Schistonchus zealandicus n. sp. was recovered from the sycones of Ficus macrophylla from St Helier’s Bay, Mt Wellington, and St Johns, suburbs of Auckland, New Zealand. It is characterised by having the opening of the excretory pore located just posterior to the anterior end of the nematode but anterior to the conus level of the stylet, a short post-vulval uterine sac (10-18 μm or 0.4-0.7 vulval body diam. long), presence of two incisures in the lateral field with many broken, non-defined lines between them, rose-thorn-shaped spicule, three pairs of subventral papillae on the male tail (one pair adcloacal on the anterior lip, one pair slightly posterior to mid-tail length, and one pair close to tail tip), a distinctive mucron on the male tail, apparent biogeographical range, and its association with F. macrophylla. The absence of a lip sector disc suggests that it is close to S. altermacrophylla, S. aureus and S. laevigatus. Molecular phylogeny of near full length small subunit and D2-D3 expansion segments of the large subunit rRNA genes supports the proposal of S. zealandicus n. sp. as a new species.
A new species of fly, Fergusonina madidum Taylor sp.n. (Diptera: Fergusoninidae) from Leptospermum madidum A.R. Bean in far north Queensland and a new species of nematode, Fergusobia leptospermum Davies sp.n. (Tylenchida: Neotylenchidae) from L. laevigatum (Gaertn.) F. Muell. in southern Victoria, Australia are described. These represent the first species of the Fergusonina fly/Fergusobia nematode mutualism to be described from the genus Leptospermum (Myrtaceae). Fergusonina madidumsp.n. forms lateral and terminal multilocular shoot bud galls enclosed in subterminal leaflets. It can be distinguished from all other species of Fergusonina by the lack of dorsal setae on abdominal segment 7 of the female. Unlike most described species of Fergusonina it also lacks the posterior cross vein m-cu in the wing. It shares this character with F. giblindavisi Taylor and F. thomasi Taylor from flower bud galls on Corymbia, but both these species are large and abdominal segment 7 of females is densely setose. Its larva is unknown but from the morphology of puparia the dorsal shield comprises 3 broad transverse bands comprising lateral rows of raised ridge-like sclerotised spicules. Its associated species of nematode is not known. Fergusobia leptospermumsp.n. is associated with cryptic lateral and terminal usually unilocular shoot bud galls. It is characterised by the combination of an open to tight C-shaped parthenogenetic female having a small ‘a’ ratio, with a short but sturdy stylet, flat anterior end; huge dorsal pharyngeal gland, reproductive system with a relatively long uterus, and a sub-conoid tail with a broadly rounded tip; a C-shaped infective female with an almost hemispherical tail tip which may or may not be ventrally hooked; and an open C-shaped male with angular spicules and peloderan bursa arising near the anterior end, and a relatively long (c’ = 2.2–3.2) sub-conoid tail with a bluntly to broadly rounded tip. Its status as a distinct species is confirmed by molecular analyses. Its associated species of fly is known only from several larvae and a puparium, and remains undescribed. The dorsal shield of this Fergusonina species comprises 7 broad bands, the first six having heavily sclerotised raised ridges and the seventh with a medial field of weak spicules. The widely separated collection localities, together with the large number of species in Leptospermum suggest that the mutualism is likely to be speciose and occupy a broad geographic range on this host.
Fergusobia (Sphaerularioidea, Tylenchida) is the only known nematode to have a dicyclic life cycle with a generation in a plant (a myrtaceous host) followed by one in an insect (a Fergusonina fly: Diptera, Fergusoninidae). The nematode and fly have a mutualistic association, with the nematode inducing a plant gall on which the fly feeds and develops, and the fly providing transport for the nematode. The life cycle, specificity, diversity and distribution of the nematode are described, and the nematode phylogeny is discussed. Fergusobia is monophyletic but its origins are unclear. This paper raises questions about Fergusobia, including: what model best accounts for evolution of the known diversity of the nematode/fly mutualism?; how are the nematode/fly life cycles coordinated?; how do the nematodes avoid resistance mechanisms of both flies and plants?; what cecidogenic processes does the nematode use?; and what is the form of parthenogenesis occurring in Fergusobia and how does it relate to the inheritance of variability? Given the models of genomes and transcriptomes now available for other plant-parasitic nematodes and the availability of technologies to examine Fergusobia, it should be possible to answer some of these questions and begin to understand how Fergusobia nematodes might have evolved.
Ficus benjamina (Moracaeae subfamily Urostigma, section Conosycea) grows naturally in tropical Asia and in Australia in the north of the Northern Territory and the Cairns region of Queensland. It is widely grown as an ornamental in more temperate regions of Australia. Schistonchus benjamina sp. n. is described from sycones of F. benjamina in Brisbane, and is differentiated from other species of Schistonchus by a combination of morphological characters including having the excretory pore opening near the head, a short post-vulval uterine sac, rose thorn-shaped spicule, lightly sclerotised stylet and spicule, and three pairs of subventral papillae on the tail (one adcloacal, one at mid-tail length and one near the tail tip); and apparent biogeographical range. Phylogenetic analyses based on D3 sequences from collections from both northern and southern Queensland suggest that S. benjamina sp. n. is a species complex, but specimens from the different locations cannot be separated on morphological or morphometric data. Schistonchus benjamina sp. n. is closest to S. microcarpus from F. microcarpa (Urostigma, section Urostigma) in China.
