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Ecological Applications : a Publication... Jul 2023Bird- and bat-mediated biocontrol benefits the productivity of tropical commodity crops such as cacao, but the ecological interactions driving these ecosystem services...
Bird- and bat-mediated biocontrol benefits the productivity of tropical commodity crops such as cacao, but the ecological interactions driving these ecosystem services remain poorly understood. Whereas birds and bats prey on herbivorous arthropods, they may also prey on arthropod mesopredators such as ants, with poorly understood consequences for pest biocontrol. We used a full-factorial experiment excluding birds, bats, and ants to assess their effects on (a) the abundance of multiple arthropod groups; (b) predation pressure on arthropods evaluated through artificial sentinel caterpillars; and (c) cacao yield over 1 year in shaded agroforestry systems of native cacao varieties in Peru. Birds and bats increased cacao yield by 118%, which translates in smallholder benefits of ca. US $959 ha year . Birds and bats decreased predation by ants and other arthropods, but contributed to the control of phytophagous taxa such as aphids and mealybugs. By contrast, ant presence increased the abundance of these sap-sucking insects, with negative impacts for cacao yield. Notably, high abundances of the dominant ant Nylanderia sp., known to attend sap-sucking insects, were associated with lower cacao yield along a distance gradient from the closest forest edge. According to these results, arthropod predation by birds and bats, rather than mesopredation by arthropods, was most responsible for increases in cacao yield. Moving forward, detailed research about their trophic interactions will be necessary to identify the cause of such benefits. Retaining and restoring the large benefits of birds and bats as well as minimizing disservices by other taxa in cacao agroforests can benefit from management schemes that prioritize preservation of shade trees and adjacent forests within agroforestry landscapes.
Topics: Animals; Arthropods; Ecosystem; Chiroptera; Cacao; Tropical Climate; Insecta; Ants; Birds; Predatory Behavior; Aphids
PubMed: 37166162
DOI: 10.1002/eap.2886 -
Journal of Theoretical Biology Feb 2023The recent discovery that some terrestrial arthropods can detect, use, and learn from weak electrical fields adds a new dimension to our understanding of how organisms...
The recent discovery that some terrestrial arthropods can detect, use, and learn from weak electrical fields adds a new dimension to our understanding of how organisms explore and interact with their environments. For bees and spiders, the filiform mechanosensory systems enable this novel sensory modality by carrying electric charge and deflecting in response to electrical fields. This mode of information acquisition opens avenues for previously unrealised sensory dynamics and capabilities. In this paper, we study one such potential: the possibility for an arthropod to locate electrically charged objects. We begin by illustrating how electrostatic interactions between hairs and surrounding electrical fields enable the process of location detection. After which we examine three scenarios: (1) the determination of the location and magnitude of multiple point charges through a single observation, (2) the learning of electrical and mechanical sensor properties and the characteristics of an electrical field through several observations, (3) the possibility that an observer can infer their location and orientation in a fixed and known electrical field (akin to "stellar navigation"). To conclude, we discuss the potential of electroreception to endow an animal with thus far unappreciated sensory capabilities, such as the mapping of electrical environments. Electroreception by terrestrial arthropods offers a renewed understanding of the sensory processes carried out by filiform hairs, adding to aero-acoustic sensing and opening up the possibility of new emergent collective dynamics and information acquisition by distributed hair sensors.
Topics: Bees; Animals; Arthropods; Spiders; Electricity; Hair
PubMed: 36410450
DOI: 10.1016/j.jtbi.2022.111357 -
Science (New York, N.Y.) Nov 2022For more than a century, the origin and evolution of the arthropod head and brain have eluded a unifying rationale reconciling divergent morphologies and phylogenetic...
For more than a century, the origin and evolution of the arthropod head and brain have eluded a unifying rationale reconciling divergent morphologies and phylogenetic relationships. Here, clarification is provided by the fossilized nervous system of the lower Cambrian lobopodian , which reveals an unsegmented head and brain comprising three cephalic domains, distinct from the metameric ventral nervous system serving its appendicular trunk. Each domain aligns with one of three components of the foregut and with a pair of head appendages. Morphological correspondences with stem group arthropods and alignments of homologous gene expression patterns with those of extant panarthropods demonstrate that cephalic domains of predate the evolution of the euarthropod head yet correspond to neuromeres defining brains of living chelicerates and mandibulates.
