Rev 07/25/2022
Litylenchus crenatae Kanzaki, Ichihara, Aikawa, Ekino & Masuya, 2019
Designated subspecies: Litylenchus crenatae mccannii Carta et al., 2020
Male:
.Ref: Kanzaki et al., 2019
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Litylenchus crenatae was described from the leaves of crenatae repens in Wellington, on the North Island of N
Extracted from leaf galls on leaves of Fagus crenata (beech) in Japan. Similar galls were seen on Alnus (elm), Ostrya (hophornbeam) and other Fagus spp. but identity with this nematode species not yet confirmed (Kanzaki et al., 2019).
In USA, Beech Leaf Disease (BLD) was first discovered in Ohio in 2012 and has since spread to stands of American beech (Fagus grandifolia Ehrh.) across much of northern Ohio, western and northern Pennsylvania, New York, and Ontario, Canada (Ewing et al. 2018; Marra and LaMondia, 2020) .It has also been found on European beech (Fagus sylvatica L.) in Ohio.
Beech trees are important shade and landscape trees. The wood is excellent as firewood.
Ecophysiological Parameters:
Mature males and females found in leaf galls from late spring to early summer. The tree hosts are deciduous so the nematodes must be able to survive elswhere, possibly on the tree, until development of new leaves. Life cycle details have not yet been elucidated.
BLD symptoms are dark interveinal darkening of leaves appearing soon after spring flush. There is some puckering, crinkling and irregular thickening of leaves. Advanced stages of the disease lead to canopy thinning and sometimes to tree death. Beech seedlings inoculated with L. crenatae mccannii develop BLD symptoms (Carta et al. 2020; Marra and Lamondia, 2020).
Nematodes extracted leaves of American and European beech in North America are most similar to Litylenchus crenatae which is associated with leaf gall symptoms on Japanese beech (Fagus crenata) (Kanzaki et al. 2019). However, North American populations differ in morphology, host range, and ribosomal DNA markers from those in Japan, the North American nematodes associated with BLD have been designated subspecies L. crenatae mccannii (Carta et al. 2020).
Host Plant Resistance, Non-hosts and Crop Rotation alternatives:
Carta, L.K., Handoo, Z.A., Li, S., Kantor, M., Bauchan, G., McCann, D., Gabriel, C.K., Yu, Q., Reed, S., Koch, J., Martin, D., Burke, D.J. 2020. Beech leaf disease symptoms caused by newly recognized nematode subspecies Litylenchus crenatae mccannii (Anguinata) described from Fagus grandifolia in North America. Forest Pathology 50:e12580. https://doi.org/10.1111/efp.12580
Ewing, C. J., Hausman, C. E., Pogacnik, J., Slot, J., & Bonello, P. (2018). Beech leaf disease: An emerging forest epidemic. Forest Pathology, 49: e12488. https://doi.org/10.1111/efp.12488
Kanzaki, N., Y. Ichihara, T. Aikawa, T. Ekino and H. Masuya. 2019. Litylenchus crenatae n. sp. (Tylenchomorpha: Anguinidae), a leaf gall nematode parasitising Fagus crenata Blume. Nematology 21:5-22.
Marra, R.F., LaMondia, J. 2020. First Report of Beech Leaf Disease, caused by the foliar nematode, Litylenchus crenatae mccannii, on American Beech (Fagus grandifolia) in Connecticut. Plant Disease 104: https://doi.org/10.1094/PDIS-02-20-0442-PDN