Different Groups Of Insects Research Articles

Extremely small wasps independently lost the nuclei in the brain neurons of at least two lineages

Anucleate animal cells are a peculiar evolutionary phenomenon and a useful model for studying cellular mechanisms. Anucleate neurons were recently found in one genus of miniature parasitic wasps of the family Trichogrammatidae, but it remained unclear how widespread this phenomenon is among other insects or even among different tissues of the same insect species. We studied the anatomy of miniature representatives of another parasitic wasp family (Hymenoptera: Mymaridae) using array tomography and found two more species with nearly anucleate brains at the adult stage. Thus, the lysis of the cell bodies and nuclei of neurons appears to be a more widespread means of saving space during extreme miniaturization, which independently evolved at least twice during miniaturization in different groups of insects. These results are important for understanding the evolution of the brain during miniaturization and open new areas of studying the functioning of anucleate neurons.

Forensic entomology: A novel approach in crime investigation

Forensic entomology is an application of studies related to insects and other arthropods in legal matters. Depth knowledge and experience of the biodiversity, biology, ecology, and behavior of forensic insects found on a human corpse or at a crime site, can provide information about time since death, location of the crime, and in some cases cause of death. Although forensic insects are used in crime investigation for three to four decades, it aroused recently as a very popular and independent branch of forensic science in crime investigation. While observing and examining insects on a corpse, knowledge of regional insects’ assemblages and their population dynamics play an important role in medico-legal entomology for an efficient criminal investigation. Forensic entomology has three components, named as urban, stored products, and medico-legal. As different groups of insects are attracted to different stages of decay, forensic insects invade the corpse in a typical sequence. The type of insects’ colonization found on corpses provides important information about the decomposition stage. Calliphoridae provides valuable evidences, particularly in determining time since death in criminal matters, where the time since death is prolonged and use of other conventional methods for estimation of time since death is limited. Two well-established ways used for estimation of post mortem interval are based on maggot’s development and succession waves of entomofauna. The latest scientific and technological developments in the field, such as its combined approach with forensic toxicology, forensic palynology, DNA based molecular identification of insect species, and other various methods to estimate post mortem interval, are many emerging fields under this periphery and forensic entomology lately became very popular among criminal investigators and forensic entomologists.

Disentangling the Benefits of Organic Farming for Beetle Communities (Insecta: Coleoptera) in Traditional Fruit Orchards

The conversion of traditional land-use systems into more intensive agriculture forms plays a main role in biodiversity loss. Within this framework, organic management has received widespread attention since it is assumed to enhance multiple taxa, including different groups of insects and plants. However, its contribution to the promotion of organism diversity is still controversial. We developed a study in traditional cherry orchards from the Jerte Valley (western Spain) to examine how coleopteran and plant assemblages are driven by farming system (organic vs. conventional), topographic features, and seasonality. The coleopteran community was examined on the basis of its taxonomic and trophic guild response. Organic orchards supported a higher number of beetle families and a greater plant species richness. Additionally, beetle and plant communities were highly correlated; conventional orchards were more homogeneous in terms of both plant and beetle composition, while organic orchards were more heterogeneous, their composition being also shaped by the hillside aspect. From a more functional approach, the different coleopteran trophic guilds exhibited varying responses to the factors analyzed. The benefits of organic farming were notable even when working in traditional systems: highly valuable habitats for overall biodiversity. Therefore, we highlight the potential of organic orchards for conservation purposes.

A Robinson Crusoe story in the fossil record: Plant-insect interactions from a Middle Jurassic ephemeral volcanic island (Eastern Spain)

