Relationship Between Weather Parameters and Female Mosquito Abundance and Distribution in Makurdi - a Mosquito Infested Area in North Central Nigeria

Abstract Background: We assessed the impact of two long-term interventions (insecticide spraying and insecticide-impregnated dog collars), previously directed against sand flies, on the abundance and distribution of mosquitoes (Culicidae) and biting midges (Ceratopogonidae). Both groups are of medical and veterinary importance in Brazil. Our objective was to determine the effect of the sand fly interventions on other biting Diptera.Methods: This study retained the original stratified randomised control trial design but was extended for 12 months. We included the 2 original intervention arms: chicken roosts sprayed with microencapsulated lambda-cyhalothrin and dogs fitted with deltamethrin-impregnated collars and a control arm with no insecticide. Adult mosquitoes and midges were sampled in 280 households at three locations (inside human dwellings, dog sleeping sites, chicken roosts). To maintain the integrity of the study objective we placed sand fly pheromone in the sprayed-insecticide arm. The sand fly pheromone has no effect on the behaviour of culicids or Culicoides.Results: We collected 3,145 culicids (9 genera, 87.6% Culex spp.) distributed relatively uniformly across all 3 arms; 41.9% at chicken roosts, 37.7% inside houses, and 20.3% at dog sleeping sites. We collected 11,464 Culicoides (15 species) found mostly at chicken roosting sites (84.7%) compared with dog sleeping sites (12.9%) or houses (2.4%). Mosquitoes and Culicoides were most abundant during the hot and rainy season. Increased daytime temperature was marginally associated with increased mosquito abundance (z=1.97; P=0.049) and Culicoides abundance (z=1.71; P=0.087). There was no significant association with daily average rainfall for either group. Household-level mosquito and midge numbers were both significantly reduced by the sprayed insecticide intervention 56% [Incidence Rate Ratio, IRR=0.54 (95% C.I. 0.30, 0.97), P≤0.05] and 53% [IRR=0.47 (0.26, 0.85), P≤0.05], respectively, compared to the control. The abundance of both Dipteran groups at dog sleeping sites was unaffected by either intervention. The sprayed insecticide significantly reduced abundance of mosquitoes inside houses (41%), at chicken roosting sites (48%) and reduced midge abundance by 51% in chicken roosting sites.Conclusions: Insecticide sprayed at chicken roosting sites reduced the abundance of mosquitoes and midges at the peridomestic level. Dog collars had no effect on numbers of any group.

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Significant reduction in abundance of peridomestic mosquitoes (Culicidae) and Culicoides midges (Ceratopogonidae): an additional benefit of a novel attract-and-kill intervention applied against Leishmania infantum transmission, in São Paulo Brazil

10.21203/rs.3.rs-28439/v1 ◽

2020 ◽

Author(s):

Mikel A. González ◽

Erin Dilger ◽

María M. Ronderos ◽

Gustavo R. Spinelli ◽

Orin Courtenay ◽

...

Keyword(s):