Topics: Animals; Arthropods; Brain; Endoderm; Phylogeny; Gene Expression; Fossils; Biological Evolution
PubMed: 36423269
DOI: 10.1126/science.abn6264 -
Arthropod Structure & Development May 2017The panarthropod head represents a complex body region that has evolved through the integration and functional specialization of the anterior appendage-bearing segments.... (Review)
Review
The panarthropod head represents a complex body region that has evolved through the integration and functional specialization of the anterior appendage-bearing segments. Advances in the developmental biology of diverse extant organisms have led to a substantial clarity regarding the relationships of segmental homology between Onychophora (velvet worms), Tardigrada (water bears), and Euarthropoda (e.g. arachnids, myriapods, crustaceans, hexapods). The improved understanding of the segmental organization in panarthropods offers a novel perspective for interpreting the ubiquitous Cambrian fossil record of these successful animals. A combined palaeobiological and developmental approach to the study of the panarthropod head through deep time leads us to propose a consensus hypothesis for the intricate evolutionary history of this important tagma. The contribution of exceptionally preserved brains in Cambrian fossils - together with the recognition of segmentally informative morphological characters - illuminate the polarity for major anatomical features. The euarthropod stem-lineage provides a detailed view of the step-wise acquisition of critical characters, including the origin of a multiappendicular head formed by the fusion of several segments, and the transformation of the ancestral protocerebral limb pair into the labrum, following the postero-ventral migration of the mouth opening. Stem-group onychophorans demonstrate an independent ventral migration of the mouth and development of a multisegmented head, as well as the differentiation of the deutocerebral limbs as expressed in extant representatives. The anterior organization of crown-group Tardigrada retains several ancestral features, such as an anterior-facing mouth and one-segmented head. The proposed model aims to clarify contentious issues on the evolution of the panarthropod head, and lays the foundation from which to further address this complex subject in the future.
Topics: Animals; Arthropods; Biological Evolution; Fossils; Head; Mouth; Phylogeny
PubMed: 27989966
DOI: 10.1016/j.asd.2016.10.011 -
Genome Biology and Evolution Aug 2021Opsins are light-sensitive proteins involved in many photoreceptive processes, including, but not limited to, vision and regulation of circadian rhythms. Arthropod...
Opsins are light-sensitive proteins involved in many photoreceptive processes, including, but not limited to, vision and regulation of circadian rhythms. Arthropod (e.g., insects, spiders, centipedes, and crabs) opsins have been extensively researched, but the relationships and function of opsins found in lineages that are evolutionarily closely related to the arthropods remains unclear. Multiple, independent, opsin duplications are known in Tardigrada (the water bears), evidencing that protostome opsin duplications are not limited to the Arthropoda. However, the relationships, function, and expression of these new opsins are still unknown. Here, we use two tardigrade transcriptomes with deep coverage to greatly expand our knowledge of the diversity of tardigrade opsins. We reconstruct the phylogenetic relationships of the tardigrade opsins and investigate their ontogenetic expression. We found that while tardigrades have multiple opsins that evolved from lineage-specific duplications of well-understood arthropod opsins, their expression levels change during ontogeny such that most of these opsins are not co-temporally expressed. Co-temporal expression of multiple opsins underpins color vision in Arthropoda and Vertebrata. Our results clearly show duplications of both rhabdomeric and ciliary opsins within Tardigrada, forming clades specific to both the Heterotardigrada and Eutardigrada in addition to multiple independent duplications within genera. However, lack of co-temporal, ontogenetic, expression suggests that while tardigrades possess multiple opsins, they are unlikely to be able to distinguish color.
Topics: Animals; Opsins; Perception; Phylogeny; Spiders; Tardigrada
PubMed: 34255030
DOI: 10.1093/gbe/evab164 -
Scientific Reports Sep 2022Invertebrate-microbial associations are widespread in the biosphere and are often related to the function of novel genes, fitness advantages, and even speciation events....
Invertebrate-microbial associations are widespread in the biosphere and are often related to the function of novel genes, fitness advantages, and even speciation events. Despite ~ 13,000 species of millipedes identified across the world, millipedes and their gut microbiota are markedly understudied compared to other arthropods. Exploring the contribution of individual host-associated microbes is often challenging as many are uncultivable. In this study, we conducted metatranscriptomic profiling of different body segments of a millipede at the holobiont level. This is the first reported transcriptome assembly of a tropical millipede Telodeinopus aoutii (Demange, 1971), as well as the first study on any Myriapoda holobiont. High-throughput RNA sequencing revealed that Telodeinopus aoutii contained > 90% of the core Arthropoda genes. Proteobacteria, Bacteroidetes, Firmicutes, and Euryarchaeota represented dominant and functionally active phyla in the millipede gut, among which 97% of Bacteroidetes and 98% of Firmicutes were present exclusively in the hindgut. A total of 37,831 predicted protein-coding genes of millipede holobiont belonged to six enzyme classes. Around 35% of these proteins were produced by microbiota in the hindgut and 21% by the host in the midgut. Our results indicated that although major metabolic pathways operate at the holobiont level, the involvement of some host and microbial genes are mutually exclusive and microbes predominantly contribute to essential amino acid biosynthesis, short-chain fatty acid metabolism, and fermentation.
