Proteomic analyses of venom from a Spider Hawk, Pepsis decorata.

Background: The composition of the venom from solitary wasps is poorly known, although these animals are considered sources of bioactive substances. Until the present moment, there is only one proteomic characterization of the venom of wasps of the family Pompilidae and this is the first proteomic characterization for the genus Pepsis. Methods: To elucidate the components of Pepsis decorata venom, the present work sought to identify proteins using four different experimental conditions, namely: (A) crude venom; (B) reduced and alkylated venom; (C) trypsin-digested reduced and alkylated venom, and; (D) chymotrypsin-digested reduced and alkylated venom. Furthermore, three different mass spectrometers were used (Ion Trap-Time of Flight, Quadrupole-Time of Flight, and Linear Triple Quadruple). Results: Proteomics analysis revealed the existence of different enzymes related to the insect's physiology in the venom composition. Besides toxins, angiotensin-converting enzyme (ACE), hyaluronidase, and Kunitz-type inhibitors were also identified. Conclusion: The data showed that the venom of Pepsis decorata is mostly composed of proteins involved in the metabolism of arthropods, as occurs in parasitic wasps, although some classical toxins were recorded, and among them, for the first time, ACE was found in the venom of solitary wasps. This integrative approach expanded the range of compounds identified in protein analyses, proving to be efficient in the proteomic characterization of little-known species. It is our understanding that the current work will provide a solid base for future studies dealing with other Hymenoptera venoms.

Proteomic analyses of venom from a Spider Hawk, Pepsis decorata

Background: The composition of the venom from solitary wasps is poorly known, although these animals are considered sources of bioactive substances. Until the present moment, there is only one proteomic characterization of the venom of wasps of the family Pompilidae and this is the first proteomic characterization for the genus Pepsis. Methods: To elucidate the components of Pepsis decorata venom, the present work sought to identify proteins using four different experimental conditions, namely: (A) crude venom; (B) reduced and alkylated venom; (C) trypsin-digested reduced and alkylated venom, and; (D) chymotrypsin-digested reduced and alkylated venom. Furthermore, three different mass spectrometers were used (Ion Trap-Time of Flight, QuadrupoleTime of Flight, and Linear Triple Quadruple). Results: Proteomics analysis revealed the existence of different enzymes related to the insect’s physiology in the venom composition. Besides toxins, angiotensin-converting enzyme (ACE), hyaluronidase, and Kunitz-type inhibitors were also identified. Conclusion: The data showed that the venom of Pepsis decorata is mostly composed of proteins involved in the metabolism of arthropods, as occurs in parasitic wasps, although some classical toxins were recorded, and among them, for the first time, ACE was found in the venom of solitary wasps. This integrative approach expanded the range of compounds identified in protein analyses, proving to be efficient in the proteomic characterization of little-known species. It is our understanding that the current work will provide a solid base for future studies dealing with other Hymenoptera venoms.

Novel neuroprotective peptides in the venom of the solitary scoliid wasp Scolia decorata ventralis.

BACKGROUND: Solitary wasp venoms may be a rich source of neuroactive substances, since their venoms are used for paralyzing preys. We have been exploring bioactive constituents of solitary wasp venoms and, in this study, the component profile of the venom from a solitary scoliid wasp, Scolia decorata ventralis, was investigated through a comprehensive analysis using LC-MS. Two peptides were synthesized, and their neuroprotective properties were evaluated. METHODS: A reverse-phase HPLC connected to ESI-MS was used for LC-MS analyses. Online mass fingerprinting was performed from TIC, and data-dependent tandem mass spectrometry gave the MS/MS spectra. The sequences of two major peptide components were determined by MALDI-TOF/TOF MS analysis, confirmed by solid phase synthesis. Using the synthetic peptides, biological activities were assessed. Cell integrity tests and neuroprotection analyzes using H2O2 as an oxidative stress inducer were performed for both peptides. RESULTS: Online mass fingerprinting revealed that the venom contains 123 components, and the MS/MS analysis resulted in 33 full sequences of peptide components. The two main peptides, α-scoliidine (DYVTVKGFSPLR) and ß-scoliidine (DYVTVKGFSPLRKA), present homology with the bradykinin C-terminal. Despite this, both peptides did not behave as substrates or inhibitors of ACE, indicating that they do not interact with this metallopeptidase. In further studies, ß-scoliidine, but not α -scoliidine, showed protective effects against oxidative stress-induced neurotoxicity in PC12 cells through integrity and metabolism cell assays. Interestingly, ß-scoliidine has the extension of the KA dipeptide at the C-terminal in comparison with α-scoliidine. CONCLUSION: Comprehensive LC-MS and MS/MS analyses from the Scolia decorata ventralis venom displayed the component profile of this venom. ß-scoliidine showed an effective cytoprotective effect, probably due to the observed increase in the number of cells. This is the first report of solitary wasp venom peptides showing neuroprotective activity.

