【摘要】 1.实验证明,在北京地区的自然坏境中猪蛔虫卵从4月至10月都能进行发育,5月至9月间能发育成侵袭性幼虫期卵。在背阳光条件下为6月至8月。实验证明,各期虫卵都能够越冬,并且保持侵袭能力。 2.虫卵发育速度最快的月份为7、8两月,土层深度为3—20厘米。土层的温度范围为24.5—39℃(平均26.3—33.3℃),含水量为9.5—19%。虫卵可于2星期内发育至侵袭性幼虫期卵。 3.实验证明,在北京地区,散布在土层3厘米以上的虫卵,由于湿度过低(含水量5%以下)或温度过高(42.5℃以上),造成虫卵不能发育成侵袭性幼虫期卵。但在背阳的条件下,在7、8月份的流行季节里,土表层由于温度、湿度均较适宜,虫卵能完全发育成侵袭性幼虫期卵。 4.在北京地区,在3厘米以下的土层,平均温度不超过33.3℃、含水量不小于9%时,虫卵有89%能发育成侵袭性幼虫期卵。 5.根据实验结果,对猪蛔虫病的防治问题进行了讨论。更多还原

【Abstract】 Studies were made on the development and viability of eggs of the pig Ascaris under natural conditions in Peking. The eggs of A. suum were mixed with loam and buried at various depths of 0, 3, 5, 10, 15 and 20 cm in both sunny and shady places. The results obtained were as follows:1. In the sunny place, the eggs of A. suum developed from April to October, and reached the infective stage from May to September. In the shady place, the eggs developed from May to September, and reached the infective stage from June to August. They did not develop but keep their viability in the winter (from November to March).2. Development of the eggs of A. suum was most rapid during July and August. In soils of 3-20cm depth with 9.5-19% moisture contents and at the temperature range of 26.3-33.3％, they reached the infective stage -within 14 days.3. The eggs of A. suum died in the soil of 0-3cm depths apparently due to too low moisture contents (less than 5%), or too high temperature (more than 42％). But the eggs survived in the surface soil of shady places during July and August.4. The eggs of A. suum placed at depths of 3-20 cm developed at an average temperature of not more than 33％ and a minimum moisture contents of 9.5%.The problem of control of the ascariasis was briefly discussed.更多还原