Search Results (31)

Insect wing base sclerites are crucial to wing function and evolution, yet their diversity beyond order-level comparisons remains poorly understood. We examine variation in wing base sclerites across Vespidae, focusing on the axillary sclerites (1Ax, 2Ax, and 3Ax), the shoulder sclerite, and associated structures. The first axillary sclerite shows distinct regional differentiation and bears a well-sclerotized knob that influences wing articulation. Additionally, 2Ax in Vespidae is a single, triangular structure with three attachment points, distinct from the two-part composition in some other wasps, which facilitates high-frequency wing vibrations. Our findings also highlight variable fusion patterns in 3Ax and its interaction with 2Ax, contributing to wing flexibility. The basiradial bridge, connecting the subcostal and radial veins, reinforces wing stability and articulation. Phylogenetic analysis based on wing-base morphology does not support the monophyly of Vespidae and differs from molecular hypotheses, but it refines previous morphological interpretations. The well-supported subfamily relationships confirm Vespinae as a monophyletic group and reveal a close association among Polistinae, Stenogastrinae, and Eumeninae, as represented by Polistes, Eustenogaster, and Oreumenes, respectively, suggesting evolutionary transitions in social behavior within the family Vespidae. The absence of a fourth axillary sclerite challenges earlier hypotheses, providing new insights into Hymenopteran wing base evolution. Two articulation models are proposed for forewings and hindwings, supported by three-dimensional reconstructions of axillary sclerites, indirect and direct flight muscles, and their attachment sites. These results refine interpretations of wasp wing mechanics, evolution, and morphological diversification across taxa. Full article

Invasive insects pose significant ecological challenges due to their interactions with other species, which can have a considerable impact on pre-existent ecosystems. In the present study, we analysed the foraging behaviour of the invasive Polistes dominula, which was first detected in NW Patagonia in 2003, and the native wasp Hypodynerus labiatus. We evaluated their foraging behaviour in two types of environments: closed habitats with dense vegetation and open habitats without surrounding bushes and trees. Additionally, we recorded the wasps’ feeding choices at three different heights within each context. Our results showed that these sympatric wasps prefer to forage in different environments and in distinct microsite strata within each environment. Polistes dominula collected food from the ground level in both open and closed habitats, while H. labiatus was more frequently observed in closed areas, gathering resources from higher strata. The observed differences suggest that the collecting sites showed minimal overlap, which may facilitate their coexistence. These findings shed new light on the behavioural processes and interspecific interactions between a highly invasive wasp and a poorly studied native species that inhabit urban and semi urban environments in Patagonia. Full article

In a warming world, mechanisms, such as the heat shock response, which plays a role in the recovery from or tolerance towards heat stress, are of increasing importance. Certain heat shock protein genes (hsps) have previously been shown to be highly inducible in several paper wasp species during high temperature stress under laboratory conditions. Here, we sought to investigate how hsps are expressed under natural daily temperature fluctuations by collecting broods from wild nests of two species of paper wasps (Polistes dominula, P. nimpha). We collected them at 06:00 and 16:00, the expected low and high points in daily hsp expression, and measured the expression of three hsps (hsp70, hsp83, hsc70). We found that the nest temperature in July could reach temperatures that result in a large upregulation of hsp expression in the laboratory. Under natural conditions, however, we found that the induction response was much more moderate and limited to the larvae. The pupae showed no response to the daily fluctuating temperature and had a constant expression similar to that of larvae in the afternoon. The similarities and differences between natural and laboratory hsp expressions highlight the importance of field studies, as they add valuable context when interpreting laboratory results. Full article

The efficacy of Hymenoptera venom immunotherapy is contingent upon the accurate identification of the insect responsible for the allergic reaction. The techniques used to detect specific IgE suffer from difficulties due to the cross-reactivity between Hymenoptera venoms (false positives), diagnostic ability, and the limited availability of allergenic components (false negatives). In this study, we analyzed the discrepancies in the results obtained with Euroline^® DPA-Dx and ImmunoCAP^® in the diagnosis of allergic reactions due to Hymenoptera stings in 151 patients. The results (positive/negative) of ImmunoCAP^® and Euroline^® agreed in 77/151 (50.99%) cases; with 15/151 (9.93%) cases positive for the same insect, and 61/151 (40.4%) cases positive for multiple insects. When the results were used to decide which venom to use for immunotherapy, there was a statistically significant discrepancy for Polistes dominula (21.8% of cases with ImmunoCAP^® compared to only 8.4% with Euroline^®). The presence of Polistes venom phospholipase (Pol d 1) in Euroline^® did not increase its ability to differentiate double sensitization to wasps. ImmunoCAP^® and Euroline^® exhibited comparable diagnostic performance in bee venom allergy. For vespid venom allergy—particularly involving Polistes species—ImmunoCAP^® appeared to show a slight diagnostic advantage, although this finding should be interpreted with caution. Full article