Isolation and characterization of FMRFamide-like peptides in the venoms of solitary sphecid wasps.

Purification of small peptide components in the venoms of the solitary sphecid wasps, Sphex argentatus argentatus and Isodontia harmandi, led to the isolation of several major peptides. Analysis of MS/MS spectra by MALDI-TOF/TOF revealed the sequence of a new peptide Sa112 (EDVDHVFLRF-NH2), which is structurally very similar to leucomyosupressin (pQDVDHVFLRF-NH2) and SchistoFLRFamide (PDVDHVFLRF-NH2), the FMRFamide-like peptides from cockroach and locust, respectively. Indeed, this new peptide, like SchistoFLRFamide, inhibited the frequency and amplitude of spontaneous contractions of the locust oviduct in a dose-dependent manner. A non-amidated peptide Sa12b (EDVDHVFLRF) was also isolated, but this peptide had no effect on spontaneous locust oviduct contraction. This is the first example of a FMRF-like peptide to be found in solitary wasp venom. Additionally, a truncated form of the myosuppressins, which has previously been synthesized and tested for biological activity, DVDHVFLRF-NH2 (Sh5b), was found for the first time as a natural product. Four other novel peptides were isolated and characterized as Sa81 (EDDLEDFNPTVS), Sa10 (EDDLEDFNPTIA), Sh41 (DDLSDFNPKV), and Sh42 (EDDLSDFNPKV). They are structurally related to each other, having a high content of acidic amino acids, but no structural similarity to any known peptides. Ion channel associated activities of Sh41 and Sh42 were tested, but did not show any activity for Na+, K+, Ca2+ channels.

Novel neuroprotective peptides in the venom of the solitary scoliid wasp Scolia decorata ventralis

Background Solitary wasp venoms may be a rich source of neuroactive substances, since their venoms are used for paralyzing preys. We have been exploring bioactive constituents of solitary wasp venoms and, in this study, the component profile of the venom from a solitary scoliid wasp, Scolia decorata ventralis, was investigated through a comprehensive analysis using LC-MS. Two peptides were synthesized, and their neuroprotective properties were evaluated. Methods A reverse-phase HPLC connected to ESI-MS was used for LC-MS analyses. Online mass fingerprinting was performed from TIC, and data-dependent tandem mass spectrometry gave the MS/MS spectra. The sequences of two major peptide components were determined by MALDI-TOF/TOF MS analysis, confirmed by solid phase synthesis. Using the synthetic peptides, biological activities were assessed. Cell integrity tests and neuroprotection analyzes using H2O2 as an oxidative stress inducer were performed for both peptides. Results Online mass fingerprinting revealed that the venom contains 123 components, and the MS/MS analysis resulted in 33 full sequences of peptide components. The two main peptides, α-scoliidine (DYVTVKGFSPLR) and β-scoliidine (DYVTVKGFSPLRKA), present homology with the bradykinin C-terminal. Despite this, both peptides did not behave as substrates or inhibitors of ACE, indicating that they do not interact with this metallopeptidase. In further studies, β-scoliidine, but not α -scoliidine, showed protective effects against oxidative stress-induced neurotoxicity in PC12 cells through integrity and metabolism cell assays. Interestingly, β-scoliidine has the extension of the KA dipeptide at the C-terminal in comparison with α-scoliidine. Conclusion Comprehensive LC-MS and MS/MS analyses from the Scolia decorata ventralis venom displayed the component profile of this venom. β-scoliidine showed an effective cytoprotective effect, probably due to the observed increase in the number of cells. This is the first report of solitary wasp venom peptides showing neuroprotective activity.(AU)

