The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform

Obrycki, John J. - One of the best experts on this subject based on the ideXlab platform.

S. Bjørnson - One of the best experts on this subject based on the ideXlab platform.

  • effects of microsporidiosis and food availability on the two spotted lady beetle adalia bipunctata l and convergent lady beetle Hippodamia convergens guerin meneville
    Journal of Invertebrate Pathology, 2019
    Co-Authors: T. Steele, S. Bjørnson
    Abstract:

    Abstract Two species of microsporidia have been described from lady beetles that are commercially available for biological control: Nosema adaliae from the two-spotted lady beetle, Adalia bipunctata L., and Tubulinosema Hippodamiae from the convergent lady beetle, Hippodamia convergens Guerin-Meneville. These pathogens delay larval development under controlled conditions, but little is known regarding the effects that microsporidia cause when their hosts are subjected to stressful conditions that are often experienced in nature. In this study, the combined effects of microsporidiosis (N. adaliae on A. bipunctata and T. Hippodamiae on H. convergens) and irregular food availability were observed on host fitness (larval development and mortality, sex ratios, and adult morphometrics). For each beetle species, 24 h-old larvae were provided either an uninfected or microsporidia-infected conspecific egg. After the egg was eaten, some larvae were provided an abundance of aphids daily, whereas others were provided aphids on an irregular basis. Development was delayed significantly for larvae that consumed a microsporidia-infected egg, and for those fed irregularly. For A. bipunctata, a significant interaction was observed between infection status and food availability. This suggests that N. adaliae-infected A. bipunctata larvae that have an irregular supply of aphids undergo further developmental delays than those with a generous food supply. This interaction was not observed for T. Hippodamiae-infected H. convergens. For both species, larval mortality and sex ratios did not differ significantly, regardless of infection status or food availability. Adults that were fed daily as larvae were significantly larger than those fed irregularly. However, the elytra of N. adaliae-infected A. bipunctata were significantly larger than the elytra of their uninfected cohorts, and T. Hippodamiae-infected H. convergens had wider pronota and head capsules than uninfected H. convergens. Because N. adaliae and T. Hippodamiae prolong larval development of their respective hosts under controlled conditions, one would expect these pathogens to cause more profound effects when their hosts experience stressful conditions. The results from this study indicate that this was the case for A. bipunctata, but not for H. convergens.

  • The convergent lady beetle, Hippodamia convergens Guérin-Méneville and its endoparasitoid Dinocampus coccinellae (Schrank): the effect of a microsporidium on parasitoid development and host preference.
    Journal of invertebrate pathology, 2013
    Co-Authors: T. Saito, S. Bjørnson
    Abstract:

    Convergent lady beetles, Hippodamia convergens Guerin-Meneville are host to the braconid endoparasitoid, Dinocampus coccinellae (Schrank) and the microsporidian pathogen, Tubulinosema Hippodamiae. The interrelationship between the endoparasitoid and the pathogen in H. convergens adults under laboratory conditions was examined by quantifying the effect of microsporidiosis on D. coccinellae development and host preference. Uninfected wasps were provided either uninfected or T. Hippodamiae-infected beetles as hosts and the development of their progeny was observed over 30 days. The duration of endoparasitoid development from egg deposition in the host until adult eclosion for D. coccinellae did not differ significantly, regardless of the infection status of the host beetle. All wasp progeny that developed within, and emerged from, T. Hippodamiae-infected beetles were infected with the microsporidian pathogen (n = 48; 100% transmission). Infected D. coccinellae adults were also provided either uninfected or T. Hippodamiae infected host beetles so that the development of their progeny could be assessed over 30 days. Endoparasitoid development did not differ significantly; however, a significantly greater proportion of beetles stung by microsporidia-infected wasps did not contain an endoparasitoid larva when dissected at the end of the 30-day trial when compared to those stung by uninfected wasps. This suggests that the pathogen may reduce wasp fecundity or egg viability. Examination of paraffin-embedded D. coccinellae adult tissues revealed an extensive microsporidian infection throughout all major organs and tissues with exception of the ovary. During host choice trials, uninfected and microsporidia-infected D. coccinellae adults pursued, took an ovipositional stance, and attacked uninfected beetles more often than microsporidia-infected hosts but these observations did not differ significantly (P > 0.05).

