Medical and Veterinary Entomology最新文献

In recent decades there has been a huge increase in the export of cut flowers from countries in Africa and elsewhere to European flower markets, with the vast majority first entering the Netherlands for local use or for export. Coincidentally, three significant livestock disease outbreaks caused by viruses associated with Africa or other tropical regions were first detected in the Netherlands (bluetongue virus serotype 8 (BTV-8), 2006, and BTV-3, 2023) and in western Germany about 200 km from the Netherlands border (Schmallenberg virus, SBV, 2011). This study aimed to determine whether Culicoides biting midges (Diptera: Ceratopogonidae), the vectors of BTV and SBV, are present within flower-packaging plants in East Africa, and therefore whether Culicoides could be unknowingly exported during the shipping of cut flowers. Field sampling was undertaken at a flower-packaging facility in Kenya, East Africa. The facility undertook all stages of cut flower production from maintaining rootstock through to packaging and shipping to an airport for international export. Trapping was undertaken at each stage of production (rootstock, propagation, inside growing greenhouses, in the packing-house, inside cold-storage rooms, during transportation) using Centers for Disease Control and Prevention (CDC) Light Emitting Diode (LED) light traps. Hand-held aspirators were used to obtain individual insects directly from flowers and around composting sites, while emergence traps studied insect emergence from compost, leaf litter and flowers discarded at quality control checkpoints. A maximum nightly catch of 269 Culicoides was identified on a half-acre smallholding, containing 15 ruminants and 40 birds, located 20 m from the nearest greenhouse. The greatest numbers of Culicoides were trapped at a pond (n = 23) and leaf-litter compost site (n = 19) within the curtilage of the flower-packaging plant. Of the seven greenhouses sampled, three had Culicoides trapped overnight (mean = 4, range: 1-9), and no Culicoides were trapped in the propagation units. No Culicoides were trapped in the pack house, cold-store, or during transportation of the flowers to the airport for shipment. No Culicoides emerged from emergence traps or were trapped when aspirating directly from flowers. This is the first study to investigate whether Culicoides are present within flower packaging plants in Africa. The results highlight that although present in small numbers both outside and within greenhouses, the presence of Culicoides declined with each stage of production. Therefore, the risk of exporting Culicoides with packaged cut flowers is non-zero but likely very small.

Ruiz, M., Alonso, R.J., Rospide, M., Acosta, D.B., Cavia, R., & Sanchez, J.P. (2025) Diversity and eco-epidemiology of ectoparasites and Rickettsia spp. associated with the opossums Didelphis albiventris Lund in livestock farms from the Argentinian Pampas region. Medical and Veterinary Entomology, 39(3), 431–444. Available from: https://doi.org/10.1111/mve.12796.

In the paper by Ruiz et al. (2025), the Data Availability Statement was incomplete. The Statement should read:

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available at: http://hdl.handle.net/11336/247755 (Ruiz et al., 2024).

The following reference should also have been included:

Ruiz, M., Alonso, R.J., Rospide, M., Acosta, D.B., Cavia, R. & Sánchez, J.P. (2024): Diversity and eco-epidemiology of ectoparasites and Rickettsia spp. associated with the opossums Didelphis albiventris Lund, 1840 in livestock farms from the Argentinian Pampas region. Consejo Nacional de Investigaciones Científicas y Técnicas. http://hdl.handle.net/11336/247755.

We apologize for this error.

The knowledge of the distribution of viruses and their associated mosquito species is still incomplete in Senegal. Additionally, data on the genetic characterization of these viruses are limited. The aim was to update knowledge on the diversity, distribution and genetic relationships of mosquito-associated viruses in Senegal through entomological and molecular surveillance. Mosquitoes were collected in October 2022 across 10 districts in Senegal. Samples were identified morphologically and processed for virome characterization using qRT-PCR and next-generation sequencing. The most common species were Culex cinereus Theobald, 1901, Culex quinquefasciatus Say, 1823, Culex neavei Theobald, 1904, and Culex poicilipes Theobald, 1904 (Diptera: Culicidae). The number of mosquitoes collected varied by habitat and district. We detected 42 isolates of 7 viruses, including Bagaza (BAGV), Barkedji, Sindbis (SINV), Usutu (USUV), Dezidougou, Densovirus and Pestivirus A (PESVA), in 6 mosquito species (Mansonia uniformis, Cx. neavei Theobald, 1901, Anopheles coustani, Cx. cinereus Laveran, 1900, Aedes aegypti Linnaeus, 1762 and Aedes vexans Meigen, 1830) (Diptera: Culicidae). The viruses were mainly detected in mosquitoes collected near ponds (92.9%). BAGV and SINV were detected for the first time in southeastern Senegal. This is also the first association of PESVA with mosquitoes in the field. Phylogenetic analyses revealed that PESVA clustered with strains from Asia and Egypt, BAGV with strains from Senegal and Spain, USUV with strains from Senegal and SINV with strains from Spain and Kenya. This study expands the understanding of mosquito–virus associations in Senegal, revealing new geographic distributions and vectors for several viruses, with implications for arbovirus emergence and surveillance strategies.

