Rev 01/09/2024
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Males:
Juveniles:
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Hirschmanniella imamuri, like H. diversa, an important pest of lotus in Japan.
Important pest in lotus (Nelumbo nucfiera) cultivation in Japan (Takagi et al., 2023).
Migratory endoparasite of roots. Juveniles and adults enter at root tip of rhizomes..
Besides parasitizing Indian lotus, Hirshcmanniells imamuri also parasitizes rice grown in flooded fields.
Ecophysiological Parameters:
Hirshcmanniells diversa and H, imamuri are considered causal agents of blackening disease or browning tuber disease "Renkon Kurokawa-Senchu-Byo" in Indian lotus (Nelumbo nucifera). Lotus cultivars include flowering forms with high value as ornamentals end edible forms with the rhizome as the edible portion. (Uematsu et al., 2020). Hirschmannielaa imamuri, like H. oryzae, is also a pasraite of rice; both cause root-rot in rice roots..
Lotus is an aquastic plant grown and cultivated in ponds or flooded fields. Edible lotus rhizomes are an important food source in Japan.
The nematodes are attracted to to young root tips of rhizomes and create narrow cavities as they invade over a period of 4-5 hours. Host cells adjacent to the cavitis are destroyed during the during infestation. Following contact with the nematodes, host cell walls and cellular contents became electron-dense and less defined, likely due to digestive enzymes secreted by the invading nematodes. Nematodes invade to a depth of about 1mm in 24 hr \ but apparently does not penetrate deeper into the rhizome (Uematsu et al., 2020).. The infection results in blackish-brown blothces as the rhizome matures.
Host Plant Resistance, Non-hosts and Crop Rotation alternatives:
Takagi, M., Sekimoto, S., Mizukubu, T., Wari, D., Akiba, M., Perry, R.N., Toyota, K. 2023. Geographical distribution and phylogenic relationships of Hirschmanniella diversa Sher (Nematoda: Pratylenchidae) in Japan. Nematology 55:45-58.