The first fossil genus and species of Tetratomidae (Coleoptera) is described, from the Lower Cretaceous amber deposits of France. The new genus represents the first insect to be recognized inside an ...opaque piece of amber, through the use of propagation phase contrast X-ray microtomography using synchrotron radiation. This new finding proves the capabilities of this imaging technique in amber inclusions, as well as increases the knowledge of fossil tenebrionoids, a group scarcely recognized in the Cretaceous fossil record.
Lotic systems, in particular temporal streams, represent an important proportion of continental waters, but are poorly studied. This is particularly clear in central Mexico, where temporal streams ...are abundant and remain poor studied despite their great potential for high diversity and the important energy within these ecosystems. The aim of this study was to analyze the environmental variables and scales at which these variables have effects on aquatic insect assemblages in a semiarid fluvial system in Central Mexico. A total of 89 genera were registered, the order Coleoptera showing the highest richness. Peak values for alpha diversity were found on permanent sites in the dry season (1D=10.63), the more stable environment in permanent streams during the dry season might accounted for this pattern. Assemblages at our study sites showed low similarity (I sub(j) < 0.45) indicating high genera replacement among sites, possibly related to differences in hydroperiod. Partition analysis indicates thatOriginal Abstract: Los sistemas loticos integrados por cauces temporales representan una alta proporcion de las aguas continentales del planeta, no obstante se encuentran entre los sistemas menos estudiados a nivel mundial. En cuanto a diversidad entomologica, el centro de Mexico -donde se ubican estos sistemas- permanece poco estudiado a pesar del alto potencial que presenta la zona de albergar una alta diversidad y de los vinculos importantes que este grupo desempena en los flujos de energia de los ecosistemas acuaticos. El objetivo del presente trabajo fue analizar las variables ambientales que determinan los cambios en la diversidad y las escalas en que tienen efecto, en las comunidades de insectos acuaticos de un sistema fluvial semiarido del centro de Mexico. Se registraron un total de 89 generos, con el orden Coleoptera presentando la mayor riqueza. Los valores mas altos de diversidad alfa se encontraron sobre sitios permanentes en la temporada de sequia (1D.T0.63), lo que se atribuye a la mayor estabilidad que presentan los sistemas fluviales en esta temporada Las comunidades establecidas sobre cauces permanentes e intermitentes presentaron baja similitud (I sub(j) <0.45), indicando un alto recambio entre comunidades establecidas sobre cauces con diferente hidroperiodo. Los analisis de distribucion ("particion") de la diversidad indican que el mayor aporte a la diversidad regional se da por cambios en la composicion de generos a nivel de nos (37%), entre temporadas (22%) y por el tipo de sistema (21%). De acuerdo con el Analisis de Correlacion Canonica las variables de mesohabitat, velocidad de corriente, calidad ecologica y orden del cauce son las que mejor explican la variacion en la presencia de los taxones. Los resultados sugieren que los sitios permanentes se encuentran actuando como fuente de especies de los sitios intermitentes y que los esfuerzos de conservacion en la region deben implementarse a escala de paisaje.
Rice fields occupy large areas in Northeastern Argentina, and in Corrientes this widespead activity has become a feature in the landscape, as it is one of the main producing provinces. The aquatic ...Coleoptera is part of the fauna inhabiting these artificial environments but little is known about this group in irrigated rice fields. The aims of this study were to determine the diversity and species richness of coleopterans in a typical rice field, and to characterize the community of water beetles through different abundance models. For this, samples were collected from an active rice field located in "El Sombrero" town, in Corrientes Province, between November 2011 and April 2012. An entomological net of 30 cm diameter was used, and species richness, diversity and equitability were calculated monthly; besides, the community composition was characterized by means of rank-abundance models. A total of 74 species of aquatic coleopterans were identified. January and February resulted the months with the highest diversity. The aquatic Coleoptera species found in most of the sampled months were adjusted to the logarithmic rank-abundance model. The data suggests that, if it is properly managed, rice cropping in Northeastern Argentina can support a diverse aquatic coleopteran fauna.Original Abstract: Las plantaciones de arroz ocupan grandes areas en el NE argentino. Corrientes es una de las principales provincias productoras de este cereal y al ser un cultivo extensivo ocupa grandes areas, las cuales pasan a ser una parte caracteristica del paisaje. Los coleopteros acuaticos forman parte de la fauna que habita en estos ambientes artificiales y poco se sabe de la fauna que habita en ellos. Los objetivos de este estudio fueron determinar la diversidad y la riqueza de especies de coleopteros en un campo tipico de arroz, y caracterizar la comunidad de escarabajos de agua a traves de los diferentes modelos de abundancia. Para ello, se realizaron muestreos con una red entomologica de 30 cm de diametro en un campo de arroz ubicada en la localidad "El Sombrero", en la provincia de Corrientes. Las muestras fueron recolectadas entre noviembre 2011 y abril 2012. La riqueza de especies, diversidad y equitatividad para todos los meses muestreados fueron calculadas. La composicion de la comunidad se caracterizo por medio de modelos de ranking-abundancia. Se identificaron 74 especies de coleopteros acuaticos. Enero y febrero fueron los meses con mayor diversidad. Las especies de coleopteros acuaticos que se registraron en la mayoria de los meses muestreados se ajustaron al modelo logaritmico. Los datos sugieren que, si se gestiona adecuadamente, los cultivos de arroz en el noreste de Argentina pueden albergar una fauna diversa de coleopteros acuaticos.
