Intestinal Helminth Infections in Feral Cats and a Raccoon Dog on Aphaedo Island, Shinan-gun, with a Special Note on Gymnophalloides seoi Infection in Cats

Four feral cats and a raccoon dog purchased from a local collector on Aphaedo Island, Shinan-gun, where human Gymnophalloides seoi infections are known to be prevalent, were examined for their intestinal helminth parasites. From 2 of 4 cats, a total of 310 adult G. seoi specimens were recovered. Other helminths detected in cats included Heterophyes nocens (1,527 specimens), Pygidiopsis summa (131), Stictodora fuscata (4), Acanthotrema felis (2), Spirometra erinacei (15), toxocarids (4), and a hookworm (1). A raccoon dog was found to be infected with a species of echinostome (55), hookworms (7), toxocarids (3), P. summa (3), and S. erinacei (1). No G. seoi was found in the raccoon dog. The results indicate that feral cats and raccoon dogs on Aphaedo are natural definitive hosts for intestinal trematodes and cestodes, including G. seoi, H. nocens, and S. erinacei. It has been first confirmed that cats, a mammalian species other than humans, play the role of a natural definitive host for G. seoi on Aphaedo Island.     

Seroprevalence of Trichinella sp. in Wild Boars (Sus scrofa) from Yanggu-gun,Gangwon-do,Korea

A total 7 outbreaks of trichinellosis have occurred in Korea, mostly as a result of consumption of raw wild boar (Sus scrofa) meat. Since only 1 serological survey on wild boars had yet been performed in Korea, the present study aimed to estimate the prevalence of trichinellosis in wild boars and some species of rodents by artificial digestion and serological examinations in Yanggu-gun, Gangwon-do, the endemic area of trichinellosis. Both the wild boar and rodent muscle samples revealed no Trichinella larvae by direct examination and artificial digestion method. However, serological examinations revealed that 4 wild boar sera samples out of 118 (3.4%) were positive to Trichinella antigen. Although the recovery of Trichinella larvae ended in a failure, it is proved for the first time that the sylvatic cycle of Trichinella has been maintained in wild boars of Gangwon-do, Korea.     

Ticks Collected from Wild and Domestic Animals and Natural Habitats in the Republic of Korea

Ticks were collected from 35 animals from 5 provinces and 3 metropolitan cities during 2012. Ticks also were collected by tick drag from 4 sites in Gyeonggi-do (2) and Jeollabuk-do (2) Provinces. A total of 612 ticks belonging to 6 species and 3 genera were collected from mammals and a bird (n=573) and by tick drag (n=39). Haemaphyalis longicornis (n=434) was the most commonly collected tick, followed by H. flava (158), Ixodes nipponensis (11), Amblyomma testudinarium (7), H. japonica (1), and H. formosensis (1). H. longicornis and H. flava were collected from all animal hosts examined. For animal hosts (n>1), the highest Tick Index (TI) was observed for domestic dogs (29.6), followed by Siberian roe deer (17.4), water deer (14.4), and raccoon dogs (1.3). A total of 402 H. longicornis (adults 86, 21.4%; nymphs 160, 39.8%; larvae 156, 38.9%) were collected from wild and domestic animals. A total of 158 H. flava (n=158) were collected from wild and domestic animals and 1 ring-necked pheasant, with a higher proportion of adults (103, 65.2%), while nymphs and larvae only accounted for 12.7% (20) and 22.2% (35), respectively. Only 7 A. testudinarium were collected from the wild boar (6 adults) and Eurasian badger (1 nymph), while only 5 I. nipponensis were collected from the water deer (4 adults) and a raccoon dog (1 adult). One adult female H. formosensis was first collected from vegetation by tick drag from Mara Island, Seogwipo-si, Jeju-do Province.     

