13 research outputs found
Sarcoptes scabiei infestation does not alter the stability of ectoparasite communities
Natural infection by the protozoan Leptomonas wallacei impacts the morphology, physiology, reproduction, and lifespan of the insect Oncopeltus fasciatus
Trypanosomatids are protozoan parasites that infect thousands of globally dispersed hosts, potentially affecting their physiology. Several species of trypanosomatids are commonly found in phytophagous insects. Leptomonas wallacei is a gut-restricted insect trypanosomatid only retrieved from Oncopeltus fasciatus. The insects get infected by coprophagy and transovum transmission of L. wallacei cysts. The main goal of the present study was to investigate the effects of a natural infection by L. wallacei on the hemipteran insect O. fasciatus, by comparing infected and uninfected individuals in a controlled environment. The L. wallacei-infected individuals showed reduced lifespan and morphological alterations. Also, we demonstrated a higher infection burden in females than in males. The infection caused by L. wallacei reduced host reproductive fitness by negatively impacting egg load, oviposition, and eclosion, and promoting an increase in egg reabsorption. Moreover, we associated the egg reabsorption observed in infected females, with a decrease in the intersex gene expression. Finally, we suggest alterations in population dynamics induced by L. wallacei infection using a mathematical model. Collectively, our findings demonstrated that L. wallacei infection negatively affected the physiology of O. fasciatus, which suggests that L. wallacei potentially has a vast ecological impact on host population growth
Winning the arms race: host–parasite shared evolutionary history reduces infection risks in fish final hosts
Parasite manipulation of intermediate hosts evolves to increase parasite trophic transmission to final hosts, yet counter selection should act on the final host to reduce infection risk and costs. However, determining who wins this arms race and to what extent is challenging. Here, for the first time, comparative functional response analysis quantified final host consumption patterns with respect to intermediate host parasite status. Experiments used two evolutionarily experienced fish hosts and two naive hosts, and their amphipod intermediate hosts of the acanthocephalan parasite Pomphorhynchus tereticollis. The two experienced fish consumed significantly fewer infected than non-infected prey, with lower attack rates and higher handling times towards the former. Conversely, the two naive fish consumed similar numbers of infected and non-infected prey at most densities, with similar attack rates and handling times towards both. Thus, evolutionarily experienced final hosts can reduce their infection risks and costs via reduced intermediate host consumption, with this not apparent in naive hosts
First report of the entomopathogenic nematode, Steinernema carpocapsae, from Moghan region of Iran and its efficacy against the turnip moth, Agrotis segetum Denis and Schiffermuller (Lepidoptera: Noctuidae), larvae
Efficacy of Turkish isolate of Steinernema feltiae (Rhabditida: Steinernematidae) in controlling the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), under laboratory conditions
Field assay using a native entomopathogenic nematode for biological control of the weevil Phyrdenus muriceus in organic eggplant crops in Argentina
Sarcoptes scabiei infestation does not alter the stability of ectoparasite communities
Antecedentes: La muestra representa un ecosistema heterogéneo donde varias especies de parásitos concurren e interactúan entre sí por el espacio y los recursos. Aunque estas interacciones pueden gobernar las características de una pequeña comunidad y pueden conformar la respuesta a perturbaciones externas, la resiliencia de las comunidades ectoparásitas a nuevas infestaciones sigue siendo poco explorada.
Métodos: Se analizó la composición del ectoparásito en comunidades ubicadas en 214 individuos de íbices ibérica (Capra pyrenaica) que habita en el Espacio Natural de Sierra Nevada, en el sur de España. Se utilizaron los esquemas de clasificación y regresión, exploramos cómo la presencia de Sarcoptes scabiei (un ácaro muy contagioso), en la muestra exterior y la manada rigen la prevalencia y abundancia de los piojos y las garrapatas. Ningún modelo se ha aplicado en el análisis para evaluar el impacto de S. scabiei sobre la estructura de las comunidades de ectoparásitos.
Resultados: Nuestros resultados sugieren que la infestación de S. scabiei actúa en tándem con muestras externas y en la manada para definir la prevalencia y abundancia de los piojos y las garrapatas. También hemos aportado pruebas de diferencias en la concurrencia de especies sólo en las primeras etapas de la infestación de S. scabiei. Con respecto a la diversidad de las especies, grabamos al ectoparásito en comunidades de íbices con S. scabiei, que alcanzó una proliferación más rápida que en individuos sanos.
Conclusiones: aunque nos muestran que la carga del ectoparásito está correlacionada con la infestación de S. scabiei, el entorno exterior y la manada, la respuesta a la infestación de la especie S. scabiei y el clima parece ser muy variable y está influido por rasgos de la historia vital del ectoparásito. Las comunidades de ectoparásitos también parecen resistentes a las perturbaciones, lo que está de acuerdo con lo previamente reportado para los endoparásitos. El futuro perfeccionamiento de la recogida de la muestra y la incorporación de los sistemas ecológicos y las variables epidemiológicas pueden permitirnos establecer efectos causales y profundizar los conocimientos sobre los mecanismos y las consecuencias de las interacciones de los ectoparásitos.Background: The host represents a heterogeneous ecosystem where multiple parasite species co-occur and interact with each other for space and resources. Although these interactions may rule the features of an infracommunity and may shape the infracommunity response to external perturbations, the resilience of ectoparasite communities to new infestations remains poorly explored.
Methods: We analysed the composition of the ectoparasite communities found on 214 individual Iberian ibexes (Capra pyrenaica) inhabiting the Sierra Nevada Natural Space, southern Spain. Using classification and regression trees, we explored how the presence of Sarcoptes scabiei (a highly contagious mite), the off-host environment and the host
sex govern the prevalence and abundance of lice and ticks. Null model analysis was applied to assess the impact of S.scabiei on the structure of the ectoparasite communities.
Results: Our results suggest that S. scabiei infestation acts in tandem with off-host environment and host sex to define the prevalence and abundance of lice and ticks. We also provided evidence for differences in species co-occurrence only at the early stages of S. scabiei infestation. Regarding species diversity, we recorded that ectoparasite communities in scabietic ibexes reached a high richness faster than those in healthy individuals.
Conclusions: Even though we show that ectoparasite burden is correlated with S. scabiei infestation, off-host environment and host sex, the species response to S. scabiei infestation and climate seem to be highly variable and influenced by ectoparasite life-history traits. Ectoparasite communities also appear resilient to perturbations which is in agreement with what was previously reported for endoparasites. Future refinement of sample collection and the incorporation of ecological and epidemiological-related variables may allow us to establish causal effects and deepen the knowledge about the mechanisms and consequences of ectoparasite interactions.Trabajo patrocinado por:
Ministerio de Economía y Competitividad. Proyecto CGL2012-40043-C02-01
Gobierno de Andalucía. Ayuda RNM-118
Fundação para a Ciência e a Tecnologia, European Social Fund y Ministério da Educação e Ciência, National Funds. Beca PhD SFRH/BD/98387/2013 para João Carvalho
Fundação para a Ciência e a Tecnologia. Programa Postdoctoral SFRH/BPD/96637/2013 para Emmanuel Serrano
Fundação para a Ciência e a Tecnologia y Ministério da Educação e Ciência, para CESAM RU (UID/AMB/50017)peerReviewe