Efficacy of the Entomopathogenic Fungus, Culicinomyces clavisporus against Larvae of the Biting Midge, Culicoides nubeculosus (Diptera: Ceratopogonidae)

Culicinomyces clavisporus, a fungal pathogen of a wide range of mosquito species, was investigated in relation to potential pathogenicity against Culicoides nubeculosus biting midge larvae. Seven different C. clavisporus strains were assayed. Each showed some degree of activity against C. nubeculosus larvae with LC₅₀ values of between 3.2×10^-5 and 1.1×10^-6 spores/mL; these effects occurred in dose-dependent manners and tended to be delayed until 72-96 h post treatment. The results are discussed in relation to incorporation of C. clavisporus into biocontrol programmes for Culicoides spp.     

The influence of environmental management and animal shelters in vector control of Culicoides (Diptera,Ceratopogonidae) in northeastern Brazil

We investigated whether biting midges in peridomestic environments are affected by environmental management practices and the presence of domestic animals. We used CDC light traps to collect midges in 112 residences across 24 locations along tourism routes of Maranhão, Brazil. The collection areas were characterized as follows: i) peridomestic area with domestic animals and without management (dirty); ii) peridomestic with domestic animals and management (clean); iii) peridomestic without animals and with management (clean); iv) peridomestic without animals and without management (dirty). The first two treatments had higher biting midge species richness and abundance, respectively. Generalized linear models indicated a positive correlation between the presence of domestic animals and midge abundance, with an approximate four‐fold increase in Culicoides (Diptera: Ceratopogonidae) abundance in peridomestic areas with animals. The same model showed that domestic animals have no influence on richness. Environmental management does not appear to influence species richness or abundance of biting midges.     

Descriptions of a new species and the pupae of two known species of Culicoides Latreille (Diptera: Ceratopogonidae) from India

Pupa, and adult male and female of Culicoides pseudosimilis n. sp., and pupae of two known species, C. selangorensis Wirth & Hubert, and C. dryadeus Wirth & Hubert, are described and illustrated. An identification key to the Indian species of Clavipalpis and Shermani species group of male Culicoides is also provided.     

Effects of seawater components on immature Culicoides molestus (Skuse) (Diptera: Ceratopogonidae)

Abstract Following analysis of beach sites and an indication that seawater components might influence larval occurrence, we studied the impact of increasing salinity and seawater concentration on survival of fourth-instar larvae of the canal biting midge, Culicoides molestus . While NaCl had little effect on immature survival, increasing the concentration of seawater increased mortality prior to the adult stage. Seawater at three and four times the normal concentration killed all immatures. Artificial elevation of seawater concentration in the sandy substrate preferred by larvae, therefore, has the potential to reduce immature midge survival. Diet also affected survival, with higher mortality of immatures that were fed fish-food flakes compared with those that were fed live nematodes.     

The swarming behaviour of the Scottish biting midge, Culicoides impunctatus (Diptera: Ceratopogonidae)

Abstract.

• 1 Swarms of Culicoides impunctatus males were examined in the field in Scotland. Most swarms were close to midge emergence/breeding grounds over a variety of vegetation, some of which clearly acted as swarm markers. Low light (0–1000 lux) and still/humid conditions favoured swarming.
• 2 Swarm size ranged between less than 10 and more than one thousand midges. The modal size was 200 individuals. The smallest swarms were usually columnar in shape and the larger swarms ovoid.
• 3 Midges behaved individually within swarms, moving in an elliptical manner characteristic of other dipterans in swarms.
• 4 Swarms were classified as either ‘persistent’ or ‘transient’ in terms of their shape, size and stability. Wind was the most influential factor in disrupting swarms.
• 5 Swarms were confirmed as mating sites for C.impunctatus.

     

Production of the predaceous midge tribes Sphaeromiini and Palpomyiini (Diptera: Ceratopogonidae) in Lake Norman,North Carolina

Production and P/B ratios of predaceous midges of the tribes Sphaeromiini and Palpomyiini (Diptera: Ceratopogonidae) collected from sublittoral and littoral depths in Lake Norman, North Carolina, were estimated by the size-frequency method. Production estimates in g dry wt/m²/yr at eight sampling locations ranged from 0.002 to 0.022. The littoral zone as a whole was more productive (0.015 g/m²/yr) than the sublittoral zone (0.006 g/m²/yr). The P/B ratios ranged from 2.37 to 3.78 among all stations and depths.     

