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Pathogen infection and conspecific density may considerably affect key life‐history traits of organisms. For naturally aggregating species, even low concentrations of pathogens or high larval densities may have detrimental effects. However, the detailed influence of these factors, particularly their interaction effect, is often overlooked in ecological and life‐history studies. To investigate the effects of conspecific density and pathogen infection on life‐history traits, we explored the influence of larval density (1 and 5 larvae cm−2, i.e., low and high density, respectively) on phenoloxidase (PO) activity, body mass, and development time of Hermetia illucens L. (Diptera: Stratiomyidae) larvae in the presence of two strains of the entomopathogenic fungus (EPF) Beauveria bassiana (Bals.‐Criv.) Vuill. We observed higher PO activity in EPF‐treated larvae than in the untreated control and a pronounced difference in PO activity between the two EPF‐strain treatments. Larvae reared at high density and treated with EPF showed higher PO activity than untreated larvae at low density. The EPF‐treated larvae and larvae reared at high density had longer larval periods than untreated larvae and larvae reared at low density, respectively. Larvae reared at high density also achieved reduced prepupal and pupal masses compared to conspecifics at low density. Interestingly, untreated larvae only achieved higher prepupal and pupal masses at low density, whereas at high density, the pattern was reversed (treated individuals had higher pupal masses). Overall, our results demonstrate that high density and fungal pathogens both induce a higher immune response compared to low density and pathogen‐free environments, but this comes with a cost of a longer larval period and reduced body mass. [ABSTRACT FROM AUTHOR]

Entomophthoralean fungi are insect pathogenic fungi and are characterized by their active discharge of infective conidia that infect insects. Our aim was to study the effects of temperature on the discharge and to characterize the variation in the associated temporal pattern of a newly discovered Pandora species with focus on peak location and shape of the discharge. Mycelia were incubated at various temperatures in darkness, and conidial discharge was measured over time. We used a novel modification of a statistical model (pavpop), that simultaneously estimates phase and amplitude effects, into a setting of generalized linear models. This model is used to test hypotheses of peak location and discharge of conidia. The statistical analysis showed that high temperature leads to an early and fast decreasing peak, whereas there were no significant differences in total number of discharged conidia. Using the proposed model we also quantified the biological variation in the timing of the peak location at a fixed temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] • Entomophthorales overwinter as fungus-killed Rhopalosiphum padi on Prunus padus. • Zoophthora cf. aphidis formed resting spores; Entomophthora planchoniana modified hyphal bodies. • A negative correlation between eggs and fungus-killed cadavers per branch was found. • Numbers of eggs and cadavers varied greatly between years and location. • Prunus padus may act as a reservoir for fungi infecting aphids in cereals. In Scandinavia, the bird cherry-oat aphid Rhopalosiphum padi overwinter as eggs on the bird cherry tree Prunus padus. Branches of P. padus were collected at the late February / early March from 17 locations in Norway over a three-year period. We found 3599 overwintering aphid eggs, 59.5% of which were dead. Further, a total of 879 overwintering fungus-killed cadavers were observed. These cadavers were found close to bud axils, where overwintering eggs were also usually attached. Cadavers were infected with either Zoophthora cf. aphidis or Entomophthora planchoniana. All the fungal-killed cadavers were filled with overwintering structures of Z. cf. aphidis (as resting spores) or E. planchoniana (as modified hyphal bodies). We found a significant negative correlation between eggs and cadavers per branch. However, both numbers of eggs and cadavers varied greatly between years and among tree locations. This is the first report of E. planchoniana overwintering in R. padi cadavers as modified hyphal bodies. We discuss whether P. padus may act as an inoculum reservoir for fungi infecting aphids in cereals in spring. [ABSTRACT FROM AUTHOR]

