Insect Trace Research Articles

Encounter with the Father of Op Art, Victor Vasarely: Research in Conservation and Art History, and Conservation Work on the Barson Collage

ABSTRACT The father of Op Art, Victor Vasarely, is the author of a paper collage called Barson, owned by the Museum of Contemporary Art, in Zagreb, which is the only such example in Croatian public cultural institutions. The collage was created in 1967 using the screen printing technique on paper glued to a paper support and then onto large-sized hardboard, and its creation was influenced by the leading objectivist artistic and philosophical trends and knowledge of the time, under the influence of which Vasarely created his art. The collage was found very dusty and with many damages on the entire surface of the paper support, such as cracks, dried and detached parts and traces of activities of insects. Works of Op Art imply an undisturbed perception of the artwork, which in the case of the Barson collage, due to caused damage, was impossible. Therefore, conservation and restoration work was carried out that included extensive research and numerous tests, followed by dry cleaning, gluing both layers of the paper carrier, removing traces of insects and the necessary, minimal retouching. The corresponding wooden frame was cleaned of a layer of dust, and the smaller, missing part was reconstructed with the same type of wood and finally retouched.

How to prove neglect in the context of the post-mortem examination

Understanding the causes, extent, and period of neglect is not only a medical but also a forensic task when it comes to legal investigations. In this study, we evaluated 46 autopsied cases where there was clear evidence of physical neglect during the last period of the deceased’s life. The age of the deceased ranged from 21 to 96 years; most of them were female (71.7%). The majority of cases (89.9%) took place in a domestic environment, with partners or relatives providing care. The most frequent post-mortem findings were pressure sores, followed by inflammatory skin changes, and signs of malnutrition and dehydration. Neglect was the cause or co-cause of death in 23% of the cases. More than half of the deceased showed severe contamination of the skin surface by excrement, and in almost 40% of the cases, fly infestation was found. The majority of insects belonged to the group of house flies (Diptera: Muscidae), mainly the common house fly, Musca domestica. By analyzing the entomological evidence, it was possible to prove an insect infestation period of at least several days ante-mortem. Since the period of neglect may be relevant in terms of legal proceedings, the present work demonstrates the particular importance of insect traces in providing this evidence. While prosecution and conviction of caregivers remain challenging, it is all the more essential that entomology and legal medicine collaborate on the analysis of findings of neglect.

Insect trace fossils as indicators of climatic conditions during the uppermost Pleistocene deposits in southern Brazilian Atlantic coast

AbstractThe Rio Grande do Sul Coastal Plain records sea-level oscillations driven by climatic changes during Quaternary glaciations, represented as four lagoon-barrier systems, the last one forming after the last glacial maximum and still active. Marine trace fossils are reported in the Pleistocene deposits, but terrestrial burrows also occur in the eolian deposits. The insect trace fossil assemblages from the uppermost Pleistocene deposits of the lagoon-barrier system III are used as relative proxies to infer the climate regimes that controlled sedimentation prior to the last glacial maximum. Two suites occur in the eolian deposits: the Vondrichnus suite, dominated by structures produced by termites, in the basal eolian beds; and the Celliforma suite, dominated by hymenopteran (bees and wasps) structures, in the upper eolian beds. The dominance of termite nests indicates humid conditions. The shift upward to the Celliforma suite signals a change in the humidity regime and the prevalence of drier conditions. The stratigraphic position of the ichnoassemblage, above the uppermost Pleistocene marine transgressive beds that formed during the last interglacial and below the record of the last glacial maximum in this coastal plain, suggests that the last glacial interval controlled this humid-dry fluctuation.

