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PloS One 2018The study of parasites in recently established populations of invasive species can shed light on the sources of invasion and possible indirect interactions between the...
Coinvasion by the ladybird Harmonia axyridis (Coleoptera: Coccinellidae) and its parasites, Hesperomyces virescens (Ascomycota: Laboulbeniales) and Parasitylenchus bifurcatus (Nematoda: Tylenchida, Allantonematidae), in the Caucasus.
The study of parasites in recently established populations of invasive species can shed light on the sources of invasion and possible indirect interactions between the alien species and native ones. We studied parasites of the global invader Harmonia axyridis (Coleoptera: Coccinellidae) in the Caucasus. In 2012, the first established population of Ha. axyridis was recorded in the Caucasus in Sochi (south of European Russia, Black Sea coast). By 2018, the ladybird had spread to a vast area: Armenia, Georgia and south Russia (Adygea, the Krasnodar territory, the Stavropol territory, Dagestan, Kabardino-Balkaria and North Ossetia). The examination of 213 adults collected in Sochi in 2018 showed that 53% were infested with Hesperomyces virescens fungi (Ascomycota: Laboulbeniales) and that 8% were infested with Parasitylenchus bifurcatus nematodes (Nematoda: Tylenchida, Allantonematidae). The examined Ha. axyridis specimens were free of the parasitic mite Coccipolipus hippodamiae. An analysis of the phylogenetic relationships of P. bifurcatus based on 18S rDNA confirmed the morphological identification of this species. Hesperomyces virescens and P. bifurcatus were first recorded in the Caucasus and Russia, although they are rather widespread in Europe. This likely indicates that they appeared as a result of coinvasion with their host because the populations of Ha. axyridis, He. virescens and P. bifurcatus in the Caucasus are isolated from the main parts of the ranges of these species in Europe. The nearest localities of Ha. axyridis is on another shore of the Black Sea, and the nearest localities of He. virescens and P. bifurcatus are more than 1000 km from the Caucasus. It is impossible to determine whether the first founders of the Caucasian population were infested with the parasites or whether the parasites were introduced by specimens of Ha. axyridis that arrived later from Europe. Harmonia axyridis was released in the region for pest control, but laboratory cultures are always free of He. virescens and P. bifurcatus. Therefore, the detection of He. virescens and P. bifurcatus indicates that the population of Ha. axyridis in the Caucasus could not have derived exclusively from released specimens. We did not find He. virescens on 400 specimens of 29 other ladybird species collected from the same localities as Ha. axyridis in the Caucasus. No reliable correlation between infestation by He. virescens and that by P. bifurcatus has been found. In addition to these two parasites, an unidentified species of the order Mermithida was recorded. This is the first documented case of Ha. axyridis infestation by a parasitic nematode of this order in nature.
Topics: Animals; Armenia; Ascomycota; Coleoptera; Georgia; Phylogeny; Russia; Tylenchida
PubMed: 30496181
DOI: 10.1371/journal.pone.0202841 -
PloS One 2023Bark beetle infestations have historically been primary drivers of stand thinning in Mexican pine forests. However, bark beetle impacts have become increasingly...
Abundance of Dendroctonus frontalis and D. mexicanus (Coleoptera: Scolytinae) along altitudinal transects in Mexico: Implications of climatic change for forest conservation.
Bark beetle infestations have historically been primary drivers of stand thinning in Mexican pine forests. However, bark beetle impacts have become increasingly extensive and intense, apparently associated with climate change. Our objective was to describe the possible association between abundance of bark beetle flying populations and the occurrence of given value intervals of temperature, precipitation and their balance, in order to have a better comprehension of the climatic space that might trigger larger insect abundances, an issue relevant in the context of the ongoing climatic change. Here, we monitored the abundance of two of the most important bark beetle species in Mexico, Dendroctonus frontalis and D. mexicanus. We sampled 147 sites using pheromone-baited funnel traps along 24 altitudinal transects in 11 Mexican states, from northwestern Chihuahua to southeastern Chiapas, from 2015 to 2017. Through mixed model analysis, we found that the optimum Mean Annual Temperatures were 17°C-20°C for D. frontalis in low-elevation pine-oak forest, while D. mexicanus had two optimal intervals: 11-13°C and 15-18°C. Higher atmospheric Vapor Pressure Deficit (≥ 1.0) was correlated with higher D. frontalis abundances, indicating that warming-amplified drought stress intensifies trees' vulnerability to beetle attack. As temperatures and drought stress increase further with projected future climatic changes, it is likely that these Dendroctonus species will increase tree damage at higher elevations. Pine forests in Mexico are an important source of livelihood for communities inhabiting those areas, so providing tools to tackle obstacles to forest growth and health posed by changing climate is imperative.