Novel neuroprotective peptides in the venom of the solitary scoliid wasp Scolia decorata ventralis

Background Solitary wasp venoms may be a rich source of neuroactive substances, since their venoms are used for paralyzing preys. We have been exploring bioactive constituents of solitary wasp venoms and, in this study, the component profile of the venom from a solitary scoliid wasp, Scolia decorata ventralis, was investigated through a comprehensive analysis using LC-MS. Two peptides were synthesized, and their neuroprotective properties were evaluated. Methods A reverse-phase HPLC connected to ESI-MS was used for LC-MS analyses. Online mass fingerprinting was performed from TIC, and data-dependent tandem mass spectrometry gave the MS/MS spectra. The sequences of two major peptide components were determined by MALDI-TOF/TOF MS analysis, confirmed by solid phase synthesis. Using the synthetic peptides, biological activities were assessed. Cell integrity tests and neuroprotection analyzes using H2O2 as an oxidative stress inducer were performed for both peptides. Results Online mass fingerprinting revealed that the venom contains 123 components, and the MS/MS analysis resulted in 33 full sequences of peptide components. The two main peptides, α-scoliidine (DYVTVKGFSPLR) and β-scoliidine (DYVTVKGFSPLRKA), present homology with the bradykinin C-terminal. Despite this, both peptides did not behave as substrates or inhibitors of ACE, indicating that they do not interact with this metallopeptidase. In further studies, β-scoliidine, but not α -scoliidine, showed protective effects against oxidative stress-induced neurotoxicity in PC12 cells through integrity and metabolism cell assays. Interestingly, β-scoliidine has the extension of the KA dipeptide at the C-terminal in comparison with α-scoliidine. Conclusion Comprehensive LC-MS and MS/MS analyses from the Scolia decorata ventralis venom displayed the component profile of this venom. β-scoliidine showed an effective cytoprotective effect, probably due to the observed increase in the number of cells. This is the first report of solitary wasp venom peptides showing neuroprotective activity.

Morphological studies on the last instar larvae of three South American species of Sphecidae (Hymenoptera: Apoidea).

As part of the effort to describe immature stages of South American apoid wasps species and to raise, describe, and illustrate new characters useful in taxonomic and phylogenetic studies of this group, the last instar larvae of three species are described: Ammophila gracilis Lepeletier de Saint Fargeau, 1845, Sphex opacus Dahlbom, 1845, Sphex dorsalis Lepeletier de Saint Fargeau, 1845. The specimens were colected in Brazil and analyzed using both optical and scainning eletronic microscope. Comparisons with other species of the genera Ammophila Kirby and Sphex Linnaeus are provided.

A study on taxonomy and phylogeny of immature stages of Sphecidae (Hymenoptera: Apoidea).

A taxonomic and phylogenetic study of Sphecidae based on morphology of last instar larvae and eggs is presented, including description of the family and a key to identify genera, tribes and subfamilies. Larval morphology of 12 species of Sphecidae was studied, along with four others used as outgroups (belonging to Ampulicidae, Crabronidae and Apidae). Thirty characters were listed from the morphological studies. Four genera were included in the analysis based only on literature. Thus, representatives of all the subfamilies and tribes of the Sphecidae were included in the analysis, except those of Stangeellini. The characters matrix was submitted to a parsimonious analysis using TNT version 1.5 and generated four equally parsimonious trees, with Length = 46, Consistence Index = 0.739, Retention Index = 0.878. The hypothesis of relationship suggested by the larvae and eggs is congruent with those suggested by the adult morphology in previous studies. The taxa Sphecidae, Sceliphrinae, Podiini, Sceliphrini, Prionychini and Ammophilinae, as well the assemblages Sceliphrinae + Chloriontinae and Sphecinae + Ammophilinae were supported by larval apomorphies. No apomorphy supporting the monophyly of Sphecinae and Sphecini was found.