Rapid assessment of feeding traces enables detection of drivers of saproxylic insects across spatial scales

Knowledge of habitat requirements of saproxylic insects and their response to habitat changes is critical for assessing the ecological impacts of forest management. Several studies have demonstrated a positive relationship of tree-species richness, deadwood volume, or structural diversity with saproxylic species diversity, while the relationship with the abundance of potential pest species have often been negative. A better understanding of which factors drive saproxylic insects’ occurrence is therefore essential for deriving urgently needed thresholds for key habitat conditions. We tested a rapid assessment method applicable at large scale based on recorded feeding galleries and boreholes assessed during the Austrian National Forest Inventory to investigate the drivers and habitat thresholds of different saproxylic insect families; i.e. Buprestidae, Cerambycidae, Curculionidae, Siricidae, at multiple spatial scales; i.e. at the object, forest stand and landscape level. We modelled the relative abundance of all insects and these families considering nineteen explanatory variables using ordinal logistic regression models. Key habitat characteristics were identified using recursive partitioning. Our results revealed complex interactions among influencing factors at different spatial scales. We showed that deadwood volume was of surprisingly little importance. Instead, individual tree characteristics were of major importance, demonstrating the value of resource quality and variability. The abundance of all saproxylic insect families increased with advancing decomposition, on trees taller than 18 m, and above a living stand volume of 41 m3ha−1. Aiming to guide forest management, not only forest type-specific, but tree species-specific deadwood management is needed, taking into account site-specific conditions, including temperature and precipitation. For assessing temporal trends in insect colonization and habitat dynamics as well as the effects of forest management, we propose a continuous monitoring of insect traces, including living but weakened trees. This will allow for further thresholds that are urgently needed for maintaining biological diversity in forest ecosystems in the face of climate change.

Fossil caddis cases from the lower Eocene Huachong Formation of the Sanshui Basin, Foshan City, Guangdong Province, South China with detrital zircon analyses

Here we describe for the first time the insect (trace) fossils from the lower Eocene Huachong Formation at the Sanshui Basin in Foshan City, Guangdong Province, South China. Three specimens of caddis cases display different morphologies, but all of them are constructed using mainly ostracods. The detrital zircon from a layer below the fossil bed is studied. Our isotopic chronological analyses of the detrital zircons reveal at least four phases of volcanic activities in this area during the Phanerozoic.

Insect traces on Lower Gondwana plants of Ib River Basin, Odisha: First record from Late Permian sediments of India

ABSTRACTThe Ib River Basin, located in the south‐eastern part of the Son‐Mahanadi Master Basin, is renowned for its reserve of well‐diversified Lower Gondwana plant megafossils. The remains of Glossopteris flora collected from a Late Permian Gondwana (Lower Kamthi Formation) exposure, near Himgir Village, Ib River Basin, Odisha, has demonstrated a record of different types of insect traces. The structures are compatible with a variety of insect activities on fossil leaves. Different feeding traces such as leaf margin and surface feeding traces, cuspate margin feeding traces, obliterated surfaces and blotch marks are found in the Glossopteris leaves. Egg pouches found along the midrib and on the lamina in the Glossopteris leaves are the traces of egg‐laying. The various traces of insect activities recorded in the present investigation reveal the survival of a diverse insect fauna during the Late Permian Glossopteris flora of India. It is the first report of its kind in the Mahanadi Gondwana Master Basin of India, and also it is the first record of insect traces in the Late Permian sediments of India.

Diet Composition of Bats in a Human-Modified Tropical Landscape

Human-modified landscapes are often composed of small and isolated natural habitat fragments immersed in agricultural and urban matrices. Within them, ecosystem services provided by wildlife, such as pest insect suppression, may decrease or even be lost leading to a substantial increase in agricultural production costs. Pest insect suppression by bats has been identified as an essential ecosystem service but remains poorly investigated. For example, we still lack a basic understanding of the proportion of pest insects that comprises the diet of many bat species. Here, we explored the diet composition of eight Brazilian bat species (78 individuals) in a human-modified landscape through the analysis of stable carbon (13C) and nitrogen (15N) isotopes. Bats were categorised into guilds: open-space aerial insectivores, narrow-space gleaning frugivores, or narrow-space gleaning nectarivores. We divided the insects collected into three groups depending on their δ13C values: forest, mixed, and pest insects. We found that open-space insectivorous bats had the highest proportion of insects in total in their diet — consuming primarily from the forest group (56%) and the pest group (34%). Interestingly, narrow-space gleaning frugivores also consumed pest insects (almost 20%). The narrow-space gleaning nectarivores had traces of insects in their diet, yet the actual proportion was inconclusive. Even though bats were from different guilds, with diets consisting mainly of plants and insects, the δ15N indicated that they fitted to similar trophic levels, as secondary consumers. Therefore, the trophic level of nectarivorous and frugivorous bats showed a more generalist diet than previously assumed. The proportion of forest insects in the diet of open-space aerial insectivores may indicate the importance of small forest patches as food resources for wildlife such as the ones included in human-modified landscapes. The bats' contribution to this ecosystem service could improve the economic conservation value of Neotropical bats in human-modified landscapes.

