首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
Previously undescribed third-stage larvae of two species of Spirurida were found in the haemocoel of the stalk-eyed mud crab Macrophthalmus hirtipes (Heller) (Ocypodidae) in New Zealand. Examinations by light and scanning electron microscopy showed that the larger larvae (about 7 mm long) belonged to a species of Ascarophis van Beneden, 1871 (Cystidicolidae), the genus including parasites of fishes, whereas the smaller larvae (about 4-5 mm long) belonged to the Acuariidae, a family with species parasitic as adults mostly in aquatic birds. In a sample of 82 specimens of M. hirtipes collected in July 2002 from Papanui Inlet, on Otago Peninsula, South Island, 74 crabs (90.2%) were infected with larval nematodes with an intensity of 1-18 (mean 4.6) nematodes per crab; no distinction between nematode species was made in these estimates, although juvenile Acuariidae greatly outnumbered larval Ascarophis. Apparently, crabs play a role as intermediate hosts of these nematode species. This is the first record of larval representatives of Cystidicolidae and Acuariidae from invertebrates in the Australasian Region.  相似文献   

3.
The authors present original observations on the species Toxascaris transfuga obtained by means of scanning electron microscopy. Attention was paid to the structure of head end, morphology of papillae of the head and abdominal end, specific morphological traits of cloacae edges and morphology of the egg surface. Presented are morphological criteria which apparently differentiate the species T. transfuga from T. leonina (Linstow, 1902). T. transfuga and T. multipapillata Kreis, 1938 seem to be conspecific.  相似文献   

4.
Morphology of the nematode Spinitectus minor harboured by Mastacembelus armatus from Burdwan, West Bengal, India was studied by light and scanning electron microscopes. The worms were described, illustrated and discussed taking into consideration of the information available relative to this species. Alate spicules, polar caps on the eggs and prodelphic uteri are clearly seen in the present LM studies and SEM photomicrographs provided detailed information about the microtopography of the worms.  相似文献   

5.
6.
7.
8.
An overview of the occurrence of species of the genus Bursaphelenchus in Romania is presented. The data is based on recent surveys conducted for the first time throughout the country, to monitor and evaluate the potential entry of the pine wood nematode, Bursaphelenchus xylophilus. Wood samples were collected from declining trees, wood‐processing companies and imported wood packaging material. Of the 895 wood samples examined, 11 contained Bursaphelenchus specimens. Morphological and molecular analyses were carried out to characterize the species detected. With respect to the possible presence of B. xylophilus, all samples were negative, confirming the absence of this quarantine pest in Romania. Nevertheless, five Bursaphelenchus species were found: B. hofmanni, B. poligraphi, B. vallesianus, B. willibaldi, and one putative new species belonging to the sexdentati group, classified here as Bursaphelenchus sp. NR512. These results constitute the first report of the genus Bursaphelenchus in Romania.  相似文献   

9.
First-stage larvae of camallanid nematodes Procamallanus (Procamallanus) laeviconchus (Wedl, 1862) and Procamallanus (Procamallanus) sp. from naturally infected Distichodus niloticus (Hasselquist) and Clarias gariepinus (Burchell), respectively, from Lake Turkana, Kenya (new geographical records) are described, being for the first time studied by scanning electron microscopy. Larvae of both species are characterised by the presence of a dorsal cephalic tooth, four submedian cephalic papillae and a pair of amphids, and by the elongate tail with several terminal digit-like processes. The latter formations probably serve for the attachment of larvae to the substrate in water when the larvae attract copepod intermediate hosts by their movements; these structures, especially their numbers, may be of taxonomic importance in camallanid nematodes.  相似文献   

10.
Abstract: The onchocercid filaria Litomosoides taylori sp. n. is described from the sigmodontine cricetid Nectomys palmipes Allen et Chapman in northeast Venezuela. A voucher specimen of the new species was used for molecular analysis of the coxI and 12S rDNA genes, and screened for the presence of the endobacterium Wolbachia pipientis. Litomosoides taylori belongs to the "sigmodontis group" of Litomosoides and a combination of characters can be used to distinguish it from the remaining 18 species forming this group. Among the five Nectomys species, all living near running water, N. squamipes also harbours Litomosoides species, L. khonae in Brazil and L. navonae in Argentina. These three Litomosoides species of the "sigmodontis group" do not share any particular characters. Gene sequences of L. taylori differ from those of the five Litomosoides species available, the three of the "carinii group" being the most distant. The new species harbours W pipientis, which is concurrent with the great majority of Litomosoides species screened to date.  相似文献   

