A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence ...A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence for their song comes from: a) their emitting songs that were complex (both tonally and rhythmically), b) their likely improvising (as inferred from their most complex songs not being repeated), c) songs based on a theme (used repeatedly), d) a bout of singing (at times) including social creativity, e) songs with a distinct beginning, middle and end section, and f) one song consisting of in part, a theme, 2) their songs are not sung in key (as determined from analysing the beginning tonal value of a note with spectral-frequency analysis), and 3) are sung in bouts, and 4) mostly with tonal-striated vocalizations (in the literature termed squawks and bray calls). Their apparent creativity (likely improvisations) and social creativity are of importance to how they evolved cognitively, to the study of song culture (between populations and delphinid species), understanding their (intra and inter-species) associations, and kinds of relationships, determining individual personalities, and perhaps will provide supporting evidence for their ability to reason. As inferred, they sing without being intentionally manipulative from: 1) their use of Gquic psychology [1] (as explained in this article), and 2) as inferred from their likely having an ability to reason [1] [2] (as deduced from their behavioural ecology (their unique exceptional evolutionary freedom), including their comparatively peaceful composure between conspecifics, in line with the proof of The Peaceful Composure Theorem), suggesting (per The Peaceful Composure Theorem) they have an egalitarian-like society. Their interspecies (displaced) aggression towards smaller odontocete species is shown to be a function of jealousies that emerge from their stronger social bonds than other species, from their compassionate nature, and females and males not pairing up in long-term associations. Species with greater cultural freedom are shown to have a more complex song providing further evidence for species culture not crucial to survival. The conclusive evidence for specie culture from my recent publications is of relevance to the scientific community’s acceptance of two new theories of evolution, and Gquic psychology. The loud burst-pulse sounds, chasing, charging and raking behaviours described in the literature could be a play behaviour, ought not be labelled as aggressive behaviours, as inferred from dog mock-fight play behaviour. In regard to future comparative behavioural ecology studies, aggressive animal behaviour should only be defined as an act of displacement (that is shown to commonly occur in the Indo-Pacific bottlenose dolphin species (Tursiops aduncus)), or as acts of biting, and hitting.展开更多
The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied.The primary aim of this study was to identify ...The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied.The primary aim of this study was to identify and quantify how wild bottlenose dolphins respond,individually and as groups,to the relative abundance of prey around a fish farm.Detailed views of dolphins' behavior were obtained by focal following individual animals whilst simultaneously collecting surface and underwater behavioral data.A total of 2150 dive intervals were analyzed,corresponding to 342 focal samples,lasting over 34 hours.Bottlenose dolphins remained submerged for a mean duration of 46.4 seconds and a maximum of 249 seconds.This study provides the first quantified data on bottlenose dolphin diving behavior in a marine fin-fish farm area.This study's results indicate that within a fish farm area used intensively by bottlenose dolphins for feeding,dolphins did not modify dive duration.Additionally,underwater observations confirmed that dolphins find it easier to exploit a concentrated food source and it appears that hunting tactic and not group size plays an important role during feeding activities.Thus,bottlenose dolphins appear capable of modifying their hunting tactics according to the abundance of prey.When top predators display behavioral responses to activities not directed at them,the task of studying all possible effects of human activities can become even more challenging.展开更多
Prostephanus truncatus （Horn） is a notorious stored grain insect pest established in Tanzania in late 1970s and currently threatening the maize industry of Zimbabwe. The devastating effects of the pest attack, deman...Prostephanus truncatus （Horn） is a notorious stored grain insect pest established in Tanzania in late 1970s and currently threatening the maize industry of Zimbabwe. The devastating effects of the pest attack, demands adequate preparation including identification of the potential invasion areas for more focused planning towards its effective management. In the current study, the potential P. truncatus invasion areas in Zimbabwe were identified based on climatic data with reference to the Tanzania situation using the geographical information system （GIS） Almanac Characterization Tool （AWhere-ACT 3.5 software）. Areas identified to be at greatest risk of invasion includes the northern part of the country, the southern-east region and a few areas in the east （Manicaland province）. Alternative host plants for P. truncatus similar to those identified in Kenya, where the pest is already endemic, were found to occur throughout Zimbabwe which could support initial colonization and subsequent perpetuation of the pest in the country. In Zimbabwe, chances that P. truncatus may spread throughout the country, should it invade the country, are high because of unregulated grain trade and the fact that most of the potential invasion areas identified in this study, are located in the major maize producing areas. Measures to delay the occurrence of the pest in Zimbabwe should focus on the high-risk areas identified.展开更多
