Medical and Veterinary Entomology最新文献

Blow flies (Diptera: Calliphoridae) are arguably the most important providers of an estimate of minimum post-mortem interval in forensic investigations. They usually undergo a post-feeding dispersal from the body. While previous studies have looked at dispersal of groups of larvae, recording the dispersal activity of individual larvae has not previously been demonstrated. A servosphere was used here to record the speed, directionality and phototaxis of individual post-feeding larvae of two species of blow fly on a smooth plastic surface over time. The servosphere rotates to compensate for the movement of an insect placed at its apex, thereby enabling its unimpeded locomotion in any direction to be studied and behavioural changes to external stimuli recorded. To our knowledge, the servosphere has not previously been used to study apodous insects. The objective of our study was to compare dispersal behaviour of Calliphora vicina Robineau-Desvoidy and Protophormia terraenovae (Robineau-Desvoidy), both common primary colonisers of human and animal cadavers, but showing different post-feeding dispersal strategies. Larvae of C. vicina generally disperse from the body while those of P. terraenovae remain on or close to the body. Our aims were to study (1) changes in dispersal speed over a 1-h period; (2) changes in dispersal speed once a day for 4 days, between the end of feeding and onset of pupariation; and (3) response of dispersing larvae to light. We demonstrated that (1) the movement of three C. vicina larvae tracked for 1 continuous hour on 1 day slowed from an average of 3 to <1.7 mms^-1; (2) the average speed of 20 larvae of C. vicina (4.08 mms^-1) recorded for 5 min once per day over a 4-day period between onset of dispersal and pupariation was significantly greater than that of P. terraenovae (2.36 mms^-1; p < 0.0001), but that speed of both species increased slightly over the 4 days; (3) the responses of larvae of C. vicina to changes in light direction from the four cardinal directions of the compass, showed that they exhibited a strong negative phototactic response within 5 s, turning to move at approximately 180° away from the new light position. While conducted to observe larval calliphorid post-feeding behaviour, the results of this proof of concept study show that apodous insects can be studied on a servosphere to produce both qualitative and quantitative data.

Among mammals, bats harbour the greatest taxonomic diversity of ectoparasitic arthropods. This is mainly due to their high mobility, wide distribution range and gregarious social behaviour. In Chile, 17 species of bats have been reported; however, their ectoparasitic arthropofauna has been little studied. There are currently 12 taxa recorded, belonging to two classes and associated with only four species of bats. This study aimed to investigate the diversity of parasitic flies associated with bats in three ecoregions: Atacama Desert, Chilean Matorral and Valdivian temperate forest. During 2021, using mist nets, bats were captured in Anzota caves (Atacama Desert ecoregion), Huelquén and Alto Jahuel (Chilean Matorral ecoregion), Cherquenco and San Patricio (Valdivian temperate forest). Each bat was carefully checked during a 15-min interval for the collection of ectoparasites. The arthropods were deposited in vials with 96% ethanol. A total of 26 bats corresponding to three species (Vespertilionidae: Histiotus magellanicus Philippi, 1866, Myotis arescens (Osgood, 1943); Phyllostomidae: Desmodus rotundus (Geoffroy, 1810)) were captured from which a total of 142 ectoparasitic arthropods were collected. Bat flies were separated/identified under a stereomicroscope. Additionally, from the fieldwork, we report the presence of other ectoparasites associated with Chilean bats. In our study, we report new host-parasite associations between Trichobius parasiticus Gervais, 1844 (Diptera: Streblidae) on D. rotundus, and Basilia silvae (Brèthes, 1913) (Diptera: Nycteribiidae) in M. arescens in Chile. Our study extended the latitudinal range of distribution for B. silvae to Araucanía region, and we report for first time T. parasiticus in the country. Additionally, partial sequences of the cytochrome c oxidase I gene were obtained from these specimens. Although there is slight morphological variation in the specimens of T. parasiticus, phylogenetic analyses suggest that they correspond to the same species. The sequences generated for B. silvae represent the first for the species. Authors recommend the use of an integrative approach in the identification of ectoparasites in poorly studied ecoregions and hosts. The integration of different markers is necessary to determine more precisely the phylogenetic relationships between South American populations and species of the genera Basilia and Trichobius.

