Dolichovespula Maculata Research Articles

Insights into the prey of Vespa mandarinia (Hymenoptera: Vespidae) in Washington state, obtained from metabarcoding of larval feces.

The northern giant hornet, Vespa mandarinia (Hymenoptera: Vespidae), was detected for the first time in North America in 2019. Four nests have since been located and removed in northwestern Washington State as part of an extensive survey and eradication program. This recent introduction into North America has prompted new research on the biology and ecology of V. mandarinia to help inform management strategies. In its native range, V. mandarinia is known to prey on a variety of insects including the economically important honey bee species Apis cerana and Apis mellifera. Although A. cerana has developed defense mechanisms against attack by V. mandarinia, A. mellifera have no such defenses and an entire hive can be quickly destroyed by only a few hornets. In North America the hornet has been observed foraging on paper wasps (Polistes dominula) and honey bees, but little else is known about prey use in its novel range. To address this knowledge gap, we employed a DNA metabarcoding approach to characterize species detected in larval feces collected from 3 of the 4 Washington V. mandarinia nests found to date. Sequences were recovered for 56 species across fourteen orders, of which 36 species were likely prey items and 20 were suspected inquilines. The most frequently detected species were other social Hymenoptera, with Dolichovespula maculata, P. dominula, and A. mellifera present in most samples. All of the species detected, except for A. mellifera, represent new prey records for V. mandarinia, with eight families of insects newly associated with giant hornets. These results suggest that V. mandarinia in Washington preys on an assortment of insects similar to those documented in its native range, and that this new invader has readily incorporated novel species into its foraging and diet.

VENOM IMMUNOTHERAPY: SELECTIVE DESENSITIZATION

<h3>Introduction</h3> A patient with venom anaphylaxis with IgE to paper wasp and honeybee, brought in hymenoptera identified as paper wasp and honeybee. We elected to desensitize to both, and not to other positive agents which were attributed to cross reactivity and agents not located in the region. <h3>Case Description</h3> A 70yoM presented after anaphylaxis to hymenoptera. He tested positive on serum venom IgE of 11.3 kU/L - paper wasp, >100 - honeybee, 2.12 - yellow jacket, 1.46 - white faced hornet; and <0.35 - yellow hornet. He brought in two specimens identified by clinic providers as a paper wasp and honeybee and underwent Rush venom immunotherapy to both agents which he tolerated well. He had subsequent field stings without systemic reaction. <h3>Discussion</h3> In patients with venom hypersensitivity, patient and exposure history remains the most important determinant in the decision for what agents to test and desensitize for. This patient tested positive to yellow jacket, not found in the region and thus was not likely the culprit and he did not bring in a white-faced hornet. It was decided they were not the likely cause of his anaphylaxis and therefore that it would be of little benefit to desensitize to these. We used exposure data to help identify what we desensitize the patient to. By selectively choosing agents based on history, we were able to desensitize the patient appropriately and avoided over utilization of health care expenses in the setting of venom shortages, by conserving the venom for testing and desensitization.

EFFECT OF OMALIZUMAB ON VENOM SPECIFIC IGE AND VENOM SKIN TESTING

<h3>Introduction</h3> Omalizumab, a monoclonal IgG antibody which binds free IgE, is indicated for the treatment of chronic spontaneous urticaria, uncontrolled nasal polyps, and moderate to severe asthma with perennial allergic sensitization. This case illustrates the effect of omalizumab on venom-specific IgE and percutaneous testing. <h3>Case Description</h3> A 48 year old female with severe persistent asthma on omalizumab for six years experienced wheezing and throat swelling within two hours of a suspected hymenoptera sting. Evaluation while patient remained on omalizumab included venom serology obtained two weeks after sting, which was positive only to paper wasp and white-faced hornet, and percutaneous testing three months after sting to honeybee, yellow jacket, and yellow hornet, which was negative through 0.1 ug/mL intradermals, at which time testing was stopped due to systemic reaction. After holding omalizumab for sixteen weeks, repeat percutaneous testing was performed but confounded by dermatographism; repeat venom serology revealed increased specific IgE to all tested hymenoptera except honeybee. <h3>Discussion</h3> To our knowledge, this is the first report describing omalizumab's effect on venom-specific IgE levels and percutaneous testing. Given previous studies that have suggested omalizumab does not convert specific IgE for environmental allergens from positive to negative, it is important for allergists to be aware of omalizumab's potential to suppress venom-specific IgE and skin test reactivity. If a patient on omalizumab with concern for venom hypersensitivity has negative serologic or percutaneous testing to hymenoptera, consideration should be given to repeating testing after omalizumab has been discontinued for four to five half-lives.