Topics: Animals; Coleoptera; Mexico; Conservation of Natural Resources; Weevils; Forests; Pinus; Trees
PubMed: 37405993
DOI: 10.1371/journal.pone.0288067 -
Zootaxa Nov 2021The monotypic genus Pagelmis Spangler, 1981 was described from six thousand specimens of Pagelmis amazonica Spangler, 1981 collected with blacklight traps in Ecuador....
The monotypic genus Pagelmis Spangler, 1981 was described from six thousand specimens of Pagelmis amazonica Spangler, 1981 collected with blacklight traps in Ecuador. For many years the known distribution of this genus was restricted to its type-locality, and recently it was recorded in Venezuela, Suriname and Brazil (Roraima State). Now, 40 years after the description of the genus, we describe the second Pagelmis species, based on male and female collected in the Amazon forest (Amazonas State, Brazil). With the description of the second species in the genus we provide an emended diagnosis of Pagelmis. Since adults of this genus were previously collected only in light traps, no habitat information was known. We collected adults of the new species in the first- and second-order streams with black, acidic water and sandy streambeds. The main substrates available in these streams were leaves and roots of riparian vegetation.
Topics: Animals; Brazil; Coleoptera; Female; Male
PubMed: 34810621
DOI: 10.11646/zootaxa.5061.2.9 -
BMC Genomics Apr 2021The lack of an understanding about the genomic architecture underpinning parental behaviour in subsocial insects displaying simple parental behaviours prevents the...
BACKGROUND
The lack of an understanding about the genomic architecture underpinning parental behaviour in subsocial insects displaying simple parental behaviours prevents the development of a full understanding about the evolutionary origin of sociality. Lethrus apterus is one of the few insect species that has biparental care. Division of labour can be observed between parents during the reproductive period in order to provide food and protection for their offspring.
RESULTS
Here, we report the draft genome of L. apterus, the first genome in the family Geotrupidae. The final assembly consisted of 286.93 Mbp in 66,933 scaffolds. Completeness analysis found the assembly contained 93.5% of the Endopterygota core BUSCO gene set. Ab initio gene prediction resulted in 25,385 coding genes, whereas homology-based analyses predicted 22,551 protein coding genes. After merging, 20,734 were found during functional annotation. Compared to other publicly available beetle genomes, 23,528 genes among the predicted genes were assigned to orthogroups of which 1664 were in species-specific groups. Additionally, reproduction related genes were found among the predicted genes based on which a reduction in the number of odorant- and pheromone-binding proteins was detected.
CONCLUSIONS
These genes can be used in further comparative and functional genomic researches which can advance our understanding of the genetic basis and hence the evolution of parental behaviour.
Topics: Animals; Coleoptera; Genome, Insect; Genomics; Reproduction; Social Behavior
PubMed: 33902445
DOI: 10.1186/s12864-021-07627-w -
Pakistan Journal of Biological Sciences... Jan 2021<b>Background and Objective:</b> Control of the stored date insects by an eco-friendly method is essential to maintain the fruit for prolonged periods,...
<b>Background and Objective:</b> Control of the stored date insects by an eco-friendly method is essential to maintain the fruit for prolonged periods, especially that dates are eaten fresh. The search for a safe method, as an alternative to commonly used chemical pesticides, is needed. The objective is to investigate CO<sub>2</sub> enriched atmosphere on the Mortality Percentage (MP) of the Saw-toothed grain beetle, <i>O. surinamensis</i>, life stages with special emphasis on reducing damage to stored dates. <b>Materials and Methods:</b> The effect of high levels of CO<sub>2</sub> as an alternative control method against the Saw-toothed grain beetle, <i>Oryzaephilus surinamensis</i> L., at different life stages was studied on infested 'Saqie' dates. Four CO<sub>2</sub> pressures (25, 50, 75 and 90 kPa, balance is nitrogen) were tested for 6, 12, 18, 24, 48, 72 and 96 hrs intervals. The response of different life stages of <i>O. surinamensis</i> to the different treatments varied according to CO<sub>2</sub> level, developmental stage and exposure period. <b>Results:</b> Mortality (%) was higher during the larval stage, followed by adults, pupae and eggs, in descending order. The larvae and adult stages were more sensitive to CO<sub>2</sub> treatment than the pupal and egg. Exposure time was more effective on eggs, larval and adult MP than the CO<sub>2</sub> atmosphere level. Mortality% at 96 hrs exposure time was almost 100% with CO<sub>2</sub> atmospheres of 50, 75 and 90 kPa. Mathematical equations were developed to model the relationship between mortality% and CO<sub>2</sub> treatments using multiple regression analyses for each life stage. <b>Conclusion:</b> The results confirmed that CO<sub>2</sub> could be applied to final food products during packaging to control the residual occurrence of insect pests after storage and before the packaging process to prevent further infestation in the final packages.
