The life history and biology of the needle nematode. Longidorus martini Merny
II. Observations on the embryonic development of eggs and life-cycle of the nematode in a mulberry field
1976 Volume 6 Pages 89-95
Details
1976 Volume 6 Pages 89-95
Eggs of Longidorus martini showed somewhat curved sausage-like shape with hemispherically rounded ends. Their dimensions were as follows: length=180.4±9.2μ, wide=43.4±2.2μ, and length/wide=4.2. From these characters, the eggs were easily distinguished from those of Xiphinema spp. co-inhabiting in mulberry field. As a results of observations on the embryonic development of the eggs at 20-25°C, stages of morula, gastrula, and vermiform were observed at 1-3, 3-8, and 7-10 days, respectively, after the beginning of the cleavage. Moulting of the larvae in the eggs was not observed and hatching of the larvae occurred between 16-23 days after the cleavage. When young females, which were collected from soils of mulberry field in winter, were inoculated to mulberry seedlings at 20-24°C, many females with fully grown gonads and ovipositing ones appeared within 2-3 weeks and 3-4 weeks, respectively. Fig, tomato, and egg plant were newly added as the hosts of the nematodes, but no host plants were found among weeds growing naturally in mulberry fields. Oviposition of this nematode in a mulberry field began in May, increased rapidly reaching the peak in June, and declined markedly or ceased in July-August. A secondary small peak of oviposition occurred again in September-October. After the peak of oviposition larvae at the three larval stage and adult females appeared at the maximum rate at intervals of approximately one month. The nematode survived for about seventeen months at room temperature (0-28°C), and more than thirty months at 0-9°C, in soils without host plants.