Since its accidental introduction from Asia, emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), has killed millions of ash trees in North America. As it continues to ...spread, it could functionally extirpate ash with devastating economic and ecological impacts. Little was known about EAB when it was first discovered in North America in 2002, but substantial advances in understanding of EAB biology, ecology, and management have occurred since. Ash species indigenous to China are generally resistant to EAB and may eventually provide resistance genes for introgression into North American species. EAB is characterized by stratified dispersal resulting from natural and human-assisted spread, and substantial effort has been devoted to the development of survey methods. Early eradication efforts were abandoned largely because of the difficulty of detecting and delineating infestations. Current management is focused on biological control, insecticide protection of high-value trees, and integrated efforts to slow ash mortality.
Insects are considered a nutritionally valuable source of alternative proteins, and their efficient protein extraction is a prerequisite for large-scale use. The protein content is usually calculated ...from total nitrogen using the nitrogen-to-protein conversion factor (Kp) of 6.25. This factor overestimates the protein content, due to the presence of nonprotein nitrogen in insects. In this paper, a specific Kp of 4.76 ± 0.09 was calculated for larvae from Tenebrio molitor, Alphitobius diaperinus, and Hermetia illucens, using amino acid analysis. After protein extraction and purification, a Kp factor of 5.60 ± 0.39 was found for the larvae of three insect species studied. We propose to adopt these Kp values for determining protein content of insects to avoid overestimation of the protein content.
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•Elateroidea sensu lato are monophyletic and sister to byrrhoid lineages.•Elateroidea sensu stricto and cantharoid lineages are reciprocally paraphyletic.•Phengodidae, ...Rhagophthalmidae and Omalisidae are sister to Elateridae incl. Drilini.•The multiple origins of soft-bodiedness, neoteny and bioluminescence are re-enforced.•We find strong support for the Telegeusidae to be made a subfamily of the Omethidae.
Elateriformia consists of Dascilloidea, Buprestoidea (jewel beetles), Byrrhoidea and Elateroidea (click beetles, fireflies and relatives). Numerous elateroid lineages contain taxa with modified metamorphosis resulting in sexual maturity while retaining larval characters. Additionally, they evolved unique defensive strategies including clicking mechanism, aposematic coloration and bioluminescence. To investigate the phylogenetic position of Elateroidea within Coleoptera, we merged 1048 newly produced 18S rRNA, 28S rRNA, rrnL mtDNA, and cox1 mtDNA sequences for ∼300 elateriform taxa with data from GenBank. The 975-taxa dataset aligned in BlastAlign was analyzed under maximum likelihood criterion. The results agreed in most aspects with the current morphology-based classification and results of molecular studies. Elateriformia were monophyletic and Elateroidea were sister to Byrrhoidea. Further, we analyzed all-data (513 elateriform taxa) and pruned matrix (417 elateriform taxa, all fragments present) using parsimony and maximum likelihood methods to reveal the phylogenetic relationships among elateroid lineages and examine the evolution of soft-bodiedness, neoteny and bioluminescence. We confirmed the monophyly of Elateroidea sensu lato and most of the families, with Telegeusidae inferred in most trees within paraphyletic Omethidae. The clade Artematopodidae+Telegeusidae+Omethidae was a sister to remaining elateroids. All topologies reject the relationships of hard-bodied Elateridae, Eucnemidae, Throscidae and Cerophytidae, formerly supposed to be a monophylum. Eucnemidae and Throscidae formed independent lineages and the position of Cerophytidae was variable – either a sister to Throscidae, or an independent lineage. The Lampyridae+Cantharidae clade was in most trees sister to Phengodidae+Rhagophthalmidae+Omalisidae+Elateridae. Molecular phylogeny of Elateroidea confirmed the multiple origins of soft-bodied, neotenic and light emiting lineages. On the basis of our molecular phylogeny, we place former Telegeusidae as a subfamily in Omethidae.
