Search

Abstract Simarouba, a neotropical genus in the family Simaroubaceae, currently lacks comprehensive genomic data in existing databases. This study aims to fill this gap by providing genomic resources for three Simarouba species, S. amara, S. versicolor, and S. glauca. It also aims to perform comparative molecular evolutionary analyses in relation to other species within the order Sapindales. The analysis of these three Simarouba species revealed the presence of the typical quadripartite structure expected in plastomes. However, some pseudogenization events were identified in the psbC, infA, rpl22, and ycf1 genes. In particular, the CDS of the psbC gene in S. amara was reduced from 1422 bp to 584 bp due to a premature stop codon. Nucleotide diversity data pointed to gene and intergenic regions as promising candidates for species and family discrimination within the group, specifically matK, ycf1, ndhF, rpl32, petA-psbJ, and trnS-trnG. Selection signal analyses showed strong evidence for positive selection on the rpl23 gene. Phylogenetic analyses indicated that S. versicolor and S. glauca have a closer phylogenetic relationship than S. amara. We provide chloroplast genomes of three Simaruba species and use them to elucidate plastome evolution, highlight the presence of pseudogenization, and identify potential DNA barcode regions.

The global use of pesticides, exceeding 4 million tons annually, poses substantial threats to public health and the environment. Numerous studies emphasize the correlation between pesticide exposure, genotoxicity, and neurobehavioral effects, which particularly impact children and agricultural workers. Recent research underscores the health risks associated with moderately toxic pesticides like chlorpyrifos. Chlorpyrifos contamination in crops, a result of extensive pesticide use since the 1960s, raises significant concerns regarding human health and the environment. Given its potential atmospheric volatilization from crops, alternative detection methods are imperative. This study employs gas chromatography coupled with mass spectrometry (GC/MS) in MS/MS mode, focusing on detecting chlorpyrifos in Chilean lettuce, using insects as indicators. Two extraction methods, micro-QuEChERS and HEADSPACE-SPME, were compared, with HEADSPACE-SPME demonstrating superior sensitivity (6.77 ng/mg per sample vs. 3.99 ng/mg per sample) and offering time- and solvent-saving advantages. Additionally, HEADSPACE-SPME preserves samples for future research, enhancing its utility. The study confirms the presence of pesticide residues in insects from lettuce crops, with 52.3% displaying chlorpyrifos when the SPME method was used. Predatory and parasitoid insect families like Braconidae and Ichneumonidae show high pesticide loads. The findings of this study emphasize the widespread contamination of chlorpyrifos in lettuce crop insects and highlight the efficacy of SPME for detection, suggesting its broader applicability for evaluating pesticide residues in horticultural systems. This optimized method holds promise for advancing chlorpyrifos contamination detection in agroecosystems, contributing to environmental monitoring and food security.

Recent studies have characterized the influence of agroecosystems on biodiversity. However, a set of components associated with the management of these areas is still neglected in landscape-level studies, especially in areas of recent agricultural intensification. The resources and conditions provided by agroecosystems to different species are highly variable in space and time, and failing to account for this variation may lead to misleading conclusions about the biodiversity status in these environments. In this perspective, we provide a conceptual overview to highlight why and which landscape components still need to be better explored to provide an adequate assessment of the agroecosystem effects on biodiversity. We used a Brazilian heterogeneous intensive-farming landscape as an example to outline the components that we believe are important for understanding biodiversity patterns in such landscapes. An in-depth description of agroecosystems can help us create better landscape-level management strategies and to design more effective green-way policies.

ABSTRACT The tomato is widely cultivated throughout the world and requires pollination by wild or managed bees to realize its full-potential fruit production. Two different sampling methods (pan trapping and active sampling) were employed in nine different properties from June to September of 2011 to investigate the richness and abundance of native bee species present in tomato crops of Center-West Brazil. A total of 465 individuals of 44 species were collected, with the composition of sampled bee species differing between the methods used. Twenty-two species were exclusively captured in pan traps, 13 others through active sampling and nine by both methods. Most of the sampled bee species can be considered effective pollinators of the tomato because they can perform buzz-pollination. By vibration, these bees can liberate pollen from anthers into the air or onto their own bodies and the stigmas of the same flower because the stigmas of the studied tomato variety are within the anther cone. Both methods exclusively sampled some species of buzz-pollinating bees, however, pan-trapping captured buzzing and non-buzzing visitors indiscriminately while active sampling captured more buzzing bees. Pan-trapping and active sampling appear to complement each other, and so the use of only one or the other would not provide a full understanding of the species richness of tomato pollinators in the field.