A new genus and species of anguinid nematode, Zeatylenchus pittosporum gen. n., sp. n., was recovered from leaves of Pittosporum tenuifolium from Hahei, Coromandel Region, North Island, New Zealand. The genus is characterised by having slender males and females, excretory pore opening near the lips and level with the knobs of the retracted stylet, pharynx with a weak non-muscular median bulb, pharyngeal glands overlapping the intestine, females with a single gonad with a quadricolumella and post-uterine sac; and males with slender arcuate spicules and the bursa arising <1 anal body diam. anterior to the cloacal aperture and extending ca 30% of distance to the tail tip. Its feeding does not induce galls, only foliar chlorosis. The species has particular characters, including a short, robust stylet with conus forming ca 40% of stylet length and small rounded compact knobs, and tail offset dorsally with a pointed tip. Molecular phylogeny of near full length small subunit, D2/D3 expansion segments of the large subunit and internal transcribed spacer rRNA genes support the description of Zeatylenchus pittosporum gen. n., sp. n. as a new genus and species.
Three new species of Schistonchus were recovered from sycones of Ficus racemosa, F. hispida and F. variegata (Moraceae Subgenus Sycomorus, Section Sycomorus) from the Cairns region in north-eastern Australia. Schistonchus baculum sp. n. is described from F. racemosa and F. hispida and is differentiated from other species of Schistonchus by a combination of morphological characters including having males with a walking-stick shape, excretory pore opening at the anterior end of the metacorpus, a long post-uterine sac, rose-thorn-shaped spicules, no gubernaculum, two pairs of subventral papillae on the tail, DNA sequence data, and apparent biogeographical range. Schistonchus fleckeri sp. n. is described from F. racemosa, F. hispida and F. variegata and is differentiated by a combination of morphological characters, including a C-shaped female and C-shaped to spiral males, the excretory pore opening near the lips, a short to medium length post-uterine sac, slender sickle-shaped spicules with a reduced rostrum, no gubernaculum, three pairs of subventral papillae on the tail, and apparent biogeographical range. Schistonchus cassowaryi sp. n. is described from F. variegata and is differentiated by a combination of morphological characters, including having C-shaped males and females, a posterior excretory pore situated posterior to the nerve ring, a short to medium length post-uterine sac, rose-thorn-shaped spicules, three pairs of subventral papillae on the tail (one adcloacal, one at mid-tail near lateral, and one near the tip), DNA sequence data, and apparent biogeographical range.
Ficus watkinsiana (sub-genus Urostigma, Section Stilpnophyllum) is endemic to Australia, growing in two disjunct populations, one in north-eastern Queensland and the other in south-eastern Queensland and north-eastern New South Wales. Schistonchus molochi sp. n. is described from F. watkinsiana in Queensland, Australia, and differentiated from other species of Schistonchus by a combination of morphological characters including having the excretory pore opening near the nerve ring, a broad head, a large, strongly sclerotised, stylet, a distinct lip sector disc with raised edges, a long post-uterine sac, rose-thorn-shaped spicule, no gubernaculum, three pairs of subventral papillae on the tail (one pair pre-cloacal on the anterior lip, one pair adcloacal on the posterior lip, and one slightly posterior to mid-tail) and bluntly rounded tail tip, and apparent biogeographical range. Presence of the lip sector disc suggests that it is closest to S. macrophylla. Schistonchus athertonensis sp. n. is also described from F. watkinsiana in Queensland and is characterised by a combination of morphological characters, including having the excretory pore opening near the nerve ring, a medium length post-uterine sac, presence of vulval flap in some specimens, rose-thorn-shaped spicule, no gubernaculum, and three pairs of subventral papillae on the tail (one pair adcloacal on the posterior lip, one at three to four-fifths of the tail length and one near the tip), a narrowly rounded tail tip, and apparent biogeographical range. Morphospecies 8, originally collected from F. obliqua, was also collected from F. watkinsiana in Queensland, and S. altermacrophylla was found with it in South Australia. These collections are further evidence of host-switching within Schistonchus.
Teratodiplogaster martini n. sp. and Parasitodiplogaster doliostoma n. sp. are described and illustrated from voucher specimens from Ficus sp. and Ficus sur Forsskål, respectively, from Martin et al. (1973). Teratodiplogaster martini n. sp. is characterised by its scoop-like lip, long and slender body, presence of a receptaculum seminis and crustaformeria-like organ in female gonads, and eight pairs of male genital papillae with an arrangement of ⟨P1, P2, P3, C, P4d, P5, (P6, P7), P8d, Ph⟩, and is distinguished from its only congener, T. fignewmani, based upon its stomatal morphology, spicule and gubernaculum morphology, and composition and structure of the female reproductive organs. Parasitodiplogaster doliostoma n. sp. is characterised by its large barrel-shaped stoma comprised of a degenerate cheilostom, well developed gymnostom occupying most of the stoma, and short stegostom with two small triangular teeth, male tail possessing nine pairs of genital papillae with an arrangement of ⟨P1, P2 (P3, C), P4d, P5, (P6, P7, Ph, P8), P9d⟩ and spike-like projection at the distal tip, and conical and smoothly tapering female tail. These characters help to distinguish typologically this new species from all 13 nominal species in the genus. The emended genus definition of Parasitodiplogaster and morphological characters of the Koerneria/Parasitodiplogaster/Teratodiplogaster clade are also discussed.