior. The seasonality of Cetoniidae was directly related to the precipitation, with higher numbers of individuals and species in the rainy season. However, the distribution varies among the phytophysiognomies, with aggregated distribution in campo sujo and gallery forest and dispersed in cerrado sensu stricto. Our results suggest that the Cetoniidae take advantage of the open Cerrado physiognomies to locate resources faster and with less energy expenditure, presenting higher diversity in these environments, despite the more ephemeral and dispersed food resources.

     

Attractiveness of dung beetles (Coleoptera: Scarabaeinae) to faeces from native mammals in different trophic guilds

Dung beetles are predominantly coprophagous and use mammalian faeces as their main food resource and for offspring rearing. However, these resources are generally ephemeral and scarce. The objective of this study was to verify the attractiveness to dung beetles of the faeces of nine native mammal species of the Cerrado biome in different trophic guilds. This study was conducted during the rainy season (October 2016 to March 2017) in two sensu stricto areas of the Cerrado in the Brasília National Park (PNB), Federal District, Brazil. Pitfalls containing faeces of nine mammals native to the region were used as bait (from three herbivores, three carnivores and three omnivores) for the collection of dung beetles. We collected 203 individuals and 19 species, and the most abundant species were Uroxys aff. thoracalis, Oxysternon palemo, Coprophanaeus spitzi and Diabroctis mirabilis. The most attractive faecal bait was from the omnivorous Chrysocyon brachyurus (32.67% of the individuals and 13 species). This study reveals variation in the attraction of dung beetles to native mammal dung of the Cerrado, with more abundance in the faeces of omnivores and carnivores and less in the faeces of herbivores. The species composition in the carnivore baits did not differ from that of the omnivore baits. These data indicate that changes in Scarabaeinae assemblages result from changes in mammal species such as those that have occurred in the Cerrado biome with the conversion to cattle production, which in recent years has caused intense fragmentation of habitats, expansion of agricultural and livestock activities and the introduction of exotic species. The mammal C. brachyurus, vulnerable to extinction in Brazil, should be a focus for future research, since its faeces support a great diversity of dung beetles in the Cerrado.     

Diversity of Cetoniidae (Insecta: Coleoptera) in the Cerrado of Central Brazil

Cetoniidae is a diverse family containing approximately 4,000 species, most of which feed on flowers and fruits. In Brazil, 72 species and 24 genera are recorded. Little is known about this family in the Central region of Brazil, and no research has previously been conducted in the ecologically important Cerrado biome. In this study, we evaluated the diversity and temporal variation of the Cetoniidae in an area of the Cerrado in the Federal District (Brazil) and verified whether the abundance and species richness were influenced by climatic variables. The study was carried out in an area of Cerrado sensu stricto at Água Limpa Farm in Brasília/DF. Beetles were collected weekly from October 2013 to September 2014 using 40 traps baited with banana and pineapple fermented with sugarcane juice. A total of 398 specimens comprising 8 genera and 15 species were collected. We observed temporal variation in abundance and richness of the Cetoniidae in direct relation to the climatic characteristics of the Cerrado, with a greater number of individuals and species appearing in the rainy season. Climatic variables such as temperature and humidity appear to have a significant effect on the diversity of Cetoniidae. This is the first study conducted on this family in Central Brazil.     

Heritability estimates and genetic correlations for body weight and scrotal circumference adjusted to 12 and 18 months of age for male Nellore cattle

Heritability estimates and genetic correlations were obtained for body weight and scrotal circumference, adjusted, respectively, to 12 (BW12 and SC12) and 18 (BW18 and SC18) months of age, for 10 742 male Nellore cattle. The adjustments to SC12 and SC18 were made using a nonlinear logistic function, while BW12 and BW18 were obtained by linear adjustment. The contemporary groups (CGs) were defined from animals born on the same farm, in the same year and birth season. The mean heritability estimates obtained using the restricted maximum likelihood method in bi-trait analysis were 0.25, 0.25, 0.29 and 0.42 for BW12, BW18, SC12 and SC18, respectively. The genetic correlations were 0.30 ± 0.11, 0.21 ± 0.13, 0.21 ± 0.11, -0.08 ± 0.15, 0.16 ± 0.12 and 0.89 ± 0.04 between the traits BW12 and BW18; BW12 and SC12; BW12 and SC18; BW18 and SC12; BW18 and SC18; and SC12 and SC18. The heritability for SC18 was considerably greater than for SC12, suggesting that this should be included as a selection criterion. The genetic correlation between BW18 and SC12 was close to zero, indicating that these traits did not influence each other. The contrary occurred between SC12 and SC18, indicating that selection using one of these could alter the other. Because of the mean magnitudes of heritabilities in the various measurements of weight and scrotal perimeter, it is suggested that the practice of individual selection for these traits is possible.     

Economic impact of exotic insect pests in Brazilian agriculture

Agriculture represents one of the major strengths of the economic sector in Brazil. The need to avoid economic losses because of insect pest populations is one of the greatest challenges faced by this sector. Insect pests have caused annual losses of US$12.0 billion to the Brazilian economy, of which approximately US$1.6 billion are because of exotic pest species. Furthermore, exotic insect species often show greater potential to cause harm than native species. In Brazil, since the late nineteenth century, 24 species of insect pests have been introduced into the country, and they have caused significant economic losses. Many of these species, including Bemisia tabaci, Hypothenemus hampei, Ceratitis capitata, Oryzophagus oryzae and Anthonomus grandis, are major crop pests, and they were accidentally introduced during trading of agricultural products. In this review, we present an overview of Brazilian agriculture, a brief history of the introduction of insect pests in the country and the Brazilian legislation on agricultural defence, and we estimate the economic losses caused to the Brazilian economy by the main insect pest species that have been introduced into Brazil over the last 112 years.     

Spatial and temporal segregation in dung beetles (Coleoptera: Scarabaeinae) in the Cerrado of Central Brazil

Biodiversity and Conservation - In dung beetles, spatial and temporal segregation is determined by the niche and evolutionary history of the species and is mediated by competition. Different...