Topics: Animals; Carbon Dioxide; Coleoptera; Food Packaging; Food Parasitology; Food Storage; Fruit; Insecticides; Life Cycle Stages; Phoeniceae
PubMed: 34486345
DOI: 10.3923/pjbs.2021.688.698 -
Bulletin of Entomological Research Feb 2020The Chinese white pine beetle Dendroctonus armandi (Coleoptera: Scolytinae) typically displays bivoltinism at altitudes below 1700 m in the Qinling Mountains, China. The...
The Chinese white pine beetle Dendroctonus armandi (Coleoptera: Scolytinae) typically displays bivoltinism at altitudes below 1700 m in the Qinling Mountains, China. The periods of host colonization and larval overwintering are two important phases in the life cycle of bark beetles, as it is during these periods that they have to contend with host plant defences and periods of intense cold, respectively. Although during different seasons, the females and males of Chinese white pine beetles show varying tolerances to host plant terpenoids, the sex ratio and survival physiology condition of the two beetle generations are unknown. We investigated the sex ratio of individuals, and also examined the body mass, energy stores, and detoxication enzymes of males and females in each of the two generations in order to determine the overall population stability of each generation. We identified a female-biased sex ratio among adults in both generations. Furthermore, patterns of body mass, energy stores, and detoxication enzymes were found to differ between the two sexes and two seasons. Compared with the males, the females have a larger body mass and higher amounts of stored lipids, which are assumed to be adaptations designed to overcome host resistance and facilitate subsequent oviposition.
Topics: Animals; Coleoptera; Cytochrome P-450 Enzyme System; Energy Metabolism; Female; Male; Seasons; Sex Ratio
PubMed: 31138336
DOI: 10.1017/S0007485319000361 -
Journal of Economic Entomology Mar 2019Regeneration of limbs lost during development has been recorded in a large number of species of hexapoda including many Coccinellids. Although regeneration has obvious...
Limb Regeneration and Interference Competition Consequences on Foraging Efficiency of Coccinella undecimpunctata and Hippodamia variegata (Coccinellidae: Coleoptera) to Their Prey, Aphis craccivora (Hemiptera: Aphididae).
Regeneration of limbs lost during development has been recorded in a large number of species of hexapoda including many Coccinellids. Although regeneration has obvious survival and fitness benefits, it has also been demonstrated to impose costs on development, reproduction, and behavior. To investigate consequences of regeneration on foraging behavior, Coccinella undecimpunctata L. and Hippodamia variegata (Goeze) larvae were treated to remove one limb, allowed to pupate and regenerate and then prey searching ability assessed. Different densities of adults were placed in Petri dishes with aphid prey and consumption assessed over a 24-h period. Amputation/regeneration, predator species, and predator density significantly affected the total number of aphids consumed. Aphid consumption rates and predation efficiency of both regenerated and control beetles significantly increased as predator density increased. Although there were significant differences in consumption between ablated/regenerated and control C. undecimpunctata at each predator densities, H. variegata did not. Further, mutual interference was significantly higher for regenerated compared with control C. undecimpunctata but not so for H. variegata. This is the first demonstration of an effect of ablation/regeneration on foraging behavior of C. undecimpunctata and suggests that H. variegata demonstrates an adaptive phenotypic response to limb regeneration. Coccinellids are widely used as biological agents and these findings concerning the impact of variation in predator density have clear implications for the management of predator-prey ratios in order to maximize efficiency of pest consumption.
Topics: Animals; Aphids; Coleoptera; Larva; Predatory Behavior; Regeneration
PubMed: 30668738
DOI: 10.1093/jee/toy421 -
Genomics Sep 2020In this study, we sequenced the mitochondrial (mt) genome of Agrilus mali (Coleoptera: Buprestidae) using next-generation sequencing, and accordingly annotated 13...
