scholarly journals Sleeping Beauties: Horizontal Transmission via Resting Spores of Species in the Entomophthoromycotina

Insects ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 102 ◽  
Author(s):  
Ann Hajek ◽  
Donald Steinkraus ◽  
Louela Castrillo

Many of the almost 300 species of arthropod-pathogenic fungi in the Entomophthoromycotina (Zoopagomycota) are known for being quite host-specific and are able to cause epizootics. Most species produce two main types of spores, conidia and resting spores. Here, we present a review of the epizootiology of species of Entomophthoromycotina, focusing on their resting spores, and how this stage leads to horizontal transmission and persistence. Cadavers in which resting spores are produced can often be found in different locations than cadavers of the same host producing conidia. Resting spores generally are dormant directly after production and require specific conditions for germination. Fungal reproduction resulting from infections initiated by Entomophaga maimaiga resting spores can differ from reproduction resulting from conidial infections, although we do not know how commonly this occurs. Reservoirs of resting spores can germinate for variable lengths of time, including up to several months, providing primary infections to initiate secondary cycling based on conidial infections, and not all resting spores germinate every year. Molecular methods have been developed to improve environmental quantification of resting spores, which can exist at high titers after epizootics. Ecological studies of biological communities have demonstrated that this source of these spores providing primary inoculum in the environment can decrease not only because of germination, but also because of the activity of mycopathogens.

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 383
Author(s):  
Nao Fujiwara-Tsujii ◽  
Hiroe Yasui

The white-spotted longicorn beetle, Anoplophora malasiaca, is one of the most destructive pests of horticultural crops and street trees. Effective controls are needed because the effect of marketed insecticides is limited. Entomopathogenic fungi offer a solution, and improving the rate of infection would be a breakthrough in this beetle’s control. The combination of pathogenic fungi and the beetle’s contact sex pheromone was suggested. The surface of the female body is covered with contact sex pheromone, which elicit male mating behavior. To develop a method for the practical control of this beetle, we evaluated the arrestant activity of female extract containing contact pheromone coated on a black glass model. Males presented with a coated model held on for 5 h (mean) during an 8-h experiment. In contrast, males presented with a control model held on for <0.3 h. Males that held onto coated models attached to fabric impregnated with conidia of the fungus Beauveria brongniartii picked up much conidia, which they then passed on to females during mating.


1995 ◽  
Vol 73 (S1) ◽  
pp. 1275-1283 ◽  
Author(s):  
Shigehito Takenaka

To develop efficient control measures against fungal plant pathogens, the dynamics of host plant colonization during disease development and the interactions among fungi within host plant tissues need to be clarified. These studies require accurate quantitative estimation of specific fungal biomass in plant tissues. This has been approached by direct-microscopic methods, cultural methods, chemical determinations of fungal components, serological methods, and molecular methods. Among these methods, serological and molecular methods provide rapid, specific, and sensitive quantitative measures of fungal biomass in host plant tissues. Therefore, studies on fungal dynamics of host plant colonization using these two methods are presented. Some examples of species interactions among pathogenic fungi within host plants, such as synergism and competition, are reviewed and the usefulness of serological and molecular methods for studies on these interactions is presented. These quantitative methods will provide helpful information for understanding the ecology of plant pathogenic fungi, such as the dynamics of host plant colonization and species interactions. Key words: quantitative methods, fungal biomass, ELISA, PCR, fungal colonization, species interaction.


1999 ◽  
Vol 34 (1) ◽  
pp. 84-100 ◽  
Author(s):  
R. E. Webb ◽  
G. B. White ◽  
K. W. Thorpe ◽  
S. E. Talley

The population dynamics of a “leading edge” (= at the edge of the expanding gypsy moth invasion) gypsy moth, Lymantria dispar (L.), population was monitored for 3 years (1995–97), with emphasis on the interactions of the gypsy moth nuclear polyhedrosis virus (LdNPV) and the fungus Entomophaga maimaiga Humber, Shimazu, & Soper. Gypsy moth populations in the woodlots varied from very sparse to high (potentially defoliating) levels. LdNPV was strongly density dependent, being confirmed only from the higher populated woodlots. In contrast, the fungus was similarly active in both sparse and highly-populated woodlots. In 1995, the fungal epizootic developed late in the season, with most larvae succumbing during stadia 5–6 and producing mainly resting spores (azygospores). Estimated mortality due to fungus averaged 68% in high-density plots and 85% in low-density plots. LdNPV mortality occurred in a two-wave epizootic, although second-wave LdNPV mortality was undoubtedly reduced because of the reduction of late-season larvae due to fungus activity. Estimated mortality due to LdNPV averaged 14% in highly-populated plots and 1% in low-population plots. In 1996, high levels of fungal-induced mortality occurred earlier in the gypsy moth season than in the previous year. Most gypsy moth larvae in 1996 died in a mid-season wave of fungal-induced mortality, with necropsied cadavers containing only conidia. This resulted in relatively few larvae surviving to late instars. At this time, a second wave of fungus-induced mortality occurred, with over half of the necropsied cadavers containing resting spores. The depletion of the gypsy moth populations by the fungus in 1995 resulted in a greatly reduced first wave of LdNPV in all plots in 1996, and perhaps due to the early appearance of the fungus in 1996, LdNPV was nearly absent from late-season larvae collected from all plots. In 1997, gypsy moth populations were uniformly low, and no dead larvae were found in any of the plots.