Combining Discordant Serum IgE and Skin Testing Improves Diagnostic and Therapeutic Accuracy for Hymenoptera Venom Hypersensitivity Immunotherapy

Diagnosis of patients with hymenoptera venom hypersensitivity consists of elucidating clinical symptoms suggestive of systemic reaction (SR) and then confirmation of sensitization via intradermal skin testing (IDST) first and serum IgE assays such as ImmunoCAP (ICAP) as a complementary modality of diagnosis. Determine the concordance between ICAP and IDST in patients with a clinical history suggestive of hymenoptera venom SR. Determine whether venom immunotherapy would change on the basis of IDST versus ICAP results. A prospective diagnostic study was designed to test the concordance between IDST and ICAP venom testing in the diagnosis of hymenoptera venom hypersensitivity. This study entailed testing both IDST and ICAP for 5 hymenoptera venoms (honey bee, wasp, yellow jacket, yellow hornet, and white-faced hornet) in both a case group with SR to hymenoptera venom (N= 70) and a control group without SR (N= 51). Significant discordance was observed between positive IDST and ICAP results for any of the 5 hymenoptera venoms (McNemar test, P= .001). In the case group, there was significant discordance for wasp (P < .0001), yellow jacket (P= .002), and white-faced hornet (P= .02). More than 47% of the case patients would have different venom immunotherapy prescriptions if ICAP and IDST had been performed during initial diagnosis versus IDST alone. Our study shows significant discordance between IDST and ICAP; however, they are complementary. On the basis of our data, we propose ICAP testing first followed by IDST for ICAP-negative venoms as an alternative and efficient diagnostic strategy.

Anaphylaxis to Vespa velutina nigrithorax: Pattern of Sensitization for an Emerging Problem in Western Countries.

To define the sensitization pattern of patients with anaphylaxis to Vespa velutina nigrithorax (VVN). We studied 100 consecutive Spanish patients with anaphylaxis to Hymenoptera venom and systematically determined specific IgE (sIgE) to whole venoms (Vespula species, Polistes dominula, Apis mellifera, Vespa crabro, and Dolichovespula maculata) and their molecular components (rApi m 1, rApi m 5, rApi m 10, rVes v 1, rVes v 5, rPol d 5, and cross-reactive carbohydrates). Specific IgE to VVN venom and its antigen 5 (nVesp v 5) were measured in a subsample. Seventy-seven patients had anaphylaxis to VVN. Of these, only 16 (20.8%) reported previous VVN stings, but were stung by other Hymenoptera. Positive sIgE (>0.35 kUA/L) to each of the whole venoms was detected in >70% of patients (Vespula species in 100%). The components showing >50% positivity were rApi m 5 (51.4%), rPol d 5 (80.0%), and rVes v 5 (98.7%). This pattern was similar to that of Vespula species anaphylaxis (n=11) but different from that of A mellifera anaphylaxis (n=10). Specific IgE to nVesp v 5 was positive in all patients (n=15) with VVN anaphylaxis and was correlated with sIgE to both rVes v 5 (R=0.931) and rPol d 5 (R=0.887). VVN has become the commonest cause of Hymenoptera anaphylaxis in our area. Most cases report no previous VVN stings. Their sensitization pattern is similar to that of patients with anaphylaxis to other Vespidae. Specific IgE to antigen-5 from VVN, Vespula species, and P dominula are strongly correlated in patients with VVN anaphylaxis.

Purification and molecular characterization of phospholipase, antigen 5 and hyaluronidases from the venom of the Asian hornet (Vespa velutina).

