Fine structure of sunken thick-walled pegs (sensilla ampullacea and coeloconica) on the antennae of mosquitoes

1975 ◽  
Vol 53 (3) ◽  
pp. 262-266 ◽  
Author(s):  
K. S. Boo ◽  
S. B. McIver
Keyword(s):  
Fine Structure ◽  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Anopheles Stephensi ◽  
The Third ◽  
Sheath Cells

Sensilla ampullacea (pegs in tubes), a type of sensillum heretofore unknown from mosquitoes, occur on the antennae of female Anopheles stephensi Liston and Aedes aegypti (L.). Sensilla coeloconica (pegs in pits) with thick-walled pegs, previously reported from A. aegypti and Culex pipiens L. also occur on the antennae of An. stephensi.The fine structure of the sensilla ampullacea and coeloconica is similar. Each sensillum consists of a non-perforated, thick-walled peg located in either a deep tube or a pit, and is innervated by three neurons. The unbranched dendrites of two neurons extend into the lumen of the peg. The dendrite of the third neuron, which is distally folded into lamellae in all of the sensilla ampullacea and some of the sensilla coeloconica, terminates beneath the peg. Three sheath cells are associated with each sensillum.Sensilla coeloconica on the antennae of female Aedes aegypti are thermoreceptors. On the basis of similarity in fine structure, sensilla coeloconica and ampullacea of An. stephensi probably also play a role in thermoreception.

SALIVARY GLANDS OF FEMALE CULEX PIPIENS: MORPHOLOGICAL CHANGES ASSOCIATED WITH MATURATION AND BLOOD-FEEDING

1975 ◽  
Vol 107 (11) ◽  
pp. 1153-1160 ◽  
Author(s):  
P. M. Barrow ◽  
S. B. McIver ◽  
K. A. Wright
Keyword(s):  
Fine Structure ◽  
Aedes Aegypti ◽  
Salivary Glands ◽  
Culex Pipiens ◽  
Anopheles Stephensi ◽  
Morphological Changes ◽  
Neck Region ◽  
Blood Feeding ◽  
Medial Lobe ◽  
Complete Development

AbstractThe salivary glands of female Culex pipiens L each consist of three lobes divisible into five regions. Fine structure indicates that two regions may be involved in solute-linked water transport and three regions may have a glandular function. The fine structure is similar to that reported for Anopheles stephensi and Aedes aegypti. In C. pipiens, an axon of presumed neurosecretory function was found associated with the neck region of the medial lobe.Complete development of the salivary glands occurs between the first and fifth days of adulthood. Morphological changes associated with blood-feeding were limited to the presence or absence of the salivary secretions in the apical cavities and duct lumen. During blood-feeding the contents of two of the glandular regions are voided, being replenished within 24 h Results are related to previous histochemical studies of the salivary glands of mosquitoes.

Fine structure of pegs on the palps of female culicine mosquitoes

1972 ◽  
Vol 50 (5) ◽  
pp. 571-576 ◽  
Author(s):  
Susan B. McIver
Keyword(s):  
Carbon Dioxide ◽  
Fine Structure ◽  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Cuticular Structure ◽  
Different Types ◽  
Thin Walled ◽  
Distinctive Cell ◽  
Sheath Cells ◽  
Culex Territans

The fine structure of the thin-walled pegs known to respond to carbon dioxide was studied in Aedes aegypti (L.), Culex pipiens L., and Culex territans Walker. Each peg is composed of an external cuticular structure with numerous pores which occur in groups, three bipolar neurons, and sheath cells. In A. aegypti two morphologically different types of neurons were found innervating the same sensillum: two electron-dense neurons and one electron-lucid neuron per peg. In addition to distinctive cell bodies and nuclei, the two types of neurons have different organization patterns of their dendritic processes within the lumen. Culex pipiens is shown to have several times more area available for perception of carbon dioxide than A. aegypti.

scholarly journals Insecticidal Activity of Bacillus laterosporus

1998 ◽  
Vol 64 (7) ◽  
pp. 2723-2725 ◽  
Author(s):  
Margarita V. Orlova ◽  
Tatyana A. Smirnova ◽  
Lyudmila A. Ganushkina ◽  
Victoria Y. Yacubovich ◽  
Roudolf R. Azizbekyan
Keyword(s):  
Aedes Aegypti ◽  
Larvicidal Activity ◽  
Insecticidal Activity ◽  
Culex Pipiens ◽  
Anopheles Stephensi ◽  
Crystalline Inclusions ◽  
Bacillus Laterosporus

ABSTRACT The Bacillus laterosporus strains 921 and 615 were shown to have toxicity for larvae of the mosquitoes Aedes aegypti, Anopheles stephensi, and Culex pipiens. The larvicidal activity of B. laterosporus was associated with spores and crystalline inclusions. Purified B. laterosporus 615 crystals were highly toxic for Aedes aegypti and Anopheles stephensi.