Sao Paulo ◽

Sand Fly ◽

Randomised Control Trial ◽

São Paulo ◽

Mosquito Abundance ◽

Household Level ◽

Sleeping Sites ◽

Abundance And Distribution ◽

And Control ◽

The Impact

Abstract Background Following the long-term (42-month) evaluation of residual insecticide (co-located with sand fly pheromone) and insecticide-impregnated dog-collars in a randomised control trial (RCT) against leishmaniasis, we assessed the impact of these interventions on the peridomestic abundance and distribution of mosquitoes (Culicidae) and midges (Ceratopogonidae) in Western São Paulo, Brazil. Both of these Dipteran groups are vectors of diseases of medical and veterinary relevance to humans and domestic animals in Brazil. Methods The interventions in the 3-arm RCT: pheromone + insecticide (PI) (chicken roosts sprayed with microencapsulated lambda-cyhalothrin), dog-collars (DC) (dogs fitted with deltamethrin-impregnated collars), and control (C) (unexposed to pyrethroids) were extended by 12 months. During that time adult mosquitoes and midges were sampled at three household locations (inside human dwellings, dog sleeping sites, chicken roosts). Results We collected 3,145 culicids (9 genera mostly Culex spp.) distributed relatively uniformly across all 3 arms; 43.5% inside houses, 36.2% at chicken roosts and 20.3% at dog sleeping sites. We collected 11,464 Culicoides (at least 15 species) found mostly at chicken roosting sites (84.7%) compared with dog sleeping sites (12.2%) or houses (3.1%). Mosquitoes and Culicoides were predominant during the hot and rainy reason. Increased daytime temperature was significantly associated with increased mosquito abundance (z = 1.97; P = 0.049) but marginally associated with Culicoides abundance (z = 1.71; P = 0.087). There was no significant association with average rainfall for either group. Household-level mosquito and midge numbers were both significantly reduced by the PI intervention 56% (Incidence Rate Ratio, IRR = 0.54 [95% C.I. 0.30, 0.97], P ≤ 0.05] and 53% (IRR = 0.47 [0.26, 0.85], P ≤ 0.05), respectively. The abundance of both Dipteran groups at dog sleeping sites was largely unaffected by the PI and DC interventions. The PI intervention significantly reduced abundance of mosquitoes inside houses (41%) and at chicken roosting sites (48%) and reduced midge abundance by 51% in chicken roosting sites. Conclusions Sprayed insecticide at chicken roosting sites reduced the abundance of mosquitoes and midges at the peridomestic level while dog collars had no effect on numbers for any group.

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Abundance and distribution of Sardinella tawilis (Herre, 1927) larvae in Lake Taal, Philippines

The Philippine Journal of Fisheries ◽

10.31398/tpjf/25.2.2018-0004 ◽

2018 ◽

pp. 16-26

Author(s):

Maria Theresa Mutia ◽

Ma. Lourdes Merilles ◽

Myla C Muyot ◽

Benjie Tordecilla

Keyword(s):

Redundancy Analysis ◽

Landscape Management ◽

Temporal Distribution ◽

Management Plan ◽

Scientific Basis ◽

Spawning Grounds ◽

Site Specific ◽

Taal Volcano ◽

Weather Parameters ◽

Abundance And Distribution

As part of the conservation efforts to address the declining population of the only freshwater Sardinella (Family Clupeidae) endemic to Lake Taal, a two-year study was conducted to determine the possible spawning grounds of Sardinella tawilis (Herre, 1927) by identifying the spatial and temporal distribution of its larvae. Fish larval samples were sorted from ichthyoplankton samples collected monthly in selected sampling stations in the lake. The morphologically identified Clupeidae larvae were determined to be S. tawilis genetically. They appeared only during March to May, with maximum abundance reaching from 700 to 1,700 ind 100m-3 during April 2015. Among the 10 water, 5 weather, and 11 biological parameters analyzed using Redundancy Analysis (RDA), temperature and other weather parameters largely influenced the temporal distribution of tawilis larvae. In terms of spatial distribution, the stations on the eastern bay of the lake showed an abundant and consistent presence of tawilis larvae for two years. Other stations which showed the presence of tawilis larvae include the southern portion of the lake, as well as in stations south to southwest area of Volcano Island. The seasonal and site-specific occurrence of tawilis larvae confirmed its spawning season and potential spawning grounds, which can serve as a scientific basis in the establishment of a Tawilis Reserve Area, as stipulated in the Unified Rules and Regulations for Fisheries in the Taal Volcano Protected Landscape Management Plan (TVPL-MP 2011).

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Stromatoporoids from the Famennian (Devonian) Wabamun Formation, Normandville oilfield, north–central Alberta, Canada

Journal of Paleontology ◽

10.1017/s0022336000018321 ◽

1988 ◽

Vol 62 (03) ◽

pp. 411-419 ◽

Cited By ~ 5

Author(s):

Colin W. Stearn

Keyword(s):

Patch Reef ◽

Abundant Species ◽

The Other ◽

North Central ◽

Biotic Crisis

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species isStylostroma sinense(Dong) butLabechia palliseriStearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described areClathrostromacf.C. jukkenseYavorsky,Gerronostromasp. (a columnar species), andStromatoporasp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).

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