Mixed infection, Trichinella spiralis and Trichinella britovi, in a wild boar hunted in the Province of Cáceres (Spain)

The etiological agents of human trichinellosis are distributed worldwide in domestic and wild animals. In Spain, two morphologically indistinguishable Trichinella species have been described—Trichinella spiralis and Trichinella britovi—that are perpetuated in both domestic and sylvatic cycles. The present work reports a double natural infection involving these species in a wild boar killed by hunters in the Province of Cáceres, Spain. After artificial digestion of the boar’s muscles, nine larvae/g were collected. These were characterized by multiplex-PCR and Western-blotting using the Trichinella-specific monoclonal antibodies US5 and US9, and both T. spiralis and T. britovi were detected. The mechanism by which this wild boar came to acquire a mixed infection remains unclear.     

A Case of Vesical and Scrotal Sparganosis Presenting as a Scrotal Mass

A 59-year-old Korean man complained of a painless scrotal hard nodule and weak urine stream. The ultrasound scan revealed a 2.2-cm sized round heteroechogenic nodule located in the extratesticular area. Microscopic hematuria was detected in routine laboratory examinations. On scrotal exploration, multiple spargana were incidentally found in the mass and along the left spermatic cord. On cystoscopy, a 10-mm sized mucosal elevation was found in the right side of the bladder dome. After transurethral resection of the covered mucosa, larval tapeworms were removed from inside of the nodule by forceps. Plerocercoids of Spirometra erinacei was confirmed morphologically and also by PCR-sequencing analysis from the extracted tissue of the urinary bladder. So far as the literature is concerned, this is the first worm (PCR)-proven case of sparganosis in the urinary bladder.     

Genetic Identification of Spirometra decipiens Plerocercoids in Terrestrial Snakes from Korea and China

Human sparganosis is a zoonotic disease caused by infection with larval forms (procercoid/plerocercoid) of Spirometra spp. The purpose of this study was to identify Spirometra spp. of infected snakes using a multiplex PCR assay and phylogenetic analysis of mitochondrial DNA sequence data from the spargana of terrestrial snakes obtained from Korea and China. A total of 283 snakes were obtained that included 4 species of Colubridae comprising Rhabdophis tigrinus tigrinus (n=150), Dinodon rufozonatum rufozonatum (n=64), Elaphe davidi (n=2), and Elaphe schrenkii (n=7), and 1 species of Viperidae, Agkistrodon saxatilis (n=60). The snakes were collected from the provinces of Chungbuk, Chungnam, and Gyeongbuk in Korea (n=161), and from China (n=122). The overall infection rate with spargana was 83% (235/283). The highest was recorded for D. rufozonatum rufozonatum (100%), followed by A. saxatilis (85%) and R. tigrinus tigrinus (80%), with a negative result for E. davidi (0%) and E. schrenkii (0%). The sequence identities between the spargana from snakes (n=50) and Spirometra erinaceieuropaei ({"type":"entrez-nucleotide","attrs":{"text":"KJ599680","term_id":"646228164","term_text":"KJ599680"}}KJ599680) or S. decipiens ({"type":"entrez-nucleotide","attrs":{"text":"KJ599679","term_id":"646228151","term_text":"KJ599679"}}KJ599679) control specimens were 90.8% and 99.2%, respectively. Pairwise genetic distances between spargana (n=50) and S. decipiens ranged from 0.0080 to 0.0107, while those between spargana and S. erinaceieuropaei ranged from 0.1070 to 0.1096. In this study, all of the 904 spargana analyzed were identified as S. decipiens either by a multiplex PCR assay (n=854) or mitochondrial cox1 sequence analysis (n=50).     

Comparative Proteomics Identifies Host Immune System Proteins Affected by Infection with Mycobacterium bovis