Topics: Amino Acids, Essential; Animals; Arthropods; Bacteroidetes; Fatty Acids, Volatile; Gastrointestinal Microbiome
PubMed: 36171216
DOI: 10.1038/s41598-022-19565-y -
Journal of Ethnobiology and... Feb 2017Traditional healing methods involving hundreds of insect and other invertebrate species are reviewed. Some of the uses are based on the tenet of "similia similibus" (let... (Comparative Study)
Comparative Study Review
Traditional healing methods involving hundreds of insect and other invertebrate species are reviewed. Some of the uses are based on the tenet of "similia similibus" (let likes be cured by likes), but not all non-conventional health promoting practices should be dismissed as superstition or wishful thinking, for they have stood the test of time. Two questions are addressed: how can totally different organ systems in a human possibly benefit from extracts, potions, powders, secretions, ashes, etc. of a single species and how can different target organs, e.g. bronchi, lungs, the urinary bladder, kidneys, etc. apparently respond to a range of taxonomically not even closely related species? Even though therapeutically used invertebrates are generally small, they nevertheless possess organs for specific functions, e.g. digestion, gas exchange, reproduction. They have a nervous system, endocrine glands, a heart and muscle tissue and they contain a multitude of different molecules like metabolites, enzymes, hormones, neurotransmitters, secretions, etc. that have come under increased scientific scrutiny for pharmacological properties. Bearing that in mind it seems likely that a single species prepared and used in different ways could have a multitude of uses. But how, for example, can there be remedies for breathing and other problems, involving earthworms, molluscs, termites, beetles, cockroaches, bugs, and dragonflies? Since invertebrates themselves can suffer from infections and cancers, common defence reactions are likely to have evolved in all invertebrates, which is why it would be far more surprising to find that each species had evolved its own unique disease fighting system. To obtain a more comprehensive picture, however, we still need information on folk medicinal uses of insects and other invertebrates from a wider range of regions and ethnic groups, but this task is hampered by western-based medicines becoming increasingly dominant and traditional healers being unable and sometimes even unwilling to transmit their knowledge to the younger generation. However, collecting and uncontrolled uses of therapeutic invertebrates can put undue pressure on certain highly sought after species and this is something that has to be borne in mind as well.
Topics: Animals; Ants; Arthropods; Bees; Cockroaches; Coleoptera; Culture; Diptera; Food; Hemiptera; Humans; Insecta; Isoptera; Medicine, Traditional; Mollusca; Spiders
PubMed: 28173820
DOI: 10.1186/s13002-017-0136-0 -
Frontiers in Endocrinology 2020Pigment-dispersing factor neuropeptides (PDFs) occur in a wide range of protostomes including ecdysozoans (= molting animals) and lophotrochozoans (mollusks, annelids,...
Pigment-dispersing factor neuropeptides (PDFs) occur in a wide range of protostomes including ecdysozoans (= molting animals) and lophotrochozoans (mollusks, annelids, flatworms, and allies). Studies in insects revealed that PDFs play a role as coupling factors of circadian pacemaker cells, thereby controlling rest-activity rhythms. While the last common ancestor of protostomes most likely possessed only one gene, two homologs, and , might have been present in the last common ancestors of Ecdysozoa and Panarthropoda (Onychophora + Tardigrada + Arthropoda). One of these homologs, however, was subsequently lost in the tardigrade and arthropod lineages followed by independent duplications of in tardigrades and decapod crustaceans. Due to the ancestral set of two genes, the study of PDFs and their receptor (PDFR) in Onychophora might reveal the ancient organization and function of the PDF/PDFR system in panarthropods. Therefore, we deorphanized the PDF receptor and generated specific antibodies to localize the two PDF peptides and their receptor in the onychophoran . We further conducted bioluminescence resonance energy transfer (BRET) experiments on cultured human cells (HEK293T) using an Epac-based sensor (Epac-L) to examine cAMP responses in transfected cells and to reveal potential differences in the interaction of PDF-I and PDF-II with PDFR from . These data show that PDF-II has a tenfold higher potency than PDF-I as an activating ligand. Double immunolabeling revealed that both peptides are co-expressed in but their respective levels of expression differ between specific cells: some neurons express the same amount of both peptides, while others exhibit higher levels of either PDF-I or PDF-II. The detection of the onychophoran PDF receptor in cells that additionally express the two PDF peptides suggests autoreception, whereas spatial separation of PDFR- and PDF-expressing cells supports hormonal release of PDF into the hemolymph. This suggests a dual role of PDF peptides-as hormones and as neurotransmitters/neuromodulators-in Onychophora.