Toriti, Magali; Durand, Aline & Fohrer, Fabien: Traces of common Xylophagous insects in wood. Atlas of identification—Western Europe

Toriti, Magali; Durand, Aline & Fohrer, Fabien: Traces of common Xylophagous insects in wood. Atlas of identification—Western Europe

The Lower Cretaceous “Continental Intercalaire” around Tidikelt (Central Sahara, Algeria): Sedimentology, palaeontology and ichnology

The Lower Cretaceous strata are exposed over a large surface in the northern part of the Ahnet basin. They consist of transgressive, horizontal formations overlying the folded Palaeozoic formations by angular unconformity across the Tidikelt region. The present study addresses the respective lithostratigraphical units of the “Continental Intercalaire” succession and their subsequent palaeo-environment in the Tidikelt area using a trace fossil analysis combined with sedimentological and palaeontologic data. The lithological and sedimentological features of the study sections recognised eleven sub-units organised within four lithological units: the Lower Clay Unit of Barremian-Neocomian age consisting of three Sub-units (Akablie Sandstone, Sidi Mahmoud Clays and Pebbly Sands); the Quartzite Sandstones Unit referred to a Late Barremian-Early Aptian age; the Middle Clay-Sandstone Unit consisting of a thick deposit of Early Aptian-Albian age, divided into five Sub-units (Tit Sandstones, In Salah Sand-Clay, In Salah Sandstone, Foum El Bouib Sandstone, and Sandstone-Clay); and the Upper Clay Unit comprising the Oued Taleh Sand and the El-Golea Clays Sub-units. Vertebrate remains all evidence a Late Albian-Early Cenomanian age for the top part of the Continental Intercalary. Ichnologic data analysis documents lower diversity of the invertebrate trace fossils: only ten ichnotaxa are recorded so far and grouped in five ichnoassemblages. Fuvial-lacustrine ichnoassemblage represents a continental ichnofacies of a fluvial-lacustrine environment: Mermia, Scoyenia and Skolithos ichnofacies. Fluvial Ichnoassemblage of the Quartzite Sandstone Unit is represented by insect trace fossils typical of the Coprinisphaera ichnofacies. Fluvio-marginal ichnoassemblage corresponds to a tidal-influenced, fluvial deposit transgressive on Unit B, represented by Skolithos and Psilonichnus ichnofacies. Lower shoreface ichnoassemblage shows the upper part of Unit C, documented by horizontal trace fossils such as Thalassinoides and vertical root traces, all supporting a lower shoreface environment in a semi-arid climate interlined by well-oxygenated episode with nutrient-rich conditions and vegetation dominance. Near to shoreface ichnoassemblage coincides with the upper unit D of coastal deposits with fluvial-tidal influence at the base (Oued Taleh Sands) associated with Scoyenia and Skolithos trace fossils and lagoon deposit of the El-Golea Clays Sub-units.

