A glance at the deep past history of insects

تغییرپذیری زمانی و مکانیشدت پرفشار سیبری ( SHI)،در دوره تشدیدگرمایش جهانی موضوع پژوهش پیش رو می‌باشد. در این راستا، از داده‌های ماهانه SLP (NCEP/NCAR Reanalysis 1)جهت استخراج شاخص SHI به عنوان بیشترین مقدار فشار در قلمرو مکانی آناستفاده شده است.با تحلیلِداده‌های آنومالی دمای سطح زمین (مرکز ملی داده‌های اقلیمی )، دو دوره متمایز قبل از سال 1973 و بعد از این سال تشخیص داده شد. در نهایت معنادار بودن تغییرات زمانی و مکانی SHI طی دو دوره مورد مطالعه، با آزمون‌های مقایسه‌ای مورد بحث و نتیجه گیری قرار گرفتند.با استخراج SHI و موقعیت مکانی مراکزِ آن در ماه‌های دسامبر، ژانویه و فوریه،مشخص شد که در دوره بعد از سال 1973(تشدیدگرمایش جهانی)، SHI تضعیف شده و دامنه تغییرات سالانه آن نسبت به دوره قبل، کاهش محسوسی داشته است که بیشتر تحت تاثیر کاهش مقادیر حداکثرSHI بوده است.همچنین مشخص شد که در این دوره، مراکز SHI به سمت 50°N و 90°E جابجا شده‌اند افزون بر آن، هم فشار5/1020 و هم فشار1034هکتوپاسکال به سمت غرب انتقال یافته‌اند، کاهش مساحت قابل ملاحظه‌ای در هم‌فشار 1034 هکتوپاسکال طی دوره تشدید گرمایش جهانی مشاهده شده است که با توجه به کاهش مقادیر حداکثر SHI قابل توجیه است.

New lacewings (Insecta, Neuroptera, Osmylidae, Nymphidae) from the Lower Cretaceous Burmese amber and Crato Formation in Brazil

A new genus and species of parasitic wasps (Hymenoptera: Diapriidae) from Hkamti mid–Cretaceous Burmese amber

Planet of the Bugs: Evolution and the Rise of Insects Scott R. Shaw 2014; 256 pages, 12 color plates University of Chicago Press, Chicago, IL ISBN-13: 978-0-226-16361-1 $27.50 (hardcover); $17.00 (softcover) ![Graphic][1] This entertainingly written and fascinating book introduces insect evolution for a general audience. Shaw inserts many other aspects of insect diversity and biology in the process, and editorializes about priorities in science and how much we still don't know about insect diversity. He brings in accounts of his own Neotropical fieldwork and paleontological features from his Wyoming environs, giving the book an engaging personal flavor. The book is well illustrated with photographs of living and fossil insects, and the thirteen pages of footnotes at the back make interesting reading in themselves. After an introductory chapter presenting the basics of insect biology, diversity, and evolution, Shaw gives a nine-chapter tour of the geologic periods relevant to arthropod and insect evolution. He keeps this 500-million-year history surprisingly lively, animating two-dimensional fossil arthropods into fascinating creatures that interacted with their environment, each other, and even dinosaurs. He launches his treatment in the Cambrian and Ordovician, with the rise of the arthropods within the early explosion of animal body plans. In … [1]: /embed/inline-graphic-1.gif

Landscape structure, habitat fragmentation, and the ecology of insects

18 - Ice ages: Species distributions, and evolution

Palaeoentomology started in the late XVIIIth century, shortly after the 10th edition of Linnaeus’ Systema Naturae (the foundation of modern taxonomy), when papers on the curiosities of insects entombed in fossil resins were published. The beginning of XIXth century (with the growing interest in geological sciences and prehistoric life) witnessed the first attempts to study and describe insects from sedimentary rocks. This discipline then developed during the XIXth and beginning of the XXth centuries; and resulted in some major works and reviews (summarizing the knowledge on fossil insects and other terrestrial arthropods) published in the geological and biological literature. The XXth century was a period of relatively slow but constant development in palaeoentomology, during which the famous “Treatise on invertebrate paleontology: Arthropoda 4. Superclass Hexapoda” (cataloguing the knowledge on fossil insects) was published (Carpenter, 1992). At the beginning of XXIst century, palaeoentomology grew significantly and exponentially; and two major manuals (“History of insects” and “Evolution of the insects”) were published (Rasnitsyn & Quicke, 2002; Grimaldi & Engel, 2005, respectively). These manuals helped to encourage more students and researchers to work on fossil insects and other terrestrial arthropods.