Chemical and Biological Characteristics of Antimicrobial α-Helical Peptides Found in Solitary Wasp Venoms and Their Interactions with Model Membranes.

Solitary wasps use their stinging venoms for paralyzing insect or spider prey and feeding them to their larvae. We have surveyed bioactive substances in solitary wasp venoms, and found antimicrobial peptides together with some other bioactive peptides. Eumenine mastoparan-AF (EMP-AF) was the first to be found from the venom of the solitary eumenine wasp Anterhynchium flavomarginatum micado, showing antimicrobial, histamine-releasing, and hemolytic activities, and adopting an α-helical secondary structure under appropriate conditions. Further survey of solitary wasp venom components revealed that eumenine wasp venoms contained such antimicrobial α-helical peptides as the major peptide component. This review summarizes the results obtained from the studies of these peptides in solitary wasp venoms and some analogs from the viewpoint of (1) chemical and biological characterization; (2) physicochemical properties and secondary structure; and (3) channel-like pore-forming properties.

New Mastoparan Peptides in the Venom of the Solitary Eumenine Wasp Eumenes micado.

Comprehensive LC-MS and MS/MS analysis of the crude venom extract from the solitary eumenine wasp Eumenes micado revealed the component profile of this venom mostly consisted of small peptides. The major peptide components, eumenine mastoparan-EM1 (EMP-EM1: LKLMGIVKKVLGAL-NH2) and eumenine mastoparan-EM2 (EMP-EM2: LKLLGIVKKVLGAI-NH2), were purified and characterized by the conventional method. The sequences of these new peptides are homologous to mastoparans, the mast cell degranulating peptides from social wasp venoms; they are 14 amino acid residues in length, rich in hydrophobic and basic amino acids, and C-terminal amidated. Accordingly, these new peptides can belong to mastoparan peptides (in other words, linear cationic α-helical peptides). Indeed, the CD spectra of these new peptides showed predominantly α-helix conformation in TFE and SDS. In biological evaluation, both peptides exhibited potent antibacterial activity, moderate degranulation activity from rat peritoneal mast cells, and significant leishmanicidal activity, while they showed virtually no hemolytic activity on human or mouse erythrocytes. These results indicated that EMP-EM peptides rather strongly associated with bacterial cell membranes rather than mammalian cell membranes.

Chemical and biological characteristics of antimicrobial alpha-helical peptides found in solitary wasp venoms and their interactions with model membranes

Solitary wasps use their stinging venoms for paralyzing insect or spider prey and feeding them to their larvae. We have surveyed bioactive substances in solitary wasp venoms, and found antimicrobial peptides together with some other bioactive peptides. Eumenine mastoparan-AF (EMP-AF) was the first to be found from the venom of the solitary eumenine wasp Anterhynchium flavomarginatum micado, showing antimicrobial, histamine-releasing, and hemolytic activities, and adopting an a-helical secondary structure under appropriate conditions. Further survey of solitary wasp venom components revealed that eumenine wasp venoms contained such antimicrobial a-helical peptides as the major peptide component. This review summarizes the results obtained from the studies of these peptides in solitary wasp venoms and some analogs from the viewpoint of (1) chemical and biological characterization; (2) physicochemical properties and secondary structure; and (3) channel-like pore-forming properties.

