Study On Biology And Life Table Of Calliptamus Italicus L.

In this thesis, the biology and life tables of Calliptamus italicus L.were studied, including embryonic and post-embryonic development, diapause, egg’s cold tolerance, free amino acids in overwintering eggs,the fly ability,, ovarian development and temperature tolerance, life table traits of experimental and natural populations.C. italicus embryonic development can be divided into 18 stages. Its embryos have three rotation patterns, including reverse transfer, rotation period and forward shift. The diapause stage during eggs embryonic development was Stage ⅩⅡ. The eggs laid in early or middle of the year(July 27 to August 16)entered diapause for overwintering, and resumed development on April 16 following year under natural conditions.While the eggs laid late of the year(On August 28 to September 4th) were not yet developed to the embryonic stage ⅩⅡ, and since November 4 started overwintering with embryonic stageⅩ, then resumed development on March 29 the next year. Some eggs started to terminated diapause since January 21, 2014. When the winter was extended,, diapausing eggs gradually increased, with eggs completely termination March 29, 2014, under natural conditions. Extending the low temperature time promoted the development of diapausing eggs and accelerated diapause termination.Under natural conditions, water content of the grasshopper fresh eggs was 48.68%-50.61%, then increased to 60.33%-62.48% for 45 d-217 d, and since maintained at 59.16%-67.53% until March 29 next year when water content of eggs rapidly increased to 75.89%-77.43%, then reached to 78.62%-79.37%when approaching to hatching. Supercooling points confirmed to normal distribution(P>0.05)for the eggs laid in September, October and March, while), but did not for those laid in August(First batch of eggs), November, December, January, February, and April(P<0.05). Egg supercooling points varied mainly between-25 ℃and-30℃ and between-10℃ and 0℃ from August to next April, with a strong correlation with temperature, declined to the lowest(-21.45℃) with decreasing 5-day-average temperature to-3.29℃from October to next January, and then increased from January to next March.The total free amino acids gradually reduced during diapause, but alanine, proline, glutamicnine,methionine, tyrosine, and phenylalanine maintained at high levels, which respectively decreased by21.08%,26.71%, 19.48%,22.18%,31.14%, and 20.96% post-diapausing, compared to those during diapause.Glutamicnine always maintained at the highest level during and after diapause.C. italicus female adults were able to fly from day-2 after emergence and attained to a strong flyer at day 6 when flight time was 18.22 min, distance 231.01 m, speed 1.26 m ? min-1, and proportion flying individuals 76.00%). The flight ability decreased from day 7 to 10. C. italicus male adults developed strong flight capability at day 2 after emergence with flight time, distance, speed and proportion by 0.64 min,13.34 m, 15.70 m ? min-1, and 40.00%, respectively, and then decreased their flight capability from day 3 to10. Flight capability was aligned with ovary development, attaining high on day 6 when ovary development was at the grade II. Both C. italicus adults could fly during the day and night, mostly from 13∶00 to15∶00 hours, C. italicus ovarian development can be divided into five main stages, namelyⅠ, Ⅱ, Ⅲ, Ⅵ,and Ⅴ, among which stageⅡcan be subdivided into early and end stages and stage Ⅲ into early,middle, late and end stages. The ovary grew steadily in length at the early and rapidly in middle and late stages, but grew slowly in width during the whole process. Mating behavior occurred at the end of stage Ⅲ(70%) and stage Ⅳ(30%). Ovarian development was completed once, or twice, under constant temperatures of 26℃, 29℃, 32℃ and 35℃. There was a significant, negative, linear correlation between the first ovarian development duration and the second(P<0.01). Under the same temperature, the duration of early ovarian development was longer than that of later development, and the fecundity of early developed ovaries was higher than that of those that developed later. In outdoor natural conditions, ovarian development was completed 1-5 times, and fecundity was higher than that observed under constant temperature indoors. C. italicus ovarian development was completed at the middle and late stages. The temperature of 23℃ was unsuitable for C. italicus ovarian development, but range of temperature of26℃-35℃ was favorable and 32℃ the best.Supercooling points of each life stage of C. italicus followed a normal distribution, and supercooling points and freezing points of its various life stages were different. The wintering eggs had the lowest supercooling point and freezing point(P<0.05) while the third instars nymphs had the highest supercooling point(P<0.05), and there were no significant differences in supercooling point between other instars or between the male and female of the adults.When Ta was 41 ℃, LT50 and LT90 of the female and male adults were the longest, which were 623.83 h, 1 604.98 h and 459.52 h, 1 181.97 h, respectively. Adult body temperature Tb and the ambient temperature Ta showed a highly significant linear correlation. When Ta rose by 0.5 ℃?min-1, the Tb rising rate was 0.30℃ ? min-1~0.36 ℃ ? min-1, and the body temperature rising rate of male adults was 0.36 ℃ ? min-1, which was significantly higher than that of female adults(0.30 ℃?min-1).Temperature strongly influenced growth and development. From 23 C to 35 C, development duration was a negatively linear function of temperature(p<0.01). Egg-to-preoviposition development time ranged from 86.8 days at 26 o C to 40.6 days at 35 o C, while there was no oviposition at 23 o C and below. An average of 687.1 degree-days was required to complete development above the lower threshold temperature(18.3 o C). Egg hatching rate, nymph and pre-adult survivorship were the lowest of 95.6 %, 72.62 %, and 0at 23 o C, while they were 97.78 %, 86.19 %, and 88.68 % at 32 o C, respectively. Mean total fecundity ranged from 41 eggs/female at 26 o C to 55 eggs/female at 32 o C. The sex ratio(% female) ranged from 30 to 52%.The intrinsic rate of population increase(rm) at different temperatures ranged from 0.0025 to 0.0445,with the highest at 32 o C. The results indicate that temperature has significant effects on the biology of C.italicus and that the optimum temperature range for its population growth is 26 o C-32 o C.