Occurrence of immature Culicoides molestus (Skuse) (Diptera: Ceratopogonidae) in relation to habitat characteristics

Abstract Analysis of beach sites on the Gold Coast, Australia, found that 14 physical and chemical habitat characteristics differed significantly between sites where numerous immatures of the canal biting midge, Culicoides molestus (Skuse), were found and sites where no midge immatures occurred. Five of the chemical factors found to reliably distinguish C. molestus habitat are major components of seawater, while another, electrical conductivity, is related to the concentration of seawater components. Calcium was the only one of the six primary components of seawater that was not a statistically significant correlate of C. molestus habitation by sand analysis. It is likely that a causative variable in occurrence of immatures is the concentration of seawater present in canals, because larvae are found where seawater component concentration is low in relation to uninhabited sites of similar appearance.     

A new Culicoides from the Amazonian region, Brazil (Diptera: Ceratopogonidae)

A new Neotropical species of biting midge Culicoides (Haematomyidium), C. kampa Felippe-Bauer, Veras & Castellon, is described and illustrated based on female specimens from the Amazonian Region.     

Detection of Leishmania amazonensis and Leishmania braziliensis in Culicoides (Diptera,Ceratopogonidae) in an endemic area of cutaneous leishmaniasis in the Brazilian Amazonia

Biting midges in the genus Culicoides act as vectors of arboviruses throughout the world and as vectors of filariasis in Latin America, the Caribbean, and parts of Africa. Although Culicoides spp. are currently not considered to be vectors of Leishmania protozoa, the high abundance of biting midges in areas with active cutaneous leishmaniasis transmission points to the possibility of Culicoides infection by these pathogens. We used PCR to test captured Culicoides species for natural infection with Leishmania spp. We tested 450 Culicoides females, divided into 30 pools of 15 individuals each, as follows: nine pools of C. foxi (135 specimens), seven pools of C. filariferus (105), seven pools of C. insignis (105), five pools of C. ignacioi (75), and two pools of C. flavivenula (30). PCR confirmed the presence of Leishmania braziliensis DNA in C. ignacioi (0.14%), C. insignis (0.14%), and C. foxi (0.11); and Le. amazonensis DNA in C. filariferus (0.14%) and C. flavivenula (0.50%). We conclude that these Culicoides species can be naturally infected, but vector competence and transmission capability must be confirmed in future studies. Our results warrant further investigation into the role of these biting midge species in the leishmaniasis epidemiological cycle.     

Comparison of a mouth aspirator and a mechanical vacuum aspirator for the collection of Culicoides midges (Diptera: Ceratopogonidae) in equids

In a controlled field trial, a mechanical vacuum and a mouth aspirator were compared with respect to Culicoides midge catching results. The two collection methods were equally applied to two Haflinger horses. Once every hour between 2 hr before sunset and sunset, midges were aspirated for 3 min directly off from the coat of each horse at the same time. In total, 16 replicate measurement days were made. To get insight into the number of (blood‐fed) midges collected on different body parts, four replicate measurement days were done in which the hourly 3‐min samples for each collecting method were separately collected and counted per body part. Mean number of Culicoides midges collected on the legs and on the belly of the horse was two times and significantly higher by the mechanical vacuum aspirator compared to the mouth aspirator. Although the mean number of Culicoides midges from the other part of the host sampled (head/neck/manes/back/flanks) was comparable between the two methods, the mean number of blood‐fed Culicoides midges was four times and significantly higher collected by the mouth aspirator compared to the mechanical vacuum aspirator. In conclusion, it can be recommended to use a mechanical vacuum aspirator instead of a mouth aspirator for the legs and belly area, where a systematic, stroke‐by‐stroke‐vacuum procedure is recommended. For the rest of the body, it is strongly recommended to use a targeted procedure by visual guidance of the presence of midges. For now, based on this experiment, we can only recommend using the mouth aspirator for this targeted approach. However, it might be worth assessing the use of the mechanical vacuum aspirator in a targeted way for future studies.     

Two new Culicoides of the paraensis species group (Diptera: Ceratopogonidae) from the Amazonian region of Peru

Two new species of the Culicoides paraensis species group, C. diversus Felippe-Bauer and C. peruvianus Felippe-Bauer, are described and illustrated based on female specimens from Amazonian region of Peru. A systematic key, table with numerical characters of females, and distribution of species of the C. paraensis group are given.     