Diverse evidence for grasslands since the Eocene in Patagonia

Timing and ecological steps of the rise and expansion of grasslands differ not only geographically but also according to the type of available information. Patagonia (Argentina) was largely considered the region where grasslands and grazers early evolved in the Eocene, mostly based on functional morphology of mammals. However, recent paleobotanical studies question this traditional view and maintain that this occurred after early Miocene. To tackle this discrepancy, we conduct a multidisciplinary and integrative approach using diverse lines of evidence obtained from middle Eocene - middle Miocene tuffaceous deposits of central and northern Patagonia. Gathered data correspond to sedimentary facies, paleosols, insect trace fossils, opal phytoliths and fossil mammals (tooth morphology, body size). Long-lasting and frequent volcanic ashfalls caused permanent disturbances in physical scenarios, biotic systems and grassy habitats; just like herbivory of mammals through coevolutionary grass-grazer mechanisms. The results indicate that soils, vegetation, insects and mammal herbivores begun synchronously to record diverse traits related to grasslands showing mosaic vegetation since middle Eocene (~44 Ma). These traits include mollic paleosols, abundant and persistent dung beetle trace fossils (Coprinisphaera ichnofacies), phytolith assemblages attributable to savannas and medium to large-size hypsodont mammals. We also track the evolutionary history after the reduction of closed forests, recognizing alternating subhumid savannas with riparian forests, where the relative frequency between grasses, palms, trees and shrubs fluctuated in time and space; and desert vegetation (shrublands) dominated by palms and shrubs during dryer periods. The advent and expansion of grasslands can be linked to the cooling and drying period subsequent to the Early Eocene Climate Optimum.

DIFFUSE TERMITINAE NESTS SHED LIGHT ON THE AFFINITIES OF LAETOLICHNUS KWEKAI (KRAUSICHNIDAE)

ABSTRACT The insect trace fossil Laetolichnus kwekai, which is composed of a small chamber extending to slender cylinders at each end, was tentatively included in the ichnofamily Krausichnidae as termite nests. New evidence presented here provides information to validate these inferences. A more complex structure formed by interconnected Laetolichnus was recently found in the same Pliocene deposits (Laetoli, Tanzania) as the isolated specimens reported previously. Our study confirms inclusion of Laetolichnus in Krausichnidae and supports the inference that it represents a nest of a social insect. Neoichnological field studies in the coastal dunes of Buenos Aires Province, Argentina, were undertaken to refine further the nature of these affinities. Survey of the dune surface revealed abundant loose fragments of termite nests of a size and shape comparable to that of L. kwekai. The fragile nests constructed by Onkotermes brevicorniger, which are described here in detail for the first time, enable us to interpret the fossil structures. They consist of connected chambers similar to the interconnected Laetolichnus. These were frequently exposed and broken by wind action resulting in loose fragments similar to the isolated Laetolichnus. The Celliforma ichnofacies represented at Laetoli, which contains L. kwekai, indicates arid or semiarid shrublands and woodlands. The distribution of O. brevicorniger also corresponds to arid and semiarid shrublands and dry woodlands of Argentina. Although the African termite producer of L. kwekai and the South American Onkotermes would be phylogenetically unrelated, the analogous structures probably reflect convergent nesting behaviors as an adaptation to similar arid to semiarid environmental conditions.

A new trace fossil produced by insects in fossil wood of Late Jurassic–Early Cretaceous Missão Velha Formation, Araripe Basin, Brazil

A new insect trace in silicified wood is described from the Upper Jurassic–Lower Cretaceous Missão Velha Formation, Araripe Basin (Northeastern Brazil). Pluriramosus missaovelhensis igen. et isp. nov. consists of a main tunnel slightly curved, parallel to the growth rings (tangencial). The main tunnel has short lateral tunnels connected to it at almost right angles and with rounded terminal portions. The internal surface of the main tunnel has parallel concave grooves (bioglyphs). Based on a review of wood boring patterns produced by modern insects, the xylophagous beetles (Coleoptera) are most likely the producers of the trace fossil due to the similarity with the borings produced by modern beetles of the Platypodidae family. This is the first trace fossil attributed to beetles for the Missão Velha Formation and the oldest record of Coleoptera for the Araripe Basin. This record contributes to the enrichment of taxonomic ichnology and expands the knowledge about ancient insects of the Araripe Basin.