Background/Objectives: Codon usage bias affects gene expression and translation efficiency across species. The effective number of codons (ENC) and GC content influence codon preference, often displaying unimodal or bimodal distributions. This study investigates the correlation between ENC and GC rankings across species and how their relationship affects codon usage distributions. Methods: I analyzed nuclear-encoded genes from 17 species representing six kingdoms: one bacteria (Escherichia coli), three fungi (Saccharomyces cerevisiae, Neurospora crassa, and Schizosaccharomyces pombe), one archaea (Methanococcus aeolicus), three protists (Rickettsia hoogstraalii, Dictyostelium discoideum, and Plasmodium falciparum),), three plants (Musa acuminata, Oryza sativa, and Arabidopsis thaliana), and six animals (Anopheles gambiae, Apis mellifera, Polistes canadensis, Mus musculus, Homo sapiens, and Takifugu rubripes). Genes in all 17 species were ranked by GC content and ENC, and correlations were assessed. I examined how adding or subtracting these rankings influenced their overall distribution in a new method that I call Two-Rank Order Normalization or TRON. The equation, TRON = SUM(ABS((GC rank₁:GC rank_N) − (ENC rank₁:ENC rank_N))/(N²/3), where (GC rank₁:GC rank_N) is a rank-order series of GC rank, (ENC rank₁:ENC rank_N) is a rank-order series ENC rank, sorted by the rank-order series GC rank. The denominator of TRON, N²/3, is the normalization factor because it is the expected value of the sum of the absolute value of GC rank–ENC rank for all genes if GC rank and ENC rank are not correlated. Results: ENC and GC rankings are positively correlated (i.e., ENC increases as GC increases) in AT-rich species such as honeybees (R² = 0.60, slope = 0.78) and wasps (R² = 0.52, slope = 0.72) and negatively correlated (i.e., ENC decreases as GC increases) in GC-rich species such as humans (R² = 0.38, slope = −0.61) and rice (R² = 0.59, slope = −0.77). Second, the GC rank–ENC rank distributions change from unimodal to bimodal as GC content increases in the 17 species. Third, the GC rank+ENC rank distributions change from bimodal to unimodal as GC content increases in the 17 species. Fourth, the slopes of the correlations (GC versus ENC) in all 17 species are negatively correlated with TRON (R² = 0.98) (see Graphic Abstract). Conclusions: The correlation between ENC rank and GC rank differs among species, shaping codon usage distributions in opposite ways depending on whether a species’ nuclear-encoded genes are AT-rich or GC-rich. Understanding these patterns might provide insights into translation efficiency, epigenetics mediated by CpG DNA methylation, epitranscriptomics of RNA modifications, RNA secondary structures, evolutionary pressures, and potential applications in genetic engineering and biotechnology. Full article

The reproductive division of labor is a fundamental characteristic of eusociality; thus, understanding the caste determination system underlying the reproductive division of labor would shed more light on the evolution of eusociality. In this review, we summarize the factors associated with caste determination in temperate Polistes paper wasps and focus on life histories associated with the loss or maintenance of caste plasticity during the adult stage among eusocial Hymenoptera. In many species of eusocial Hymenoptera, caste trajectories are differentiated by nutrition during the larval stages, indicating that caste plasticity is either absent or has not yet been confirmed. However, in temperate Polistes wasps, nutrition during the larval stage only causes biases in caste trajectory, with castes ultimately determined by environmental factors, such as day length and temperature, and colony conditions during the adult stage, indicating high caste plasticity during this stage. Therefore, morphological dimorphism and physiological differences between castes, such as in dopamine levels, have not been found in temperate Polistes wasps at emergence. This plasticity in temperate paper wasps could reflect the fact that females destined to be workers also have a chance to mate with males (especially early males) after emergence, leaving the possibility that they can produce daughters in the emerging year. Full article

Sensitization to cross-reactive allergens complicates identifying the culprit insect in Hymenoptera venom allergy via diagnostic tests. This study evaluates sensitization to hyaluronidases (Api m 2 from honey bee (Apis mellifera) venom, HBV; Pol d 2 from European paper wasp (Polistes dominula) venom, PDV; and Ves v 2.0101 and Ves v 2.0201 from yellow jacket (Vespula vulgaris) venom, YJV) and their cross-reactivity in allergic patients from Italy, Spain, and Germany using ImmunoCAPs, ELISA, and basophil activation tests. Sensitization rates were 45% for Api m 2 in HBV-allergic subjects, 25% for Pol d 2 in PDV-allergic individuals, and 20% and 10% for Ves v 2.0201 and Ves v 2.0101 in YJV-allergic patients, respectively. Patients primarily sensitized to Api m 2 showed minimal cross-reactivity to vespid hyaluronidases, whereas those primarily sensitized to Pol d 2 or Ves v 2.0201 exhibited IgE reactivity to Api m 2. Neither Pol d 2 nor Ves v 2.0201 triggered basophil activation. Cross-reactivity of Api m 2, Pol d 2, and Ves v 2.0201 depends on the primary sensitizing venom. Sensitization to Pol d 2 and Ves v 2.0201 remains below 25%, yet these patients may exhibit cross-reactivity to Api m 2. Conversely, HBV-allergic patients sensitized to Api m 2 show minimal reactivity to Pol d 2 or Ves v 2.0201. Full article