Mycobacteria of the Mycobacterium tuberculosis complex (MTBC) greatly impact human and animal health worldwide. The mycobacterial life cycle is complex, and the mechanisms resulting in pathogen infection and survival in host cells are not fully understood. Eurasian wild boar (Sus scrofa) are natural reservoir hosts for MTBC and a model for mycobacterial infection and tuberculosis (TB). In the wild boar TB model, mycobacterial infection affects the expression of innate and adaptive immune response genes in mandibular lymph nodes and oropharyngeal tonsils, and biomarkers have been proposed as correlates with resistance to natural infection. However, the mechanisms used by mycobacteria to manipulate host immune response are not fully characterized. Our hypothesis is that the immune system proteins under-represented in infected animals, when compared to uninfected controls, are used by mycobacteria to guarantee pathogen infection and transmission. To address this hypothesis, a comparative proteomics approach was used to compare host response between uninfected (TB-) and M. bovis-infected young (TB+) and adult animals with different infection status [TB lesions localized in the head (TB+) or affecting multiple organs (TB++)]. The results identified host immune system proteins that play an important role in host response to mycobacteria. Calcium binding protein A9, Heme peroxidase, Lactotransferrin, Cathelicidin and Peptidoglycan-recognition protein were under-represented in TB+ animals when compared to uninfected TB- controls, but protein levels were higher as infection progressed in TB++ animals when compared to TB- and/or TB+ adult wild boar. MHCI was the only protein over-represented in TB+ adult wild boar when compared to uninfected TB- controls. The results reported here suggest that M. bovis manipulates host immune response by reducing the production of immune system proteins. However, as infection progresses, wild boar immune response recovers to limit pathogen multiplication and promote survival, facilitating pathogen transmission.     

红外相机技术在北京雾灵山自然保护区兽类资源调查中的应用

为了调查北京市雾灵山自然保护区兽类资源情况,自2013年7月至2014年5月,在雾灵山32个位点处布放红外相机进行系统调查,累积相机工作日3630天,共拍摄到兽类有效照片494张,鉴定出10种动物,包括：狍（Capreolus capreolus）、斑羚（Nemorhaedus goral）、猪獾（Arctonyx collaris）、岩松鼠（Sciurotamias davidianus）、野猪（Sus scrofa）、狗獾（Meles meles）、豹猫（Felis bengalensis）、花鼠（Tamias sibiricus）、草兔（Lepus capensis）和黄鼬（Mustela sibirica）,隶属于4目7科;从分布型来看,这10种兽类主要以古北型为主（占70%）。常拍种有狍、岩松鼠、斑羚和猪獾;较常拍种有野猪、狗獾、豹猫、花鼠、草兔;偶拍种有黄鼬。文中还对不同海拔和不同植被类型动物相对丰富度、累积拍摄物种数与相机工作日关系及兽类G-F指数等进行了探讨。     

Toxoplasma gondii B1 Gene Detection in Feces of Stray Cats around Seoul,Korea and Genotype Analysis of Two Laboratory-Passaged Isolates

The increasing prevalence of Toxoplasma gondii infection in the human population in the Republic of Korea (= Korea) is due to various reasons such as an increase in meat consumption. However, the importance of cats in transmitting T. gondii infection through oocysts to humans has seldom been assessed. A total of 300 fecal samples of stray cats captured around Seoul from June to August 2013 were examined for T. gondii B1 gene (indicating the presence of oocysts) using nested-PCR. Fourteen (4.7%) of 300 cats examined were positive for B1 gene. Female cats (7.5%) showed a higher prevalence than male cats (1.4%). Cats younger than 3 months (5.5%) showed a higher prevalence than cats (1.5%) older than 3 months. For laboratory passage of the positive samples, the fecal suspension (0.2 ml) of B1 gene positive cats was orally inoculated into experimental mice. Brain tissues of the mice were obtained after 40 days and examined for the presence of tissue cysts. Two isolates were successfully passaged (designated KNIH-1 and KNIH-2) and were molecularly analyzed using the SAG5D and SAG5E gene sequences. The SAG5D and SAG5E gene sequences showed high homologies with the ME49 strain (less virulent strain). The results indicated the importance of stray cats in transmitting T. gondii to humans in Korea, as revealed by detection of B1 gene in fecal samples. T. gondii isolates from cats were successfully passaged in the laboratory for the first time in Korea.     