New mastoparan peptides in the venom of the solitary eumenine wasp eumenes micado

Comprehensive LC-MS and MS/MS analysis of the crude venom extract from the solitary eumenine wasp Eumenes micado revealed the component profile of this venom mostly consisted of small peptides. The major peptide components, eumenine mastoparan-EM1 (EMP-EM1: LKLMGIVKKVLGAL-NH2) and eumenine mastoparan-EM2 (EMP-EM2: LKLLGIVKKVLGAI-NH2), were purified and characterized by the conventional method. The sequences of these new peptides are homologous to mastoparans, the mast cell degranulating peptides from social wasp venoms; they are 14 amino acid residues in length, rich in hydrophobic and basic amino acids, and C-terminal amidated. Accordingly, these new peptides can belong to mastoparan peptides (in other words, linear cationic a-helical peptides). Indeed, the CD spectra of these new peptides showed predominantly a-helix conformation in TFE and SDS. In biological evaluation, both peptides exhibited potent antibacterial activity, moderate degranulation activity from rat peritoneal mast cells, and significant leishmanicidal activity, while they showed virtually no hemolytic activity on human or mouse erythrocytes. These results indicated that EMP-EM peptides rather strongly associated with bacterial cell membranes rather than mammalian cell membranes

Peptide Toxins in Solitary Wasp Venoms.

Solitary wasps paralyze insects or spiders with stinging venom and feed the paralyzed preys to their larva. Accordingly, the venoms should contain a variety of constituents acting on nervous systems. However, only a few solitary wasp venoms have been chemically studied despite thousands of species inhabiting the planet. We have surveyed bioactive substances in solitary wasp venoms found in Japan and discovered a variety of novel bioactive peptides. Pompilidotoxins (PMTXs), in the venoms of the pompilid wasps Anoplius samariensis and Batozonellus maculifrons, are small peptides consisting of 13 amino acids without a disulfide bond. PMTXs slowed Na⁺ channel inactivation, in particular against neuronal type Na⁺ channels, and were rather selective to the Nav1.6 channel. Mastoparan-like cytolytic and antimicrobial peptides are the major components of eumenine wasp venoms. They are rich in hydrophobic and basic amino acids, adopting a α-helical secondary structure, and showing mast cell degranulating, antimicrobial and hemolytic activities. The venom of the spider wasp Cyphononyx fulvognathus contained four bradykinin-related peptides. They are hyperalgesic and, dependent on the structure, differently associated with B1 or B2 receptors. Further survey led to the isolation of leucomyosuppressin-like FMRFamide peptides from the venoms of the digger wasps Sphex argentatus and Isodontia harmandi. These results of peptide toxins in solitary wasp venoms from our studies are summarized.

Differential Properties of Venom Peptides and Proteins in Solitary vs. Social Hunting Wasps.

The primary functions of venoms from solitary and social wasps are different. Whereas most solitary wasps sting their prey to paralyze and preserve it, without killing, as the provisions for their progeny, social wasps usually sting to defend their colonies from vertebrate predators. Such distinctive venom properties of solitary and social wasps suggest that the main venom components are likely to be different depending on the wasps' sociality. The present paper reviews venom components and properties of the Aculeata hunting wasps, with a particular emphasis on the comparative aspects of venom compositions and properties between solitary and social wasps. Common components in both solitary and social wasp venoms include hyaluronidase, phospholipase A2, metalloendopeptidase, etc. Although it has been expected that more diverse bioactive components with the functions of prey inactivation and physiology manipulation are present in solitary wasps, available studies on venom compositions of solitary wasps are simply too scarce to generalize this notion. Nevertheless, some neurotoxic peptides (e.g., pompilidotoxin and dendrotoxin-like peptide) and proteins (e.g., insulin-like peptide binding protein) appear to be specific to solitary wasp venom. In contrast, several proteins, such as venom allergen 5 protein, venom acid phosphatase, and various phospholipases, appear to be relatively more specific to social wasp venom. Finally, putative functions of main venom components and their application are also discussed.

A simple non-invasive technique for venom milking from a solitary wasp Delta conoideum Gmelin (Hymenoptera: Vespidae).

Prospecting wasp, ant and bee venom for active bio-molecules has gained considerable interest among researchers in recent years. Collecting sufficient quantity of venom from solitary wasps without sacrificing them is often difficult. Here we describe a non-invasive technique for collecting venom from a solitary wasp Delta conoideum Gmelin (Red-backed potter wasp). Venom was milked by presenting an agar block to a single female wasp for stinging. The venom was extracted from the agar block using ACN: water solvent system. The total protein in venom was estimated quantitatively and the presence of peptides in the venom was confirmed by MALDI-TOF analysis. The proposed technique is non-invasive and pure venom can be repeatedly 'milked' using this method from other wasps and also bees without the need for sacrificing a large number of individuals.

