| Studies on the Biological Characteristics of Luehdorfia chinensis Leech (the second class state protection animals) and Danaus chrysippus L. in Yanshan, Yongxiu County, Jiangxi province, the main contents and conclusions were as follows:1. At natural conditions of Yanshan, L. chinensis had only one generation every year, overwintering with pupae, Overwinter ended at the middle of February. The activity peak of the adults was in March and April. Pupated at the beginning of May, then went into dormancy. Hatching period was 21～27days, and hatching mainly happened at 4:00 to 6:00 and 11:00 to 16:00. accounting for 74.90% in the total of one day incubation. The time of molting in different instars larvae were a little different, which mainly happened at the early morning and around noon and few took place in the noon. The fifth instar larvae pupate mainly happened in 9:00 to 11:00,15:00 to 18:00 and 20:00 to 23:00,67.66% of the total number. Adult eclosion mainly happened at 8:00 to 11:00(67.66%), and its peak at 9:00 to 10:00. The day when adult emergence, if the weather is sunny, they can mate. The mating mainly happened at 12:00 to 14:00(87.42%). Length of mating was 18.93±7.75min.At the natural climatic conditions of Yanshan, in addition to the prepupal period, the other stages of growth were longer than them at the temperature of 20-25 degrees, and the difference is significant. At natural conditions, the average of the egg and larvae period were 23.12d and 46.67d, but under the temperature of 20-25 degrees, they were 16.04d and 33.09d. The larvaes were fed with Asarum forbesii, A.sieboldii and local A. forbesii, the pupate rate had no significant differences, but the period of growth had slightly differences. This shows that the introduced L. chinensis could fit in with local A. forbesii.The 1st～3rd instar larvae preference in groups feeding, The lengths of active feeding and gap in groups is relatively more stable. Correlation analysis with the lengths of active feeding and gap of the 4th instar larvae at 2nd,4thand 6th daily ages, which is similar with the analysis of the five instar by Hu Cui et al, probably through the digestive capacity of feedback mechanisms regulate its feeding initiation and termination.2. At natural conditions of Yanshan, Danaus chrysippus L. had 5 or 6 generation every year and the generations overlapped. It can start breeding in the Yanshan at the middle of April, and had two activity peak, the end of June and the beginning of September. The adult and larvae all died at the end of November, can not overwinter, the pupa can not emergence now and aslo the next year. Hatching mainly happened at 5:00 to 11:00(83.23%). The time of molting in different instars larvae were basically the same, the peak time at 8:00 to 10:00,and few took place in the noon and afternoon. Mature larvae pupate mainly occurred at 4:00-10:00(83.47%). The adult eclosion mainly happened at 5:00 to 14:00 and its peak at 8:00 to 10:00(58.82%). The adult mating mainly happened at 10:00 to 16:00(84.15%). Length of Mating was 94.60±22.39min. At the natural climatic conditions of Yanshan June and July, the stages of growth were significantly shorter than them at September and October. At June and July, the average of the egg, larvae and pupal period were 3.09d,8.32d and 8.73d, but at September and October, they were 8.82d,23.23d and 22.71d.Different nectariferous plants had different comether function to D. chrysippus adult, placed Cleome spinosa L., Celosia argentea L., Zinnia elegans L. and so on, add up to 11 nectariferous plants in the ecological park. Through experimental observation, C. argentea (27.04%)had the strongest attractive effect, and then Asclepias curassavica L.(22.96%).In the red. yellow, green, orange, cyan and colorless transparent environment, they had no significant effect on color ratio (grass green and pale orange)of pupae. However, statistics show that groups of red. blue and colorless transparent tend to induce grass green pupae, and yellow, green and orange tend to induce light orange pupae.D. chrysippus lay fewer eggs at September and October, only 55.59% of it at June and July, and significantly different, but the life of the female was longer than it at June and July. In the area of Yanshan. the net reproductive rate (Ro) of D. chrysippus at June and July(Ro=49.217) was higher than it at September and October (Ro=25.262). Intrinsic rate of increase (rm) and finite rate of increase (λ) at June and July(rm=0.157,λ.=1.170) were also higher than them at September and October(rm =0.057.λ=1.059). D. chrysippus complete one generation need only 25.034 days at June and July, which need 56.802 days at September and October, but no significant effect on the sex ratio of D. chrysippus. From the above parameters, the conclusion can be drawn that the month of June and July was more suitable for breeding. |
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