We present here the first record of plant-insect interactions from an ephemeral volcanic island that was placed 150 km away from the nearest continental mass. The island was formed and destroyed during the Aalenian (Middle Jurassic) in a shallow sea of the southwestern Tethyan realm corresponding today to a place located in eastern Spain. These plant-insect interactions were mainly documented in leaves of Cycadophytes (comprising both Cycads and Bennettitales), and they have been described and classified into different Damage Types (DTs) and Functional Feeding Groups (FFGs). The interactions were assigned to 11 different DTs including different types of hole feeding, margin feeding, surface feeding, piercing and sucking, mining(?), and some putative ovipositional scars. The presence of these interactions implies that the island was colonized by different groups of insects, including orders such as Coleoptera, Hemiptera, Odonata, or Lepidoptera. The low variety and incidence of interactions comparing with other Middle Jurassic plant-insect interactions assemblages indicate that the diversity of insects was not high, possibly due to the difficulty of reaching this island by various lineages, the small size of the landmass of the island, and the limited food availability (mainly Cycadophytes). Possible colonization strategies could be by atmospheric dispersion, using floating remains of plants or pterosaurs as vectors, by active flight for Lepidoptera, or by rafting and floating in marine currents for flightless or other insects. • First study of plant-insect interactions from the Jurassic of the Iberian Peninsula. • Comparison with other mid-Jurassic plant-insect interactions. • Identification of possible culprits for the different damages. • Discussion on colonization strategies by insects during the Jurassic.

The Chrysidoidea Wasps (Hymenoptera, Aculeata) in Conventional Coffee Crops and Agroforestry Systems in Southeastern Brazil

Agroforestry systems represent the integration of agricultural crops with native vegetation. These systems are of great importance to minimize the agricultural impact in the land through intercropping of these vegetations. Despite of the importance of Chrysidoidea as parasitoids wasps associated with different groups of insects, there is no study comparing the assemblages of these hymenopterans in conventional and agroforestry systems in Brazil. The “Pontal do Paranapanema”, located in the extreme west of the state of São Paulo (Brazil), has historically been occupied by coffee crops and some small areas of agroforestry systems. Therefore, this study aimed to verify the abundance and composition of Chrysidoidea wasp fauna in different conventional coffee crops and agroforestry systems located in this region. To do so, we collected in six different localities in the “Pontal do Paranapanema” using a Malaise trap in each locality with collections occurring monthly between June 2011 and July 2012. A total of 3,623 Chrysidoidea specimens of three families were collected: Bethylidae, with four genera and a total of 3,396 individuals, representing 93.73% of the total collected; Chrysididae with 11 genera and 151 individuals (4.16%), and Dryinidae with five genera and 76 individuals (2.09%). In terms of abundance, the agroforestry was responsible for most of the individuals collected (n = 2029), followed by the conventional systems with 1,406 individuals and the transitional with 188. The most abundant genera were Epyris and Dissomphalus, responsible for about 92% of the total of Chrysidoidea collected. Most of the genera of Chrysididae were collected in the conventional systems alone or in both conventional and agroforestry systems. For Bethylidae and Dryinidae, no genera were found exclusively in the conventional system. It is expected that the structural complexity of each one of the different ecosystems impact directly in the fauna of Chrysidoidea parasitoids associated.

Differential effects of fertilisers on pollination and parasitoid interaction networks

Grassland fertilisation drives non-random plant loss resulting in areas dominated by perennial grass species. How these changes cascade through linked trophic levels, however, is not well understood. We studied how grassland fertilisation propagates change through the plant assemblage into the plant-flower-visitor, plant-leaf miner and leaf miner-parasitoid networks using a year's data collection from a long-term grassland fertiliser application experiment. Our experiment had three fertiliser treatments each applied to replicate plots 15m2 in size: mineral fertiliser, farmyard manure, and mineral fertiliser and farmyard manure combined, along with a control of no fertiliser. The combined treatment had the most significant impact, and both plant species richness and floral abundance decreased with the addition of fertiliser. While insect species richness was unaffected by fertiliser treatment, fertilised plots had a significantly higher abundance of leaf miners and parasitoids and a significantly lower abundance of bumblebees. The plant-flower-visitor and plant-herbivore networks showed higher values of vulnerability and lower modularity with fertiliser addition, while leaf miner-parasitoid networks showed a rise in generality. The different groups of insects were impacted by fertilisers to varying degrees: while the effect on abundance was the highest for leaf miners, the vulnerability and modularity of flower-visitor networks was the most affected. The impact on the abundance of leaf miners was positive and three times higher than the impact on parasitoids, and the impact on bumblebee abundance was negative and double the magnitude of impact on flower abundance. Overall, our results show that while insect species richness was unaffected by fertilisers, network structure changed significantly as the replacement of forbs by grasses resulted in changes in relative abundance across trophic levels, with the direction of change depending on the type of network. Synthesis. By studying multiple networks simultaneously, we were able to rank the relative impact of habitat change on the different groups of species within the community. This provided a more holistic picture of the impact of agricultural intensification and provides useful information when deciding on priorities for mitigation.