Prevalence of Onchocerca japonica and O. takaokai infections in the Japanese wild boar,Sus scrofa leucomystax,and the Ryukyu wild boar,S. s. riukiuanus,in Japan

Reports of zoonotic infections with Onchocerca japonica (Nematoda: Filarioidea), which parasitizes the Japanese wild boar, Sus scrofa leucomystax, have recently increased in Japan. To predict the occurrence of infection in humans, it is necessary to determine the prevalence of O. japonica infection in the natural host animals. We investigated the presence of adult worms in the footpads, and of microfilariae in skin snips, taken from the host animals, between 2000 and 2018. Onchocerca japonica was found in 165 of 223 (74%) Japanese wild boars in Honshu and Kyushu. Among the nine regions studied, the highest prevalence of O. japonica infection was found in Oita, Kyushu, where 47 of 52 (90.4%) animals were infected. The ears were the predilection sites for O. japonica microfilariae. Adult worms of O. japonica were found more frequently in the hindlimbs than in the forelimbs of the host animals. Onchocerca takaokai was found in 14 of 52 (26.9%) Japanese wild boars in Oita. In Kakeroma Island among the Nansei Islands, both O. japonica and O. takaokai were isolated from the Ryukyu wild boar, S. s. riukiuanus. These observations could help predict future occurrences of human zoonotic onchocercosis in Japan.     

Investigating the Role of Free-Ranging Wild Boar (Sus scrofa) in the Re-Emergence of Enzootic Pneumonia in Domestic Pig Herds: A Pathological,Prevalence and Risk-Factor Study

Enzootic pneumonia (EP) caused by Mycoplasma hyopneumoniae has a significant economic impact on domestic pig production. A control program carried out from 1999 to 2003 successfully reduced disease occurrence in domestic pigs in Switzerland, but recurrent outbreaks suggested a potential role of free-ranging wild boar (Sus scrofa) as a source of re-infection. Since little is known on the epidemiology of EP in wild boar populations, our aims were: (1) to estimate the prevalence of M. hyopneumoniae infections in wild boar in Switzerland; (2) to identify risk factors for infection in wild boar; and (3) to assess whether infection in wild boar is associated with the same gross and microscopic lesions typical of EP in domestic pigs. Nasal swabs, bronchial swabs and lung samples were collected from 978 wild boar from five study areas in Switzerland between October 2011 and May 2013. Swabs were analyzed by qualitative real time PCR and a histopathological study was conducted on lung tissues. Risk factor analysis was performed using multivariable logistic regression modeling. Overall prevalence in nasal swabs was 26.2% (95% CI 23.3–29.3%) but significant geographical differences were observed. Wild boar density, occurrence of EP outbreaks in domestic pigs and young age were identified as risk factors for infection. There was a significant association between infection and lesions consistent with EP in domestic pigs. We have concluded that M. hyopneumoniae is widespread in the Swiss wild boar population, that the same risk factors for infection of domestic pigs also act as risk factors for infection of wild boar, and that infected wild boar develop lesions similar to those found in domestic pigs. However, based on our data and the outbreak pattern in domestic pigs, we propose that spillover from domestic pigs to wild boar is more likely than transmission from wild boar to pigs.     

Fishborne Trematode Metacercariae in Freshwater Fish from Guangxi Zhuang Autonomous Region, China

A survey was performed to investigate the infection status of fishborne trematode (FBT) metacercariae in freshwater fish from Guangxi Zhuang Autonomous Region, China. A total of 307 freshwater fish of 31 species were collected from 5 administrative regions of Guangxi Zhuang Autonomous Region. They were examined by artificial digestion method from July 2003 to August 2004. No metacercariae were detected in fish from Fusui-xian. In fish from Mashan-xian and a market in Nanning, 3 species of metacercariae, Haplorchis taichui, Haplorchis pumilio, and Centrocestus formosanus, were mainly detected. Metacercariae (8 in number) of Clonorchis sinensis were found in 1 Chanodichthys dabryi purchased from a market in Nanning. In fish from Yangshuo, Metagonimus yokogawai metacercariae were detected from all 18 fish species examined. Total 13 C. sinensis metacercariae were found in 3 out of 10 Hemibarbus maculatus from Yangshuo. All 7 Zacco platypus from Yangshuo were infected with 8-112 Echinochasmus perfoliatus metacercariae. In fish from Binyang-xian, H. pumilo metacercariae were mainly detected in all 5 fish species examined, and only 1 metacercaria of C. sinensis was found in a Hemiculter leucisculus. From the above results, it was confirmed that some species of freshwater fish play a role of second intermediate hosts for FBT in Guangxi Zhuang Autonomous Region, China. In particular, 4 species of intestinal flukes, M. yokogawai, H. taichui, H. pumilio, and C. formosanus, were prevalent in fish hosts, whereas C. sinensis metacercariae were detected only in 3 fish species.     

