Abstract
Two species of aphelench, Bursaphelenchus rufipennis n. sp. and
Ektaphelenchus obtusus, were isolated from the 'nematangia', cocoon-like
structures found at the base of the hind wings of Dendroctonus rufipennis.
The nematangia contained adult females of E. obtusus and the dauer juveniles
of B. rufipennis n. sp. Only B. rufipennis n. sp. could be cultured on
Monilinia fructicola on LGPDA (lactic acid-treated, glycerol-supplemented,
potato dextrose agar). The new species of Bursaphelenchus is described and
figured and some additional morphological characters are ascribed to E.
obtusus, E. josephi, E. sandiaensis, E. smaelus (= E. prolobos) and E.
terebranus after examination of type and/or voucher specimens.
Bursaphelenchus rufipennis n. sp. has an adult body length of ca 500-1000
μm, medium a ratios (ca 25-38 for females and ca 30-40 for males), b ratios
of ca 8-13 (female) and 7-11 (male), c ratios of ca 15-22 (female and male),
c′ ratios of ca 3-4 (female) and ca 2-3 (male), and is characterised by
three incisures in the lateral field, mitten-shaped spicules and a conical
female tail that curves ventrally and possesses a variable tail tip. The new
species is morphologically closest to B. corneolus, B. curvicaudatus, B.
gerberae, B. paracorneolus and B. talonus. Morphological examination of type
and/or voucher specimens of five Ektaphelenchus species revealed coarse
transverse body annulation and three pairs of male caudal papillae (except
for the two species where males are not described). Clear typological
differences were observed among these five Ektaphelenchus species in the
structure of the lip region, presence/absence of stylet knobs and male
spicule morphology. Although these characters have not been consistently
documented in the past, they may be diagnostic for species in the genus.
Molecular phylogenetic analysis based on SSU and D2/D3 LSU sequences
revealed that B. rufipennis n. sp. was closest to B. paracorneolus and that
E. obtusus was closest to species of Ektaphelenchoides and a
Cryptaphelenchus sp.