Neozygites osornensis sp. nov., a fungal species causing mortality to the cypress aphid Cinara cupressi in Chile.

An entomophthoralean fungus causing epizootics in populations of the cypress aphid, Cinara cupressi Buckton, in Chile is described as a new species, Neozygites osornensis Montalva et Barta. The aphid pathogen is described based on morphological characters. An exhaustive description, illustrations and a comparison with closely related species are provided. The fungus differs from similar Neozygites species by smaller hyphal bodies, nuclei, primary conidia, capilliconidia and capilliphores and by noticeably different shape of capilliconidia. A key to aphid-pathogenic species of Neozygites is also included.

Pathology and epizootiology of Entomophaga maimaiga infections in forest Lepidoptera.

The insect-pathogenic fungal pathogen Entomophaga maimaiga is endemic to northeastern Asia and was first found in North America in 1989. Due to repeated epizootics and spread within populations of the major forest defoliator in northeastern North America, the gypsy moth (Lymantria dispar), this pathogen has gained much notoriety. Although this pathogen was purposely introduced to North America for biological control of L. dispar in 1910 to 1911, it is questionable whether it became established at the time of release and then remained at innocuous levels until relatively recently. Alternatively, the fungal strain present in North America today could be a more recent accidental introduction. DNA analysis demonstrates that this pathogen differs significantly from North American members of the same species complex (the Lepidoptera-specific Entomophaga aulicae species complex), and, to date, isolates of this introduced pathogen display little heterogeneity in North America. Nonsusceptible lepidopteran larvae have been identified, and either E. maimaiga is unable to penetrate the cuticle or the fungus cannot survive within the hemocoel. In the latter case, although E. maimaiga grows as protoplasts lacking cell walls in the host hemolymph, glycoproteins on plasma membranes of the protoplasts could lead to host recognition. Epizootiological studies demonstrate a clear association between fungal activity and environmental moisture but little association with host density under hypothesized conditions of high fungal density. Prediction of the occurrence of epizootics is not yet possible. E. maimaiga is easily established in new areas by releasing azygospores, but the ability to use this pathogen further for biological control will depend, in large part, on the development of mass production systems.

A novel computerised image analysis method for the measurement of production of conidia from the aphid pathogenic fungus Erynia neoaphidis.

A semi-automated method has been developed for the quantification and measurement of conidia discharged by the aphid pathogen Erynia neoaphidis. This was used to compare conidiation by E. neoaphidis-mycosed pea aphid cadavers, mycelial plugs cut from agar plates, mycelial pellets from shake flasks and by mycelial pellets from different phases of liquid batch fermenter culture. Aphid cadavers discharged significantly more and significantly smaller conidia than plugs or pellets. The volume of conidia discharged was stable over the period of discharge (80 h), but more detailed analysis of the size frequency distribution showed that more very small and very large conidia were discharged after 5 h incubation than after 75 h incubation. Biomass harvested at the end of the exponential growth phase in batch fermenter culture produced significantly more conidia than biomass from any other growth phase. The implications of these findings for the development of production and formulation processes for E. neoaphidis as a biological control agent are discussed.

The occurrence of two species of Entomophthorales (Entomophthoromycota), pathogens of Sitobion avenae and Myzus persicae (Hemiptera: Aphididae), in Tunisia.

The natural occurrence of entomophthoralean fungi pathogenic towards aphids on cereal and potato crops was investigated in the years 2009, 2010, and 2011. Infected aphids were sampled in three bioclimatic zones in Tunisia (Beja, Cap bon, and Kairouan) and fungal species were determined based on morphological characters such as shape, size, and number of nuclei in the primary conidia. Polymerase Chain Reaction (PCR) on the internal transcribed spacer 1 region (ITS1) was used to verify morphological determination. Both methods gave consistent results and we documented for the first time the natural occurrence of two fungal species from the order Entomophthorales (phylum Entomophthoromycota), Pandora neoaphidis and Entomophthora planchoniana. Both fungi were recorded on the aphid species Sitobion avenae and Myzus persicae on barley ears and potato leaves, respectively. Moreover, natural mixed infections by both species (P. neoaphidis and E. planchoniana) were documented on the target aphids. This investigation provides basic information of entomopathogenic fungi infecting economically important aphids in Tunisia.

Neozygites abacaridis sp. nov. (Entomophthorales), a new pathogen of phytophagous mites (Acari, Eriophyidae).

A new entomopathogenic fungus, described here as Neozygites abacaridis n. sp. (Zygomycetes: Entomophthorales), has been found on the mites Abacarus hystrix, Aculodes dubius, and A. mckenziei (Acari: Eriophyidae). It differs from other Neozygites species affecting mites by its small, globose primary conidia, short-ovoid, smoky coloured capilliconidia, and very short capillary conidiophores-which are usually not longer than the spore length. This pathogen infected mite individuals in autumn (from mid-August until mid-November) on Lolium perenne, Agrostis stolonifera, and Festuca rubra. It caused 0.5-1% host's mortality in the vicinity of Siedlce (Eastern Poland) and up to 2-8%, on an average in Puszczykowo (Wielkopolski National Park near Poznan), where its prevalence on some plants reached 13%.

Entomophthora leyteensis Villacarlos & Keller sp. nov. (Entomophthorales: Zygomycetes) infecting Tetraleurodes acaciae (Quaintance) (Insecta, Hemiptera: Aleyrodidae), a recently introduced whitefly on Gliricidia sepium (Jaq.) Walp. (Fabaceae) in the Philippines.

Entomophthora leyteensis Villacarlos & Keller sp. nov., a species of Entomophthorales infecting the whitefly Tetraleurodes acaciae on Gliricidia sepium in the Philippines is described. Disease prevalence monitored weekly for 8 weeks indicated that the fungus could cause 8-31% infection within the whitefly population. Epizootics due to this fungus occurred in Inopacan, Leyte. Sampling live whitefly adults and dissecting them on glass slides for microscopic examination of fungal structures was found to give a better measure of prevalence than actual counts of infected insect cadavers. E. leyteensis is an important mortality factor for T. acaciae. Some speculations on the origin of the fungus are discussed here.