| The occurence dynamics of Athetis lepigone during the night and through the year inTai’an, and the control and monitoring application of sex attractant to Athetis lepigone werestudied to lay theoretical foundation for forecasting and integrated control of Athetis lepigone.The biological and ecological characteristics were analyzed using the age-stage, two-sex lifetable to make clear the intrinsic ecological characteristics for its serious damage. Besides, thesupercooling points during the development duration were studied to make sure of the coldhardiness. The results are as follows：According to the general trend of Athetis lepigones’ occurence dynamics, the adultspeaked in4periods: overwintering generation, first generation, second generation and thirdgeneration occurred in the beginning of May, the middle of June to early July, the late July toearly August and the late August to the early September, Respcectively. the eclosion ofoverwintering adult lasts for long time but had a smaller numbers in overwintering generation;The number of adults was large from the first generation to the third generation; and thelargest number is the second generation adults.During the night, Athetis lepigone adults appeared after7:30with the graduallyincreased number over time, peaked during8:00~9:00, then decreased and nearly disappearedafter12:00. During the night, appeared time focused on20:00to22:30, especially from20:30to21:30. The number of adults were influenced by night temperature, larger number appearedunder the hot weather. The ratio of female to male was1:1.26.The mean developmental durations of Athetis lepigone were83.66,54.96,39.36,33.98and27.08days, respectively at19℃,22℃,25℃,28℃and31℃. The developmental periodsof each stage shortened as the temperature rose. The developmental rates of every stagerelated linearly to different temperatures significantly. The developmental thresholdtemperature and effective accumulative temperature of four stages were researched and thoseof the whole generation were7.72±0.54℃and486.71±20.99degree-days, respectively.The mortality of Athetis lepigone was16%,19%,23%,18.18%and22.67%,respectively at19℃,22℃,25℃,28℃and31℃.Larva stage had the highest mortality, thenegg stage, and the survival rate in pupae stage was highest, so larva was a key weak stage. The intrinsic ecological characteristics of Athetis lepigone were analyzed using theage-stage, two-sex life table. At19℃,22℃,25℃,28℃and31℃the mean fecundity was189.88,182.56,174.86,185.21and104.26eggs/female in sequence. The ratio of female tomale related with the size of laboratory population sample was1:1.10,1:1.07,1:1.24,1:1.29and1:1.34successively. Total preoviposition period of female counted from birth（TPOP）was84.31,54.72,38.83,34.12and26.12days in turn. The intrinsic rate of increase （r） was0.0502,0.0756,0.0998,0.1149and0.1243d-1, respectively and increased when temperaturerose. The net reproduction rate（R0）was75.95,71.20,60.04,65.07and34.52in sequence.The mean generation time（T）was86.1,56.45,41.03,36.34and28.49days successively. Thelife expectancy of a newborn egg, the finite rate of increase（λ）, was1.0516,1.0785,1.1050,1.1218and1.1324d-1, respectively. The gross reproduction rate（GRR）was208.48,130.37,129.6,93.88and57.12separately.The supercooling points of third instar larva, mature larva and pupae were tested. Thesupercooling point was8.4,13.49and15.6, and the freezing point was2.35,4.73and5.92, respectively. It is obvious that the point of third instar larva was lower than the maturelarva and pupae but there is no big difference between the mature larva and pupae. So,theoretically, the Instar larva and pupae can live through the winter. According to the test, thesupercooling point of mature larva was12.51℃,12.22℃,13.22℃,15.35℃and15.7℃from July to November, the supercooling point of pupae was14.41℃,15.24℃,15.6℃,16.87℃,17.4℃. And their supercooling point decreased as the temperature decreasedin order to adapt the environment. So the Athetis lepigone had a strong ability of coldhardness.The male internal reproductive organs of Athetis lepigones are composed of two testes, apair of seminal vesicle, the ducts ejaculatorius and accessory glands. The female reproductiveorgans are composed of a pair of ovaries, two paired oviducts, a commoned oviductand, thereceptaculum seminis, and accessory glands. The female reproductive organs can be dividedinto5levels. |
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