Domestic,peridomestic and wild hosts in the transmission of Trypanosoma cruzi in the Caatinga area colonised by Triatoma brasiliensis

The role played by different mammal species in the maintenance of Trypanosoma cruzi is not constant and varies in time and place. This study aimed to characterise the importance of domestic, wild and peridomestic hosts in the transmission of T. cruzi in Tauá, state of Ceará, Caatinga area, Brazil, with an emphasis on those environments colonised by Triatoma brasiliensis. Direct parasitological examinations were performed on insects and mammals, serologic tests were performed on household and outdoor mammals and multiplex polymerase chain reaction was used on wild mammals. Cytochrome b was used as a food source for wild insects. The serum prevalence in dogs was 38% (20/53), while in pigs it was 6% (2/34). The percentages of the most abundantly infected wild animals were as follows: Thrichomys laurentius 74% (83/112) and Kerodon rupestris 10% (11/112). Of the 749 triatomines collected in the household research, 49.3% (369/749) were positive for T. brasiliensis, while 6.8% were infected with T. cruzi (25/369). In captured animals, T. brasiliensis shares a natural environment with T. laurentius, K. rupestris, Didelphis albiventris, Monodelphis domestica, Galea spixii, Wiedomys pyrrhorhinos, Conepatus semistriatus and Mus musculus. In animals identified via their food source, T. brasiliensis shares a natural environment with G. spixii, K. rupestris, Capra hircus, Gallus gallus, Tropidurus oreadicus and Tupinambis merianae. The high prevalence of T. cruzi in household and peridomiciliar animals reinforces the narrow relationship between the enzootic cycle and humans in environments with T. brasiliensis and characterises it as ubiquitous.     

Cryptosporidium erinacei and C. parvum in a group of overwintering hedgehogs

This study describes cryptosporidiosis in an overwintering group of 15 European hedgehogs (Erinaceus europaeus), comprising 3 adults and 12 juveniles. Four juvenile hedgehogs were hospitalised with anorexia, malodorous diarrhoea and dehydration. Immediate parasitological examinations revealed the presence of Cryptosporidium sp. in these animals and also in 5 other juveniles. All hedgehogs were coproscopically monitored for 4 months over the winter season. Shedding of Cryptosporidium oocysts persisted from 6 to 70 days. Repeated shedding of Cryptosporidium oocysts occurred in 3 animals after 4 months subsequent to the first outbreak. Clinical signs were observed only at the beginning of the outbreak (apathy, anorexia, general weakness, mild dehydration, and malodorous faeces with changed consistence – soft/diarrhoea) in the 4 hospitalised juveniles. Overall 11 hedgehogs were Cryptosporidium-positive, both microscopically and by PCR methods. Sequence analyses of SSU rRNA and gp60 genes revealed the presence of C. parvum IIdA18G1 subtype in all positive hedgehogs. Moreover, 3 hedgehogs had a mixed infection of the zoonotic C. parvum and C. erinacei XIIIaA19R13 subtype. Cryptosporidium infections can be rapidly spread among debilitated animals and the positive hedgehogs released back into the wild can be a source of the infection for individuals weakened after hibernation.     

Environmental radioactivity damages the DNA of earthworms of Fukushima Prefecture,Japan

Radioactive materials released in 2011 during the accident at Japan's Fukushima nuclear power plant are expected to become concentrated in wildlife via the food web, triggering DNA damage. However, the extent of this wildlife DNA damage remains unknown. We explored the effects of exposure to environmental radiation on the DNA of wild boars (Sus scrofa leucomystax) and earthworms (Megascolecidae) and examined the modes of transfer of radioactivity to these animals. We used a comet assay to analyze the DNA damage in animals collected from regions with low (0.28 μSv/h) and high (2.85 μSv/h) levels of atmospheric radiation. We constructed a model food web featuring the wild boar as the top predator, and we measured the radioactivity levels in soil, plant material, earthworms, and wild boar. The extent of DNA damage in wild boars did not differ significantly between animals captured in the two regions, but earthworms from the “high-dose” region had a significantly greater extent of DNA damage than did those from the “low-dose” region. Radioactive material can be accumulated either directly from the soil or indirectly via plant ingestion. Wildlife inhabiting radioactively contaminated areas is at high risk of DNA damage although the risk varies among species because of the differences in foraging habits. The long-term results of the observed DNA damage must be studied.     