  • The effects of two microsporidian pathogens on the two-spotted lady beetle, Adalia bipunctata L. (Coleoptera: Coccinellidae).
    Journal of Invertebrate Pathology, 2012
    Co-Authors: T. Steele, S. Bjørnson
    Abstract:

    Abstract Two-spotted lady beetles, Adalia bipunctata L. are available for biological pest control in North America. Lady beetles are known to host microsporidia and although these pathogens are able to infect more than one host under laboratory conditions, little is known regarding the effects of more than one microsporidian pathogen on host fitness. In this study, egg cannibalism was used to examine the effects of the microsporidium Tubulinosema Hippodamiae from Hippodamia convergens and an undescribed microsporidium from A. bipunctata (alone and in combination) on A. bipunctata host fitness (larval development and mortality, sex ratio, adult fecundity and longevity). Development was prolonged significantly for larvae that were infected with the undescribed microsporidium but T. Hippodamiae had no effect and as a result, conclusions could not be made regarding the effects of both pathogens on larval development. The two microsporidia had no effect on sex ratios (1♀:1♂) or on adult fecundity and longevity. Spores were detected in the majority of smear preparations of individuals that were fed microsporidia-infected eggs and molecular analysis confirmed the identity of both pathogens in sampled individuals. T. Hippodamiae spores were smaller than spores of the undescribed microsporidium (3.76 ± 0.03 × 2.32 ± 0.02 μm and 5.43 ± 0.06 × 2.75 ± 0.03 μm, respectively) and although the former stained less intensely than did those of latter, spores of the two pathogens are difficult to differentiate when examined by light microscopy alone. The ability of some microsporidia to infect more than one lady beetle host makes it difficult to conclude with certainty as to the number of species that are present in infected Adalia when specimens are examined solely by light microscopy.

  • ultrastructure and molecular characterization of a microsporidium tubulinosema Hippodamiae from the convergent lady beetle Hippodamia convergens guerin meneville
    Journal of Invertebrate Pathology, 2011
    Co-Authors: S. Bjørnson, T. Saito, H Wang
    Abstract:

    Abstract Hippodamia convergens, the convergent lady beetle, is available for aphid control in home gardens and in commercial food production systems throughout the United States and Canada. Beetles received from commercial insectaries for biological control are occasionally infected with a microsporidium. The objective of this study was to describe the pathogen by means of ultrastructure, molecular characterization and tissue pathology. All stages of the microsporidium were in direct contact with the host cell cytoplasm. Early developmental stages were proximal to mature spores and both were observed throughout the tissue sections that were examined. Merogony resulted from binary fission. Early-stage sporoblasts were surrounded by a highly convoluted plasma membrane and contained an electron-dense cytoplasm and diplokaryon. Ovoid to elongated late-stage sporoblasts were surrounded by a relatively complete spore wall. The polar filament, polaroplast, and anchoring disk were readily observed within the cell cytoplasm. Mature spores were typical of terrestrial microsporidia, with a thickened endospore surrounded by a thin exospore. Spores contained well-defined internal structures, including a diplokaryon, lamellar polaroplast and a slightly anisofilar polar filament with 10–14 coils arranged in a single or double row. A prominent indentation was evident at the apical end of the spore wall proximal to the anchoring disk. Aberrant spores were also observed. These had a fully developed endospore and exospore but lacked any discernable internal spore structures, and were, instead, filled with lamellar or vesicular structures. Typical and aberrant spores measured 3.58 ± 0.2 × 2.06 ± 0.2 μm (n = 10) and 3.38 ± 0.8 × 2.13 ± 0.2 μm (n = 10), respectively. Spores were observed in longitudinal muscle surrounding the midgut and within the fat body, Malpighian tubules, pyloric valve epithelium, ventral nerve cord ganglia, muscles and ovaries. The hindgut epithelium was often infected but the connective tissues were rarely invaded. The life cycle and pathology of the microsporidium bears some resemblance to Nosema Hippodamiae, the only microsporidium reported from H. convergens by Lipa and Steinhaus in 1959. Molecular characterization of the pathogen genomic DNA revealed that it is 99% similar to Tubulinosema acridophagus and T. ratisbonensis, two pathogens that infect Drosophila melanogaster and 98% similar to T. kingi from D. willistoni. Based on similarities in pathogen ultrastructure and the molecular information gained during this study, we propose that the microsporidium in H. convergens be given the name Tubulinosema Hippodamiae.