Topics: Animals; Arthropod Proteins; Arthropods; Female; Male; Neuropeptides; Pigments, Biological; Receptors, Neuropeptide; Transcriptome
PubMed: 32477266
DOI: 10.3389/fendo.2020.00273 -
Zootaxa Mar 2020An updated and extensively revised checklist of the arthropods of Hispaniola (Dominican Republic and Haiti) is presented 11 years after the publication of the original...
An updated and extensively revised checklist of the arthropods of Hispaniola (Dominican Republic and Haiti) is presented 11 years after the publication of the original in 2008. It integrates and quantifies all the terrestrial and surrounding marine arthropod species (plus those of Tardigrada and Onychophora), reported in the zoological literature for Hispaniola through the middle of 2019. A total of 9,920 valid species (8,202 extant and 1,718 fossil) are listed, which represents an increase of 1,683 species (1,369 extant and 314 fossil) from the original list. The largest component is Insecta (6,784 extant and 1,136 fossil), including 2,206 extant species of Coleoptera, 1,042 species of Hemiptera, 929 species of Diptera, 913 species of Lepidoptera and 774 species of Hymenoptera. Emphasis is on reviewing and updating the original list, including all newly recorded taxa and all pertinent taxonomic changes proposed since then. Important corrections have been made, and explanatory notes have been added. For example, multiple authors have confused the Lesser Antillean island of Dominica with the Dominican Republic. This error is much more common in the literature than was initially recognized. Erroneous records attributing species from one island to the other have been identified and corrected. The original spelling of the cricket species Scapsipedus bastardoi Otte Perez-Gelabert, 2009, dedicated to Dominican biologist Ruth H. Bastardo, is corrected to Scapsipedus bastardoae nom. emend. High species endemism is typical of the biota of Caribbean islands. In this checklist, a total of 3,161 arthropod species (38.6%) are considered endemic or unique to Hispaniola. Among the speciose groups with higher levels of endemism are the Diplopoda (91.6%), Orthoptera (90.1%), Trichoptera (82.6%), Coleoptera (49.3%) and Araneae (47.5%). Also, a total of 201 arthropod species (174 insects + 27 non-insects) are identified as introduced to the island. The accompanying bibliography complements the taxonomic information and includes over 5,000 titles.
Topics: Animals; Arthropods
PubMed: 32230049
DOI: 10.11646/zootaxa.4749.1.1 -
BMC Evolutionary Biology Jul 2018Hemocyanin transports O in the hemolymph of many arthropod species. Such respiratory proteins have long been considered unnecessary in Myriapoda. As a result, the...
BACKGROUND
Hemocyanin transports O in the hemolymph of many arthropod species. Such respiratory proteins have long been considered unnecessary in Myriapoda. As a result, the presence of hemocyanin in Myriapoda has long been overlooked. We analyzed transcriptome and genome sequences from all major myriapod taxa - Chilopoda, Diplopoda, Symphyla, and Pauropoda - with the aim of identifying hemocyanin-like proteins.
RESULTS
We investigated the genomes and transcriptomes of 56 myriapod species and identified 46 novel full-length hemocyanin subunit sequences in 20 species of Chilopoda, Diplopoda, and Symphyla, but not Pauropoda. We found in Cleidogona sp. (Diplopoda, Chordeumatida) a hemocyanin-like sequence with mutated copper-binding centers, which cannot bind O. An RNA-seq approach showed markedly different hemocyanin mRNA levels from ~ 6 to 25,000 reads per kilobase per million reads. To evaluate the contribution of hemocyanin to O transport, we specifically studied the hemocyanin of the centipede Scolopendra dehaani. This species harbors two distinct hemocyanin subunits with low expression levels. We showed cooperative O binding in the S. dehaani hemolymph, indicating that hemocyanin supports O transport even at low concentration. Further, we demonstrated that hemocyanin is > 1500-fold more highly expressed in the fertilized egg than in the adult.
CONCLUSION
Hemocyanin was most likely the respiratory protein in the myriapod stem-lineage, but multiple taxa may have independently lost hemocyanin and thus the ability of efficient O transport. In myriapods, hemocyanin is much more widespread than initially appreciated. Some myriapods express hemocyanin only at low levels, which are, nevertheless, sufficient for O supply. Notably, also in myriapods, a non-respiratory protein similar to insect storage hexamerins evolved from the hemocyanin.
Topics: Amino Acid Sequence; Animals; Arthropods; Base Sequence; Binding Sites; Copper; Evolution, Molecular; Genetic Variation; Hemocyanins; Monophenol Monooxygenase; Oxygen; Phylogeny; Protein Subunits; RNA, Messenger
PubMed: 29976142
DOI: 10.1186/s12862-018-1221-2