黑龙江省东完达山地区东北虎猎物种群现状及动态趋势

猎物种群丰度是限制虎分布和数量的关键因子,因此猎物种群密度监测和估算是虎保护的重要内容之一。应用采用大样方法,地理信息系统技术和多元统计分析,研究了黑龙江东完达山东部地区东北虎猎物种群(马鹿、狍子和野猪)现状及动态变化趋势。结果表明:研究地区马鹿的种群平均密度为(0.2010±0.0270)只/km²、狍子的平均种群密度为(0.4980±0.0436)只/km²、野猪的平均种群密度为(0.3423±0.0275)只/km²。单因素方差分析表明,在相同生境下,3种有蹄类密度在在阔叶混交林中和杂木林中差异极为显著;不同的生境,3种猎物的猎物的密度也存在着显著差异。相关分析表明马鹿密度和野猪密度程正相关,而马鹿密度和狍子密度、狍子密度和野猪密度则不相关。 同1989年该地区东北虎猎物种群相比:1989-2002年的13 a时间内马鹿的年平均递减率为13.48%、狍子的年平均递减率为12.69%、野猪的年平均递减率为1.89%。     

Recurred Sparganosis 1 Year after Surgical Removal of a Sparganum in a Korean Woman

Sparganosis, an infection due to the plerocercoid of Spirometra erinacei, are found worldwide but the majority of cases occur in East Asia including Korea. This report is on a recurred case of sparganosis in the subcutaneous tissue of the right lower leg 1 year after a surgical removal of a worm from a similar region. At admission, ultrasonography (USG) of the lesion strongly suggested sparganosis, and a worm was successfully removed which turned out to be a sparganum with scolex. Since sparganum has a variable life span, and may develop into a life-threatening severe case, a patient once diagnosed as sparganosis should be properly followed-up for a certain period of time. Although imaging modalities were useful for the diagnosis of sparganosis as seen in this case, serological test such as ELISA should also be accompanied so as to support the preoperative diagnosis.     

Prevalence of Zoonotic Trematode Metacercariae in Freshwater Fish from Gangwon-do,Korea

The infection status of zoonotic trematode metacercariae was investigated in a total of 2,293 freshwater fish collected from 11 rivers or streams in 9 administrative regions of Gangwon-do, Korea for 5 years (2009-2013). All fish were collected by netting methods and examined using the artificial digestion methods. Clonorchis sinensis metacercariae were detected in 4 fish species, i.e., Pungtungia herzi, Squalidus japonicus coreanus, Acheilognathus rhombeus, and Ladislabia taczanowskii, from only Hantangang in Cheorwon-gun. Metagonimus spp. metacercariae were found in 1,154 (50.3%) fish and their average number per infected fish was 55.8. Among the positive fish species, especially Tribolodon hakonensis from Namdaecheon in Yangyang-gun and Plecoglossus altivelis from Osipcheon in Samcheok-si were most heavily infected. Centrocestus armatus metacercariae were detected in 611 (26.7%) fish and the average metacercarial burden per infected fish was 1,032. Two chub species, Zacco platypus and Zacco temminckii were highly and heavily infected with C. armatus metacercariae in almost all regions surveyed. Echinostoma spp. metacercariae were also found in 24 fish from a few localities, but their numbers per fish infected were very low. From the above results, it is confirmed that the metacercariae of intestinal flukes, especially Metagonimus spp. and C. armatus, were heavily infected, while C. sinensis metacercariae were rarely found in fish from Gangwon-do, Korea.     