  • natural enemies of the convergent lady beetle Hippodamia convergens guerin meneville their inadvertent importation and potential significance for augmentative biological control
    Biological Control, 2008
    Co-Authors: S. Bjørnson
    Abstract:

    Abstract Each year, Hippodamia convergens adults are collected from their overwintering sites in California and made commercially available for aphid control in agriculture and in home gardens. This study examines the prevalence of natural enemies encountered in commercially available H. convergens from three commercial suppliers. Microsporidia were detected in individuals from 13 of 22 shipments (0.9% prevalence, range 0–3%). Spore dimensions (3.9 ± 0.1 × 2.5 ± 0.1 μm; n  = 50) were similar to those of Nosema Hippodamiae (reported previously from H. convergens ), Nosema tracheophila and Nosema coccinellae (reported from other coccinellids). Because H. convergens are sold in large quantities, thousands of microsporidia-infected beetles could be released each time H. convergens are used. Three distinct eugregarines were observed in H. convergens (0.2% prevalence) but none were similar in size to Gregarina barbarara , the only eugregarine reported from H. convergens. Although eugregarines are usually considered as mutualist symbionts or weak pathogens, the relationship between eugregarines and coccinellids is not fully understood. The hymenopteran parasitoid, Dinocampus coccinellae , was found in beetles from all shipments (8% mean parasitism, range: 3–15%). Significantly more females were parasitized than males. The importation and release of D. coccinellae undermine the success of biological control programs and may artificially increase the number of parasitoids in an area where H. convergens are released. Verticillium sp. (2% prevalence; range: 0–9%) was also observed but its role is unknown. Beetle quantities and sex ratios were also assessed.

Elme-tumpay Araseli - One of the best experts on this subject based on the ideXlab platform.

Hesler, Louis S. - One of the best experts on this subject based on the ideXlab platform.

Bijan Hatami - One of the best experts on this subject based on the ideXlab platform.

  • Study of Predatory Lady Beetles Fauna (Coleoptera, Coccinellidae) Associated with Pomegranate Orchards on Aphis punicae Passerini in the Najafabad Region (Isfahan Province), Iran
    Journal of Biological Control, 2016
    Co-Authors: Zahra Fattah-almanan, Alireza Jalalizand, Bijan Hatami
    Abstract:

    Lady beetles (Coleoptera: Coccinellidae) as a biological control agent are a group of beetles with a considerable diversity and adaptation in different habitats. Among aphids, Aphis punicae Passerini (Hemiptera: Aphididae) is one of the most important pests of pomegranate orchards in Iran. This pest reduces plant vigor, facilitate the growth of mold on leaves, and consequently influences crop quality and yield. Study on the fauna of predatory ladybugs associated with pomegranate orchards was conducted that were feeding on Aphis punicae in the Najafabad region (Isfahan province, Iran). Twelve species of 8 genera were collected Sampled specimens were identified according to their morphological, male and female genitalia characters using identification keys. The identified species were as follow: Adalia bipunctata (Linnaeus, 1758), Coccinella septempunctata Linnaeus, 1758, Coccinella undecimpunctata  Linnaeus, 1758, Exochomus undulates Weise, 1878, Hippodamia variegate (Goeze, 1777), Hippodamia tredecimpunctata ( Linnaeus, 1758), Oenopia conglobata (Linnaeus, 1758), Oenopia oncina (Olivier, 1808), Propylea quatuordecimpuctata (Linnaeus, 1758), Psyllobora vigintiduopunctata (Linnaeus, 1758), Scymnus syriacus (Marseul, 1868), Scymnus mongolicus (Weise, 1890).