The aim of this study was to purify potential allergenic components of Vespa velutina venom, the yellow legged Asian Hornet, and perform a preliminary characterization of the purified proteins. Starting from the whole venom of V.velutina, several chromatographic steps allowed to purify the phospholipase (named Vesp v 1), as well as the antigen 5 (Vesp v 5, the only allergenic component described as such so far). The two hyaluronidase isoforms found (Vesp v 2A and Vesp v 2B) cannot be separated from each other, but they are partially purified and characterized. Purity of the isolated proteins in shown by SDSPAGE, as well as by the results of the N-terminal sequencing. This characterization and nLC-MS/MS data provide most of the sequence for Vesp v 1 and Vesp v 5 (72 and 84% coverage, respectively), confirming that the whole sequences of the isolated natural components match with the data available in public transcriptomic databases. It is of particular interest that Vesp v 1 is a glycosylated phospholipase, a fact that had only described so far for the corresponding allergen components of Dolichovespula maculata and Solenopsis invicta. The availability of the complete sequences of Vespa velutina components permits comparison with homologous sequences from other Hymenoptera. These data demonstrate the higher similarity among the species of the genera Vespa and Vespula, in comparison to Polistes species, as it is especially observed with the hyaluronidases isoforms: the isoform Vesp v 2A only exists in the former genera, and not in Polistes; in addition, the most abundant isoform (Vesp v 2B) exhibits 93% sequence identity with the Ves v 2 isoform of Vespula vulgaris. Finally, the isolated components might be useful for improving the diagnosis of patients that could be allergic to stings of this invasive Asian hornet, as it has been the case of an improved diagnosis and treatment of other Hymenoptera-sensitized patients.

Isolation, Structure Elucidation, and Total Synthesis of Dolichovespulide, a Sesquiterpene from Dolichovespula Yellowjackets.

As part of an ongoing program to identify sex attractant pheromone components that mediate sexual communication in yellowjacket wasps, a novel sesquiterpene was isolated from body surface extracts of virgin bald-faced hornet queens, Dolichovespula maculata. The gross structure of this sesquiterpene was proposed through microscale spectroscopic analyses, and the configuration of the central olefin was subsequently confirmed by total synthesis. This new natural product (termed here dolichovespulide) represents an important addition to the relatively small number of terpenoids reported from the taxonomic insect family Vespidae.

Variation in pollinator potential to carry a blueberry fungal pathogen and assessment of transfer efficiency in two managed bee species

Plant diseases are ubiquitous in agricultural systems and are major sources of economic loss. Vaccinium corymbosum, or highbush blueberry, is an economically important crop affected by an insect-vectored, fungal pathogen, Monilinia vaccinii-corymbosi, or mummy berry disease. Highbush blueberry yield is maximized through outcrossed pollination; however, the pathogen is vectored by pollinators. We used field collections and molecular techniques to identify floral visitors to highbush blueberry and quantify levels of pathogen spores carried by each visiting species. We also conducted a cage trial using single flower visits to determine differences in vectoring efficiency between two managed pollinators, Apis mellifera and Bombus impatiens. We found that bees, flies, and wasps were all common visitors, and that all bee species and several fly and wasp species carried the pathogen. Of the bee species, A. mellifera most often tested positive for the pathogen, while Dolichovespula maculata (Bald-faced Hornet) tested positive most among wasps and Mallota posticata among flies. Considering only individuals that tested positive, mummyberry levels per individual were highest in D. maculata and Andrena bees, and relatively low in flies. In cage trials, we found no differences between A. mellifera and B. impatiens in pathogen load or transfer efficiency, suggesting that these managed species are equally capable of vectoring mummyberry during a single visit to a blighted stem and then a flower. This research demonstrates the variety of floral visitors that carry mummyberry and that two common commercial pollinator species have similar potential to vector mummyberry to blueberry flowers during a single visit.

Cuticular hydrocarbons determine sex, caste, and nest membership in each of four species of yellowjackets (Hymenoptera: Vespidae)