Several species of ectoparasites, including chewing lice and mites are closely associated with their hosts. The Andean condor (Vultur gryphus) is globally listed as vulnerable by the IUCN and its population has been steadily declining in recent decades suggesting a potential extinction of associated entomofauna. The purpose of this study was to record the species of ectoparasites infesting three individuals of Andean condor found dead in the ‘Páramo del Almorzadero’ Santander Department, Northeastern Colombia. One juvenile (male) and two adults (male and female) Andean condors received for necropsy were carefully examined for ectoparasite infestation. Specimens were collected and preserved in ethanol (70%) for taxonomic studies. Morphologic identification and morphometric records were made under light microscopy. Some specimens were also prepared for scanning electron microscopy and others were subjected to DNA extraction to amplify and obtain sequences of the cytochrome-C oxidase subunit I (COI) gene for phylogenetic analyses. Lice were collected from the juvenile condor and the adult female and identified as Falcolipeurus assesor (Phthiraptera: Ischnocera) in the juvenile condor (8 females, 19 males and 8 nymphs) and the adult (1 female); Colpocephalum trichosum (Phthiraptera: Amblycera) in the juvenile (19 females, 24 males and 1 nymph) and the adult (2 females, 2 males and 3 nymphs); and Cuculiphilus zonatus (Phthiraptera: Amblycera) in the juvenile (40 females, 43 males and 15 nymphs) and the adult (1 male and 2 nymphs). Moreover, one mite collected from the juvenile condor was identified as Ancyralges cathartinus (Acari: Astigmata) (1 female). Morphometric data was obtained for the adult stages of F. assesor (6 females and 13 males), C. trichosum (9 females and 9 males) and C. zonatus (10 females and 10 males). We obtained the first DNA sequences of COI for F. assessor, and C. trichosum, where phylogenetic tree analysis showed that F. assessor is more closely related to Falcolipeurus marginalis, and C. trichosum to Colpocephalum kelloggi. This represents the first record of parasites in Andean condor from Colombia and contributes to the knowledge of chewing lice and mites associated with an endemic and endangered bird species. Further studies on Andean condor ectoparasites should be focused on documenting host–parasite interactions and potential health impacts in these wild birds.

Mosquito traps, historically used for surveillance and research, have gained prominence as a tool for mosquito control, amidst concern over the environmental impact and increased resistance to insecticide-based methods. In this study, we tested the effectiveness of a mass trapping barrier design with two types of traps, Mosquito Magnet (MM) traps and BG-Protector (BGP) traps. This experiment was conducted in three coastal camping areas in southern France between summer and autumn 2022, where the presence of floodwater mosquito species with anthropophilic preferences like Aedes caspius represents a year-long nuisance. MM traps were set around the campsite as a barrier to interfere with mosquitoes from entering the campsites, whereas BGP traps were set within the campsites, with the aim of diverting mosquitoes away from humans at peak activity hours. Over 210,000 mosquitoes of 11 species from 4 genera were collected by both trap types across treatment campsites, with no significant differences in mosquito community samplings between BGP and MM traps. Barrier traps effectively targeted Ae. caspius, reducing total mosquito abundance in two of the three study sites by 34% and 55%. This study provides valuable insights into the efficacy and feasibility of using mass trapping barriers as a complementary control strategy for mosquito species in wetlands.

Globalisation, climate change and international trade are the factors contributing to the spread of Aedes albopictus (Diptera: Culicidae) and Ae. aegypti into new areas. In newly invaded habitats, these non-native species can serve as arbovirus disease vectors or increase the risk of disease spill over. These mosquitoes continue to emerge in new areas where they have or will have overlapping ranges with other resident mosquito species. The study investigates how invasive Aedes mosquitoes compete with the native Culex pipiens in Türkiye, which might affect the overall mosquito population dynamics and disease transmission risks. Both Aedes species exhibited contrasting responses to interspecific competition with Cx. pipiens. While Ae. albopictus suffers reduced emergence primarily in larger containers with abundant food, Ae. aegypti surprisingly thrives in mixed cultures under all food conditions. Adult Cx. pipiens emergence drops by half against Ae. albopictus and under specific conditions with Ae. aegypti. Competition influences mosquito size differently across species and life stages. Culex pipiens females grow larger when competing with Ae. aegypti, potentially indicating resource advantage or compensatory strategies. However, Ae. albopictus size shows more nuanced responses, suggesting complex interactions at play. Understanding how invasive and native mosquitoes interact with each other can provide insights into how they adapt and coexist in shared habitats. This knowledge can inform effective control strategies. The study highlights the differential responses of invasive Aedes species and the potential for managing populations based on their competitive interactions with the native Cx. pipiens. It can contribute to improved monitoring and prediction systems for the spread of invasive mosquitoes and the associated disease risks.