  • Study of Predatory Lady Beetles Fauna (Coleoptera, Coccinellidae) Associated with Pomegranate Orchards on Aphis punicae Passerini in the Najafabad Region (Isfahan Province), Iran
    Journal of Biological Control, 2016
    Co-Authors: Zahra Fattah-almanan, Alireza Jalali-zand, Bijan Hatami
    Abstract:

    Lady beetles (Coleoptera: Coccinellidae) as a biological control agent are a group of beetles with a considerable diversity and adaptation in different habitats. Among aphids, <em>Aphis punicae</em> Passerini (Hemiptera: Aphididae) is one of the most important pests of pomegranate orchards in Iran. This pest reduces plant vigor, facilitate the growth of mold on leaves, and consequently influences crop quality and yield. Study on the fauna of predatory ladybugs associated with pomegranate orchards was conducted that were feeding on <em>Aphis punicae</em> in the Najafabad region (Isfahan province, Iran). Twelve species of 8 genera were collected Sampled specimens were identified according to their morphological, male and female genitalia characters using identification keys. The identified species were as follow: <em>Adalia bipunctata</em> (Linnaeus, 1758), <em>Coccinella septempunctata</em> Linnaeus, 1758, <em>Coccinella undecimpunctata</em> Linnaeus, 1758, <em>Exochomus undulates</em> Weise, 1878, <em>Hippodamia variegate</em> (Goeze, 1777), <em>Hippodamia tredecimpunctata</em><em> (</em>Linnaeus, 1758), <em>Oenopia conglobata</em> (Linnaeus, 1758), <em>Oenopia oncina</em> (Olivier, 1808), <em>Propylea quatuordecimpuctata</em> (Linnaeus, 1758), <em>Psyllobora vigintiduopunctata</em> (Linnaeus, 1758), <em>Scymnus syriacus</em> (Marseul, 1868), <em>Scymnus mongolicus </em>(Weise, 1890).

  • Study of Predatory Lady Beetles Fauna (Coleoptera, Coccinellidae) Associated with Pomegranate Orchards on Aphis punicae Passerini in the Najafabad Region (Isfahan Province), Iran
    Journal of Biological Control, 2016
    Co-Authors: Zahra Fattah-almanan, Alireza Jalalizand, Bijan Hatami
    Abstract:

    Lady beetles (Coleoptera: Coccinellidae) as a biological control agent are a group of beetles with a considerable diversity and adaptation in different habitats. Among aphids, Aphis punicae Passerini (Hemiptera: Aphididae) is one of the most important pests of pomegranate orchards in Iran. This pest reduces plant vigor, facilitate the growth of mold on leaves, and consequently influences crop quality and yield. Study on the fauna of predatory ladybugs associated with pomegranate orchards was conducted that were feeding on Aphis punicae in the Najafabad region (Isfahan province, Iran). Twelve species of 8 genera were collected Sampled specimens were identified according to their morphological, male and female genitalia characters using identification keys. The identified species were as follow: Adalia bipunctata (Linnaeus, 1758), Coccinella septempunctata Linnaeus, 1758, Coccinella undecimpunctata  Linnaeus, 1758, Exochomus undulates Weise, 1878, Hippodamia variegate (Goeze, 1777), Hippodamia tredecimpunctata ( Linnaeus, 1758), Oenopia conglobata (Linnaeus, 1758), Oenopia oncina (Olivier, 1808), Propylea quatuordecimpuctata (Linnaeus, 1758), Psyllobora vigintiduopunctata (Linnaeus, 1758), Scymnus syriacus (Marseul, 1868), Scymnus mongolicus (Weise, 1890).