Acceleration of oviposition by removing the egg sac in Pardosa T-insignita (Araneae: Lycosidae)

Abstract

In Kyushu Pardosa T-insignita lays eggs in spring and autumn. However, when the egg sac was removed after 1 or 2 days after oviposition, the 2nd oviposition occurred within the period of 3 to 4 weeks. Number of eggs was about 50 in the 1st and about 33 in the 2nd. In the ovaries just after the 1st oviposition, there were about 150 auxocytes of different sizes. Each of them was attached to the outside of the ovary by a solid funiculus. At the end of 4 weeks after oviposition, in case of keeping the egg sac intact, the largest auxocytes measured about 184 μ in diameter in some individuals; whereas, in case of removing the egg sac after 1 or 2 days after oviposition, the development of the stored auxocytes proceeded rapidly and in some individuals they reached the maximum size of about 476 μ in diameter. Ovulation occurred when the eggs were about 450 μ in diameter. Germinal vesicle was about 33 μ in diameter in the auxocyte of the diameter of about 40 μ. With development of auxocytes, the germinal vesicles also increased in size. The maximum size of them was about 67 μ in diameter in mature eggs. Yolk nucleus was about 23 μ in diameter when the auxocytes were about 70 to 90 μ in diameter. The size of it remained almost unchanged until ovulation. Yolk granules were formed when the auxocytes reached the size of about 150 μ in diameter. The maximum size of them was about 56 μ in diameter in the eggs deposited. © 1977, Arachnological Society of Japan. All rights reserved.