In temperate regions, insect pathogenic fungi face the challenge of surviving through the winter. Winter is a time when hosts are immobile, low in number or are present in a stage which is not susceptible to infection. Fungi from Entomophthoromycota have so far been known to survive the winter in two ways: either as (1) thick-walled resting spores released into environment from dead hosts, or as (2) structures inside the dead host (e.g., hyphal bodies). Here we report, from the Danish environment, a third way to survive the winter, namely a slow progression and transmission of Entomophthora schizophorae in adult dipteran Pollenia hosts that hibernate in clusters in unheated attics, sheltered areas outdoors (under bark etc.). Fungus-killed sporulating flies were observed outside very early and very late in the season. By sampling adults at the time of their emergence from hibernation in late winter/early spring we documented that the fungus was naturally prevalent and killed flies after a period of incubation. Experimentally we documented that even at the low temperature of 5 °C, the fungus was able to maintain itself in Pollenia cohorts for up to 90 days. From these observations the full winter cycle of this fungus is elucidated. The three types of winter survival are discussed in relation to fungus epidemic development. [ABSTRACT FROM AUTHOR]

Abstract: The entomopathogenic fungus Pandora neoaphidis is a recognized pathogen of aphids, causes natural epizootics in aphid populations, and interacts and competes with aphid predators and parasitoids. Survival of entomophthoralean fungi in periods of unsuitable weather conditions or lack of appropriate host insects is accomplished mainly by thick-walled resting spores (zygospores or azygospores). However, resting spores are not known for some entomophthoralean species such as P. neoaphidis. Several hypotheses of P. neoaphidis winter survival can be found in the literature but so far these hypotheses do not include the presence of resting spores. Resting spores were found in an aphid population where P. neoaphidis was the only entomophthoralean fungus observed during surveys conducted in organic horticultural crops in greenhouses and open fields in Buenos Aires province, Argentina. This study sought to use molecular methods to confirm that these resting spores were, in fact, those of P. neoaphidis while further documenting and characterizing these resting spores that were produced in vivo in aphid hosts. The double-walled resting spores were characterized using light and transmission electron microscopy. The Argentinean resting spores clustered together with P. neoaphidis isolates with bootstrap values above 98 % in the small subunit ribosomal RNA (SSU rRNA) sequence analysis and with bootstrap values above 99 % the Internal Transcribed Spacer (ITS) II region sequence analysis. This study is the first gene-based confirmation from either infected hosts or cultures that P. neoaphidis is able to produce resting spores. [Copyright &y& Elsevier]

Three DNA regions (ITS 1, LSU rRNA and GPD) of isolates from the insect-pathogenic fungus genus Entomophthora originating from different fly ( Diptera) and aphid ( Hemiptera) host taxa were sequenced. The results documented a large genetic diversity among the fly-pathogenic Entomophthora and only minor differences among aphid-pathogenic Entomophthora. The evolutionary time of divergence of the fly and the aphid host taxa included cannot account for this difference. The host-driven divergence of Entomophthora, therefore, has been much greater in flies than in aphids. Host-range differences or a recent host shift to aphid are possible explanations. [ABSTRACT FROM AUTHOR]

Abstract: Isolates of the entomopathogenic fungus Entomophthora muscae were obtained from houseflies sampled at five stables on Zealand during an epidemic in fall 2005. DNA fingerprints were generated from single conidia from 40 E. muscae isolates using the PCR-based method of Inter-Simple Sequence Repeats (ISSR). This resulted in fingerprint patterns consisting of about 50 fragments, of which, 14 were polymorphic. From the polymorphic loci we estimated the reproductive mode, genetic differentiation and gene diversity of E. muscae populations using the statistics of index of association, Weir & Cockerhams theta and Nei''s analysis of gene diversity in subdivided populations. Our results revealed no significant differences in allele frequencies among the five populations. The index of association test rejected the null hypothesis of random mating, but the test for paired locus compatibility showed weak or no linkage between loci indicating recombination or homoplasy in the dataset. From this study we cannot exclude the possibility that the population genetic structure underlying E. muscae epidemics could be panmictic consisting of several lineages with a high level of reciprocal migration. [Copyright &y& Elsevier]