The simuliid fauna of Laos is among the most poorly known of any country in the world, only seven species having been recorded. We explored the Laotian simuliid fauna as an opportunity to test reproductive isolation and the minute morphological differences between two of the country's common isomorphic nominal species—Simulium chamlongi Takaoka & Suzuki (Diptera: Simuliidae) and Simulium luculentum Takaoka, Srisuka & Saeung (Diptera: Simuliidae). Both are members of the widespread Simulium variegatum group. Using the band patterns of the giant chromosomes in the larval silk glands, we showed that S. chamlongi and S. luculentum are reproductively isolated, no hybrids having been found. Molecular analyses indicated that the two species are genetically distinct, with a minimum genetic divergence of 2.91%. Analysis of a fragment of the vertebrate cytochrome b gene revealed that the blood hosts of S. chamlongi and S. luculentum in Laos include humans and water buffaloes (Bubalus bubalis Linnaeus) (Artiodactyla: Bovidae), respectively. Diagnostic morphological characters provided in the original species descriptions were substantiated for pupae and females but not for larvae or males. Our chromosomal analyses also revealed a third reproductively isolated species, possibly new, with a unique IIS chromosomal sequence. The absence of a uniquely shared inversion among the three species indicates that the S. variegatum group lacks a defining chromosomal synapomorphy.

The blowflies (Calliphoridae) represent a significant portion of schizophoran fly diversity, comprising approximately 2000 known species. Among them, the genus Calliphora Robineau-Desvoidy is one of the largest, with over 100 species primarily distributed in the Holarctic Region and Australasia. Blowflies include several ubiquitous species and are primarily recognised for their medical and veterinary importance. In the Afrotropics, Calliphora was previously known from only two species: the native Calliphora croceipalpis Jaennicke and the introduced Calliphora vicina Robineau-Desvoidy. Two new distinctive species of Calliphora collected during recent fieldwork in Ethiopia are described using methods of integrative taxonomy. Calliphora teraramma sp. n. is characterised by peculiar male genitalia, with large cerci and a minute phallus. Calliphora mesay sp. n. is characterised by morphological and molecular traits, a close relative of the cosmopolitan C. vicina. In addition, we developed a cytochrome c oxidase subunit I (COI) barcode reference library for Palaearctic and Afrotropical Calliphora species, including 33 newly generated barcodes. Molecular species delimitation analyses using the software Automatic Barcode Gap Discovery (ABGD) and Assemble Species by Automatic Partitioning (ASAP), implemented through the recently developed integrative platform Spart Explorer, largely support morphological species concepts.

The ‘oviposition preference-offspring performance’ hypothesis (PPH) proposes that females select oviposition sites that optimise offspring performance. For Aedes aegypti L. (Diptera: Culicidae), the main vector of dengue in the Americas, it is expected that females prefer to lay eggs in containers with high nutritional quality, where developmental success is maximised. In this study we aimed to test the PPH in relation to three detritus decomposition time treatments (3, 14 and 42 days). Oviposition was studied during 1 week in three contiguous ovitraps (one per decomposition time treatment) at 18 sites. Immature development in the three treatments was studied at constant densities (20 larvae) or at realistic densities (eggs/treatment in the oviposition study). The number of eggs from the oviposition study and a performance index based on development time, wing length and survival in the immature development study were compared between treatments. Both the oviposition site selection and the subsequent larval development were affected by the detritus decomposition time. Females laid fewer eggs in the 3-day treatment (mean: 16 eggs) than in the 14- and 42-day treatments (mean: 65 and 62 eggs respectively). Immature developmental performance was inversely related to decomposition time at constant densities, and at realistic densities, immatures performed even worse in the longer decomposition time treatments due to higher larval densities. Thus, the effects of detritus decomposition time seem to act in opposite directions for oviposition site selection and immature development success, which does not align with the PPH. One possible explanation for this apparent contradiction is that containers with short detritus decomposition times could indicate a frequent replacement of water, and that females might be selecting signals associated with habitat permanence to ensure the completion of development of their offspring.

The biting midges, Culicoides peregrinus Kieffer and Culicoides oxystoma Kieffer (Diptera: Ceratopogonidae) are the most significant vector species of bluetongue virus (BTV) in the Oriental region, including India. Rearing of these vector species was cumbersome; previous researchers supplemented the rearing substrates primarily with cattle dung (the habitat), yeast and nutrient broth. Other investigations reiterated that an enriched milieu of live bacteria is required for the oviposition and developmental progression of the immatures as they failed to develop in sterile medium. Therefore, bacteria-based approaches provide novel opportunities for artificial rearing. This investigation tries to simplify and create a cleaner version of rearing based on different bacterial strains. The substrate bacterial strains were biochemically characterised, and their influence on oviposition, hatching and larval development was analysed and evaluated under laboratory conditions. We artificially reared two vector species by utilising three different strains of Bacillus cereus and one strain of Alcaligenes faecalis retrieved from the substrates. The results demonstrated that gravid females select their oviposition substrates based on stimuli derived from live microorganisms that indicate the suitability of the developmental substrate for immature development. Bacillus cereus 1B stimulated the greatest extent of egg hatching (>99%), larval survivability (>74%), pupae formation (>83%) and adult emergence (>98%) in both species. This present investigation proposes to utilise B. cereus 1B as an alternative approach to artificially rear and establish laboratory colonies of these vector species.

