Aedes aegypti
is a day-biting, highly anthropophilic mosquito and a potential vector of dengue and chikungunya in India.
A. aegypti
is a container breeder, generally oviposit in the stored and fresh ...water bodies, and discarded containers near residential areas that provide suitable habitats for oviposition by gravid females. The diurnal activity and endophilic nature of these mosquitoes have increased the frequency of contact with human being. Assured blood meal from human host in an infested area leads to increased disease occurrence. Gravid mosquitoes can potentially be lured to attractant-treated traps and could subsequently be killed with insecticides or growth regulators. In this direction, oviposition by
A. aegypti
females to aryl hydrazono esters (AHE)-treated bowls at 10 ppm concentration was tested in dual choice experiment, and their orientation response to these ester compounds was studied in Y-tube olfactometer. Among the esters tested, AHE-2, AHE-11 and AHE-12 elicited increased egg deposition with oviposition activity indices (OAI) of +0.39, +0.24 and +0.48, respectively, compared to control; in contrast, AHE-8, AHE-9 and AHE-10 showed negative oviposition response with OAI of −0.46, −0.35 and −0.29, respectively, at 10 mg/L. In the Y-tube olfactometer bioassay, AHE-2 attracted 60 % females compared to control, while to the odour of AHE-11 and AHE-12, about 70 % of the females were trapped in treated chambers. In contrast, only 27–30 % of gravid females entered the chamber releasing AHE-8, AHE-9 and AHE-10 odour plumes, while 70 % entered control chamber, evincing a possible non-preference of treatment odours as well as interference with olfactory receptors. These compounds have the potential for application as oviposition stimulants or deterrents for surveillance and control of mosquito population using ovitraps.
Oviposition deterrent activity of three mosquito repellents namely diethyl phenyl acetamide (DEPA), diethyl benzamide (DEB) along with diethyl toluamide (DEET) was studied in the laboratory against
...Aedes aegypti
,
A. albopictus
, and
Culex quinquefasciatus
mosquitoes. All the repellents evaluated at three log concentrations 0.1, 0.01, and 0.001 % in comparison with control by dual choice method. The oviposition response and oviposition activity index (OAI) was estimated by counting number of eggs laid in both the treatment and control. Mean OAI determined for
A. aegypti
was in the range of −0.23 to +0.22, −0.3 to +0.27, and +0.04 to +0.33 for DEPA, DEET, and DEB, respectively, whereas it was −0.77 to −0.035, −0.92 to +0.001, and −0.77 to −0.07 for
A. albopictus
and −0.927 to −0.251, −1 to −0.41, and −0.94 to −0.17 for
C. quinquefasciatus
. The oviposition deterrent activity was observed in the order of DEET > DEPA > DEB. Similarly, the response of species toward the repellents as oviposition deterrent was in the trend of
C. quinquefasciatus
>
A. albopictus
>
A. aegypti
. The finding suggests potential role of mosquito repellents as oviposition deterrent.
Programmable Logic Controllers (PLC) are frequently used by a good number of companies like steel plants, biscuit manufacturing companies, etc. Various plants/companies use two PLC at a time: one ...operative, and the other as a hot standby to avoid big losses. Analysis of the reliability, and profit of a hot standby PLC system is of great importance; and hence the present paper examines such a system wherein two PLC are working in master-slave fashion. Initially, the master unit is operative, and the slave unit is in hot standby. The slave unit can also fail, but with a lower failure rate than the master unit. The master unit has the priority of operation mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp;mp; repair over the slave unit. While operating, the latest information from the master unit keeps on transferring to the slave unit. There are three types of failure: minor, major-repairable, and major-irreparable. The ordinary repairman who stays with the system repairs the minor failures. The expert repairman who is available upon demand repairs the major failures. Various measures of the system effectiveness, such as the mean time to system failure, steady-state availability, busy period of the ordinary as well as expert repairmen, expected number of replacements, etc. are obtained by using semi-Markov processes, and regenerative point Techniques. Profit incurred to the system is evaluated, and a graphical study is also made. Real data from an industrial application is used in this study.
A novel series of aryl hydrazono esters (AHE) (1–13) were synthesized (yield 76–98%) to study the oviposition responses in
Aedes albopictus (Skuse) mosquitoes for the first time. At a concentration ...of 10
μg
ml
−1 in dual choice experiment, among the screened compounds, AHE-12 showed remarkable oviposition attractant activity with an oviposition activity index (OAI) of +0.299 (greater than 95% confidence limit) comparable to
p-cresol (OAI +0.320) which is well-reported oviposition attractant for
Aedes aegypti. Conversely, AHE-10 exhibited highest oviposition deterrent activity with OAI −0.247. The possible utilization of these compounds will be in integrated vector management strategies.
A novel series of aryl hydrazono esters (AHE) (1–13) were synthesized (yield 76–98%) to study the oviposition responses in
Aedes albopictus (Skuse) mosquitoes for the first time. At a concentration of 10
μg
ml
−1 in dual choice experiment, among the screened compounds, AHE-12 showed remarkable oviposition attractant activity with an oviposition activity index (OAI) of +0.299 (greater than 95% confidence limit) comparable to
p-cresol (OAI +0.320) which is well-reported oviposition attractant for
Aedes aegypti. Conversely, AHE-10 exhibited highest oviposition deterrent activity with OAI −0.247. The possible utilization of these compounds will be in integrated vector management strategies.
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