[Objectives] This study was conducted to screen out pesticides that are highly effective against Tetranychus truncatus Ehara. [Methods] Nine kinds of pesticides were used to control pests on soybean. A petri dish effi...[Objectives] This study was conducted to screen out pesticides that are highly effective against Tetranychus truncatus Ehara. [Methods] Nine kinds of pesticides were used to control pests on soybean. A petri dish efficacy test was first performed in laboratory,then a leaf efficacy test was performed in a greenhouse,and finally,three kinds of agents with good efficacy in the two tests were selected for field control tests. [Results] The indoor and outdoor test results showed that abamectin was the best agent,which showed efficacy higher than 96%,followed by bifenthrin,whose efficacy was higher than 93%. It can be seen that abamectin is the best choice for the prevention and control of T. truncatus,and bifenthrin can also be used according to the situation. [Conclusions] This study provides a theoretical basis for the control of T. truncatus.展开更多
The effects of sublethal concentrations of methanol extract of sesbania sesban plant on survival rate, egg laying of Bulinus truncatus snails, hatchability of their eggs, infection rate with Schistosoma haemato- bium ...The effects of sublethal concentrations of methanol extract of sesbania sesban plant on survival rate, egg laying of Bulinus truncatus snails, hatchability of their eggs, infection rate with Schistosoma haemato- bium miracidia, cercarial production and certain physiological parameters of treated snails were stu- died. The sublethal concentrations of the tested plant extract (LC0, LC10 and LC25) caused considerable reduction in survival rates;egg production of B. runcates snails;hatchability of eggs as well as in the infectivity of Schistosoma haematobium miracidia to the snail. Also, the tested concentrations reduced the cercarial production per snail and the period of cer-carial shedding. The glucose level in haemolymph of exposed snails was elevated while the glycogen, pro-tein content and the activities of hexokinase (HK), pyruvatekinase (PK) and lactate dehydrogenase (LDH) showed a decrease in soft tissues when compared with the control group. It was concluded that the app lication of sublethal concentration of methanol ex- tracts of Sesania sesban may be helpful in snail con- trol as it interferes with the snails’ biology and phy- siology.展开更多
[ Objectives] This study was conducted to investigate the effect of silicon fertilizer on maize growth and Tetranychus truncatus Ehara. [ Methods ] Yougui and Guishen were selected and sprayed onto maize for 1, 2 and ...[ Objectives] This study was conducted to investigate the effect of silicon fertilizer on maize growth and Tetranychus truncatus Ehara. [ Methods ] Yougui and Guishen were selected and sprayed onto maize for 1, 2 and 3 times, forming difference treatments. [ Results ] Spraying the two kinds of silicon fertilizers for different times promoted the growth of plant height, leaf length, leaf width and leaf thickness of maize, increased chlorophyll contents in maize leaves and yield of single ear, and also adversely affected T. truncatus （i. e. , increased the death rate of T. truncatus）. The more the treatment times of silicon fertilizer, the more remarkable the effect, and the higher the adverse effect on T. truncatus. [ Conclusions] In production, spraying silicon fertilizer onto maize for 2 -3 times could realize the purposes of increasing maize yield and alleviating the danlage by T. truncatus.展开更多
Laboratory interspecific competition and grain-hosts selection experiments involving maize weevil (MW), Sitophilus zeamais (Motsch.) and larger grain borer (LGB), Prostephanus truncatus (Horn) were performed under amb...Laboratory interspecific competition and grain-hosts selection experiments involving maize weevil (MW), Sitophilus zeamais (Motsch.) and larger grain borer (LGB), Prostephanus truncatus (Horn) were performed under ambient temperature and relative humidity (25°C - 35°C and 70% - 80% relative humidity) in their major host cereal, maize grains. The species reproductive rate and grain-hosts preference were evaluated by a number of emerged adults. In combined infestation, both species competed intensively by simultaneously increasing their individuals’ emergence, 9-fold or greater than when reared alone. Even though both species simultaneously increased their progeny, S. zeamais was the dominant competitor and had a significant suppressant effect on P. truncatus. The selection result of grain-hosts showed that P. truncatus placed in the environment containing both uninfested maize grains and grains previously infested by S. zeamais, the insect prefers uninfested grains. Indeed, P. truncatus individuals’ emergences were significantly more important to uninfested grains than to infested grains. The weevil-infested grains seemed to have deterrent and detrimental effects on P. truncatus. Conversely, S. zeamais selection of grain-hosts was significantly (P = 0.0001) more attracted by P. truncatus infested grains than to uninfested grains. Sitophilus zeamais individuals’ emergences were significantly (P = 0.0008) more important to infested grains than to uninfested grains. The S. zeamais preference on grains previously infested would be stimulated by P. truncatus larval vibrations in grain.展开更多