[Display omitted] • Two new species from the fungal genus Strongwellsea (Entomophthorales) are described. • Strongwellsea selandia infects adult Helina evecta (Diptera). • Strongwellsea gefion infects adult Helina reversio (Diptera). • The two new species differ from other described species from the genus. • Differences include morphology of spores, genetic identity, and host species. Two new species from the genus Strongwellsea (Entomophthorales: Entomophthoraceae) that infect adult flies from the genus Helina (Muscidae) are described: Strongwellsea selandia Eilenberg & Humber infecting adult Helina evecta (Harris), and Strongwellsea gefion Eilenberg & Humber infecting adult Helina reversio (Harris). The descriptions are based on pathobiological, phenotypical and genotypical characters. The new species differ from other described members from the genus Strongwellsea by a) pathobiology as revealed by natural host species, b) morphology of primary conidia, c) color of resting spores, and d) genotypical clustering based on analysis of ITS2. The two new species have only been documented from North Zealand, Denmark. [ABSTRACT FROM AUTHOR]

Strongwellsea crypta Eilenberg & Humber. [Display omitted] • Strongwellsea crypta is a new species infecting its dipteran host adult Botanophila fugax. • The description includes symptoms on the infected host, and morphology of spores. A new species from the genus Strongwellsea (Entomophthorales: Entomophthoraceae) is described: Strongwellsea crypta Eilenberg & Humber from adult Botanophila fugax (Meigen) (Diptera: Anthomyiidae). The description is based on pathobiological, phenotypical and genotypical characters. The abdominal holes in infected hosts develop rapidly and become strikingly large and edgy, almost rhomboid in shape. The new species S. crypta differs from S. castrans, the only described species infecting flies from Anthomyiidae, by: (a) naturally infecting another host species, (b) by having significantly longer primary conidia, and (c) by genotypical clustering separately from that species when sequencing ITS2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Laboratory infection bioassay with conidia shower from Pandora sp. nov. mycelial mat. • The entomopathogen infects insect families Psyllidae and Triozidae. • Survival times of fruit crop pests are significantly reduced after inoculation. • No interaction between phytoplasma infection of vector, host plant and the fungus. • Pandora sp. nov. has high potential to become a biocontrol agent for vector control. A new but still unpublished entomopathogenic fungus (ARSEF13372) in the genus Pandora (Entomophthorales: Entomophthoraceae) was originally isolated from Cacopsylla sp. (Hemiptera: Psyllidae). Several species of the genus Cacopsylla vector phloem-borne bacteria of the genus ' Candidatus Phytoplasma', which cause diseases in fruit crops such as apple proliferation, pear decline and European stone fruit yellows. To determine Pandora 's host range and biocontrol potential we conducted laboratory infection bioassays; Hemipteran phloem-feeding insects were exposed to conidia actively discharged from in vitro produced mycelial mats of standardized area. We documented the pathogenicity of Pandora sp. nov. to species of the insect families Psyllidae and Triozidae, namely Cacopsylla pyri L., C. pyricola (Foerster), C. picta (Foerster, 1848), C. pruni (Scopoli), C. peregrina (Foerster), and Trioza apicalis Foerster. The occurrence of postmortem signs of infection on cadavers within 10 days post inoculation proved that Pandora sp. nov. was infective to the tested insect species under laboratory conditions and significantly reduced mean survival time for C. pyri (summer form and nymph), C. pyricola , C. picta , C. pruni , C. peregrina and T. apicalis. Assessing a potential interaction between phytoplasma, fungus and insect host revealed that phytoplasma infection (' Candidatus Phytoplasma mali') of the vector C. picta and/or its host plant apple Malus domestica Borkh. did not significantly impact the survival of C. picta after Pandora sp. nov. infection. The results from infection bioassays were discussed in relation to Pandora sp. nov. host range and its suitability as biocontrol agent in integrated pest management strategies of psyllid pests, including vector species, in orchards. [ABSTRACT FROM AUTHOR]

Molecular methods were used to determine the generic placement of two species of Entomophthorales known only from resting spores. Historically, these species would belong in the form-genus Tarichium , but this classification provides no information about phylogenetic relationships. Using DNA from resting spores, Zoophthora independentia , infecting Tipula ( Lunatipula ) submaculata in New York State, is now described as a new species and Tarichium porteri , described in 1942, which infects Tipula ( Triplicitipula ) colei in Tennessee, is transferred to the genus Zoophthora . We have shown that use of molecular methods can assist with determination of the phylogenetic relations of specimens within the form-genus Tarichium for an already described species and a new species for which only resting spores are available. [ABSTRACT FROM AUTHOR]