The National Ecological Observatory Network (NEON) seeks to facilitate ecological prediction at a continental scale by measuring processes that drive change and responses at sites across the United States for thirty years. The spatial distribution of observations of terrestrial organisms and soil within NEON sites is determined according to a “design‐based” sample design that relies on the randomization of sampling locations. Development of the sample design was guided by high‐level NEON objectives and the multitude of data products that will be subjected to numerous analytical approaches to address the causes and consequences of ecological change. A requirement framework permeates the NEON design, ensuring traceability from each facet of the design to the high‐level requirements that make the NEON mission statement actionable. Requirements were developed for the terrestrial sample design to guide the key components of the design: Randomizing the sample locations ensures the unbiased collection of data, is appropriate for organisms and soil, and provides data suitable for a variety of analyses. Stratification increases efficiency and allows sampling to focus on those parts of the landscape measured by other NEON observation platforms. Attention to the sample size and spatial plot allocation ensures that data products will be sufficient to inform questions asked of the data and the NEON objectives. Establishing a framework with the capacity for re‐evaluate and design iteration allows for adaption to unexpected challenges and optimization of the sample design based on early data returns. The utility of the NEON sampling design is highlighted by its application across terrestrial systems. The data generated from this unique design will be used to quantify patterns in: the abundance and diversity of small mammals, breeding birds, insects, and soil microbes; vegetation structure, biomass, productivity, and diversity; and soil biogeochemistry.

Abstract. Marine microorganisms trapped in amber are extremely rare in the fossil record, and the few existing inclusions recovered so far originate from very few pieces of Cretaceous amber from France. Marine macroscopic inclusions are also very rare and were recently described from Cretaceous Burmese amber and Early Miocene Mexican amber. Whereas a coastal setting for the amber source forests is generally proposed, different scenarios have been suggested to explain how these marine inclusions can become trapped in a resin of terrestrial origin. These scenarios include an introduction of marine organisms (i) through high tides, (ii) from storms and resulting in flooding of the littoral/estuarine forest floor, (iii) in resin dropped into the sea in mangrove-type settings, or (iv) by wind and sea spray. We investigated the possibility of a wind-driven introduction of marine microorganisms into tree resins using modern coastal conifer forests with the highly resinous Cook pine (Araucaria columnaris) in New Caledonia as a model for the Cretaceous amber forests from France. By exposing fresh resin surfaces on the seaward side of the trees and the collection of older in situ resins, we confirmed that marine microorganisms can become trapped on sea-exposed resin, along with remnants from terrestrial organisms, and salt crystals. We suggest that, for cases where only a few marine inclusions are discovered in an amber deposit, an origin from aeolian background deposition is feasible. However, a more energetic but possibly still aeolian event is likely needed to explain the high numbers of marine microorganisms embedded in pieces of Cretaceous amber from France.

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The evolution of complete metamorphosis in insects is a key innovation that has led to the successful diversification of holometabolous insects, yet the origin of the pupa remains an enigma. Here, we analyzed the expression of the pupal specifier gene broad (br), and the effect on br of isoform-specific, double-stranded RNA-mediated silencing, in a basal holometabolous insect, the beetle Tribolium castaneum. All five isoforms are weakly expressed during the penultimate instar and highly expressed during the prepupal period of the final instar. Application of hydroprene, a juvenile hormone analog, during the penultimate instar caused a repeat of the penultimate br expression patterns, and the formation of supernumerary larvae. Use of dsRNA against the br core region, or against a pair of either the br-Z2 or br-Z3 isoform with the br-Z1 or br-Z4 isoform, produced mobile animals with well-differentiated adult-like appendages, but which retained larval-like urogomphi and epidermis. Disruption of either the br-Z2 or the br-Z3 isoform caused the formation of shorter wings. Disruption of both br-Z1 and br-Z4 caused the appearance of pupal traits in the adults, but disruption of br-Z5 had no morphological effect. Our findings show that the br isoform functions are broadly conserved within the Holometabola and suggest that evolution of br isoform expression may have played an important role in the evolution of the pupa in holometabolous insects.

