Male honey bees fly and gather at Drone Congregation Areas (DCAs), where drones and queens mate in flight. DCAs occur in places with presumably characteristic features. Using previously described landscape characteristics and observations on flight direction of drones in nearby apiaries, 36 candidate locations were chosen across the main island of Puerto Rico. At these locations, the presence or absence of DCAs was tested by lifting a helium balloon equipped with queen-sex-pheromone-impregnated bait, and visually determining the presence of high numbers of drones. Because of the wide distribution of honey bees in Puerto Rico, it was expected that most of the potential DCAs would be used as such by drones and queens from nearby colonies. Eight DCAs were found in the 36 candidate locations. Locations with and without DCAs were compared in a landscape analysis including characteristics that were described to be associated with DCAs and others. Aspect (direction of slope) and density of trails were found to be significantly associated with the presence of DCAs.
Although oral dental tissue is a vertebrate attribute, trunk dental tissue evolved in several extinct vertebrate lineages but is rare among living species. The question of which processes trigger dental-tissue formation in the trunk remains open, and would shed light on odontogenesis evolution. Extra-oral dental structures (odontodes) in the trunk are associated with underlying dermal bony plates, leading us to ask whether the formation of trunk bony plates is necessary for trunk odontodes to emerge. To address this question, we focus on Loricarioidei: an extant, highly diverse group of catfish whose species all have odontodes. We examined the location and cover of odontodes and trunk dermal bony plates for all six loricarioid families and 17 non-loricarioid catfish families for comparison. We inferred the phylogeny of Loricarioidei using a new 10-gene dataset, eight time-calibration points, and noise-reduction techniques. Based on this phylogeny, we reconstructed the ancestral states of odontode and bony plate cover, and find that trunk odontodes emerged before dermal bony plates in Loricarioidei. Yet we discovered that when bony plates are absent, other surface bones are always associated with odontodes, suggesting a link between osteogenic and odontogenic developmental pathways, and indicating a remarkable trunk odontogenic potential in Loricarioidei.
Phylogenetic inference artifacts can occur when sequence evolution deviates from assumptions made by the models used to analyze them. The combination of strong model assumption violations and highly heterogeneous lineage evolutionary rates can become problematic in phylogenetic inference, and lead to the well-described long-branch attraction (LBA) artifact. Here, we define an objective criterion for assessing lineage evolutionary rate heterogeneity among predefined lineages: the result of a likelihood ratio test between a model in which the lineages evolve at the same rate (homogeneous model) and a model in which different lineage rates are allowed (heterogeneous model). We implement this criterion in the algorithm Locus Specific Sequence Subsampling (LS³), aimed at reducing the effects of LBA in multi-gene datasets. For each gene, LS³ sequentially removes the fastest-evolving taxon of the ingroup and tests for lineage rate homogeneity until all lineages have uniform evolutionary rates. The sequences excluded from the homogeneously evolving taxon subset are flagged as potentially problematic. The software implementation provides the user with the possibility to remove the flagged sequences for generating a new concatenated alignment. We tested LS³ with simulations and two real datasets containing LBA artifacts: a nucleotide dataset regarding the position of Glires within mammals and an amino-acid dataset concerning the position of nematodes within bilaterians. The initially incorrect phylogenies were corrected in all cases upon removing data flagged by LS³.
Molecular detection of predation by identifying prey markers in the digestive tract of predators has developed into a powerful tool to assess predator-prey systems in which diet identification is too time consuming or impossible. Here we explore its utility for detecting predation of the pest mite Raoiella indica Hirst by the predatory mite Amblyseius largoensis Muma, taking advantage of the color the predator acquires after eating this mite to cross-reference our results. For this, a ~410 bp segment of the cytochrome c oxidase subunit I (COI) mitochondrial gene marker specific for the subfamily Tetranychoidea was used. Amblyseius largoensis that had recently eaten were collected from greenhouse colonies containing both mites, and isolated from any other food source. Predator mites were taken for fingerprinting at 24, 48, 72 and 96 h of starving after collection, and the same process was repeated a second time, offering pollen as an alternative food source to see whether detection changed. Lastly, a sampling trial was conducted in the greenhouse, in which mites were collected regardless of their color and frozen immediately for fingerprinting. Raoiella indica DNA was detected for 48 h on starving predators, and for 96 h on those who had eaten pollen. The segment was detected in 26 % of the samples collected on the trial. This technique needs refinement specific for this system, but the results obtained here confirm that it could turn into a very useful tool for assessing aspects of this predator-prey system.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.