Wolbachia and Spiroplasma are intracellular bacteria that are of great interest to entomologists,because of their ability to alter insect host biology in multiple ways.In the spider mite Tetranychus truncatus,co-infec...Wolbachia and Spiroplasma are intracellular bacteria that are of great interest to entomologists,because of their ability to alter insect host biology in multiple ways.In the spider mite Tetranychus truncatus,co-infection of Wolbachia and Spiroplasma can induce cytoplasmic incompatibility(CI)and fitness costs;however,lttle is known about the effect of co-infection at the genetic level and the molecular mechanisms underlying CI.In this study,we explored the influence of the two symbionts on male mite host fitness and used RNA sequencing to generate the transcriptomes of T truncatus with four different types of infection.In total,we found symbiont-infected lines had a higher hatch proportion than the uninfected line,and the development time of the uninfected line was longer than that of the other lines.Co-infection changed the expression of many genes related to digestion detoxification,reproduction,immunity and oxidation reduction.Our results indicate that co-infection of Wolbachia and Spiroplasma confers multiple effects on their hosts,and helps iluminate the complex interactions between endosymbionts and arthropods.展开更多
Background:Control of snail intermediate hosts has been proved to be a fast and efficient approach for interrupting the transmission of schistosomiasis.Some plant extracts have shown obvious molluscicidal activity,and...Background:Control of snail intermediate hosts has been proved to be a fast and efficient approach for interrupting the transmission of schistosomiasis.Some plant extracts have shown obvious molluscicidal activity,and a new compound Luo-Wei,also named tea-seed distilled saponin(TDS),was developed based on the saponins extracted from Camellia oleifera seeds.We aimed to test the molluscicidal activity of 4%TDS against the intermediate host snails in China and Egypt,and evaluate its environmental safety to non-target organisms.Methods:In the laboratory,Oncomelania hupensis,Biomphalaria alexandrina and Bulinus truncatus were exposed to 4%TDS,and the median lethal concentration(LC5o)was estimated at 24,48 and 72 h.In the field,snail mortalities were assessed 1,2,3 and 7 d post-immersion with 2.5 g/m34%TDS and 1,3,7 and 15 d post-spraying with 5 g/m24%TDS.in addition,the acute toxicity of 4%TDS to Japanese quail(Coturnixjaponica),zebrafish(Brachydanio rerio)and freshwater shrimp(Macrobrachium nipponense)was assessed by estimations of LC5o or median lethal dose(LD5o).Results:In the laboratory,the LC5o values of 4%TDS for O.hupensis were 0.701,0.371 and 0.33 mg/L at 24,48 and 72 h,respectively,and 4%TDS showed a 0.33 mg/L 24 h LC5o against B.alexandrina,and a 1.396 mg/L 24 h LCs0 against B.truncatus.Across all study regions,the pooled mortalities of O.hupensis were 72,86,94 and 98%at 1,2,3 and 7 d,following field immersion of 4%TDS at a dose of 2.5 g/m3,and were 69,77,85 and 88%at 1,3,7 and 15 d,following field spraying at 5 g/m2,respectively.4%TDS had moderate toxicity to Japanese quail(7 d LD5o>60 mg/kg)and to shrimp(96 h LCs0=6.28 mg/L;95%CI:3.53-11.2 mg/L),whereas its toxicity to zebrafish was high(96 h LCso--0.15 mg/L;95%CI:0.14-0.17 mg/L).Conclusions:4%TDS is active against O.hupensis,B.alexandrina and B.truncatus under laboratory and field conditions,and it may be a candidate molluscicide of plant origin.展开更多
Objective:To investigate the predation efficacy of the freshwater leech,Limnatis nilotica(L.nilotica)as a potential biological control agent against different stages of the Bulinus truncatus(B.truncatus),the intermedi...Objective:To investigate the predation efficacy of the freshwater leech,Limnatis nilotica(L.nilotica)as a potential biological control agent against different stages of the Bulinus truncatus(B.truncatus),the intermediate host of human Schistosoma haematobium,under laboratory conditions.Methods:The leech L.nilotica and the snail B.truncatus were collected from El Kiryab Agriculture Scheme,Sudan.Thereafter,the predatory activity of the leech was evaluated against eggs,neonates and adults of the snail in a series of different experiments under laboratory conditions.Results:The findings showed that the L.nilotica leech was a voracious predator towards the eggs and neonates of B.truncatus snails with a shell length of up to 3 mm,as well as of adult snails with an shell length greater than 3 mm.Conclusions:The results showed that L.nilotica had a significant impact on B.truncatus populations.However,long term studies under natural field conditions are needed to support these results.展开更多
Accurate estimations of animal population size are pivotal for implementing management strategies properly.Recapture technique based on sounds as a specimen identifcation mark has barely been used for marine mammals.H...Accurate estimations of animal population size are pivotal for implementing management strategies properly.Recapture technique based on sounds as a specimen identifcation mark has barely been used for marine mammals.However,inferring abundance estimates from acoustic methods could enhance the accuracy and precision of population size assessments.Here,we tested the possibility of using signature whistles as individual marks for estimating the size of common bottlenose dolphin(Tursiops truncatus)populations.Data were continuously collected for 326 days in 2015–2016,by using a fxed acoustic device located in the Sicily Strait(Italy).The SIGID method was applied