Cuticular hydrocarbons (CHCs) of social insects have typically been studied for their roles in reproductive signaling (i.e., fertility) rather than sexual signaling (i.e., interest in mating), resulting in little information about CHCs of males and virgin females. This dearth of information applies particularly to social wasps. We tested the hypothesis that CHCs differentiate sex, caste, and nest membership in each of four yellowjacket species (baldfaced hornets, Dolichovespula maculata; southern yellowjackets, Vespula squamosa; western yellowjackets, V. pensylvanica; V. alascensis). Cold-euthanized queens (21), gynes (81), workers (125), and males (77) from 35 nests were extracted with pentane, and each of the resulting 304 extracts was analyzed by gas chromatography (GC) and GC–mass spectrometry to identify and quantify CHC constituents (aliphatic alkanes and alkenes; mono-, di-, and tri-methyl-branched alkanes). To determine whether caste and sex differ in CHC profiles of wasps, linear discriminant analyses were performed, using Z-transformed relative CHC peak areas as predictor variables and sex and caste, or nest, as grouping variables. When caste and sex were used as a grouping variable, plots of the first two discriminant functions revealed that wasps from each of the four species clustered into their respective groups (queens, gynes, workers, males), with significant differences in group centroids, as measured by Wilks’ lambda. When nest was used as a grouping variable, plots of the first two discriminant functions revealed that workers from each of the four species and males from each of three species (insufficient sample size for V. pensylvanica) clustered according to nest. Diagnostic power calculations show greater inter-caste than inter-nest variation. Our data support the above hypothesis and inspire future studies to determine the definitive role(s) that gyne- and male-specific CHCs play in the context of sexual communication, from the perspective of both males and females.

Maculatic Acids-Sex Attractant Pheromone Components of Bald-Faced Hornets.

Yellowjackets in the genera Vespula and Dolichovespula are prevalent eusocial insects of great ecological and economic significance, but the chemical signals of their sexual communication systems have defied structural elucidation. Herein, we report the identification of sex attractant pheromone components of virgin bald-faced hornet queens (Dolichovespula maculata). We analyzed body surface extracts of queens by coupled gas chromatographic-electroantennographic detection (GC-EAD), isolated the compounds that elicited responses from male antennae by high-performance liquid chromatography (HPLC), and identified these components by GC mass spectrometry (MS), HPLC-MS, and NMR spectroscopy. In laboratory olfactometer experiments, synthetic (2Z,7E)-3,7-dimethyldeca-2,7-diendioic acid (termed here maculatic acid A) and (2Z,7E)-10-methoxy-3,7-dimethyldeca-10-oxo-deca-2,7-dienoic acid (termed here maculatic acid C) in binary combination significantly attracted bald-faced hornet males. These are the first sex attractant pheromone components identified in yellowjackets.

Maculatic Acids—Sex Attractant Pheromone Components of Bald‐Faced Hornets

AbstractYellowjackets in the genera Vespula and Dolichovespula are prevalent eusocial insects of great ecological and economic significance, but the chemical signals of their sexual communication systems have defied structural elucidation. Herein, we report the identification of sex attractant pheromone components of virgin bald‐faced hornet queens (Dolichovespula maculata). We analyzed body surface extracts of queens by coupled gas chromatographic–electroantennographic detection (GC‐EAD), isolated the compounds that elicited responses from male antennae by high‐performance liquid chromatography (HPLC), and identified these components by GC mass spectrometry (MS), HPLC‐MS, and NMR spectroscopy. In laboratory olfactometer experiments, synthetic (2Z,7E)‐3,7‐dimethyldeca‐2,7‐diendioic acid (termed here maculatic acid A) and (2Z,7E)‐10‐methoxy‐3,7‐dimethyldeca‐10‐oxo‐deca‐2,7‐dienoic acid (termed here maculatic acid C) in binary combination significantly attracted bald‐faced hornet males. These are the first sex attractant pheromone components identified in yellowjackets.

Species Composition, Abundance and Seasonal Phenology of Social Wasps (Hymenoptera: Vespidae) in Wisconsin Vineyards.

Social wasps can be serious pests in fruit growing plantings and are becoming increasingly problematic for grape growers. In this study, we conducted two experiments to assess the species composition and seasonal phenology of social wasps in Wisconsin vineyards in 2015 and 2017. In 2015, three attractants were used: (1) wine; (2) heptyl butyrate (HB); and (3) acetic acid and isobutanol (AAIB) and in 2017, two attractants were used: HB and AAIB. In both years, the same eight species were trapped from the genera Vespula, Dolichovespula, and Polistes. The predominant wasp species trapped were Vespula maculifrons, Vespula vidua, Vespula flavopilosa, and Vespula germanica in 2015 and V. maculifrons, V. flavopilosa, V. germanica, and Dolichovespula maculata in 2017, in order of total abundance. The populations of V. vidua decreased in 2017 compared to 2015, indicating large inter-annual variation. In both years, AAIB lures trapped significantly more V. flavopilosa, V. maculifrons, and V. germanica, the three most prevalent species during grape harvest, than HB, whereas HB lures trapped more V. vidua than AAIB. Wine was generally attractive to all species in 2015. This study identifies for the first time the wasp species present in Wisconsin commercial vineyards using chemical attractants. This knowledge, along with the seasonal phenology of these pest species, will help facilitate the development of management strategies for social wasps in commercial vineyards.

