scholarly journals EVALUATION OF ORANGE OIL APPLIED BY THREE BACKPACK SPRAYERS AGAINST AEDES AEGYPTI AND CULEX QUINQUEFASCIATUS

2021 ◽  
Vol 68 (1) ◽  
pp. 101-104
Author(s):  
Rui-De Xue

A solvent orange oil has been used to mix with permethrin and PBO as a commercial adulticide product called Aqualure® 20-20 for control of adult mosquitoes. The orange oil at 2.7% and 3.5% sprayed by three backpack sprayers, Hudson battery operated sprayer modified with a Solo nozzle, hand pump sprayer Solo-425, and Birchmeire battery operated sprayer, against caged adult female Aedes aegypti Linn. and Culex quinquefasciatus Say resulted in 89%–100% mortality of Ae. aegypti and 100% mortality of Cx. quinquefasciatus. The three different backpack sprayers did not show any significant differences in the percent mortality. Our test results demonstrate that orange oil alone at a high dose (3.5 %) showed effective insecticidal characteristics against both species of adult mosquitoes.

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 129
Author(s):  
Matthew W. Hopken ◽  
Limarie J. Reyes-Torres ◽  
Nicole Scavo ◽  
Antoinette J. Piaggio ◽  
Zaid Abdo ◽  
...  

Urban ecosystems are a patchwork of habitats that host a broad diversity of animal species. Insects comprise a large portion of urban biodiversity which includes many pest species, including those that transmit pathogens. Mosquitoes (Diptera: Culicidae) inhabit urban environments and rely on sympatric vertebrate species to complete their life cycles, and in this process transmit pathogens to animals and humans. Given that mosquitoes feed upon vertebrates, they can also act as efficient samplers that facilitate detection of vertebrate species that utilize urban ecosystems. In this study, we analyzed DNA extracted from mosquito blood meals collected temporally in multiple neighborhoods of the San Juan Metropolitan Area, Puerto Rico to evaluate the presence of vertebrate fauna. DNA was collected from 604 individual mosquitoes that represented two common urban species, Culex quinquefasciatus (n = 586) and Aedes aegypti (n = 18). Culex quinquefasciatus fed on 17 avian taxa (81.2% of blood meals), seven mammalian taxa (17.9%), and one reptilian taxon (0.85%). Domestic chickens dominated these blood meals both temporally and spatially, and no statistically significant shift from birds to mammals was detected. Aedes aegypti blood meals were from a less diverse group, with two avian taxa (11.1%) and three mammalian taxa (88.9%) identified. The blood meals we identified provided a snapshot of the vertebrate community in the San Juan Metropolitan Area and have potential implications for vector-borne pathogen transmission.


Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 596
Author(s):  
Anuluck Junkum ◽  
Wanchai Maleewong ◽  
Atiporn Saeung ◽  
Danita Champakaew ◽  
Arpaporn Chansang ◽  
...  

Ligusticum sinense Oliv. cv. is a species of Umbelliferae (Apiaceae), a large plant family in the order Apiales. In this study, L. sinense hexane extract nanoemulsion gel (LHE-NEG) was investigated for mosquito repellency and compared to the standard chemical, N,N-diethyl-3-methylbenzamide (DEET), with the goal of developing a natural alternative to synthetic repellents in protecting against mosquito vectors. The results demonstrated that LHE-NEG afforded remarkable repellency against Aedes aegypti, Anopheles minimus, and Culex quinquefasciatus, with median protection times (MPTs) of 5.5 (4.5–6.0), 11.5 (8.5–12.5), and 11.25 (8.5–12.5) h, respectively, which was comparable to those of DEET-nanoemulsion gel (DEET-NEG: 8.5 (7.0–9.0), 12.0 (10.0–12.5), and 12.5 (10.0–13.5) h, respectively). Evaluation of skin irritation in 30 human volunteers revealed no potential irritant from LHE-NEG. The physical and biological stability of LHE-NEG were determined after being kept under heating/cooling cycle conditions. The stored samples of LHE-NEG exhibited some changes in appearance and differing degrees of repellency between those kept for 3 and 6 heating/cooling cycles, thus providing slightly shorter MPTs of 4.25 (4.0–4.5) and 3.25 (2.5–3.5) h, respectively, when compared to those of 5.0 (4.5–6.0) h in fresh preparation. These findings encourage commercially developed LHE-based products as an alternative to conventional synthetic repellents in preventing mosquito bites and helping to interrupt mosquito-borne disease transmission.


2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Izuchukwu Azuka Okafor ◽  
Uchenna Somtochukwu Nnamah ◽  
Jude Nnaka

Abstract Background Purslane is a widely distributed shrub used for the treatment of different ailments. The increasing reproductive complications associated with herbal treatments have led to the need to critically evaluate the safety and/or reproductive potentials of commonly used plant extracts. This study investigated the reproductive effect of methanolic extracts of Portulaca oleracea (MEPO) in adult female Wistar rats. Results Group C showed a significant decrease both in relative ovarian weight (p = 0.000), and relative uterine weight (p = 0.037), when compared with the control. There were no significant (p ˃ 0.05) changes in the levels of follicle-stimulating hormone, luteinizing hormone, progesterone, and estradiol. When compared to the control, groups B and C showed abnormal estrous cycle and cycle arrest especially at the metestrus phase with mild congestion of a few blood vessels in the ovary and uterus. Conclusions MEPO may possess some anti-fertility effect, as it disrupts the estrous cycle of adult female Wistar rats; although it has no major effect on the reproductive hormones, uterus, and ovarian histology of adult female Wistar rats. However, high dose consumption should be taken with precaution.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Sunil Dhiman ◽  
Kavita Yadav ◽  
B. N. Acharya ◽  
Raj Kumar Ahirwar ◽  
D. Sukumaran

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.


2021 ◽  
pp. 108120
Author(s):  
Appadurai Daniel Reegan ◽  
Pachaiyappan Saravana Kumar ◽  
Antony Cruz Asharaja ◽  
Chitra Devi ◽  
Sithi Jameela ◽  
...  

2008 ◽  
Vol 41 (6) ◽  
pp. 658-663 ◽  
Author(s):  
Maria das Graças Vale Barbosa ◽  
Nelson Ferreira Fé ◽  
Alexandre Herculano Ribera Marcião ◽  
Ana Paula Thomé da Silva ◽  
Wuelton Marcelo Monteiro ◽  
...  

A biodiversidade da Região Amazônica inclui diversas espécies de vetores artrópodes em seus diferentes ecótopos, possibilitando o surgimento de doenças como malária, filarioses e arboviroses. De agosto de 2001 a julho de 2002, realizou-se coletas de culicídeos no domicílio, peridomicílio e nas matas da Comunidade São João, área rural de Manaus, Amazonas. Foram capturados 1.240 culicídeos, pertencentes às subfamílias Culicinae (99%) e Anophelinae (1%), somando 50 espécies. O predomínio entre as tribos foi nitidamente de Culicini, com 904 (72,9%) exemplares, destacando-se as espécies Culex usquatus (22,6%) e Culex quinquefasciatus (17,7%). Do total de culicídeos, 1.077 (86,9%) exemplares foram capturados no interior das matas, 101 (8,1%) no peridomicílio e 62 (5%) no intradomicílio. O ecótopo com maior diversidade de espécies foi a mata. Assinalou-se a presença de Anopheles darlingi, Anopheles triannulatus, Aedes aegypti, Haemagogus janthinomys e outros vetores comprovados ou potenciais.


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