to identify Signature Whistles Types(SWTs)over 7,000 h of recordings.Eighty SWTs were detected as long as their stereotyped fundamental frequency contours were repeated in bouts of at least 6 renditions.The mean SWTs monthly recording rate resulted in 0.19(Standard deviation=0.16),with 20 SWTs recorded over 5 or more different encounters(until a maximum of 30 encounters).The Jolly–Seber model(with POPAN formulation)was run in Mark software to estimate the population size.The estimated population size resulted in 171 bottlenose dolphins(95%confdence interval=137–215).Even if the detection and identifcation of signature whistles required crucial precautions,and animals could be detected differently from visual techniques,the population size estimate obtained was comparable with previous results based on physical marks data.These outcomes demonstrated that signature whistles can be considered a strongly effective tool for integrating traditional mark-recapture techniques with fnely estimated dolphins’population abundances.展开更多
Schistosomiasis is a public health concern in Benin. Freshwater snails of the genus Bulinus serve as intermediate hosts for schistosomes, trematode parasites responsible for bilharzia. The urinary form, caused by Schi...Schistosomiasis is a public health concern in Benin. Freshwater snails of the genus Bulinus serve as intermediate hosts for schistosomes, trematode parasites responsible for bilharzia. The urinary form, caused by Schistosoma haematobium, is the most widespread and is transmitted to humans by these mollusks, with Bulinus truncatus and Bulinus globosus being the most important species. Effective strategies to combat the transmission of these parasites require a prior understanding of the molecular characterization of Bulinus snails. For this purpose, 293 Bulinus snails were collected and morphologically identified from two localities in southern Benin, Sô-Ava and Azowlissè. The snails were preserved in absolute alcohol. To achieve the set objectives, DNA was extracted from the collected biological material, and SSU gene fragments were amplified. Using PCR-RFLP, the amplified fragments were digested with the restriction endonucleases HaeIII, HinfI, and DdeI to perform molecular characterization. In this study, 80 individuals of B. globosus and 10 of B. truncatus were subjected to molecular analysis. The PCR-RFLP profiles showed bands of different sizes for the Bulinus species when analyzed with the three endonucleases using the SSU molecular marker. PCR-RFLP analysis revealed that the snails belonged to the freshwater genus Bulinus, including Bulinus globosus and B. truncatus, based on reference profiles from studies conducted in Nigeria, which enabled precise identification of these gastropods. This study provided initial insights, although still incomplete, into the molecular diversity of these species.展开更多
Background Researching a water-borne disease in the middle of the Sahara desert might not seem the most relevant concern.However,nomadic Sahelian pastoralists health concerns regarding their livestock and anecdotal re...Background Researching a water-borne disease in the middle of the Sahara desert might not seem the most relevant concern.However,nomadic Sahelian pastoralists health concerns regarding their livestock and anecdotal reports about trematode infections of Fasciola spp.and Schistosoma spp.in desert-raised animals justified an exploratory study focusing on the lakes of Ounianga in Northern Chad.The aim was to test whether trematode parasites such as Schistosoma spp.occur in human populations living around the Sahara desert lakes of Ounianga Kebir and Ounianga Serir in northern Chad.Methods The study was carried out in January 2019 and comprised of three components.First,a cross sectional survey based on a random sample drawn from the population to detect infections with S.haematobium and S.mansoni;second,focus group discussions exploring disease priorities,access to health and health seeking behaviour;and third,surveying water contact sites for intermediate host snails.Samples of trematode parasites and snails were confirmed on species level by molecular genetic methods.For parasitological and malacological surveys descriptive statistics were performed.Qualitative data analysis included the full review of all transcripts,followed by a descriptive and explorative thematic analysis.Results Among 258 participants,the overall S.haematobium prevalence using urine filtration was 39.2%[95%confidence interval(CI):33.5–45.1%],with 51.5%of the infected suffering from heavy infection.The intermediate host snail of S.haematobium(Bulinus truncatus)occurred at water contact sites near both study villages,revealing the potential for local transmission.Although a positive S.mansoni point-of-care circulating cathodic antigen(POC-CCA)test result was obtained from 8.6%(95%CI 5.7–12.8%)of the samples,no intermediate host snails of S.mansoni were found,and the relevance of S.mansoni remains uncertain.Qualitative findings underline the importance of morbidity caused by urinary schistosomiasis,and the lack of access to diagnostics and treatment as a major health concern.Conclusions This research revealed a high prevalence of urinary schistosomiasis in the population living around the lakes of Ounianga in the Sahara,a United Nations Educational,Scientific and Cultural Organization(UNESCO)world heritage site in Chad.Despite the high public health importance of the associated morbidity expressed by the population,there is no access to diagnostics and treatment.Further work is needed to develop and test a context-adapted intervention.展开更多