The study of population dynamics in a vertical forest gradient provides basic information on the aspects of insect vector natural history that influence the rate of pathogen transmission. In Mexico, these studies are remarkably limited for sand flies recognised as Leishmania vectors. This study analyses the temporal dynamics of sand fly species (Diptera: Psychodidae) along vertical strata of a tropical dry forest in Yucatán, Mexico, an area previously identified as a transmission hotspot for Leishmania mexicana. Bimonthly samplings were conducted over 1 year by using six CDC light traps in the understory and six traps in the canopy. During the collection period, forest attributes and environmental data (temperature and relative humidity) were recorded for each ecotope. In total, 630 individuals were sampled, of which 68% were collected in the understory and 32% in the canopy. No significant differences in species diversity and abundance were detected between the two ecotopes. Psathyromyia shannoni (Dyar) and Dampfomyia deleoni (Fairchild and Hertig) were the only species structured in the vertical dimension. Observed diversity in both strata responds similarly across both monthly and seasonal time scales. Data analyses indicated that relative humidity influenced the vertical distribution of P. shannoni and D. deleoni, although the magnitude and direction of this effect varied by species. Psathyromyia shannoni exhibited contrasting responses to relative humidity between the canopy and the understory, independent of sex, suggesting that additional environmental factors not assessed in this study may modulate its vertical distribution. Despite the limitations of our work, these findings contribute to the knowledge on the population dynamics of sand flies in the tropical forests of the Yucatán Peninsula.

Fleas (Insecta: Siphonaptera) are recognised vectors of bacteria that affect human and other animal health, whose reservoirs are in the majority mammals. Among these, some species of the genera Rickettsia (Rickettsiales: Rickettsiaceae) and Bartonella (Rhizobiales: Bartonellaceae) are emerging and re-emerging throughout the world; however, their circulation across vast regions of Argentina and numerous animal species, particularly wild species remains largely unknown. The study of wild animal roadkill provides valuable insights into parasitic associations and the presence of pathogenic microorganisms, allowing the generation of a health alert in certain ecosystems. The aim of this study was to describe the diversity of fleas associated with roadkilled wild native meso-mammals in the extreme northeast of Argentinian Patagonia, and to detect the presence of Rickettsia and Bartonella bacteria. Five host species were examined, including Chaetophractus villosus Desmarest (Cingulata: Chlamyphoridae); Didelphis albiventris Lund (Didelphimorphia: Didelphidae); Lagostomus maximus Desmarest (Rodentia: Chinchillidae); Leopardus geoffroyi d'Orbigny and Gervais (Carnivora: Felidae) and Lycalopex gymnocercus Fischer (Carnivora: Canidae). A total of 248 fleas were recovered, identified as Hectopsyllidae: Hectopsylla broscus Jordan and Rothschild and Hectopsylla cypha Jordan; Malacopsyllidae: Phthiropsylla agenoris Rothschild and Malacopsylla grossiventris Weyenbergh; Pulicidae: Ctenocephalides felis Bouché and Pulex irritans Linnaeus. Molecular analysis detected two flea-borne pathogenic bacteria: Rickettsia felis (Bouyer et al.), found in C. felis from D. albiventris, and Bartonella rochalimae (Eremeeva et al.), reported here for the first time in Argentina, detected in P. agenoris from C. villosus, and in P. irritans from L. maximus and L. gymnocercus. The results contribute to knowledge of flea diversity in Argentinian Patagonia and provide new information about flea-borne pathogens circulating in the wildlife of this region. Furthermore, this study is the first in Argentina to investigate ectoparasites and their associated bacteria in roadkilled animals, making a pioneering contribution to the field. The interesting findings highlight the importance of implementing and expanding road ecology studies, which could easily be replicated in other regions where information gaps on flea and flea-borne bacteria diversity still exist.

Tick-borne rickettsiosis has posed a significant threat to Egypt, with various pathogenic Rickettsia species being reported. In this study, 134 ticks were collected from camels in Esna City, Luxor, Egypt and all were identified as Hyalomma dromedarii through both morphological and molecular techniques. Using specific primers targeting the citrate synthase (gltA), outer membrane protein A (ompA) and 17 kD antigen (17 kDa) genes, Rickettsia japonica was detected via conventional and nested PCR assays. Remarkably, two samples tested positive for R. japonica across all three genes, indicating a prevalence of 1.5%. Phylogenetic analysis based on the gltA, ompA and 17 kDa genes confirmed the presence of R. japonica within H. dromedarii ticks. This is the first reported detection of R. japonica in Egypt. These findings highlight the urgent need to investigate the origin and spread of R. japonica in the country and underscore the importance of continuous surveillance and data collection on lesser-known pathogens circulating in ticks as part of Egypt's public health efforts to manage tick-borne diseases.