The activity of some pyrethroids, DDT and lindane in smoke from coils for biting inhibition, knockdown and kill of mosquitoes (Diptera, Culicidae)

1975 ◽  
Vol 65 (1) ◽  
pp. 97-107 ◽  
Author(s):  
P. R. Chadwick
Keyword(s):  
Aedes Aegypti ◽  
Guinea Pigs ◽  
Culex Pipiens ◽  
Anopheles Stephensi ◽  
Host Finding ◽  
Inhibiting Activity ◽  
Culex Pipiens Fatigans ◽  
Relative Potencies

AbstractThe action of smoke from smouldering mosquito coils against Aedes aegypti(L.), Anopheles stephensi List. and Culex pipiens fatigans Wied. was studied. Smokes from lindane or DDT coils did not inhibit biting of guinea-pigs by Ae. aegypti or A. stephensi nor did they cause knockdown. The pyrethroids (allethrin, pyrethrins, bioallethrin and S-bioallethrin in that order) were increasingly effective in knocking down and killing C. p. fatigans and Ae. aegypti, and their bite-inhibiting activity on Ae. aegypti and A. stephensi increased in the same sequence. Pyrethrins were inferior to allethrin for knockdown of A. stephensi. Smoke from a bioallethrin coil inhibited Ae. aegypti from probing and taking blood from man. Tests in a cylinder of 0·034 m3 and a room of 25 m3 suggested approximate relative potencies of 1:2:4 for allethrin, bioallethrin and S-bioallethrin, the bite-inhibitory and knockdown actions being closely associated. Use of gauze-ended test cages reduced the range of relative potencies. The discussion suggests that the sequence of effects exerted by smoke on a mosquito entering a room is deterrency, expellency, interference with host finding, bite inhibition, knockdown and, eventually, death.

Fine Structure of the Malpighian Tubules of the Mosquito, Culex pipiens

1971 ◽  
Vol 29 ◽  
pp. 402-403
Author(s):  
Brendan Clifford
Keyword(s):  
Fine Structure ◽  
Culex Pipiens ◽  
Stellate Cell ◽  
Malpighian Tubule ◽  
Cell Types ◽  
Instar Larva ◽  
Malpighian Tubules ◽  
Calliphora Erythrocephala ◽  
Distinct Cell ◽  
Basal Plasma

An ultrastructural investigation of the Malpighian tubules of the fourth instar larva of Culex pipiens was undertaken as part of a continuing study of the fine structure of transport epithelia.Each of the five Malpighian tubules was found to be morphologically identical and regionally undifferentiated. Two distinct cell types, the primary and stellate, were found intermingled along the length of each tubule. The ultrastructure of the stellate cell was previously described in the Malpighian tubule of the blowfly, Calliphora erythrocephala by Berridge and Oschman.The basal plasma membrane of the primary cell is extremely irregular, giving rise to a complex interconnecting network of basal channels. The compartments of cytoplasm entrapped within this system of basal infoldings contain mitochondria, free ribosomes, and small amounts of rough endoplasmic reticulum. The mitochondria are distinctive in that the cristae run parallel to the long axis of the organelle.

Estudio y evaluación de depredadores y bacterias entomopatógenas de Aedes aegypti (L.) y Culex pipiens (L.), como potenciales agentes de control

2010 ◽  
Author(s):  
◽  
María Cecilia Tranchida
Keyword(s):  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Principal Vector ◽  
La Plata

Aedes aegypti y Culex pipiens se encuentran entre las principales especies de mosquitos vectores de enfermedades a nivel mundial. Ambas, son de gran importancia sanitaria en la Argentina. Aedes aegypti, es el principal vector del dengue y la fiebre amarilla. Está presente en la Argentina desde 1983, cuando fue confirmada su reemergencia en nuestro país. A partir de entonces comenzaron a detectarse casos de dengue hasta que el último brote de esta enfermedad en 2009 produjo 24.720 casos autóctonos confirmados por la OPS a nivel nacional. Culex pipiens es vector de algunas filariasis, y de importantes arbovirosis como la ocasionada por el virus del Nilo Occidental. La actividad vectorial de este mosquito se ve incrementada en zonas donde la densidad de zanjas de desagüe domiciliario es elevada, ya que este tipo de ambiente constituye un lugar propicio para su desarrollo. De su importancia sanitaria nace la necesidad de controlar su actividad vectorial, manteniendo las poblaciones en bajas densidades. El objetivo de este trabajo fue desarrollar estrategias para el control de A. aegypti y C. pipiens, basadas en métodos biológicos, eficaces, permanentes y seguros para el ambiente, mediante el empleo de enemigos naturales presentes en las poblaciones de ambas especies. En este trabajo, fueron evaluados copépodos, turbelarios y peces como depredadores; y bacterias entomopatógenas (α-protobacterias y bacterias esporulantes). El estudio de los copépodos, tuvo como objetivo identificar a la comunidad de copépodos larvívoros que se desarrolla en los criaderos de mosquitos, ubicados en los alrededores de la ciudad de La Plata, para identificar nuevas especies capaces de depredar mosquitos que habitan recipientes artificiales (A. aegypti y C. pipiens). La diversidad de copépodos larvívoros fue mayor en los cuerpos de agua permanentes. Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus fueron seleccionados por su capacidad depredadora. En el laboratorio fueron evaluadas: la capacidad de depredación de ambos sexos y diferentes estadios, preferencia de especie presa, y la tasa de depredación diaria. Las hembras de estas especies de copépodos presentaron mayor capacidad depredadora. No se detectó preferencia de los copépodos hacia ninguna de las especies de mosquitos. También se evaluó la tolerancia a la desecación y la capacidad de vivir en el agua que se acumula en los recipientes artificiales. Diacyclops uruguayensis y A. robustus sobrevivieron en las condiciones de sequía ensayadas en este estudio, pero D. uruguayensis mostró una menor supervivencia en el agua de recipientes artificiales. Macrocyclops albidus no sobrevivió en condiciones de sequía ni toleró el agua extraída de los recipientes artificiales. La supervivencia de M. longisetus ante estas condiciones, fue reducida. Se concluyó que las especies D. uruguayensis y A. robustus podrían ser buenos candidatos para el control de especies de mosquitos que crían en recipientes artificiales.