2007 ◽  
Vol 85 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Shota Jikumaru ◽  
Toshikazu Sano

Attachment of late-instar Lymantria dispar L. (Lepidoptera: Lymantriidae) cadavers killed by Entomophaga maimaiga Humber, Shimazu et Soper (Zygomycetes: Entomophthorales) on trunks of five dominant tree species was determined in a broadleaf forest in southwestern Japan. The highest numbers of cadavers were found attached to the trunk of Pasania glabra (Thunb.) Oerst., while there were moderate numbers of cadavers on the trunks of Quercus glauca Thunb. and Quercus serrata Thunb. and no cadavers were found attached to trunks of Ilex pedunculosa Miq. and Clethra barbinervis Sieb. et Zucc.. All examined cadavers contained E. maimaiga resting spores. The differences in cadaver attachment among tree species may influence density of E. maimaiga resting spores around tree bases, which act as reservoirs for fungal survival during unfavorable periods or over numerous years. Our results provide important information as to where to collect E. maimaiga resting spores for biological control of L. dispar, especially in forests containing many tree species.


2001 ◽  
Vol 11 (5) ◽  
pp. 637-647 ◽  
Author(s):  
Ann E. Hajek ◽  
Micheal M. Wheeler ◽  
Callie C. Eastburn ◽  
Leah S. Bauer

2014 ◽  
Vol 2014 ◽  
pp. 1-18
Author(s):  
Beslin Leena Grace

For the conservation of biodiversity, it is not sufficient to preserve the living organisms or their gametes alone, because keeping fishes in aquaria or their gametes in freezers cannot conserve the full range of biodiversity which is due to the loss of the ecological complexity in their original habitats. For promoting richer biodiversity in the future, more complexity in biological communities is essential in their natural environments. In order to prevent depletion of biodiversity due to environmental alterations or other ways, it is necessary to understand how the diversity of life particularly at the species level is maintained and it is equally necessary to know how the terminal extinction of species takes place under natural conditions. Moreover, a database on fishery resources of the concerned environment is essential to make decision about specific programmes on conservation of fish germplasm resources. Hence, the present study aims to quantify the fish and shellfish resources of the selected backwaters such as Kadinamkulam, Veli, and Poonthura to know the real stocks present in such environments.


2007 ◽  
Vol 111 (3) ◽  
pp. 324-331 ◽  
Author(s):  
Louela A. Castrillo ◽  
Lene Thomsen ◽  
Punita Juneja ◽  
Ann E. Hajek

Fermentation ◽  
2019 ◽  
Vol 5 (4) ◽  
pp. 86 ◽  
Author(s):  
Lisa Granchi ◽  
Donatella Ganucci ◽  
Giacomo Buscioni ◽  
Silvia Mangani ◽  
Simona Guerrini

Saccharomyces cerevisiae populations occurring in spontaneous wine fermentations display a high polymorphism, although few strains are generally able to dominate the fermentative process. Recent studies have suggested that these indigenous S. cerevisiae strains are representative of a specific oenological ecosystem, being associated to a given wine-producing area or a single winery. In contrast, according to other ecological studies, no correlation between genotypic and phenotypic groups of the native S. cerevisiae strains and their origin was found. In this work, several S. cerevisiae strains were isolated in consecutive years from spontaneous fermentations carried out in the same wineries located in different oenological areas in Tuscany, and their persistence was assessed by molecular methods. Some predominant S. cerevisiae strains persisted in different fermentations in the same winery from one year to another and they seemed to be representative of a single winery rather than of an oenological area. Therefore, data suggested the idea of the “winery effect” or a microbial terroir at a smaller scale. The use of these typical strains as starter yeasts could provide wines with the distinctive characteristics of a particular winery or sub-zone.


2002 ◽  
Vol 134 (2) ◽  
pp. 269-279 ◽  
Author(s):  
Ronald M. Weseloh ◽  
Theodore G. Andreadis

AbstractBioassays and direct counts were used to assess the abundance of resting spores of the gypsy moth, Lymantria dispar (L.), fungal pathogen, Entomophaga maimaiga Humber, Shimazu and Soper in forest soils. Resting spores in soil collected in October, January, and March and held under refrigeration germinated as readily as spores collected in April, but those collected in April germinated faster. Bioassays of resting spores in soils from different sites in Connecticut were directly related to results obtained from physically counting spores in the soil, and weakly correlated with a previously developed forest-based bioassay. The number of resting spores in a site was inversely related to the number of years since the site had last been defoliated by the gypsy moth, resulting in an implied maximum viability of resting spores of about 10 years. This maximum longevity was similar to a direct measure of long-term resting-spore viability. The study implies that resting-spore load in the soil may be an important determinant of the ability of the pathogen to control the gypsy moth.


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