An assemblage of large-sized insect traces in paleosols from the middle Miocene of northern Patagonia related to the climatic optimum

A new assemblage of large insect trace fossils is recognized in paleosols of the middle Miocene pyroclastic deposits from extra-Andean north Patagonia. This assemblage includes Racemusichnus jacobacciensis igen. isp. nov., the largest trace fossil in paleosols attributed to solitary insects. R. jacobacciensis is represented by clusters of two to seven thickly walled cylinders horizontally orientated in the paleosol. The cluster arrangement, its orientation, the large size and wall of the cylinders suggest a dung beetle, probably a representative of the Geotrupidae as the possible trace maker. The new ichnoassemblage, also comprising large-sized specimens of Coprinisphaera ispp., Teisseirei barattinia and Feoichnus challa, belongs to the Rosellichnus assemblage-SAPIA of the Coprinisphaera Ichnofacies. Mollic paleosols along with the trace fossils, mammal remains and previous data for this unit suggest an open grassy habitat compatible with high productive grass savannas, under a temperate-warm and seasonal subhumid climate. This assemblage of large-sized trace fossils is attributed to highly productive ecosystems related to the rise of temperature occurred during the Middle Miocene Climatic Optimum.

Detection and monitoring of insect traces in bioaerosols.

Studies on bioaerosols have primarily focused on their chemical and biological compositions and their impact on public health and the ecosystem. However, most bioaerosol studies have only focused on viruses, bacteria, fungi, and pollen. To assess the diversity and composition of airborne insect material in particulate matter (PM) for the first time, we attempted to detect DNA traces of insect origin in dust samples collected over a two-year period. These samples were systematically collected at one-month intervals and categorized into two groups, PM2.5 and PM10, based on the aerodynamic diameter of the aerosol particles. Cytochrome-c oxidase I (COI) was the barcoding region used to identify the origins of the extracted DNA. The airborne insect community in these samples was analyzed using the Illumina MiSeq platform. The most abundant insect sequences belonged to the order Hemiptera (true bugs), whereas order Diptera were also detected in both PM2.5 and PM10 samples. Additionally, we inferred the presence of particulates of insect origin, such as brochosomes and integument particles, using scanning electron microscopy (SEM). This provided additional confirmation of the molecular results. In this study, we demonstrated the benefits of detection and monitoring of insect information in bioaerosols for understanding the source and composition. Our results suggest that the PM2.5 and PM10 groups are rich in insect diversity. Lastly, the development of databases can improve the identification accuracy of the analytical results.

Xylophagous insects of the wooden floor of Camelin block (Fréjus, France): An interdisciplinary approach combining archaeology and anthraco-entomology

Preventive excavation in the ancient Forum Iulii city (Fréjus, southern France) in 2013 revealed a housing block where a very well preserved charred wooden floor was discovered. It was laid in a house dating back to the first half of the 1st century AD and used as the floor of a room decorated with painted plaster. It was destroyed by fire around 70 AD. The ligneous species used for its construction (Aleppo pine, Scots pine, beech and fir) were characterized by anthracological analysis. Numerous traces of xylophagous insects and lignivorous fungi were observed. Their identification, their number and their distribution in the floor open on to very interesting new interpretations for both anthracologists and archaeologists as regards the condition of timber, the original source of the infestation, and the historical record of the building. This study is a direct and unprecedented application of a key for identifying traces of wood-boring insects in charred remains from the Roman period. Field samples were tested during the excavation of Camelin block, and microscope observation protocols were adapted to entomo-archaeology during anthraco-analysis.

A fossorial petalurid trace fossil from the Albian of Patagonia

Maichnus wetkaroae igen. isp. nov., from the Albian of Patagonia, is composed of two or three ellipsoidal oblate chambers connected to shafts that show swellings and concentrically laminated linings. Such laminated linings are also present in chambers, and probably originated by radial backfilling and/or the successive discharges of liquid organic excretions. This unique morphology occurs in paleosols showing evidence of waterlogging. Trace fossil morphology and the occurrence of traces in clusters in waterlogged soils indicate that M. wetkaroae igen. isp. nov. represents larval burrows of fossorial petalurids. This is the first record of Odonatan trace fossils from paleosols and also the oldest one. M. wetkaroae igen. isp. nov. is one of the oldest insect trace fossils recorded from paleosols. It represents the first and unique paleontological evidence of the ancient origin of the burrowing behavior of petalurids postulated only theoretically until now in evolutionary scenarios of Odonata.