Evidence for sex pheromones and inbreeding avoidance in select North American yellowjacket species

AbstractLittle is known about the roles of sex pheromones in mate‐finding behavior of social wasps (Vespidae). Working with the aerial yellowjacket, Dolichovespula arenaria (Fabricius), baldfaced hornet, Dolichovespula maculata (L.), western yellowjacket, Vespula pensylvanica (Saussure), southern yellowjacket, Vespula squamosa (Drury), and Vespula alascensisPackard, we tested the hypotheses (1) that gynes produce an airborne sex pheromone attractive to males, and (2) that males are more strongly attracted to non‐sibling gynes based on olfactory cues. A field experiment provided the first definitive evidence that D. arenaria gynes attract males. Surprisingly, we did not find such evidence in similar field experiments for sexual attractiveness of gynes of V. squamosa, V. pensylvanica, V. alascensis, or D. maculata. In Y‐tube olfactometer experiments with three of these species (D. arenaria, D. maculata, V. pensylvanica), only D. maculata gynes attracted males, provided they were non‐siblings, implying an olfactory‐based mechanism of nestmate recognition and inbreeding avoidance. Lack of sex attraction responses for V. pensylvanica, V. alascensis, and V. squamosa in this study does not rule out pheromone‐mediated sexual communication. Instead, it highlights the possibility that pheromonal signaling may be dependent on the presence of appropriate contextual cues.

Yeasts Harbored by Vespine Wasps in the Pacific Northwest.

The ecological role of social wasps has been extensively studied, but little is known about symbiotic relationships of these wasps with microbes. Recently, it was shown that vespid wasps in Europe carry yeasts, predominantly Saccharomyces cerevisiae, in their gastrointestinal (GI) tract. Interestingly, this niche allowed for sexual recombination of yeasts to occur and the formation of novel hybrid species. Our goals were 1) to survey the GI tract of eusocial wasps in the Pacific Northwest for the presence of yeasts and 2) to compare the diversity of such yeasts to that described for wasps in Europe. The GI tracts of 19 individual wasps from five species were plated, and 27 yeast-like colonies were identified to the species level. Yeasts in the genera Lachancea and Hanseniaspora each comprised ∼30% of the isolates; ∼25% were identified as Metschnikowia spp., with the remaining 10% belonging to Rhodotorula. Four bacterial isolates were identified as Escherichia coli, Enterococcus faecalis, and two isolates of Stenotrophomonas maltophilia. Yeasts were present at all life stages of the wasps except for two unfed gynes of Dolichovespula maculata (L.) that contained only bacteria. The presence of a particular yeast species was not correlated with any wasp species. Furthermore, S. cerevisiae was not found in any wasp species. This highlights an interesting difference in the life cycle of both S. cerevisiae and wasps in Europe and the Pacific Northwest, and prompts further studies on the interactions of these microbes with their host wasps.

Application of recombinant antigen 5 allergens from seven allergy-relevant Hymenoptera species in diagnostics

Hymenoptera stings can cause severe anaphylaxis in untreated venom-allergic patients. A correct diagnosis regarding the relevant species for immunotherapy is often hampered by clinically irrelevant cross-reactivity. In vespid venom allergy, cross-reactivity between venoms of different species can be a diagnostic challenge. To address immunological IgE cross-reactivity on molecular level, seven recombinant antigens 5 of the most important Vespoidea groups were assessed by different diagnostic setups. The antigens 5 of yellow jackets, hornets, European and American paper wasps, fire ants, white-faced hornets, and Polybia wasps were recombinantly produced in insect cells, immunologically and structurally characterized, and their sIgE reactivity assessed by ImmunoCAP, ELISA, cross-inhibition, and basophil activation test (BAT) in patients with yellow jacket or Polistes venom allergy of two European geographical areas. All recombinant allergens were correctly folded and structural models and patient reactivity profiles suggested the presence of conserved and unique B-cell epitopes. All antigens 5 showed extensive cross-reactivity in sIgE analyses, inhibition assays, and BAT. This cross-reactivity was more pronounced in ImmunoCAP measurements with venom extracts than in sIgE analyses with recombinant antigens 5. Dose-response curves with the allergens in BAT allowed a differentiated individual dissection of relevant sensitization. Due to extensive cross-reactivity in various diagnostic settings, antigens 5 are inappropriate markers for differential sIgE diagnostics in vespid venom allergy. However, the newly available antigens 5 from further vespid species and the combination of recombinant allergen-based sIgE measurements with BAT represents a practicable way to diagnose clinically relevant sensitization in vespid venom allergy.