文摘A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence for their song comes from: a) their emitting songs that were complex (both tonally and rhythmically), b) their likely improvising (as inferred from their most complex songs not being repeated), c) songs based on a theme (used repeatedly), d) a bout of singing (at times) including social creativity, e) songs with a distinct beginning, middle and end section, and f) one song consisting of in part, a theme, 2) their songs are not sung in key (as determined from analysing the beginning tonal value of a note with spectral-frequency analysis), and 3) are sung in bouts, and 4) mostly with tonal-striated vocalizations (in the literature termed squawks and bray calls). Their apparent creativity (likely improvisations) and social creativity are of importance to how they evolved cognitively, to the study of song culture (between populations and delphinid species), understanding their (intra and inter-species) associations, and kinds of relationships, determining individual personalities, and perhaps will provide supporting evidence for their ability to reason. As inferred, they sing without being intentionally manipulative from: 1) their use of Gquic psychology [1] (as explained in this article), and 2) as inferred from their likely having an ability to reason [1] [2] (as deduced from their behavioural ecology (their unique exceptional evolutionary freedom), including their comparatively peaceful composure between conspecifics, in line with the proof of The Peaceful Composure Theorem), suggesting (per The Peaceful Composure Theorem) they have an egalitarian-like society. Their interspecies (displaced) aggression towards smaller odontocete species is shown to be a function of jealousies that emerge from their stronger social bonds than other species, from their compassionate nature, and females and males not pairing up in long-term associations. Species with greater cultural freedom are shown to have a more complex song providing further evidence for species culture not crucial to survival. The conclusive evidence for specie culture from my recent publications is of relevance to the scientific community’s acceptance of two new theories of evolution, and Gquic psychology. The loud burst-pulse sounds, chasing, charging and raking behaviours described in the literature could be a play behaviour, ought not be labelled as aggressive behaviours, as inferred from dog mock-fight play behaviour. In regard to future comparative behavioural ecology studies, aggressive animal behaviour should only be defined as an act of displacement (that is shown to commonly occur in the Indo-Pacific bottlenose dolphin species (Tursiops aduncus)), or as acts of biting, and hitting.
基金Funding for this research came from the Bottlenose Dolphin Research Institute-BDRI and private donations
文摘The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied.The primary aim of this study was to identify and quantify how wild bottlenose dolphins respond,individually and as groups,to the relative abundance of prey around a fish farm.Detailed views of dolphins' behavior were obtained by focal following individual animals whilst simultaneously collecting surface and underwater behavioral data.A total of 2150 dive intervals were analyzed,corresponding to 342 focal samples,lasting over 34 hours.Bottlenose dolphins remained submerged for a mean duration of 46.4 seconds and a maximum of 249 seconds.This study provides the first quantified data on bottlenose dolphin diving behavior in a marine fin-fish farm area.This study's results indicate that within a fish farm area used intensively by bottlenose dolphins for feeding,dolphins did not modify dive duration.Additionally,underwater observations confirmed that dolphins find it easier to exploit a concentrated food source and it appears that hunting tactic and not group size plays an important role during feeding activities.Thus,bottlenose dolphins appear capable of modifying their hunting tactics according to the abundance of prey.When top predators display behavioral responses to activities not directed at them,the task of studying all possible effects of human activities can become even more challenging.
文摘Prostephanus truncatus （Horn） is a notorious stored grain insect pest established in Tanzania in late 1970s and currently threatening the maize industry of Zimbabwe. The devastating effects of the pest attack, demands adequate preparation including identification of the potential invasion areas for more focused planning towards its effective management. In the current study, the potential P. truncatus invasion areas in Zimbabwe were identified based on climatic data with reference to the Tanzania situation using the geographical information system （GIS） Almanac Characterization Tool （AWhere-ACT 3.5 software）. Areas identified to be at greatest risk of invasion includes the northern part of the country, the southern-east region and a few areas in the east （Manicaland province）. Alternative host plants for P. truncatus similar to those identified in Kenya, where the pest is already endemic, were found to occur throughout Zimbabwe which could support initial colonization and subsequent perpetuation of the pest in the country. In Zimbabwe, chances that P. truncatus may spread throughout the country, should it invade the country, are high because of unregulated grain trade and the fact that most of the potential invasion areas identified in this study, are located in the major maize producing areas. Measures to delay the occurrence of the pest in Zimbabwe should focus on the high-risk areas identified.
