Life cycle and population dynamics of Bursaphelenchus willibaldi (Nematoda: Rhabditida: Aphelenchoididae) in vitro

Abstract

Summary To develop models of forest ecosystem functioning, it is necessary to estimate parameters of the population dynamics of nematode species. Parameters of ontogenesis of Bursaphelenchus willibaldi from oak in culture of the fungus Botrytis cinerea were determined in vitro: oviposition began 2.7 (1-3) days after inoculation with adult nematodes; timelines of juvenile formation were: second-stage juveniles: 3.2 (3-4) days, third-stage juveniles: 3.6 (3-5) days, fourth-stage juveniles: 4.8 (3-6) days, first generation (1G) ended with a J4 moulting to adult after 5.8 (4-6) days. One day after the formation of the first generation, nematodes left the 2% potato-sugar agar (PSA) medium with the feed fungus and moved upwards, forming a migratory group (MG). In PSA the total nematode abundance reached peaks on day 11 (2G) and in the MG on day 27 (4.5G). The fecundity of females during population growth was determined as 3.4 (2.1-5.9) eggs day−1 and a model of exponential population growth was developed for total nematodes , ; and for females , . Under conditions of unrestricted reproduction and temperature of 21-23°C, the nematode and fungus can colonise 1 m3 of PSA-like medium in 36.8 days. The survival stage in the propagative generation was presumably J4. The female lifespan consists of a feeding and reproductive phase in the PSA (6 days) and a survival phase in the MG (1 month to 1 year). In MG, nematodes formed swarming groups of 20-200 individuals.

New Records of Wood- and Bark-Inhabiting Nematodes from Woody Plants with a Description of Bursaphelenchus zvyagintsevi sp. n. (Aphelenchoididae: Parasitaphelenchinae) from Russia

“…Reports of B. eremus and B. michalskii are new findings of these species for Russia. Thus, the total number of Bursaphelenchus species reported from Russia increased to 18 and included the following species: B. africanus [ 54 ], B. borealis [ 14 , 55 ], B. crenati [ 8 ], B. eremus (this study), B. eroshenkii [ 56 ], B. fraudulentus [ 21 , 55 ]; (this study), B. fuchsi [ 57 ], B. hellenicus [ 21 , 55 ], B. hylobianus [ 14 , 55 ], B. kolymensis [ 13 , 58 ], B. leoni [ 55 ], B. michalskii (this study), B. mucronatus [ 17 , 55 , 59 , 60 ] and this study, B. paracorneolus [ 55 ], B. rockyi [ 61 ], B. ulmophilus [ 6 ], B. willibaldi [ 28 ] and this study, and B. zvuagintsevi sp. n. (this study).…”

“…The suspensions extracted from bark and obtained from insects were studied under the stereomicroscope Mikromed MC-5 Zoom LED and the nematodes were picked out with a needle to select different taxa for propagation in vitro. Extracted nematodes were cultivated on laboratory cultures of the fungus Botryotinia fuckeliana , (de Bary) Whetzel, 1945 (= Botrytis cinerea Pers., 1794), growing on 2% potato dextrose agar medium at 22 °C [ 28 , 103 ]. Aphelenchoides heidelbergi , Aphelenchoides sp.1, Bursaphelenchus eremus , B. fraudulentus , B. michalskii , B. mucronatus , B. willibaldi and B. zvyagintsevi sp.…”

“…In Russia, wood- and bark-inhabiting nematodes have been intensively studied and lists of associated species have been reported in several publications [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. However, with the exception of Bursaphelenchus , the identification of species was based on morphology only and, therefore, now requires molecular confirmation.…”

Discovery and Characterization of Four Aphelenchid Species from Cultivated Regions of Southern Alberta, Canada

“…The new species can be distinguished from A. angusticaudatus [39] by the presence of males vs. absence; a longer body length of females, 728.0 (564.0-978.0) µm vs. (550-610) µm; a lower b value of females, 9.0 (8.0-10.0) vs. (11-13); a higher c value of females 17.0 (15.0-21.0) vs. (12)(13)(14)(15)(16)(17)(18); and a lower c ′ value of females, 3.4 (2.8-4.0) vs. 5.1. From A. cyrtus, by having an almost straight body habitus of females vs. arc-shaped; swelling type stylet knobs vs. distinctly knobbed; spicule shape (condylus elongated rounded, rostrum small, blunt conical, lamina less wide, gradually tapers towards the rounded distal end vs. (after drawings) condylus and rostrum appear pointed, lamina is wider, distal end appears pointed); the position of the tail mucro (central vs. appears ventrally located); habitat (post-harvest potato field vs. lichens, mushroom amended with flax and straw additives); longer body lengths of females, 728.0 (564.0-978.0) µm vs. (500-570) µm, and males, 720.0 (624.0-859.0) µm vs. (500-510) µm; a higher a value of females, 34.0 (31.0-38.0) vs. (24-28), and males, 33.5 (30.0-36.5) vs. (26)(27).…”

“…Here, we investigated both new and known species of Aphelenchus Bastian [14], Aphelenchoides, and Robustodorus (Goodey [15]) Andrássy [16], recovered from southern Alberta's arable regions. Among these genera, Aphelenchoides is the most species-rich, with 181 known species [17], followed by Aphelenchus (12 species), and Robustodorus (4 species) [18][19][20][21]. Though these genera are known for their mycetophagy and plant-parasitic tendencies [22,23], none of the member species has previously been reported from southern Alberta.…”