First report of Culicoides boyi (Diptera: Ceratopogonidae) in France

Culicoides boyi Nielsen, Kristensen & Pape 2015 (Diptera: Ceratopogonidae), described in Denmark in 2015, is reported in France. This species is closely related to Culicoides pulicaris (Linnaeus 1758) and can only be distinguished from this species by a subtle variation in spot wing pattern and by calculation of maxillary palpal ratio.     

基于光学显微镜和扫描电镜的新替库蠓成虫形态观察(双翅目： 蠓科)(英文)

【目的】通过发现更多的形态特征,以实现库蠓属Culicoides近似种的准确鉴定和区分。【方法】利用扫描电镜和光学显微镜观察新替库蠓Culicoides newsteadi Austen成虫的形态特征细节,包括具有重要鉴定意义的结构特征,如两性成虫的复眼、触角、触须、口器、中胸盾板、小盾板、翅、后足胫节、爪和生殖器等结构。【结果】发现新替库蠓雌成虫具有6种触角感器,包括腔锥感器、短毛形感器、长毛形感器、刺形感器、直锥形感器和弯直锥形感器;雌雄成虫的盾斑均呈卵形;雄成虫的阳基侧突端部具复杂分支。雌成虫的复眼连接处距离为1.3个小眼面;雌成虫大颚呈剑状,具14~17枚三角形齿;雄成虫后足胫节具16~19枚端梳。【结论】通过光学显微镜和扫描电镜获得的形态特征不仅为蠓科的分类和系统发育研究提供更多的信息,而且为流行病研究和疾控工作提供更多的帮助,进而为蠓科昆虫形态信息的数字化、立体化和网络化提供资料。     

Species Diversity and Seasonal Distribution of Culicoides spp. (Diptera: Ceratopogonidae) in Jeju-do,Republic of Korea

Biting midges belonging to the genus Culicoides (Diptera: Ceratopogonidae) were collected by Mosquito Magnet^® and black light traps at 5 sites on Jeju-do, Republic of Korea (Korea), from May-November 2013 to determine species diversity and seasonal distribution. A total of 4,267 specimens were collected, of which 99.9% were female. The most common species was Culicoides tainanus (91.8%), followed by C. lungchiensis (7.2%) and C. punctatus (0.6%), while the remaining 4 species accounted for <0.5% of all Culicoides spp. that were collected. High numbers of C. tainanus were collected in May, followed by decreasing numbers through August, and then increasing numbers through November when surveillance was terminated. Peak numbers of C. lungchiensis were collected during September, with low numbers collected from May-August and October-November. The presence of C. lungchiensis in Korea was confirmed by morphological and molecular analyses.     

Biting of anthropophilic Culicoides fulvithorax (Diptera: Ceratopogonidae), a vector of Mansonella perstans in Nigeria

Anthropophilic Culicoides were investigated in a rural community endemic for Mansonella perstans in Ijebu North area of western Nigeria between December 2003 and October 2004. Three hundred and fifty-nine adults of Culicoides fulvithorax collected by human bait in the morning were dissected for Mansonella perstans larvae, and 1.95% of infection rate was found. Seasonal abundance of C. fulvithorax was investigated by monthly biting rates, and showed that higher prevalence was observed in rainy season, with peak in September. Culicoides prevalence was positively correlated with rainfall and relative humidity, but not temperature. Human perceptions on the behavior of these biting midges were determined by interviewing 854 self-selected villagers, of which 86.5% of the interviewees confessed having experienced Culicoides bites. Between 76.5 and 99.1% of the various age groups complained body reactions to Culicoides bites. Itching was the most frequent body reaction. No interviewees associated Culicoides with transmission of any parasitic infections. The results showed need to adequately control Culicoides in the community.     

Description of the Pupa of Culicoides crucifer Clastrier (Diptera: Ceratopogonidae)

The pupa of Culicoides crucifer Clastrier is described, illustrated and photomicrographed by using binocular microscope and phase-contrast microscopy from material collected in an artificial container in Manaus, Brazil. The pupa shows features typical of pupae occurring in calm and clean waters, and it is compared with its similar congeners of the subgenus Haematomyiidium, Culicoides annuliductus Wirth and Culicoides debilipalpis Lutz.