Evidence for a Nest Defense Pheromone in Bald-Faced Hornets, Dolichovespula Maculata, and Identification of Components.

In eusocial insects like Bald-faced hornets, Dolichovespula maculata, nest defense is essential because nests contain a large number of protein-rich larvae and pupae, and thus are attractive to nest predators. Our objectives were to investigate whether D. maculata exhibit pheromone-mediated nest defense, and to identify and field test any pheromone components. We tested for pheromone-mediated nest defense behavior of D. maculata by placing a paired box-apparatus near the entrance of D. maculata nests, and treating both boxes with a solvent control, or one of the two boxes with a solvent control and the other with either venom sac extract, the putative source of nest defense pheromone, or synthetic pheromone. The sound impulses caused by nest mates attempting to sting or strike the boxes were recorded for 3min. Compared to the double-control treatment, the number of strikes increased 27-fold when one of the two boxes was treated with venom sac extract, providing evidence for an alarm response. The box treated with venom sac extract also induced a significantly greater proportion of strikes than the corresponding control box, providing evidence for a target-oriented response. Analyzing venom sac extract by gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry resulted in the identification of seven candidate pheromone components: (a) dimethylaminoethanol, (b) dimethylamino ethyl acetate, (c) 2,5-dimethylpyrazine, (d) N-3-methylbutylacetamide, (e) 2-heptadecanone, (f) (Z)-8-heptadecen-2-one, and (g) (Z)-10-nonadecen-2-one. Testing in paired-box bioassays blends of the nitrogen-containing volatile components a-d, the less volatile ketones e-g, or both (a-g), indicated that a-d primarily have an alarm function. The ketones e-g, in contrast, induced target-oriented responses, possibly marking the box, or potential nest predators, for guided and concerted attacks, or enhancing the alarm-inducing effect of the volatile pheromone components, as shown in honey bees. Comparing the behavioral effects of venom sac extract, blends a-d, e-g, and a-g, venom sac extract was most effective in triggering the full complement of alarm and target-oriented responses. These comparisons further suggested that a component is missing in the group of components that triggers the alarm rather than the target-oriented response.

Trapping Social Wasps (Hymenoptera: Vespidae) in Nurseries with Acetic Acid and Isobutanol

Abstract European hornet, Vespa crabro L., damages bark of nursery trees, and most vespid species can be a sting hazard to nursery personnel when nests are disturbed. We tested acetic acid and isobutanol lures in traps for V. crabro spring queens to determine the seasonality of vespid captures and compare the efficacy of patterns of trap placement in Tennessee nurseries. Forty traps in transects from nursery tree blocks into the forest captured 547 vespid queens during 2001 and 2002. These were 78.8% Vespula maculifrons (Buysson), 6.9% Vespula squamosa (Drury), 6.8% V. crabro, 4.8% Dolichovespula maculata (L.), 2.6% Vespula flavopilosa Jacobson, and 0.2% Vespula vidua (Saussure). Total worker and male wasp captures in these traps were 2525 and 28, respectively. Polistes spp. (n = 416) were also trapped. Peak queen trap catch was in April for V. crabro and V. maculifrons and in May for other Vespula. Numbers of worker wasps captured were greater within nursery blocks or at field-forest edges compared with ...