Preparation, characterization and comparative toxicity of nanopermethrin against Anopheles stephensi and Culex pipiens

2021 ◽  
Author(s):  
Pedram Ebrahimnejhad ◽  
Seyed Hassan Nikookar ◽  
Mahmoud Fazeli‐Dinan ◽  
Seyed Payman Ziapour ◽  
Ali Farmoudeh ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Anopheles Stephensi ◽  
Comparative Toxicity

scholarly journals Behavioural response of mosquito vectors Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus to synthetic pyrethroid and organophosphorus-based slow-release insecticidal paint

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Sunil Dhiman ◽  
Kavita Yadav ◽  
B. N. Acharya ◽  
Raj Kumar Ahirwar ◽  
D. Sukumaran
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Anopheles Stephensi ◽  
Slow Release ◽  
Disease Risk ◽  
Mosquito Species ◽  
Escape Time ◽  
Behavioural Avoidance ◽  
Vector Mosquito ◽  
Contact Exposure

Abstract Background The direct toxicological impact of insecticides on vector mosquitoes has been well emphasized; however, behavioural responses such as excito-repellency and physical avoidance as a result of insecticide exposure have not been much studied. We have demonstrated the excito-repellency and behavioural avoidance in certain vector mosquito species on exposure to a slow-release insecticidal paint (SRIP) formulation in addition to direct toxicity. Methods A SRIP formulation developed by the Defence Research and Development Establishment, Gwalior, contains chlorpyriphos, deltamethrin and pyriproxyfen as active insecticides. Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti mosquitoes were used to study the excito-repellency response of the formulation. The experiments were performed in a specially designed dual-choice exposure and escape chamber made of transparent polymethyl methacrylate. For the experiments, the SRIP formulation was applied undiluted at a rate of 8 m2 per kg on 15 cm2 metallic surfaces. Mosquitoes were introduced into the exposure chamber, and observations of the movement of mosquitoes into the escape chamber through the exit portal were taken at 1-min intervals for up to 30 min. Results The evaluated formulation displayed strong excito-repellency against all three tested vector mosquito species. Results showed that the ET50 (escape time 50%) for Ae. aegypti, An. stephensi and Cx. quinquefasciatus was 20.9 min, 14.5 min and 17.9 min for contact exposure (CE) respectively. Altogether in CE, the escape rates were stronger in An. stephensi mosquitoes at different time intervals compared to Ae. aegypti and Cx. quinquefasciatus mosquitoes. The probit analysis revealed that the determined ET did not deviate from linearity for both non-contact exposure (NCE) and placebo exposure (PE) (χ2 ≤ 7.9; p = 1.0) for Ae. aegypti mosquitoes and for NCE (χ2 = 8.3; p = 1.0) and PE (χ2 = 1.7; p = 1.0) treatments in Cx. quinquefasciatus. Mortality (24 h) was found to be statistically higher (F = 6.4; p = 0.02) in An. stephensi for CE but did not vary for NCE (p ≥ 0.3) and PE (p = 0.6) treatments among the tested mosquito species. Survival probability response suggested that all the three tested species displayed similar survival responses for similar exposures (χ2 ≤ 2.3; p ≥ 0.1). Conclusion The study demonstrates the toxicity and strong behavioural avoidance in known vector mosquito species on exposure to an insecticide-based paint formulation. The combination of insecticides in the present formulation will broaden the overall impact spectrum for protecting users from mosquito bites. The efficacy data generated in the study provide crucial information on the effectiveness of the tested formulation and could be useful in reducing the transmission intensity and disease risk in endemic countries.

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