基金Supported by the Cooperative Project Between the People's Republic of China and the Republic of Korea (413090094)。
文摘[Objectives] This study was conducted to screen out pesticides that are highly effective against Tetranychus truncatus Ehara. [Methods] Nine kinds of pesticides were used to control pests on soybean. A petri dish efficacy test was first performed in laboratory,then a leaf efficacy test was performed in a greenhouse,and finally,three kinds of agents with good efficacy in the two tests were selected for field control tests. [Results] The indoor and outdoor test results showed that abamectin was the best agent,which showed efficacy higher than 96%,followed by bifenthrin,whose efficacy was higher than 93%. It can be seen that abamectin is the best choice for the prevention and control of T. truncatus,and bifenthrin can also be used according to the situation. [Conclusions] This study provides a theoretical basis for the control of T. truncatus.
文摘The effects of sublethal concentrations of methanol extract of sesbania sesban plant on survival rate, egg laying of Bulinus truncatus snails, hatchability of their eggs, infection rate with Schistosoma haemato- bium miracidia, cercarial production and certain physiological parameters of treated snails were stu- died. The sublethal concentrations of the tested plant extract (LC0, LC10 and LC25) caused considerable reduction in survival rates;egg production of B. runcates snails;hatchability of eggs as well as in the infectivity of Schistosoma haematobium miracidia to the snail. Also, the tested concentrations reduced the cercarial production per snail and the period of cer-carial shedding. The glucose level in haemolymph of exposed snails was elevated while the glycogen, pro-tein content and the activities of hexokinase (HK), pyruvatekinase (PK) and lactate dehydrogenase (LDH) showed a decrease in soft tissues when compared with the control group. It was concluded that the app lication of sublethal concentration of methanol ex- tracts of Sesania sesban may be helpful in snail con- trol as it interferes with the snails’ biology and phy- siology.
基金Supported by College Students' Innovation and Enterpreneurship Traning Program of Yanbian University(ydbksky2017507)
文摘[ Objectives] This study was conducted to investigate the effect of silicon fertilizer on maize growth and Tetranychus truncatus Ehara. [ Methods ] Yougui and Guishen were selected and sprayed onto maize for 1, 2 and 3 times, forming difference treatments. [ Results ] Spraying the two kinds of silicon fertilizers for different times promoted the growth of plant height, leaf length, leaf width and leaf thickness of maize, increased chlorophyll contents in maize leaves and yield of single ear, and also adversely affected T. truncatus （i. e. , increased the death rate of T. truncatus）. The more the treatment times of silicon fertilizer, the more remarkable the effect, and the higher the adverse effect on T. truncatus. [ Conclusions] In production, spraying silicon fertilizer onto maize for 2 -3 times could realize the purposes of increasing maize yield and alleviating the danlage by T. truncatus.
文摘Laboratory interspecific competition and grain-hosts selection experiments involving maize weevil (MW), Sitophilus zeamais (Motsch.) and larger grain borer (LGB), Prostephanus truncatus (Horn) were performed under ambient temperature and relative humidity (25°C - 35°C and 70% - 80% relative humidity) in their major host cereal, maize grains. The species reproductive rate and grain-hosts preference were evaluated by a number of emerged adults. In combined infestation, both species competed intensively by simultaneously increasing their individuals’ emergence, 9-fold or greater than when reared alone. Even though both species simultaneously increased their progeny, S. zeamais was the dominant competitor and had a significant suppressant effect on P. truncatus. The selection result of grain-hosts showed that P. truncatus placed in the environment containing both uninfested maize grains and grains previously infested by S. zeamais, the insect prefers uninfested grains. Indeed, P. truncatus individuals’ emergences were significantly more important to uninfested grains than to infested grains. The weevil-infested grains seemed to have deterrent and detrimental effects on P. truncatus. Conversely, S. zeamais selection of grain-hosts was significantly (P = 0.0001) more attracted by P. truncatus infested grains than to uninfested grains. Sitophilus zeamais individuals’ emergences were significantly (P = 0.0008) more important to infested grains than to uninfested grains. The S. zeamais preference on grains previously infested would be stimulated by P. truncatus larval vibrations in grain.
基金supported in part by a grant-in-aid for Scientific Research(31672035,31871976)from the National Natural Science Foundation of China.
文摘Wolbachia and Spiroplasma are intracellular bacteria that are of great interest to entomologists,because of their ability to alter insect host biology in multiple ways.In the spider mite Tetranychus truncatus,co-infection of Wolbachia and Spiroplasma can induce cytoplasmic incompatibility(CI)and fitness costs;however,lttle is known about the effect of co-infection at the genetic level and the molecular mechanisms underlying CI.In this study,we explored the influence of the two symbionts on male mite host fitness and used RNA sequencing to generate the transcriptomes of T truncatus with four different types of infection.In total,we found symbiont-infected lines had a higher hatch proportion than the uninfected line,and the development time of the uninfected line was longer than that of the other lines.Co-infection changed the expression of many genes related to digestion detoxification,reproduction,immunity and oxidation reduction.Our results indicate that co-infection of Wolbachia and Spiroplasma confers multiple effects on their hosts,and helps iluminate the complex interactions between endosymbionts and arthropods.