Visual and olfactory cues for mate recognition in male pumpkin beetle, Aulacophora foveicollis

Visual and olfactory mediated cues play a major role in mate selection in different groups of insects. This study aimed to observe if there is any role of mate color (under different wavelengths) and/or cuticular hydrocarbons in mate selection of Aulacophora foveicollis. In this study, visual cues and olfactory cues showed a vital role for male A. foveicollis to find mates. Males preferred (81%) orange (similar body colour) coloured glass model than white (52%) and black (49%) under the visible spectrum; whereas under the UV spectrum white coloured model was more preferred (77%) than orange (60%) and black (48%) coloured. In contrast, unresponsive males were very high though white coloured model was still preferred (36.67%) than orange (24.44%) or black (22.22%) coloured under IR spectrum. It was also observed that body surface waxes can play alone an olfactory cue for male mate selection (attraction was 67%) from short distance. Under the visual spectrum, when both visual and olfactory cues were presented, attraction of males toward all orange (93%), white (74%), and black (71%) coloured glass bead model increased. Even under UV and IR spectra attraction increased when body surface extract of female was applied on the glass models though the preference was more towards white coloured model than orange as previous. Male A. foveicollis showed less preference towards black colour. These works provide evidence that both visuals and olfactory cues can act separately as well as synergistically to find mates for male insects. These findings will be helpful for sustainable pest management program.

Diversity of Insect Sesquiterpenoid Regulation.

Insects are arguably the most successful group of animals in the world in terms of both species numbers and diverse habitats. The sesquiterpenoids juvenile hormone, methyl farnesoate, and farnesoic acid are well known to regulate metamorphosis, reproduction, sexual dimorphism, eusociality, and defense in insects. Nevertheless, different insects have evolved with different sesquiterpenoid biosynthetic pathway as well as products. On the other hand, non-coding RNAs such as microRNAs have been implicated in regulation of many important biological processes, and have recently been explored in the regulation of sesquiterpenoid production. In this review, we summarize the latest findings on the diversity of sesquiterpenoids reported in different groups of insects, as well as the recent advancements in the understanding of regulation of sesquiterpenoid production by microRNAs.

Taxonomic contribution on the Andean species of Aegognathus (Coleoptera: Lucanidae) with two new species from Colombia and Peru

ABSTRACTThe Andes represent one of the most important eco-regions of the world, fostering an enormous number of taxa associated with different altitudinal gradients. In the past two decades, there has been an increase in the description of different groups of insects, as in the case of the Lucanidae whose number of described species significantly rose in countries such as Peru and Bolivia. Aegognathus, a genus described originally from Peru, gained four new species during the last decade. Since then, the genus has not received proper taxonomic treatment, lacking updated information such as the actual distribution of some species, genitalic descriptions, female descriptions and identification keys. This paper aims to offer new taxonomic knowledge for the Andean species of Aegognathus, with a redescription of the type species, A. waterhousei Leuthner, the description of two new species and an identification key for the Andean taxa, as well as, the discussion of some possible implications in future conservation studies related to the distribution data of the studied taxa.http://www.zoobank.org/urn:lsid:zoobank.org:pub:D7A3FB96-F47D-4420-97BB-FFC399649564

The Fixator-A simple method for mounting of arthropod specimens and photography of complex structures in liquid.

Mounting and preparing arthropods in liquids for photography and further investigations is a challenging task and may lead to unsatisfactory results and, in the worst case, to damage to specimens. A new method is presented here, which allows the fixation of specimens of different sizes under various degrees of pressure. The method is illustrated by three case studies from different groups of insects and arachnids.

