不同组织源食物对大头金蝇生长发育的影响

Effect of Feeding on Different Tissues on Larva Development of Chrysomya megacephala(Diptera:Calliphoridae)

目的观察猪的不同脏器组织来源食物对大头金蝇(Chrysomya megacephala)生长发育的影响。方法在25℃恒温条件下,分别利用猪的脑、肝、肌肉,以及肌肉与脂肪的混合物(7︰3)各200 g饲养大头金蝇幼虫,约200只/组。幼虫孵化16 h后,每12 h测量幼虫的体长和体重,并测各组蛹长和蛹重,每次取样10只。观察记录各组不同阶段的样本数量,并计算发育历期,统计各实验组幼虫及蛹的死亡率和成虫的性别比,比较各组之间的差异。结果肝组幼虫生长缓慢,与其他3组比较达到最大体长和体重的时间延迟36 h,其2龄和3龄幼虫期及总发育历期明显大于其他3组(P<0.01)。混合食物组幼虫最大体长[(14.89±0.39)mm]显著小于脑组、肌肉组和肝组[分别为(17.81±0.54)、(16.94±0.43)和(17.14±0.27)mm](P<0.01),肝组和混合食物组幼虫最大体重[分别为(73.5±6.8)和(63.0±5.4)mg]均显著小于脑组和肌肉组[分别为(91.2±7.5)和(86.3±7.3)mg](P<0.01)。混合食物组蛹长显著小于脑组、肌肉组和肝组(P<0.01),混合食物组和肝组蛹重均显著小于脑组和肌肉组(P<0.01)。混合食物组幼虫和蛹的死亡率分别为(9.8±3.1)%和(8.9±3.1)%,显著高于脑组[(5.5±3.1)%和(4.6±1.5)%]、肌肉组[(4.7±2.2)%和(3.8±2.0)%]和肝组[(5.4±2.3)%和(4.8±1.7)%)](均P<0.01),后3组之间差异无统计学意义(P>0.05)。各组成虫的性别比差异无统计学意义(P>0.05)。结论取食肝组织的大头金蝇幼虫发育历期较长,取食含有30%脂肪的混合食物的幼虫及蛹的体长和体重较小,死亡率亦较高。

Objective To observe the effect of feeding on different pig tissues on the development of Chrysomya megacephala larvae. Methods About 200 larvae each were reared on four different substrates, i.e. pig＇s brain, liver, muscle and a mixture of minced pork muscle and fat （7：3） at a constant temperature of 25 ~C. Length and weight of larvae and pupae were measured at 12 h interval 16 h after eclosion. 10 larvae or pupae were collected each time. The time of development, mortality, and sex ratio of adults were recorded. Results Three replicated experiments showed that the larvae fed on liver grew slowly, time of reaching maximum length and weight was delayed for about 24-36 h, and the duration of larva development was longer than that of other groups （P〈0.01）. The mean maximal larval length in mixture group [（14.89±0.39） mm] was statistically shorter than that of brain group, muscle group and liver group, [（17.81±0.54）, （16.94±0.43） and （17.14±0.27） mm, respectively] （P〈0.01）. The mean maximal larval weight in liver group [（73.5±6.8） mg] and mixture group [（63.0±5.4）mg] was statistically lighter than brain group [（91.2±7.5）mg] and muscle group [（86.3±7.3）mg] （P〈0.01）. The pupal length in mixture group was statistically shorter than that of other 3 groups （P〈0.01）. The pupal weight of mixture group and liver group was statistically lighter than that of brain group and muscle group （P〈0.01）. The larval and pupal mortality of mixture group [（9.8_±3.1）% and （8.9_±3.1）%] was statistically higher than that of brain group [（5.5±3.1）% and （4.6±_1.5）%], muscle group [（4.7±_2.2）% and （3.8±_2.0）%] and liver group [（5.4±2.3）% and （4.8±1.7）%] （P〈0.01）. There was no significant difference in the sex ratio among the four groups （/%0.05）. Conclusion The develop- ment duration of the larvae fed on liver is longer than other groups. The body length and weight of larvae and pupae fed on mixture diet are less than other groups with higher mortality.