基金the National Science and Technology Pillar Program(grant No.2009BAI78B07 and 2009BAI78B04)National S&T Major Program(grant No.2012ZX10004-220)+3 种基金Shanghai Science and Technology Committee(grant No.11XD1405400)Jjiangsu Provincial Health and Family Planning Commission(grant No.QNRC2016621 and H2018097)Wuxi Municipal Bureau of Science and Technology(grant No.CSE31N1730)Bill&Melinda Gates Foundation.
文摘Background:Control of snail intermediate hosts has been proved to be a fast and efficient approach for interrupting the transmission of schistosomiasis.Some plant extracts have shown obvious molluscicidal activity,and a new compound Luo-Wei,also named tea-seed distilled saponin(TDS),was developed based on the saponins extracted from Camellia oleifera seeds.We aimed to test the molluscicidal activity of 4%TDS against the intermediate host snails in China and Egypt,and evaluate its environmental safety to non-target organisms.Methods:In the laboratory,Oncomelania hupensis,Biomphalaria alexandrina and Bulinus truncatus were exposed to 4%TDS,and the median lethal concentration(LC5o)was estimated at 24,48 and 72 h.In the field,snail mortalities were assessed 1,2,3 and 7 d post-immersion with 2.5 g/m34%TDS and 1,3,7 and 15 d post-spraying with 5 g/m24%TDS.in addition,the acute toxicity of 4%TDS to Japanese quail(Coturnixjaponica),zebrafish(Brachydanio rerio)and freshwater shrimp(Macrobrachium nipponense)was assessed by estimations of LC5o or median lethal dose(LD5o).Results:In the laboratory,the LC5o values of 4%TDS for O.hupensis were 0.701,0.371 and 0.33 mg/L at 24,48 and 72 h,respectively,and 4%TDS showed a 0.33 mg/L 24 h LC5o against B.alexandrina,and a 1.396 mg/L 24 h LCs0 against B.truncatus.Across all study regions,the pooled mortalities of O.hupensis were 72,86,94 and 98%at 1,2,3 and 7 d,following field immersion of 4%TDS at a dose of 2.5 g/m3,and were 69,77,85 and 88%at 1,3,7 and 15 d,following field spraying at 5 g/m2,respectively.4%TDS had moderate toxicity to Japanese quail(7 d LD5o>60 mg/kg)and to shrimp(96 h LCs0=6.28 mg/L;95%CI:3.53-11.2 mg/L),whereas its toxicity to zebrafish was high(96 h LCso--0.15 mg/L;95%CI:0.14-0.17 mg/L).Conclusions:4%TDS is active against O.hupensis,B.alexandrina and B.truncatus under laboratory and field conditions,and it may be a candidate molluscicide of plant origin.
文摘Objective:To investigate the predation efficacy of the freshwater leech,Limnatis nilotica(L.nilotica)as a potential biological control agent against different stages of the Bulinus truncatus(B.truncatus),the intermediate host of human Schistosoma haematobium,under laboratory conditions.Methods:The leech L.nilotica and the snail B.truncatus were collected from El Kiryab Agriculture Scheme,Sudan.Thereafter,the predatory activity of the leech was evaluated against eggs,neonates and adults of the snail in a series of different experiments under laboratory conditions.Results:The findings showed that the L.nilotica leech was a voracious predator towards the eggs and neonates of B.truncatus snails with a shell length of up to 3 mm,as well as of adult snails with an shell length greater than 3 mm.Conclusions:The results showed that L.nilotica had a significant impact on B.truncatus populations.However,long term studies under natural field conditions are needed to support these results.
基金the project“BIOforIU project PONa3_00025-Multidisciplinary Infrastructure for the Study and Development of Marine and Terrestrial Biodiversity in the Perspective of Innovation Union.”Part of the analysis was funded under the National Recovery and Resilience Plan(NRRP),Mission 4 Component 2 Investment 1.4-Call for tender No.3138 of 16 December 2021,rectifed by Decree n.3175 of 18 December 2021 of Italian Ministry of University and Research funded by the European Union-NextGenerationEU,Award Number:Project code CN_00000033,Concession Decree No.1034 of 17 June 2022 adopted by the Italian Ministry of University and Research,Project title"National Biodiversity Future Center-NBFC".