Consistent Associations between Body Size and Hidden Contrasting Color Signals across a Range of Insect Taxa.

While there have been a number of recent advances in our understanding of the evolution of animal color patterns, much of this work has focused on color patterns that are constantly displayed. However, some animals hide functional color signals and display them only transiently through behavioral displays. These displays are widely employed as a secondary defense following detection when fleeing (flash display) or when stationary (deimatic display). Yet if displays of hidden colors are so effective in deterring predation, why have not all species evolved them? An earlier study suggested that the hidden antipredatory color signals in insects are more likely to have evolved in species with large size because either (or both) (i) large cryptic prey are more frequently detected and pursued or (ii) hidden color signals in large prey are more effective in deterring predation than in small prey. These arguments should apply universally to any prey that use hidden signals, so the association between large size and hidden contrasting color signals should be evident across diverse groups of prey. In this study, we tested this prediction in five different groups of insects. Using phylogenetically controlled analysis to elucidate the relationship between body size and color contrast between forewings and hind wings, we found evidence for the predicted size-color contrast associations in four different groups of insects, namely, Orthoptera, Phasmatidae, Mantidae, and Saturniidae, but not in Sphingidae. Collectively, our study indicates that body size plays an important role in explaining variation in the evolution of hidden contrasting color signals in insects.

Local Insect Damage Reduces Fluctuating Asymmetry in Next-year’s Leaves of Downy Birch

Insect herbivory imposes stress on host plants. This stress may cause an increase in leaf fluctuating asymmetry (FA), which is defined as the magnitude of the random deviations from a symmetrical leaf shape. We tested the hypothesis that differences in leaf FA among individual shoots of downy birch, Betula pubescens, are at least partly explained by local damage caused by insects in the previous year. Unexpectedly, we found that in the year following the damage imposed by miners, leafrollers and defoliators, damaged birch shoots produced leaves with lower FAs compared to shoots from the same tree that had not been damaged by insects. This effect was consistent among the different groups of insects investigated, but intra-species comparisons showed that statistical significance was reached only in shoots that had been damaged by the birch leaf roller, Deporaus betulae. The detected decrease in leaf FA in the year following the damage agrees with the increases in shoot performance and in antiherbivore defence. The present results indicate that within-plant variation in leaf FA may have its origin in previous-year damage by insects, and that FA may influence the current-year’s distribution of herbivory.

Extraction of chitin from six different insect species as alternative source for biological applications

Chitosan, the most dominant and abundant polymer in scientific researches with its wide range biopharmaceutical and biomedical applications is now extracted from different interesting resources in large and valuable quantities. Six different groups of insects were used in this study. These were Ground dark beetle, Solitary (Carpenter) bee, Damsel fly, Earwig, Black bug and Egyptian grasshopper. These insect species showed easy capturing and preparation through deproteinization, demineralization and dehydration. By using Infrared spectrophotometry technology and calculating the degree of deacetylation, the potential effect of these insects can be insured as alternative source for chitin extraction and chitosan industrial applications.

From an old sound recording to a new species in the genus Horatosphaga (Orthoptera: Tettigonioidea: Phaneropterinae: Acrometopini)