Insect trace fossils in Pleistocene deposits from the Pityusic Islands (Balearic Archipelago, Western Mediterranean): Ichnotaxonomy and palaeoenvironmental significance

Insect trace fossils attributable to the Celliforma ichnofacies (Rebuffoichnus casamiquelai and Palmiraichnus castellanosi) are recorded from the Pleistocene deposits of nine sites from the Pityusic islands. These deposits, characterized by aeolian and colluvial strata interbedded with two types of palaeosols with a high amount of trace fossils, show a strong relationship with environmental changes occurred during the Pleistocene. The Celliforma Ichnofacies is typical of well-drained palaeosols with low vegetation indicating semiarid to sub-humid conditions. According to the abundance of ichnospecies in each type of palaeosol, Palmiraichnus castellanosi indicates that bees preferred to nest in wetter conditions, whereas Rebuffoichnus casamiquelai, indicates that coleopterans could live under drier conditions, even in this case when its abundance is relatively high within periods with increased rainfall.

Flora and insect trace fossils from the Mio-Pliocene Quebrada del Toro locality (Gobernador Solá, Salta, Argentina)

Foliar impressions were recorded for the first time in the Mio-Pliocene lacustrine sediments at the Quebrada del Toro outcrop (Salta, Argentina). Here we describe a horsetail (Equisetum cf. giganteum L.), ferns (Pteris cf. deflexa Link., Pteris cf. plumula Desv., Circinites pteridoides nov. gen. et nov. sp.) and monocotyledons (Typha cf. latifolia L., Scirpites sp., Poacites sp., Rhizomatites cyperoides nov. gen. et nov. sp., Schoenoplectus californicus, Cyperocarpus sp. 1, Cyperocarpus sp. 2 and Cyperocarpus sp. 3). A few impressions contain insect traces, which correspond with marginal (Phagophytichnus regularis Vasilenko and Phagophytichnus ekowskii van Amerom), non-marginal excisions (Folifenestra polylobata nov. isp.) and piercing and sucking (Circulifolites concavus nov. igen et nov. isp). The inferred paleoenvironment reflects a flora related with water bodies surrounded by open terrestrial areas and limited by a forest. Based on the sedimentological context and plant community composition, we conclude that the plant fossils preserved at the Quebrada del Toro outcrop were deposited in a lagoon environment, comparable to a reed bed. Similar Mio-Pliocene deposits in Northern Argentina were found at the Palo Pintado Formation (Salta, Argentina). The sedimentological characteristics and the paleofloristic similitudes between the Quebrada del Toro outcrop and Palo Pintado Formation support the age assigned to the first fossiliferous location.

Plant-insect interactions in the fossil flora of the Bajo de Veliz Formation (Gzhelian - Asselian): San Luis, Argentina

This article presents a detailed description of insect trace fossils found in the megaflora of the Gzhelian-Asselian of the Bajo de Veliz. Plant-insect interactions are analyzed on 212 specimens of leaves from this flora, characterized by glossopterid (Gangamopteris, Euryphyllum, Glossopteris), cordaitales, sphenophytes, pteridosperms, lycophytes, conifers and seeds. Marginal feeding, surface and oviposition traces and galling predominate, as compared to the poor representation of piercing and sucking traces. Necrotic tissue was identified on leaves of the genera Euryphyllum, Gangamopteris, Glossopteris and bipinnate fronds of Botrychiopsis, suggesting that damage was produced while the plants were alive. The first reported evidence of galling for Botrychiopsis and piercings traces in Gangamopteris leaves for Gondwana are described.

The modern and fossil record of farming behavior

AbstractFarming is a behavior in which an organism promotes the growth and reproduction of other organisms in or on a substrate as a food source. A number of trace fossils have been suggested to record the occurrence of farming behavior. These include the deep-sea graphoglyptid trace fossils, proposed to be microbial farms on the seafloor, and terrestrial fossil social insect nests thought to represent fungicultural behavior. The presumed farming behavior of graphoglyptids is the basis of the ethological category agrichnia. Four criteria have been proposed as diagnostic of farming behavior, and these can be applied to both observed modern and proposed trace fossil examples of farming behavior. The evidence for farming behavior in the social insect trace record is strong but is much weaker in the case of graphoglyptids. The use of agrichnia as an ethological category should be limited to well-supported cases.