The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is considered a major economic threat in many regions worldwide. In order to better understand the flight capacity of B. dorsalis and its physiological basis, the functions and regulatory roles of juvenile hormone (JH) in the flight muscle of B. dorsalis were studied under a controlled environment. JH titer of B. dorsalis varied with age and sex. Females have higher JH titers and better flight capabilities than males, given that the increase in JH also corresponded to the ovarian development and maturation in females. The flight duration and distance of both males and females increased with the gradual increase of JH titer after adult emergences. Both JH titer and flight capability peaked in 15-d-old adult and declined subsequently with age. Flight activity stimulated the production of JH as adults flown for 24 h on the flight mills have the highest JH titers compare to adults flown on shorter flight durations. Adults treated with 0.5 µg and 5 µg of JH III were able to fly long durations and long distances, nevertheless when JH titer was too low or too high, it would restrict the flight ability of the fly. The mutual reinforcement of JH and flight activity provides fundamental understanding on the physiological aspects of the flight capability and dispersal, which facilitates strategies for the long-term control of this destructive pest.

东方果蝇Bactrocera dorsalis（Hendel）（双翅目：T科）被认为是世界范围内许多地区的主要经济威胁。为了更好地了解背果蝇的飞行能力及其生理基础，研究了在受控环境下少年激素（JH）在背果蝇飞行肌肉中的功能和调控作用。背侧双歧杆菌的JH效价因年龄和性别而异。鉴于JH的增加也对应于雌性的卵巢发育和成熟，因此雌性的JH效价和飞行能力要比雄性好。成年后，随着JH效价的逐渐增加，雄性和雌性的飞行时间和距离均增加。JH滴度和飞行能力在15天大的成年人中达到峰值，然后随年龄下降。飞行活动刺激了JH的产生，因为与在较短飞行时间中飞行的成年飞机相比，在飞行工厂飞行24小时的成年飞机的JH效价最高。用0.5 µg和5 µg JH III治疗的成虫能够长距离飞行并能长距离飞行，但是，当JH效价太低或太高时，它将限制果蝇的飞行能力。