Among insects, Orthoptera are a group famous for communicating by sound. This is especially true for bush-crickets (or katydids; Tettigonioidea). All acoustically active species produce sound by rubbing the fore wings (tegmina) against each other, using a stridulatory file situated on the lower side of the left tegmen and a scraper formed by the inner edge of the right tegmen (see e.g., Ragge & Reynolds 1998). Bush-cricket species of the tribe Acrometopini often have complicated stridulatory files and also complex songs, as shown in a recent study (Hemp et al. 2017). During the preparation of that paper we discovered a sound record of a species of the group taken on 16th March 1972 by the entomologist David Hollis in Angola as part of the multi-disciplinary entomological South Western Africa Expedition (for more details see Lane et al. 2011, Pethers 2016). Hollis (principally a hemipterist) published several papers on different groups of insects (see http://bionames.org/authors/David%20Hollis; incomplete), including Orthoptera (see Ingrisch & Willemse 2004). The sound recording was deposited in the British Museum (Natural History) Library of Recorded Insect Sounds, and was later made openly accessible in the BioAcoustica repository (Baker et al. 2015). Hollis had found the animal at light, recorded it on the same day singing on a bush, and brought the specimen (together with two conspecific males) to the Natural History Museum (NHM), London. Here it was later identified as Horatosphaga ?stuhlmanni (Karsch 1896) by D. Ragge, the curator of Orthoptera at the NHM at that time. Under this name (Horatosphaga ?stuhlmanni) the song was described in Hemp et al. 2017. Horatosphaga males are fully winged while females are flightless and plump; sexual dimorphism reaches its extreme form in this group of species. Species of this genus are mostly recorded from open grasslands in savanna habitats up to montane elevations (e.g. H. heteromorpha, Hemp 2013).

The mitochondrial gene order and CYTB gene evolution in insects

Over millions of years of evolution, the genomes of modern insects have accumulated a significant number of mutations, which often can lead up a blind alley when carrying out phylogenetic research. Genomic differences between some representatives belonging to the same family or group are often so great that they demand using nonconventional methods of the phylogenetic analysis. It is known that molecular evolution goes by the way of not only single nucleotide substitutions, but also by larger genomic reorganizations, such as insertion or deletion of large genome fragments, and even changing the order of genes. Mitochondrial DNA genes (mtDNA) are quite often used as markers for phylogenetic research into many organisms including arthropods, because mtDNA is multicopied, is inherited maternally, does not undergo recombination and accumulates mutations quickly enough (relative to the nuclear genome). To date, a large number of full nucleotide sequences of mitogenomes (thousands of organisms) has been deposited in public databases; however, their phylogenetic analysis has obstacles, especially for representatives of the insects (Insecta), whose evolution takes a considerable part of geological time. In this work we describe the application and a comparison of two ways of the phylogenetic analysis for different groups of insects. The first method uses the variability of the nucleotide sequence of mtDNA, and the second one analyses the order of genes in full mitochondrial genomes of insects that can be used as an additional marker in phylogenetic research into representatives of the order Hymenoptera.

Transovarial Transmission of Symbionts in Insects.

Many insects, on account of their unbalanced diet, live in obligate symbiotic associations with microorganisms (bacteria or yeast-like symbionts), which provide them with substances missing in the food they consume. In the body of host insect, symbiotic microorganisms may occur intracellularly (e.g., in specialized cells of mesodermal origin termed bacteriocytes, in fat body cells, in midgut epithelium) or extracellularly (e.g., in hemolymph, in midgut lumen). As a rule, symbionts are vertically transmitted to the next generation. In most insects, symbiotic microorganisms are transferred from mother to offspring transovarially within female germ cells. The results of numerous ultrastructural and molecular studies on symbiotic systems in different groups of insects have shown that they have a large diversity of symbiotic microorganisms and different strategies of their transmission from one generation to the next. This chapter reviews the modes of transovarial transmission of symbionts between generations in insects.

Analysis of the karyotype structure in Ricolla quadrispinosa (Linneus, 1767): inferences about the chromosomal evolution of the tribes of Harpactorinae (Heteroptera, Reduviidae).

The subfamily Harpactorinae is composed of six tribes. Phylogenetic studies bring together some of Harpactorinae tribes, but by and large the data on evolutionary relationships of the subfamily are scarce. Chromosome studies are of great importance for understanding the systematics of different groups of insects. For Harpactorinae, these studies are restricted to some subfamilies and involved only conventional chromosome analysis. This work analyzed cytogenetically Ricolla quadrispinosa (Linneus, 1767). The chromosome number was determined as 2n = 24 + X1X2Y in males. In metaphase II the autosomal chromosomes were organized in a ring with the pseudo-trivalent of sex chromosomes in its center. After C-banding followed by staining with DAPI, AT-rich blocks in autosomes were observed and the negatively heteropycnotic sex chromosomes. The data obtained, together with existing data for other species of the group, indicated that different chromosomal rearrangements are involved in the evolution of the species. In addition, a proposal of karyotype evolution for the subfamily, based on existing phylogenetic studies for the group is presented.