In this study, we sequenced the mitochondrial (mt) genome of Agrilus mali (Coleoptera: Buprestidae) using next-generation sequencing, and accordingly annotated 13 protein-coding, 22 tRNA, and 2 rRNA genes and a 1458-bp non-coding region. Comparative analysis indicated that the mt genome of A. mali is relatively conserved, with a typical gene content and order identical to those of other coleopterans. However, the newly sequenced mt genome is characterized by a relatively higher A + T content compared with that of other species within the family Buprestidae. Phylogenetic analysis based on Bayesian inference revealed that the evolutionary relationship among the six infraorders of the suborder Polyphaga is (Scirtiformia + (Elateriformia + ((Scarabaeiformia + Staphyliniformia) + (Bostrichiformia + (Cucujiformia))))). However, the topology indicated that the family Buprestidae is a sister group to other Polyphaga infraorders, excluding Scirtiformia as a monophyly, and thus the monophyly of Elateriformia was not supported. This study not only presents the mt genome of a species in the family Buprestidae and a comparative analysis of jewel beetles but also examines the contribution of mt genomes in elucidating phylogenetic relationships within the suborder Polyphaga of Coleoptera.
Topics: Animals; Coleoptera; Genome, Mitochondrial; Phylogeny
PubMed: 32360911
DOI: 10.1016/j.ygeno.2020.04.026 -
Genes Oct 2019Gene expression profiles can change dramatically between sexes and sex bias may contribute specific macroevolutionary dynamics for sex-biased genes. However, these...
Gene expression profiles can change dramatically between sexes and sex bias may contribute specific macroevolutionary dynamics for sex-biased genes. However, these dynamics are poorly understood at large evolutionary scales due to the paucity of studies that have assessed orthology and functional homology for sex-biased genes and the pleiotropic effects possibly constraining their evolutionary potential. Here, we explore the correlation of sex-biased expression with macroevolutionary processes that are associated with sex-biased genes, including duplications and accelerated evolutionary rates. Specifically, we examined these traits in a group of 44 genes that orchestrate sperm individualization during spermatogenesis, with both unbiased and sex-biased expression. We studied these genes in the broad evolutionary framework of the Insecta, with a particular focus on beetles (order Coleoptera). We studied data mined from 119 insect genomes, including 6 beetle models, and from 19 additional beetle transcriptomes. For the subset of physically and/or genetically interacting proteins, we also analyzed how their network structure may condition the mode of gene evolution. The collection of genes was highly heterogeneous in duplication status, evolutionary rates, and rate stability, but there was statistical evidence for sex bias correlated with faster evolutionary rates, consistent with theoretical predictions. Faster rates were also correlated with clocklike (insect amino acids) and non-clocklike (beetle nucleotides) substitution patterns in these genes. Statistical associations (higher rates for central nodes) or lack thereof (centrality of duplicated genes) were in contrast to some current evolutionary hypotheses, highlighting the need for more research on these topics.
Topics: Animals; Coleoptera; Databases, Genetic; Evolution, Molecular; Gene Regulatory Networks; Genes, Insect; Insecta; Male; Phylogeny; Sex Characteristics; Spermatogenesis; Spermatozoa; Transcriptome
PubMed: 31590243
DOI: 10.3390/genes10100776 -
PloS One 2019We studied the saproxylic beetle community inhabiting deadwood in remnants of riparian cloud forests in "La Antigua" basin, in central Veracruz (Mexico). We assessed the...
We studied the saproxylic beetle community inhabiting deadwood in remnants of riparian cloud forests in "La Antigua" basin, in central Veracruz (Mexico). We assessed the influence of deadwood features (tree species, trunk position, trunk diameter, trunk volume and decomposition stages) on saproxylic beetle diversity. In order to assess the stability of beetle species-deadwood interactions, we also analyzed the ecological networks structure. A total of 63 deadwood trunks, belonging to four tree species, were sampled by standardized hand-collection throughout well-preserved remnants of riparian cloud forest. We found that tree species and deadwood decay stage are the main drivers that determine the diversity and stability of saproxylic beetle species interactions. Our results indicate that Quercus corrugata is the main tree species in terms of maintaining the significantly highest saproxylic beetle diversity, but with no stable interactions (saproxylic beetle-deadwood). A nested network structure was detected for Clethra mexicana and Liquidambar styraciflua, with a pool of core (generalist) saproxylic beetle species. We observed that beetle diversity from the early and late deadwood stages comprises distinct assemblages and the four stages of decomposition showed a nested network structure. During deadwood succession, community composition and guilds changed among networks; the early successional stage had more specialized xylophagous beetles, while other guilds (mycophagous, saprophagous and zoophagous) arrive later and become the core species in the advanced stages of decomposition networks. Heliscus tropicus (Passalidae) is a key species constituting the core of all of the networks and could be considered an ecosystem engineer in cloud forests. By exploring links between saproxylic beetles and deadwood characteristics, we can further our understanding of species interaction in order to develop management strategies oriented towards the protection of species and their habitats in this threatened ecosystem.
Topics: Animals; Biodiversity; Coleoptera; Forests; Mexico; Trees
PubMed: 30978221
DOI: 10.1371/journal.pone.0214920