Until now, no study has examined the future range dynamics of major invasive wasp species to assess their future impacts on global apiculture. Here, we developed 12 species distribution models to calibrate the future range dynamics of 12 major invasive Vespidae wasp species under a unified framework. An increase in their habitat suitability was identified in more than 75% of global land. Substantial range expansions were detected for all 12 species, and they were primarily induced by future climate changes. Notably, Polistes dominula and Vespa crabro had the largest potential ranges under all scenarios, suggesting their greater impact on global apiculture. Polistes chinensis and Vespa velutina nigrithorax had the highest range expansion ratios, so they warrant more urgent attention than the other species. Polistes versicolor and P. chinensis are expected to exhibit the largest centroid shifts, suggesting that substantial shifts in prioritizing regions against their invasions should be made. Europe and the eastern part of the USA were future invasion hotspots for all major invasive wasp species, suggesting that apiculture might face more pronounced threats in these regions than in others. In conclusion, given their substantial range shifts, invasive wasps will likely have increasingly negative impacts on global apiculture in the future. Full article

Venom immunotherapy (VIT) protects up to 98% of treated Hymenoptera allergy patients from reactions with new stings. A correct diagnosis with the identification of the venom causing the allergic reaction is essential to implementing it. The knowledge of the Hymenoptera foraging habits when the sting takes place in a food environment would allow the culprit insect to be known. Images of Hymenoptera occurring in environments where there was human food were recorded in Spain, including the date of the image, the place description and its geolocation. The insects’ genus and species were identified by an entomologist. Results: One hundred and fifty-five images depicting 71 insects were analyzed. The identified insects were Vespula (56), Vespa (7), Polistes (4), Cerceris (2), Bombus (1) and Apis (1). Most (97.1%) of the images were obtained in summer and early autumn, outdoors in terraces (64%). Meat was the food associated with 47.9% of the images. In protein-rich foods, Vespula was found in 89%. Conclusions: Vespula was the main Hymenoptera associated with food environments in our country (78.87%), and in most of the cases (71%), the food involved is a source of protein, such as meat or seafood. In that environment, the probability that the insect is a Vespula would be 89%. Full article

The paper wasp Polistes dominula is a thermophilic species originating from the Mediterranean climate, but is now widely spread in Europe. They live in quite differing habitats; and as synanthropic species, they have been established in human settlement areas. They build a single small comb at protected places with a favorable microclimate. We measured the temperature of the wasps, the nests and their environment at typical nesting sides in Austria (Europe) in the temperate climate, in order to reveal relationships between nest and body temperature and the habitats’ microclimate. The temperatures of the comb and of the wasps’ body were in a wide range (~20–37 °C) above the ambient air temperature at the nest. This is an advantage as higher temperatures accelerate the development speed of the brood. However, the mean comb temperature did not exceed approximately 38.6 °C. This was managed by cooling efforts of the adult wasps. The ambient air temperature near the nest (~1–2 cm) was always clearly elevated above the ambient air temperature at a local standard weather station in the habitat. A comparison with climate-model-generated macroclimate data revealed the necessity of measuring microclimate data for a reliable description of the insects’ thermal environment. Full article

Gynes of paper wasps (Polistes sp.) spend the cold season in sheltered hibernacles. These hibernacles protect against predators and adverse weather conditions but offer only limited protection against low temperatures. During overwintering diapause, wasps live on the energy they store. We investigated the hibernacles’ microclimate conditions of species from the Mediterranean (Italy, P. dominula, P. gallicus) and temperate (Austria, P. dominula) climates in order to describe the environmental conditions and calculate the energetic demand of overwintering according to standard metabolic rate functions. The temperatures at the hibernacles differed significantly between the Mediterranean and temperate habitats (average in Austria: 3.2 ± 5.71 °C, in Italy: 8.5 ± 5.29 °C). In both habitats, the hibernacle temperatures showed variance, but the mean hibernacle temperature corresponded closely to the meteorological climate data. Cumulative mass-specific energetic costs over the studied period were the lowest for the temperate P. dominula population compared with both Mediterranean species. The lower costs of the temperate species were a result of the lower hibernacle temperature and acclimation to lower environmental temperatures. Model calculations with an increased mean temperature of up to 3 °C due to climate change indicate a dramatic increase of up to 40% in additional costs. Full article