Temporal and interspecific variation in rates of spread for insect species invading Europe during the last 200 years

Globalization is triggering an increase in the establishment of alien insects in Europe, with several species having substantial ecological and economic impacts. We investigated long-term changes in rates of species spread following establishment. We used the total area of countries invaded by 1171 insect species for which the date of first record in Europe is known, to estimate their current range radius (calculated as [invaded area]0.5/π). We estimated initial rates of radial spread and compared them among different groups of insects for all years (1800–2014) and for a subset of more recent decades (1950–2014). Accidentally introduced species spread faster than intentionally introduced species. Considering the whole period 1800–2014, spread patterns also differ between feeding guilds, with decreasing spread rates over residence time in herbivores but not in detritivores or parasitic species. These decreases for herbivorous species appeared mainly in those associated with herbaceous plants and crops rather than woody plants. Initial spread rate was significantly greater for species detected after 1990, roughly 3–4 times higher than for species that arrived earlier. We hypothesize that the political changes in Europe following the collapse of the Iron Curtain in 1989, and the further dismantling of customs checkpoints within an enlarged European Union (EU) have facilitated the faster spread of alien insect species. Also, the number of species first recorded in the Eastern Bloc of the politically-divided Europe before 1989 was lower than for the rest of Europe. A detailed analysis of six recent invaders indicated a dominant role of long-distance translocations related to human activities, especially with the plant trade, in determining rates of spread.

Structure of Nests and Colony Sizes of the European Hornet (Vespa crabro) and Saxon wasp (Dolichovespula saxonica) (Hymenoptera: Vespinae) in Urban Conditions

Studies of different groups of insects in urban areas sometimes show large populations, greater than in non-urban areas. The reason for this is a presence in the cities some of dominating species which often occur almost en masse.This group includes, inter alia, hymenopterans and especially social wasps (Vespinae). Colonies and nests of two wasp species, the European hornet (Vespa crabro) and Saxon wasp (Dolichovespula saxonica) in areas of the city of Łódź in Poland were studied. Whole colonies positioned both in buildings as well in natural places, size of societies, parameters their nests, differentiation of cells in combs and their location were investigated. We also studied the correlation between the size of the nest and societies of these insects. It was found that nests established in the buildings are much larger, produced more individuals of reproductive castes and thus obtained a better reproductivesuccess especially for the hornet colonies whose queens prefer the buildings as a place to nest.

Contaminants as habitat disturbers: PAH-driven drift by Andean paramo stream insects

Contaminants can behave as toxicants, when toxic effects are observed in organisms, as well as habitat disturbers and fragmentors, by triggering avoidance responses and generating less- or uninhabited zones. Drift by stream insects has long been considered a mechanism to avoid contamination by moving to most favorable habitats. Given that exploration and transportation of crude oil represent a threat for surrounding ecosystems, the key goal of the present study was to assess the ability of autochthonous groups of aquatic insects from the Ecuadorian paramo streams to avoid by drift different concentrations of polycyclic aromatic hydrocarbons (PAH) contained in the soluble fraction of locally transported crude oil. In the laboratory, different groups of insects were exposed to PAH for 12h. Three different assays, which varied in taxa and origin of the organisms, concentrations of PAH (0.6–38.8µgL−1), and environment settings (different levels of refuge and flow) were performed. For Anomalocosmoecus palugillensis (Limnephilidae), drift was a major cause of population decline in low concentration treatments but at higher concentrations mortality dominated. PAH was highly lethal, even at lower concentrations, for Chironomidae, Grypopterygidae (Claudioperla sp.) and Hydrobiosidae (Atopsyche sp.), and, therefore, no conclusion about drift can be drawn for these insects. Contamination by PAH showed to be a threat for benthic aquatic insects from Ecuadorian paramo streams as it can cause a population decline due to avoidance by drift and mortality.