Sexual behavior of the digger wasp Sphex ingens Smith (Hymenoptera, Sphecidae)

A species' mating system depends on its spatial distribution and temporal availability of mating opportunities, as well as on the resources that create these opportunities. In addition, for many species, courtship is driven by specific behaviors that precede and follow copulation. Although Sphex ingens is a taxonomically well known species of digger wasp, its ecology and behavior remain poorly known. Hence, we analyzed patterns and trends of sexual behavior, in order to understand whether courtship can persist in a polygamous mating system. We monitored by video wasp populations in Ilha Grande, southeastern Brazil. Based on the observed behaviors, we calculated stochastic probabilities with a Markov chain to infer on behavioral trends. We recorded four behavioral phases based on 19,196 behavioral acts observed in 224 copulation attempts. There were no significant differences in common behavioral acts between males and females. The copulation patterns, conflicts, and trends observed in S. ingens clearly show the influence of sexual selection in its promiscuous mating system.

An actinomycete isolate from solitary wasp mud nest having strong antibacterial activity and kills the Candida cells due to the shrinkage and the cytosolic loss.

An actinomycetes strain designated as MN 2(6) was isolated from the solitary wasp mud nest. The isolate was identified using polyphasic taxonomy. It produced the extensive branched brown substrate and white aerial hyphae that changed into grayish black. The aerial mycelia produced the spiral spore chains with rugose spore surface. The growth was observed between temperature range of 27-37°C, pH 8-10 and below salt concentration of 6% (w/v). The comparative analysis of 16S rRNA gene sequence and phylogenetic relationship showed that strain MN 2(6) lies in clade with Streptomyces hygroscopicus subsp. hygroscopicus NRRL 2387(T), Streptomyces sporocinereus NBRC 100766(T) and Streptomyces demainii NRRL B-1478(T) with which it shares a 16S rRNA gene sequence similarity of 99.3%. The strain MN 2(6) can be differentiated from type strains based on phenotypic characteristics. The strain MN 2(6) showed most promising activity against Gram-positive, Gram-negative bacteria, acid-fast bacilli and Candida species suggesting broad-spectrum characteristics of the active metabolite. Evaluation of anti-candidal activity of the metabolite of strain MN 2(6) by scanning electron microscopy (SEM) revealed changed external morphology of yeast. It kills the Candida cells due to the shrinkage and the cytosolic loss. However, further studies are required to elucidate the structure of the active metabolite produced by the isolate MN 2(6).

Nesting Biology of Podium angustifrons Kohl (Hymenoptera, Sphecidae) in an Araucaria Forest Fragment / Biologia de nidificação de Podium angustifrons Kohl (Hymenoptera, Sphecidae) em um fragmento de floresta com araucárias

Podium angustifrons Kohl 1902 is a species of solitary wasp which nests in pre-existing cavities, with neotropical distribution in Argentina, Bolivia, Brazil, Colombia, Guyana and French Guyana. The aim of this study was to investigate the nesting biology of P. angustifrons, discussing aspects of their life history. To capture its nests, wooden trap-nests were installed in the Parque Municipal das Araucárias, Guarapuava (PR), Brazil, from January 2003 to April 2009. A total of 29 nests were collected, all during the warmer months. These showed no vestibular and intercalary cells, and their closures were made up of chewed plants and mud mixed with organic materials and resin-coated surfaces, sometimes showing a layer of lichens. The cells were provisioned with various wild species of cockroaches (Chorisoneura sp, Riata sp and Helgaia sp) in the nymph stage and/or adults. The sex ratio was 4.6 females per male, significantly higher that the expected 1:1. Most pre-pupae entered diapause in winter with development time ranging from 187 to 283 days for females and 180 to 283 days for males. Deaths occurred in 41.66% of cells provisioned, 33.33% were attributed to faulty development and 8.33% to Chrysididae.