There is growing evidence that paper wasps’ (Polistes’) fate as workers or reproductive females (gynes) is affected by cues that exist at the larval stage and during eclosion. The nutritional requirements for workers and gynes are different early in their adult lives. Males are short-lived and have different nutritional needs than females. To determine the relative importance of larval and adult cues, we reared Polistes metricus individuals from prepupae to adults isolated from known environmental cues shown to affect caste differentiation. Individuals were given access to two foods with different ratios of protein and carbohydrates. Levels of protein, amino acids, carbohydrates and lipids were measured after the feeding trials. If larval experience drove feeding behavior in adults, we expected to see differences in protein and carbohydrate intake as well as differences in nutrient levels. Females showed no differences in feeding or nutrient levels. Males had lower levels of protein and amino acids than females but had similar feeding results to females. Full article

Parasitic moths are common in social wasp (Hymenoptera) nests, attacking many species of Polistinae and a few species of Vespinae. In the Republic of Korea, two moth species are known to parasitize the brood of Polistes rothneyi koreanus: Pyralis regalis (Pyralidae) and Anatrachyntis japonica (Cosmopterigidae). Although previously reported elsewhere, a novel case of parasitization was recently documented in the Republic of Korea, in which Hypsopygia mauritialis (Pyralidae) was identified in the nests of social wasps. Pyralis regalis is the most common parasitic moth in the Republic of Korea, feeding on the nests of 11 species of social wasps, mostly the Korean Vespa species. To that list of hosts, we add a species of Dolichovespula and two species of Polistes. Parasitism of Vespa velutina nigrithorax, an invasive alien hornet, by both P. regalis and H. mauritialis, was observed for the first time. However, their potential to control invasive alien hornets is expected to be low. This study provides new insights into the diversity of nest-parasitic moths in social wasp nests and their hosts in the Republic of Korea, and highlights the potential for these moths to impact pest populations. Full article

Modern plant biosecurity strategies include the use of a wide range of living organisms regulating the number, development and spread of harmful organisms at an economically safe level. We aimed to study the species composition of entomophages of the Leptinotarsa decemlineata Say and their efficiency in pest control. We observed the population dynamics of the stink bug Perillus bioculatus Fabr. and the Colorado potato beetle from 2013 to 2015. Besides, the species composition of entomophages of the Colorado potato beetle in Krasnodar Krai (a region in southwestern Russia) was researched in 2013–2015. The study showed that with a ratio of P. bioculatus: Colorado beetle 1:10–1:15, the efficiency of the entomophage is about 98%. In addition to P. bioculatus, there are other insects that feed on the Colorado potato beetle. Among them, it is worth noting Zicrona caerulea L., Polistes gallicus L., representatives of the Coccinellidae family, etc. The food base and parasitic activity of scelionid ovi-eaters and phasia flies are the main biotic factors influencing the number of predatory bugs. The possibility of combined use of P. bioculatus and preparations of biological origin was studied. The survival rate of adult P. bioculatus under the use of insecticides based on Bacillus thuringiensis var. thuringiensis and Streptomyces avermitilis (ex., Burg et al.) Kim and Goodfellow was 97% and 91%; that of older nymphs—58% and 52%, respectively. Chemical preparations destroyed all age stages of the predator. Full article

The increase in invasive alien species is a concern for the environment. The establishment of some of these species may be changing the balance between pathogenicity and host factors, which could alter the defense strategies of native host species. Vespid species are among the most successful invasive animals, such as the genera Vespa, Vespula and Polistes. Bee viruses have been extensively studied as an important cause of honey bee population losses. However, knowledge about the transmission of honey bee viruses in Vespids is a relevant and under-researched aspect. The role of some mites such as Varroa in the transmission of honey bee viruses is clearer than in the case of Vespidae. This type of transmission by vectors has not yet been clarified in Vespidae, with interspecific relationships being the main hypotheses accepted for the transmission of bee viruses. A majority of studies describe the presence of viruses or their replicability, but aspects such as the symptomatology in Vespids or the ability to infect other hosts from Vespids are scarcely discussed. Highlighting the case of Vespa velutina as an invader, which is causing huge losses in European beekeeping, is of special interest. The pressure caused by V. velutina leads to weakened hives that become susceptible to pathogens. Gathering this information is necessary to promote further research on the spread of bee viruses in ecosystems invaded by invasive species of Vespids, as well as to prevent the decline of bee populations due to bee viruses. Full article