黑龙江凤凰山国家级自然保护区野猪冬季容纳量及最适种群密度

近年黑龙江省凤凰山国家级自然保护区野猪数量不断增长,人猪冲突加剧,保护区资源保护管理工作面临较大管理压力.为确定野猪种群的实际数量,同时评估该保护区的野猪的容纳量水平,以便为保护区管理局针对野猪的管理提供相关指导意见.2009-2010年冬季,在保护区采用样带调查、雪地足迹链跟踪和观察食痕的方法,并结合已有野猪生态研究确定野猪食性.野猪主要食物种类包括:木贼(Equisetum hiemale)、红松(Pinus koraiensis)果实松籽、胡桃楸(Juglans mandshurica)果实核桃、蒙古栎(Quecusmongolica)果实橡子、稠李(Padus racemosa)、榛子(Corylus heterophlla)、苔草(Carex spp.)、辽东葱木(Aralia elata).研究期间共布设长3-5km、单侧宽度50m、总长134 km的样带30条.调查中,每隔200 m布设10 m×10 m的大样方,并在每个大样方中央及四角布设1 m×1 m的小样方,共布设大样方350个,小样方1 750个.通过样方调查,统计野猪栖息生境当年可食植物枝条及其食物种类,然后计算其食物的总供给量,再结合食物营养成分,通过粗蛋白、粗纤维、粗脂肪的能量转换,按照每克粗蛋白和粗纤维的能量转换系数为16.74kJ、每克粗脂肪的能量转换系数为37.66 kJ,确定野外生境食物总能量供给.结合野猪冬季日营养需求,以能量为基础估算保护区野猪的营养容纳量.在种群密度调查过程中,通过足迹链判断个体方法为:单一清晰足迹链确定为一个体所留,30m内多条足迹穿越同一样带被认为是一个野猪群所留,调查中根据个体分开时的足迹链数确定野猪个体数,同时将粪便、卧迹、啃食痕迹作为个体判断的辅助信息.研究结果表明:凤凰山保护区内能够提供的总能量为7.375 ×107MJ,冬季平均每头野猪生存所需能量为(14 677.698±409.92) MJ,野猪营养容纳量为(1 006±28)头,种群密度为(3.79±0.11)头/km2.此外,调查中发现30余个野猪套及2头野猪被猎杀现场,反应出当地的人猪冲突较为严重.结合调查中发现的野猪套数量及野猪被猎杀概率,对野猪种群数量引入20％的死亡风险系数.最终确定凤凰山野猪种群的最适数量在(603±17)头左右,最适密度为(2.27±0.06)头/km2.通过样带法调查得出凤凰山自然保护区实际野猪种群数量为(596±155)头,密度(2.24±0.58)头/km2,已趋近营养容纳量.因此,野猪并未过量,不能采取狩猎等降低种群数量的措施,同时保护区也应对野猪种群进行持续监控,防止野猪种群过度繁殖以至成灾.     

Seasonal variation and natural infection of Lutzomyia antunesi (Diptera: Psychodidae: Phlebotominae), an endemic species in the Orinoquia region of Colombia

Lutzomyia antunesi has been commonly reported in outbreaks of cutaneous leishmaniasis (CL) in the Orinoquia region of Colombia. The bionomics of this species were studied in the municipality of Villavicencio (Meta, Colombia). Sandflies were captured over the course of one week per month for one year in intradomiciliary, peridomiciliary and extradomiciliary housing areas. The captures were performed from 06:00 pm-06:00 am using CDC light traps and the females were processed for polymerase chain reaction (PCR) to detect Leishmania spp. A total of 22,097 specimens and 19 species were captured of which Lu. antunesi (89%) and Lutzomyia walkeri (5%) were the most abundant. Other species recognised as anthropophilic (Lutzomyia panamensis, Lutzomyia gomezi, Lutzomyia flaviscutellata and Lutzomyia fairtigi) were present in very low abundance (< 2%). Natural infection with Leishmania spp was detected using PCR in Lu. antunesi, Lu. panamensis and Lu. flavicutellata, showing infection rates of 1%, 4.8% and 7.5%, respectively. The present paper provides information on various ecological aspects of Lu. antunesi. An analysis of seasonality shows that this species increases in abundance in the hottest months (December, January and February), directly correlating with the maximum temperature and inversely correlating with precipitation. The natural infection rate is associated with the peaks of highest abundance.