Three new species of parasitoid wasp are described and figured from Early Miocene (Early Burdigalian) compression fossils from Rubielos de Mora Basin, Spain. These wasps are significant as they are representative of two families exceedingly rare in the fossil record. The first is a species of the family Perilampidae (Chalcidoidea) and, aside from an old and unconfirmed record of an undescribed Perilampus in Baltic amber, is the only documented fossil of this lineage. Perilampus renzii, new species, is described from a single female. The remaining two species are both of the family Megaspilidae (Ceraphronoidea), which is otherwise known in the fossil record solely from a paucity of species preserved in fossil resins. Conostigmus lazaros, new species, and C. chthonios, new species, are distinguished from each other as well as modern congeners.

Over the last 20 years, compression fossils of feathers surrounding dinosaurs have greatly expanded our understanding of the origin and evolution of feathers. One of the most peculiar feather morphotypes discovered to date are rachis dominated feathers (RDFs), which have also been referred to as proximally ribbon-like pennaceous feathers (PRPFs). These elongate feathers are only found in the tail plumage, typically occurring in pairs with both streamer (not proximally ribbon-like) and racket-plume morphologies recognized. Here we describe a large sample set of isolated and paired RDFs from Upper Cretaceous Burmese amber (~ 99 Ma). Amber preserves the finest details of these fragile structures in three dimensions, demonstrating that RDFs form a distinct feather morphotype with a ventrally open rachis, and with significant variability in pigmentation, microstructure, and symmetry.

Past claims have been made for fossil DNA recovery from various organisms (bacteria, plants, insects and mammals, including humans) dating back in time from thousands to several million years BP. However, many of these recoveries, especially those described from million-year-old amber (fossil resin), have faced criticism as being the result of modern environmental contamination and for lack of reproducibility. Using modern genomic techniques, DNA can be obtained with confidence from a variety of substrates (e.g. bones, teeth, gum, museum specimens and fossil insects) of different ages, albeit always less than one million years BP, and results can also be obtained from much older materials using palaeoproteomics. Nevertheless, new attempts to determine if ancient DNA (aDNA) is present in insects preserved in 40 000-year old sub-fossilised resin, the precursor of amber, have been unsuccessful or not well documented. Resin-embedded specimens are therefore regarded as unsuitable for genetic studies. However, we demonstrate here, for the first time, that although a labile molecule, DNA is still present in platypodine beetles (Coleoptera: Curculionidae) embedded in six-year-old and two-year-old resin pieces from Hymenaea verrucosa (Angiospermae: Fabaceae) collected in Madagascar. We describe an optimised method which meets all the requirements and precautions for aDNA experiments for our purpose: to explore the DNA preservation limits in resin. Our objective is far from starting an uncontrolled search for aDNA in amber as it was in the past, but to start resolving basic aspects from the DNA preservation in resin and search from the most modern samples to the ancient ones, step by step. We conclude that it is therefore possible to study genomics from resin-embedded organisms, although the time limits remain to be determined.

New Zealand is an island continent that completed its split from the Gondwanan continent at 52 Ma, harbouring an iconic biota of tuatara, kiwi and weta. The sooty mould community is a distinctive trophic element of New Zealand forest ecosystems that is driven by plant-feeding sternorrhynchan Hemiptera. These produce honeydew, which supports fungal growth, which in turn supports numerous endemic invertebrates, including endemic New Zealand beetle families. Ancient New Zealand insect fossils are rare but a single fossil of a sooty mould cyclaxyrid was recently described from Cretaceous Burmese amber, a family that was previously known from two extant New Zealand species. Well-preserved fossils like this one are recasting Earth history, and, based on a wealth of additional specimens, we re-evaluate the taxonomy of Cretaceous cyclaxyrids and one Eocene species here transferred to Cyclaxyridae. Cyclaxyridae are highly tied to the sooty mould community and have now been discovered to occur in disparate biogeographic realms in deep time. Our discovery indicates that the family, and perhaps the sooty mould community in general, was widespread in Pangaea from at least the Cretaceous and survived as a relict in New Zealand. Persistence of a sooty mould ecosystem in New Zealand and fungal specialization may not necessarily be an evolutionary 'dead-end' for cyclaxyrids and other insects.