•The Fusarium–Euwallacea ambrosia beetle mutualism evolved ∼20million years ago.•Fusaria and the Euwallacea ambrosia beetles that farm them are both monophyletic.•The mutualism was shaped more by ...multiple host shifts than diversifying coevolution.•Several exotic Fusarium–Euwallacea mutualists threaten avocado production worldwide.•Evidence exists consistent with hybrid introgression between Euwallacea species.
The mutualism between xyleborine beetles in the genus Euwallacea (Coleoptera: Curculionidae: Scolytinae) and members of the Ambrosia Fusarium Clade (AFC) represents one of 11 known evolutionary origins of fungiculture by ambrosia beetles. Female Euwallacea beetles transport fusarial symbionts in paired mandibular mycangia from their natal gallery to woody hosts where they are cultivated in galleries as a source of food. Native to Asia, several exotic Euwallacea species were introduced into the United States and Israel within the past two decades and they now threaten urban landscapes, forests and avocado production. To assess species limits and to date the evolutionary diversification of the mutualists, we reconstructed the evolutionary histories of key representatives of the Fusarium and Euwallacea clades using maximum parsimony and maximum likelihood methods. Twelve species-level lineages, termed AF 1–12, were identified within the monophyletic AFC and seven among the Fusarium-farming Euwallacea. Bayesian diversification-time estimates placed the origin of the Euwallacea–Fusarium mutualism near the Oligocene–Miocene boundary ∼19–24Mya. Most Euwallacea spp. appear to be associated with one species of Fusarium, but two species farmed two closely related fusaria. Euwallacea sp. #2 in Miami-Dade County, Florida cultivated Fusarium spp. AF-6 and AF-8 on avocado, and Euwallacea sp. #4 farmed Fusarium ambrosium AF-1 and Fusarium sp. AF-11 on Chinese tea in Sri Lanka. Cophylogenetic analyses indicated that the Euwallacea and Fusarium phylogenies were largely incongruent, apparently due to the beetles switching fusarial symbionts (i.e., host shifts) at least five times during the evolution of this mutualism. Three cospeciation events between Euwallacea and their AFC symbionts were detected, but randomization tests failed to reject the null hypothesis that the putative parallel cladogenesis is a stochastic pattern. Lastly, two collections of Euwallacea sp. #2 from Miami-Dade County, Florida shared an identical cytochrome oxidase subunit 1 (CO1) allele with Euwallacea validus, suggesting introgressive hybridization between these species and/or pseudogenous nature of this marker. Results of the present study highlight the importance of understanding the potential for and frequency of host-switching between Euwallacea and members of the AFC, and that these shifts may bring together more aggressive and virulent combinations of these invasive mutualists.
The tribe Coccinellini is a group of relatively large ladybird beetles that exhibits remarkable morphological and biological diversity. Many species are aphidophagous, feeding as larvae and adults on ...aphids, but some species also feed on other hemipterous insects (i.e., heteropterans, psyllids, whiteflies), beetle and moth larvae, pollen, fungal spores, and even plant tissue. Several species are biological control agents or widespread invasive species (e.g., Harmonia axyridis (Pallas)). Despite the ecological importance of this tribe, relatively little is known about the phylogenetic relationships within it. The generic concepts within the tribe Coccinellini are unstable and do not reflect a natural classification, being largely based on regional revisions. This impedes the phylogenetic study of important traits of Coccinellidae at a global scale (e.g. the evolution of food preferences and biogeography).