Co-invasion, characterized by the simultaneous introduction of hosts and parasites with the latter establishing themselves in native hosts, is a phenomenon of ecological concern. Rattus rattus, a notorious invasive species, has driven the extinction and displacement of numerous avian and mammalian species and serves as a key vector for diseases affecting both humans and wildlife. Among the parasites hosted by R. rattus are fleas, which exhibit obligate parasitic behaviour, a generalist nature and high prevalence, increasing the likelihood of flea invasion. Simultaneously, invasive species can serve as hosts for native parasites, leading to potential amplification or dilution of parasite populations in the environment. In Chile, R. rattus has been present since the 17th century because of the arrival of the Spanish colonizers through the ports and has spread throughout urban, rural and wild Chilean territories. This study aims to evaluate whether co-invasion of native fleas of invasive rats occurs on native rodents in Chile and to determine whether black rats have acquired flea native to Chile during their invasion. For this, we captured 1132 rodents from 26 localities (20° S–53° S). Rattus rattus was found coexisting with 11 native rodent species and two species of introduced rodents. Among the native rodents, Abrothrix olivacea and Oligoryzomys longicaudatus exhibited more extensive sympatry with R. rattus. We identified 14 flea species associated with R. rattus, of which only three were native to rats: Xenopsylla cheopis, Leptopsylla segnis and Nosopsyllus fasciatus. These three species presented a higher parasite load in black rats compared to native fleas. Leptopsylla segnis and N. fasciatus were also found associated with native rodent species that cohabit with R. rattus. The remaining species associated with R. rattus were fleas of native rodents, although they were less abundant compared to those associated with native rodents, except for Neotyphloceras pardinasi and Sphinctopsylla ares. Although there has been evidence of flea transmission from rats to native species, the prevalence and abundance were relatively low. Therefore, it cannot be definitively concluded that these fleas have established themselves in native rodent populations, and hence, they cannot be classified as invasive fleas. This study underscores R. rattus’ adaptability to diverse environmental and geographical conditions in Chile, including its capacity to acquire fleas from native rodents. This aspect has critical implications for public health, potentially facilitating the spread of pathogens across various habitats where these rats are found.

Aboelhadid, S.M., Ibrahium, S.M., Abdel-Baki, A.S., Hassan, K.M., Arafa, W.M., Aboud, H.M. et al. (2024) An investigation of the acaricidal activity of benzyl alcohol on Rhipicephalus annulatus and Rhipicephalus sanguineus and its synergistic or antagonistic interaction with commonly used acaricides. Medical and Veterinary Entomology, 38(1), 1–12. Available from: https://doi.org/10.1111/mve.12698

In the affiliation of the author Khaled Mahmoud Hassan, the institution ‘Department of Animal Health Research Institute, Beni-Suef, Egypt’ was incorrect. This should read: Department of Parasitology, Beni-Suef Laboratory, Animal Health Research Institute (AHRI), Agriculture Research Center (ARC), Beni-Suef, Egypt.

We apologize for this error.

Gadelhaq, S.M., Aboelhadid, S.M., Abdel-Baki, A.S., Hassan, K.M., Arafa, W.M., Ibrahium, S.M. et al. (2023) D-limonene nanoemulsion: lousicidal activity, stability, and effect on the cuticle of Columbicola columbae. Medical and Veterinary Entomology, 37(1), 63–75. Available from: https://doi.org/10.1111/mve.12607

In the affiliation of the author Khaled Mahmoud Hassan, the institution ‘Department of Animal Health Research Institute, Beni-Suef, Egypt’ was incorrect. This should read: Department of Parasitology, Beni-Suef Laboratory, Animal Health Research Institute (AHRI), Agriculture Research Center (ARC), Beni-Suef, Egypt.

We apologize for this error.

Model forecasts of the spatiotemporal occurrence dynamics of diseases are necessary and can help understand and thus manage future disease outbreaks. In our study, we used ecological niche modelling to assess the impact of climate on the vector suitability for bluetongue disease, a disease affecting livestock production with important economic consequences. Specifically, we investigated the relationship between the occurrence of bluetongue outbreaks and the environmental suitability of each of the four vector species studied. We found that the main vector for bluetongue disease, Culicoides imicola, a typically tropical and subtropical species, was a strong predictor for disease outbreak occurrence in a region of southern Portugal from 2004 to 2021. The results highlight the importance of understanding the climatic factors that might influence vector presence to help manage infectious disease impacts. When diseases impact economically relevant species, the impacts go beyond mortality and have important economic consequences.