Abstract: Objective To study the control effects of Pyrausta nubilalis and evaluating economic benefit by ultra-low volume spraying by unmanned aerial vehicle(UAV)in fields in the hope of providing guidance for developing high-efficiency flight control technology which might be scientific,reasonable and suitable for Xinjiang practical production.MethodBy comprehensive consideration of factors including control effect,retrieved yield loss,insecticide cost input,net benefit and input-output ratio in fields,systemic evaluation of different kinds of chemical treatment was provided for optimal pesticide and dosage in flight control for Pyrausta nubilalis in Xinjiang desert and oasis ecological zone.Result34;spinetoram and methoxy-fenozide(Sipinnuo)at dosage of 450.0 mL/hm2 was the best in the control effect,retrieved yield loss and input-output ratio,which were up to 6,050.85 kg/hm2,9,264.30 yuan/hm2 and 1:20.62,respectively;The second one that produced better result was avermectin and cholorantraniliprole(Langat)at dosage of 600 mL/hm2,control effect,retrieved yield loss and input-output ratio,which were up to 84.18;,6,041.25 kg/hm2,9,219.0 yuan/hm2 and 1:20.62,90 mL/hm2,8,368.5 yuan/hm2 and 1:28.76,respectively.In addition,the addition of special agents for flight control improved the effectiveness of the field control up to 27.58;.ConclusionOptimal use of insecticcdes and the dosage of corresponding insecticide in practical production was proposed as follows: 34;spinetoram and methoxyfenozide(Sipinnuo)SC 450.0 mL/hm2,avermectin and cholrantraniliprode(Laangat)SC 600.0 mL/hm2,20;chlorantranili prole(Coragen)SC 90 mL/hm2,45;emanectin benzoate and lufenuron(Pukemeng)water dispersidble granules 225.0 g/hm2,and special agents for flight control should be added simultaneously.