11.
12.
Two little-known nematode species of the genus Spinitectus Fourment, 1883, S. petrowi Belous, 1965 (prevalence 25%, intensity 1-8) and S. gigi Fujita, 1927 (prevalence 10%, intensity 2-3), were collected from the gastrointestinal tract of the yellow catfish, Pelteobagrus fulvidraco (Richardson), from Liangzihu Lake, Hubei Province, central China, in September of 2002. The light and scanning electron microscopical examination of this material, supplemented by a few museum specimens of S. gigi collected from the catfish Clariasfuscus (Lacépède) in southern China, made it possible to study in detail the morphology of these parasite species and to redescribe them. The first species, whose correct name is S. petrowi Belous, 1965, exhibits some morphological features (e.g., unusually short vestibule, shape of pseudolabia and of the left spicule) not found in most other congeners; a unique feature is the presence of peculiar pairs of transversely oriented peg-like cuticular spines with rounded ends on the ventral surface of the female tail. Spinitectus gigi was found to have 28-31 cuticular spines in the first ring, relatively long distances between the 2nd-7th rings of spines, and anterior rings divided into 2 sectors; the excretory pore is located at the level of the 4th ring of cuticular spines; males posses 4 pairs of preanal- and 6 pairs of postanal caudal papillae and a pair of small phasmids. Spinitectus bagri Wang, Wu et Yu, 1993 and S. wulingensis Yu et Wang, 1997 are considered junior synonyms of S. petrowi, whereas S. clariasi Ky, 1971, S. ophicephali Ky, 1971 and S. yuanjiangensis Wang, Wu et Yu, 1997 are regarded to be junior synonyms of S. gigi. Spinitectus petrowi was not previously reported from China.  相似文献   

13.
The entomopathogenic nematodes (EPNs)Steinernema feltiae (under the trade name Entonem) andHeterorhabditis bacteriophora (under the trade name Larvanem) were evaluated as potential control agents ofParahypopta caestrum, the major pest of the asparagus crop in Greece. In laboratory experiments the two nematodes provided equal insect suppression, but significant differences were found in the time it took them to kill the larvae.S. feltiae caused high levels of mortality within 24 h and the highest level at 48 h. In contrast,H. bacteriophora required 96 h to achieve the highest level of mortality. In field experiments, the nematodes provided equal insect suppression as compared with the insecticide cadusaphos and the mixture teflubenzuron +Bacillus thuringiensis var.kurstaki. No significant differences were found in the effectiveness of the insecticides used, but there were significant differences between the control and treatments. The findings showed thatS. feltiae andH. bacteriophora could be used to control the insectP. caestrum in asparagus culture. http://www.phytoparasitica.org posting Jan. 10, 2007.  相似文献   

14.
Two new gonad-infecting species of Philometra Costa, 1845 (Philometridae), P. brevicollis sp. n. and P. mira sp. n., are described from the ovary of the brownstripe red snapper, Lutjanus vitta (Quoy et Gaimard) (Lutjanidae, Perciformes), from the South Pacific Ocean off the coast of New Caledonia. Based on light and scanning electron microscopy examination, these new nematodes are compared with all other gonad-infecting species of Philometra. The former species (males and mature and gravid females available) mainly differs from its congeners in the length of males (5.39-5.92 mm), equally long spicules (279-312 microm), and the gubernaculum (151-168 microm), in that the distal end of the gubernaculum bears dorsolateral transverse lamella-like structures, and in the structure of the male caudal end. The latter species (only males available) is characterized by the length of males (3.47-3.66 mm), equally long spicules (96-105 microm), and the gubernaculum (78-84 microm), the absence of a dorsal reflected barb or lamella-like structures on the distal end of gubernaculum, and by the structure of the male caudal end. Judging from the occurrence in the host, P. brevicollis is the main philometrid parasitizing the gonads of L. vitta, in which it can reproduce, whereas this fish probably serves as only the paradefinitive host for P. mira. Both P. brevicollis and P. mira are the first nominal species of Philometra described from fishes of the family Lutjanidae.  相似文献   