Podium angustifrons Kohl 1902 é uma espécie de vespa solitária que nidifica em cavidades pré-existentes, com distribuição na Argentina, Bolívia, Brasil, Colômbia, Guiania e Guiana Francesa. O objetivo deste estudo foi investigar a biologia de nidificação desta espécie, discutindo aspectos de sua história de vida. Para captura seus ninhos, foram instaladas ninhos-armadilha de madeira no Parque Municipal das Araucárias, Guarapuava (PR), Brasil, de Janeiro 2003 até Abril de 2009. Foram coletados 29 ninhos, durante todos os meses quentes. Os ninhos não apresentaram células vestibulares e intercalares, seus fechamentos são constituídos por material vegetal mascado, seguido de barro misturado a materiais orgânicos, revestidos por resina, podendo ter uma camada de liquens. As células foram aprovisionadas com diferentes espécies de baratas silvestres (Chorisoneura sp, Riata sp e Helgaia sp) em estágio de ninfa e/ou adulto. A maioria das pré-pupas entrou em diapausa no inverno com tempo de desenvolvimento de 187 a 283 dias para as fêmeas e 180 a 283 dias para machos. Ocorreu mortalidade em 41,66% das células aprovisionadas, sendo 33,33% causado por falha de desenvolvimento e 8,33% por cleptoparasitas da família Chrysididae.

Chemical and biological characterization of four new linear cationic á-helical peptides from the venoms of two solitary eumenine wasps

Four novel peptides were isolated from the venoms of the solitary eumeninewasps Eumenes rubrofemoratus and Eumenes fraterculus. Their sequences were determined by MALDI-TOF/ TOF (matrix assisted laser desorption/ionization time-of-flight mass spectrometry)analysis, Edman degradation and solid-phase synthesis. Two of them, eumenitin-R (LNLKGLIKKVASLLN) and eumenitin-F (LNLKGLFKKVASLLT), are highly homologous to eumenitin, an antimicrobial peptide from a solitary eumeninewasp, whereas the other two, EMP-ER (FDIMGLIKKVAGAL-NH2) and EMP-EF (FDVMGIIKKIAGAL-NH2), are similar to eumenine mastoparan-AF (EMP-AF), a mast cell degranulating peptide from a solitary eumeninewasp. These sequences have the characteristic features of linear cationic cytolyticpeptides; rich in hydrophobic and basic amino acids with no disulfide bond, and accordingly, they can be predicted to adopt an amphipathic a-helix secondary structure. In fact, the CD (circular dichroism) spectra of these peptides showed significant a-helical conformation content in the presence of TFE (trifluoroethanol), SDS (sodium dodecylsulfate) and asolectin vesicles. In the biological evaluation, all the peptides exhibited a significant broad-spectrum antimicrobial activity, and moderate mast cell degranulation and leishmanicidal activities, but showed virtually no hemolytic activity.

Nesting behavior of Podium denticulatum Smith (Hymenoptera: Sphecidae)

The nesting behavior of Podium denticulatum Smith was studied on the campus of Ribeirão Preto of the Universidade de São Paulo, SP, Brazil, from September 2003 to August 2005. The wasps established their nests in bamboo canes ranging from 11.4 cm to 26.2 cm in length and from 0.7 cm to 1.8 cm in internal diameter. Podium denticulatum nested almost exclusively in the hot and wet season (September-April), producing at least five generations per year. The cell provisioning was made with adult and nymphal cockroaches (Blattellidae) which were arranged venter-up and with the head inward toward the inner end of the cell. The construction of a temporary closure occurred in cells that took more than one day to be provisioned. The cells provisioned with a greater number of prey were more likely to produce females than males. The nests included 1-6 brood cells separated by mud partitions and arranged in a linear series. The innermost cells of the nests produced females, and the outermost cells produced males. Nests were parasitized by Eulophidae (Melittobia sp.), Chrysididae and Tachinidae.