Characterization of Juvenile Stages of Bursaphelenchus crenati Rühm, 1956 (Nematoda: Aphelenchoidoidea)

Abstract

In this study juvenile stages of Bursaphelenchus crenati (Sexdentati group) were distinguished based mainly on the genital primordium structure. Dauer stage juveniles were sampled under elytra of Hylesinus crenatus in galleries in bark of the wilted Fraxinus excelsior in the Voronezh region of Russia and were multiplied in laboratory cultures on the fungus Botrytis cinerea. Individual development included five stages (J1-J4 and adults) separated by molts. The first molt J1 to J2 occurred inside the egg and the J2 was at the hatching stage. Sex of juvenile stages can be identified using the morphology and size of the genital primordia and a body size of nematodes. Sex of juveniles may be identified from the J3 stage by the presence of the cloacal primordium in male juvenile and orientation of the germinal zone of the genital primordium. A tabular key to developmental stages of B. crenati is given. The body grows during molts and within each stage. The body increases rapidly after J3 stage combined with the most active cellular differentiation and elongation of the genital primordium. The dauer juveniles collected from elytra of vector beetles were similar to the third juvenile stage of the propagative generation by genital primordium structure and body size.

Spread and Harmfulness of Infectious Diseases of the Main Forest-Forming Species in Zhytomyr Polissia of Ukraine

“…The main infectious agents that lead to ash dieback are fungi (Chandelier et al, 2016;Lygis et al, 2005; Langer, 2017) (Hymenoscyphus fraxineus, which is present in Ukraine) (Davydenko et al, 2013), bacteria (Pseudomonas syringae pv. savastanoi, which causes ash tuberculosis and is registered in the forests of Ukraine) , nematodes (Ryss & Polyanina, 2018), mycoplasmosis (Bricker & Stutz, 2004), representatives of harmful entomofauna (Davydenko & Meshkova, 2017;Korda et al, 2019), as well as the influence of climatic and soil-hydrological factors (Goberville et al, 2016).…”

Myco- and microorganisms in the tuberculosis pathology of the common ash in Ukraine and interaction between them

“…Mico-and microorganisms are an integral part of the forest biocenosis, which determines its depth, which is directly involved in all stages of growth and development of woody plants and the utilization of mortmass and detritus. Among the systematic and functional groups of myco-and microbiota, a special place is occupied by phytopathogenic endophytes of various trophic specializations, capable of causing significant ecological, economic and social damage under certain conditions, which is confirmed by deep pathology 2013), bacteria (Cherpakov, 2012;Goychuk et al, 2019), nematodes (John, 1967;Ryss & Polyanina, 2018), mycoplasmas (Bricker & Stutz, 2004), representatives of harmful entomofauna (Korda et al, 2019), as well as the influence of climatic and soil-hydrological indicators (Goberville et al, 2016), however, no consensus has been reached yet.…”