文摘Accurate estimations of animal population size are pivotal for implementing management strategies properly.Recapture technique based on sounds as a specimen identifcation mark has barely been used for marine mammals.However,inferring abundance estimates from acoustic methods could enhance the accuracy and precision of population size assessments.Here,we tested the possibility of using signature whistles as individual marks for estimating the size of common bottlenose dolphin(Tursiops truncatus)populations.Data were continuously collected for 326 days in 2015–2016,by using a fxed acoustic device located in the Sicily Strait(Italy).The SIGID method was applied to identify Signature Whistles Types(SWTs)over 7,000 h of recordings.Eighty SWTs were detected as long as their stereotyped fundamental frequency contours were repeated in bouts of at least 6 renditions.The mean SWTs monthly recording rate resulted in 0.19(Standard deviation=0.16),with 20 SWTs recorded over 5 or more different encounters(until a maximum of 30 encounters).The Jolly–Seber model(with POPAN formulation)was run in Mark software to estimate the population size.The estimated population size resulted in 171 bottlenose dolphins(95%confdence interval=137–215).Even if the detection and identifcation of signature whistles required crucial precautions,and animals could be detected differently from visual techniques,the population size estimate obtained was comparable with previous results based on physical marks data.These outcomes demonstrated that signature whistles can be considered a strongly effective tool for integrating traditional mark-recapture techniques with fnely estimated dolphins’population abundances.
文摘Schistosomiasis is a public health concern in Benin. Freshwater snails of the genus Bulinus serve as intermediate hosts for schistosomes, trematode parasites responsible for bilharzia. The urinary form, caused by Schistosoma haematobium, is the most widespread and is transmitted to humans by these mollusks, with Bulinus truncatus and Bulinus globosus being the most important species. Effective strategies to combat the transmission of these parasites require a prior understanding of the molecular characterization of Bulinus snails. For this purpose, 293 Bulinus snails were collected and morphologically identified from two localities in southern Benin, Sô-Ava and Azowlissè. The snails were preserved in absolute alcohol. To achieve the set objectives, DNA was extracted from the collected biological material, and SSU gene fragments were amplified. Using PCR-RFLP, the amplified fragments were digested with the restriction endonucleases HaeIII, HinfI, and DdeI to perform molecular characterization. In this study, 80 individuals of B. globosus and 10 of B. truncatus were subjected to molecular analysis. The PCR-RFLP profiles showed bands of different sizes for the Bulinus species when analyzed with the three endonucleases using the SSU molecular marker. PCR-RFLP analysis revealed that the snails belonged to the freshwater genus Bulinus, including Bulinus globosus and B. truncatus, based on reference profiles from studies conducted in Nigeria, which enabled precise identification of these gastropods. This study provided initial insights, although still incomplete, into the molecular diversity of these species.
文摘Background Researching a water-borne disease in the middle of the Sahara desert might not seem the most relevant concern.However,nomadic Sahelian pastoralists health concerns regarding their livestock and anecdotal reports about trematode infections of Fasciola spp.and Schistosoma spp.in desert-raised animals justified an exploratory study focusing on the lakes of Ounianga in Northern Chad.The aim was to test whether trematode parasites such as Schistosoma spp.occur in human populations living around the Sahara desert lakes of Ounianga Kebir and Ounianga Serir in northern Chad.Methods The study was carried out in January 2019 and comprised of three components.First,a cross sectional survey based on a random sample drawn from the population to detect infections with S.haematobium and S.mansoni;second,focus group discussions exploring disease priorities,access to health and health seeking behaviour;and third,surveying water contact sites for intermediate host snails.Samples of trematode parasites and snails were confirmed on species level by molecular genetic methods.For parasitological and malacological surveys descriptive statistics were performed.Qualitative data analysis included the full review of all transcripts,followed by a descriptive and explorative thematic analysis.Results Among 258 participants,the overall S.haematobium prevalence using urine filtration was 39.2%[95%confidence interval(CI):33.5–45.1%],with 51.5%of the infected suffering from heavy infection.The intermediate host snail of S.haematobium(Bulinus truncatus)occurred at water contact sites near both study villages,revealing the potential for local transmission.Although a positive S.mansoni point-of-care circulating cathodic antigen(POC-CCA)test result was obtained from 8.6%(95%CI 5.7–12.8%)of the samples,no intermediate host snails of S.mansoni were found,and the relevance of S.mansoni remains uncertain.Qualitative findings underline the importance of morbidity caused by urinary schistosomiasis,and the lack of access to diagnostics and treatment as a major health concern.Conclusions This research revealed a high prevalence of urinary schistosomiasis in the population living around the lakes of Ounianga in the Sahara,a United Nations Educational,Scientific and Cultural Organization(UNESCO)world heritage site in Chad.Despite the high public health importance of the associated morbidity expressed by the population,there is no access to diagnostics and treatment.Further work is needed to develop and test a context-adapted intervention.
