Since, 1976 to 2014, DDT, and from 2015 till date, alpha cypermethrin insecticide is being sprayed for two rounds per year as indoor residual spray up to 1.8 meter i.e 6 feet height in human dwellings as well as full cattle sheds in Bihar, India, as a part of Kala -azar elimination programme. This is being practiced due to the belief that in indoor resting Phlebotomus argentipes the vector of kala azar cannot hop beyond 6feet (1.8 meter) height. A study was therefore conducted between July to

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... vember 2016 in three villages of highly kala azar endemic block Warisnagar, district Samastipur of Bihar to understand whether the vertical distribution of indoor resting population of present day P.argentipes is the same or there is variation. During the entire study period it was noted that minimum 20.3 to maximum 59.6 percent (Median value 38) P.argentipes were found to rest beyond 6 feet (between 1.8 to 2.00s meter). Significant numbers (27.8%) of gravid and fully blood fed (5.4%) females were found to rest above 1.8meter (6ft) height. Therefore, full IRS coverage (beyond 1.8 meter), in human dwellings and cattle sheds may give good results in terms of human and sand fly contact as being done in malaria control programme in India.