We present the most comprehensive phylogenetic analysis of Coccinellini to date, based on three nuclear and one mitochondrial gene sequences of 38 taxa, which represent all major Coccinellini lineages. The phylogenetic reconstruction supports the monophyly of Coccinellini and its sister group relationship to Chilocorini. Within Coccinellini, three major clades were recovered that do not correspond to any previously recognised divisions, questioning the traditional differentiation between Halyziini, Discotomini, Tytthaspidini, and Singhikaliini. Ancestral state reconstructions of food preferences and morphological characters support the idea of aphidophagy being the ancestral state in Coccinellini. This indicates a transition from putative obligate scale feeders, as seen in the closely related Chilocorini, to more agile general predators.
Our results suggest that the classification of Coccinellini has been misled by convergence in morphological traits. The evolutionary history of Coccinellini has been very dynamic in respect to changes in host preferences, involving multiple independent host switches from different insect orders to fungal spores and plants tissues. General predation on ephemeral aphids might have created an opportunity to easily adapt to mixed or specialised diets (e.g. obligate mycophagy, herbivory, predation on various hemipteroids or larvae of leaf beetles (Chrysomelidae)). The generally long-lived adults of Coccinellini can consume pollen and floral nectars, thereby surviving periods of low prey frequency. This capacity might have played a central role in the diversification history of Coccinellini.
Phosphine is the most widely used fumigant for stored grain insect pests, and resistance to phosphine has evolved in several species worldwide. This study was designed to determine the presence of ...phosphine resistance in 34 populations of Rhyzopertha dominica (F.) collected from the United States and Canada. Adult R. dominica were sampled and subjected to a discriminatory dose toxicity assay of exposure to 20 ppm of phosphine for 20 h of exposure to distinguish a susceptible R. dominica adult by death from a resistant beetle that survives the treatment. All but two of the 34 geographic populations surveyed had some beetles that were resistant to phosphine, and the frequency of resistance varied from 97% in a population from Parlier, California to 0% in beetles from both Carnduff, Saskatchewan and Starbuck, Manitoba. Probit analyses of dose-mortality bioassays with beetles from a laboratory-susceptible strain and those from five of the populations sampled were used to calculate resistance ratio factors (RRs) based on the ratio of LC50 (estimate for the concentration to kill 50% of a test group) in the sampled population to the LC50 for the susceptible strain.The highest RR for the five resistant populations was nearly 596-fold in beetles from Belle Glade, Florida, whereas the lowest RR in that group was 9-fold in Wamego, Kansas.This study revealed that phosphine resistance in R. dominica is common across North America and some populations have levels of resistance that may pose challenges for continued use of phosphine for their management.
Insects’ intestinal microbes have profound effects on the host's physiological traits, which can impact their physiology at both the local (gut) and systemic (body) levels. Nevertheless, the ...molecular mechanisms underlying host‐microbiota interactions, especially in non‐model insects, remain elusive. Recently, tissue‐specific transcriptomic analysis has been highlighted as a robust tool in studying host–microbe interactions. Plagiodera versicolora is a worldwide leaf‐eating pest that primarily feeds on willows and poplar. The interplay between gut microflora and this host beetle has yet to be studied. Herein, we investigate the effects of the gut microbiota on the body mass of P. versicolora larvae, compare the nutrition status of larvae in absence and presence of gut microbiota, and profile gut bacterial loads throughout its developmental larval stages. We then perform comparative transcriptomic analysis of gut and body tissues in axenic and non‐axenic larvae. Finally, we confirm the expression patterns of representative genes in nutritional metabolism and immunity. Results show that weight growth is retarded in conventional larvae, with a concomitant increase of total bacterial load by the 5th development day, and germ‐free larvae have a higher glucose content than conventional‐reared larvae. Both nutritional and immunological analyses indicate that gut bacteria are a burden in the beetle's larval development. These findings elucidate the impacts of gut microbiota on P. versicolora, and provide insight into tissue‐specific responses to gut microflora in this pest at the genetic level, boosting our understanding of the molecular mechanisms underlying host–microbe interactions in leaf beetles and beyond.
Weight growth is retarded in conventional larvae, with a concomitant increase of total bacterial load by the 5th development day, and germ‐free larvae have a higher glucose content than conventional‐reared larvae. Both nutritional and immunological analyses indicated that gut bacteria are a burden in the beetle's larval development.
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