Characteristics of reproductive dormancy in overwintering adult female Kallima inachus
Author of the article:LI Jing** ZHOU Cheng-Li*** SHI Lei*** YAO Jun LIAO Huai-Jian DU Ting
Author's Workplace:Research Institute of Resources Insects, Chinese Academy of Forestry, Key Laboratory of Cultivating and Utilization of Resources Insects of State Forestry Administration, Kunming 650224, China
Key Words:Kallima inachus, reproductive dormancy, oocyte development, diapause, overwintering
Abstract:
[Objectives] To investigate reproductive, overwintering
dormancy, including the natural duration of dormancy and its successive stages,
to improve the conservation, artificial cultivation and utilization of wild
populations of Kallima inachus (Doyére, 1840). [Methods] The reproductive development of female adults
in a semi-natural experimental population in early summer was graded according
to the degree of oocyte development. The stage of dormancy (i.e. diapause or
quiescence) was determined mainly by whether female adults in the early
overwintering period resumed ovarian development under suitable environmental
conditions. The developmental status of overwintering females held in
conditions similar to the natural environment was inspected at regular
intervals to determine the period of natural dormancy. Overwintering females
were transferred to experimental conditions of 25 ℃ (L︰D =15︰9 and RH 70 %) at regular intervals to determine when
diapause was terminated, as indicated by the resumption of ovarian development. [Results] (1) 2-day-old
female adults developed oocytes with yolk in early summer, and all
females had mature oocytes on the 14th day after eclosion. There was a significant linear relationship between
reproductive development and age that could be divided into four stages. (2)
After incubation for 12 days in conditions similar to that of the natural
environment in early summer (25 ℃, L : D =15 : 9
and RH 70 %), 11 day-old overwintering adults
that had eclosed in early October did not initiate reproductive development. (3)
Most ten-day-old female adults that had eclosed on September 8 became
reproductively dormant when held under semi-natural environmental conditions,
although a few still continued reproductive development. All but one of the
female adults that eclosed on October 1 were reproductively dormant from
mid-October to late December when held under semi- natural environmental
conditions but ovarian development began in some individuals in early January
of the following year. (4) Female adults could not resume reproductive
development rapidly at 25 ℃ until mid to late December, but
by late December most individuals had resumed development at 25 ℃, although
a small number still showed no sign of ovarian development, indicating
individual differences in diapause intensity. [Conclusion] The overwintering,
reproductive dormancy of K. inachus is a typical diapause. While the majority of female adults in a semi-natural
experimental population were reproductively dormant from mid-September to late
January, some individuals began ovarian development in early January.
Overwintering female adults were at the stage of diapause maintenance till the
beginning of December, and gradually entered a period of post-diapause
quiescence from late December.