15.
Abstract: Over a 7-year period, parasites have been collected from 28 species of groupers (Serranidae, Epinephelinae) in the waters off New Caledonia. Host-parasite and parasite-host lists are provided, with a total of 337 host-parasite combinations, including 146 parasite identifications at the species level. Results are included for isopods (5 species), copepods (19), monogeneans (56), digeneans (28), cestodes (12), and nematodes (12). When results are restricted to those 14 fish species for which more than five specimens were examined and to parasites identified at the species level, 109 host-parasite combinations were recorded, with 63 different species, of which monogeneans account for half (32 species), and an average of 4.5 parasite species per fish species. Digenean records were compared for 16 fish species shared with the study of Cribb et al. (2002); based on a total of 90 parasite records identified at the species level, New Caledonia has 17 new records and only seven species were already known from other locations. We hypothesize that the present results represent only a small part of the actual biodiversity, and we predict a biodiversity of 10 different parasite species and 30 host-parasite combinations per serranid. A comparison with a study on Heron Island (Queensland, Australia) by Lester and Sewell (1989) was attempted: of the four species of fish in common and in a total of 91 host-parasite combinations, only six parasites identified at the species level were shared. This suggests strongly that insufficient sampling impairs proper biogeographical or ecological comparisons. Probably only 3% of the parasite species of coral reef fish are already known in New Caledonia.  相似文献   

16.
Journal of Plant Diseases and Protection - Pratylenchus bolivianus (Nematoda, Pratylenchidae) an important parasitic lesion nematode of ornamental and crop plants was found in association with...  相似文献   

17.
Wood packaging material (WPM) is an important pathway for the spread of non‐native plant pests. To reduce the likelihood of plant pest movement with WPM, the International Standard for Phytosanitary Measures No. 15: “Regulation of Wood Packaging Material in International Trade” (ISPM 15) was developed in the framework of the International Plant Protection Convention. To be compliant with this Standard, WPM shipped internationally must be either heat‐treated or fumigated, regardless of any specific characteristics of the WPM. The objective of this survey was to determine if Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae) or insects, especially Monochamus spp. (Coleoptera: Cerambycidae), were present in a specific subset of softwood boxes. While not compliant with ISPM 15, these boxes had been treated with wood preservatives, stored indoors for over five years, and, in addition to meeting various quality standards, almost all had a moisture content below 20 percent. United States Department of Agriculture staff inspected a sample of 630 softwood boxes, focusing on those showing signs of possible pest infestation. Based on a binomial distribution with an efficacy of detection equal to 0.95, a sample size of 630 provides a 95 percent confidence of detecting pests if >0.5 % of boxes are infested. No B. xylophilus or insect pests were found in the boxes, though other nematode genera (Aphelenchoides, Aphelenchus, and Filenchus), which feed on decomposing fungi in wood and do not damage trees, were found in 21 boxes. This study demonstrates that not all types of WPM present a high phytosanitary risk. It may be worthwhile to consider an amendment to ISPM 15 to differentiate between various risk categories of WPM in order to minimize costs and environmental impacts associated with treatments currently prescribed in ISPM 15.  相似文献   

18.
Examination of the original literature concerning species of Philometra (Philometridae, Dracunculoidea) parasitic in the abdominal cavity of European cyprinids revealed that P. abdominalis Nybelin, 1928 is a junior synonym of P. ovata (Zeder, 1803), a parasite of cyprinids of the genera Gobio, Phoxinus and Leuciscus. The valid name of the species parasitizing cyprinids of the genera Abramis, Rutilus and Vimba, mostly reported erroneously as P. ovata, is P. cyprinirutili (Creplin, 1825) comb. n.  相似文献   

19.
Infestation levels of the red palm weevil, Rhynchophorus ferrugineus (Oliver, 1790) and its natural enemies on palm trees in recreation areas were investigated in the Adana province of Turkey in 2008. The trunks of dead palms were sampled for R. ferrugineus and for the presence of entomopathogenic nematodes. While 20% of Phoenix canariensis Hort. were found to be killed by R. ferrugineus , only 2 trees from other species, 1 Washingtonia filifera (L. Linden) and 1 Phoenix dactlylifera L., were killed. Only one species of entomopathogenic nematode, Heterorhabditis bacteriophora ( Poinar, 1975 ) (Nematoda: Heterorhabditidae), was isolated from the R. ferrugineus specimens. Seasonal mortality rate in the total larval population (total 565 larval specimens) of R. ferrugineus was 69%. H. bacteriophora resulted in a significant mortality rate (80%) in the pupae population (total 314 pupal specimens). Overall, 70% of the total of 879 pre-adult specimens were found to be fatally infested by the attacks of this nematode. Heterorhabditis bacteriophora killed few adults, corresponding to 2% of the overall mortality rate. It is concluded that H. bacteriophora could be evaluated as a potential candidate for biological control of R. ferrugineus in the Mediterranean region.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号