Tricky cases in in-vitro diagnostics of hymenoptera venom allergy

Hymenoptera stings give rise to anaphylactic reactions in 1.2-3.5 % of the population. The risk of repeat anaphylaxis following subsequent stings is greatly reduced through immunotherapy with the culprit venom. A prerequisite for allergen-specific immunotherapy is a precise diagnostic work-up. We review the efficacy of currently available in-vitro diagnostic tests for hymenoptera venom allergy in different clinical scenarios. A targeted literature review in PubMed and a review of the current guideline on hymenoptera venom allergy were performed. For illustrative purposes, a series of clinical cases from our allergy department are presented. The correct diagnosis in hymenoptera venom allergy is influenced by a number of factors including patients' ability to identify the insect and time lapsed to diagnostic tests. The high rate of clinically irrelevant sensitizations, cross-reactivity and suboptimal sensitivity of the currently available diagnostic tests further complicate the picture. In the case of multiple sensitizations, molecular allergy diagnostics has improved the detection of clinically relevant sensitizations allowing the cost and risks of unnecessary double immunotherapy to be avoided. This is true in particular with regard to wasp venom allergy. For bee venom allergy, improvements in molecular allergy diagnostics have shown promising results and their implementation in clinical practice is planned. In patients with no sensitization in skin or serological tests but with a convincing history of insect sting anaphylaxis, the increased sensitivity of a basophil activation test may deliver crucial evidence of venom sensitization. The value of the basophil activation test may be further improved using specific marker allergens. The diagnosis of allergy to paper wasps (Polistinae) and white-faced hornets (Dolichovespula) remains problematic as they show partial cross-reactivity to wasp venom and specific marker allergens particular to these, still have to be identified.

Clinical Features and the Diagnostic Value of Component Allergen-Specific IgE in Hymenoptera Venom Allergy

PurposeAlthough patient history is vital for the diagnosis of hymenoptera venom allergy, specific IgE detection is also important to identify the culprit insect and monitor the effect of immunotherapy. We evaluated the diagnostic value of serum-specific IgE detection of hymenoptera venom component allergens and documented changes in allergen-specific IgE after immunotherapy.MethodsFifty-six hymenoptera venom allergy patients receiving venom immunotherapy were recruited from Ajou University Hospital, Korea. The clinical manifestations of the patients were noted, and serum-specific IgE detection was performed, using conventional venom extracts as well as component allergens. Data were analyzed retrospectively.ResultsA total of 35 (62.5%) patients were male, and 33 (73.3%) patients were atopic. The mean patient age was 44.9±13.8 years. Localized reactions occurred in 23.2% of patients, and systemic reactions occurred in 76.8%. The most common clinical manifestations included skin involvement, such as urticaria and angioedema, and respiratory involvement. Yellow jackets were the most frequent culprit insect, followed by yellow hornets, white-faced hornets, honeybees, and paper wasps, as determined at the time of diagnosis. Double sensitization to both Apidae and Vespidae species was detected in 70.9% of patients. The positive predictive values (PPV) of rVes v 5-specific and rPol d 5-specific IgE detection were 85.7% and 87.5%, respectively, which correlated well with conventional venom extract-specific IgE detection (r=0.762 and r=0.757, respectively). In contrast, the PPV of rApi m 1-specific IgE detection at the time of diagnosis was 34.8%. Three years of venom immunotherapy resulted in decreased venom-specific IgE, particularly IgE specific for Vespidae venom components.ConclusionsStings by yellow jackets and male sex may be risk factors for hymenoptera venom allergy in Korea. Vespidae component-specific IgE, but not Apidae component-specific IgE, had diagnostic and monitoring value in hymenoptera venom allergy comparable to that of conventional hymenoptera venom extract-specific IgE.

Discrete dimorphism among castes of the bald-faced hornet Dolichovespula maculata (Hymenoptera: Vespidae) in different phases of the colony cycle

Morphological and physiological caste differences were compared from colonies of Dolichovespula maculata in middle and late phases of the colony cycle. The females showed three patterns of ovarian development and only females classified as queens were inseminated. In both phases, queens were larger than workers for most measures. Discriminant analyses showed high distinction of caste in both phases. We also found highly pronounced qualitative differences: workers had hairs covering the entire body whereas queens had no hair and also some colour differences in the gaster. These results indicate that D. maculata presents pre-imaginal differentiation as seen in other Vespinae, and that size variation occurs from colony to colony such that queens of one colony may be comparable to workers of a different colony although the castes are always distinguishable within colonies.