UNINTENTIONAL INTRODUCTIONS INTO CALIFORNIA:

Within California, the sugarbeet cyst nematode (Heterodera schachtii) and the dagger nematode (Xiphinema index which transmits grapevine fanleaf virus) are two examples of how nematodes that are not thought to be native to the state have become widely distributed. The cabbage cyst nematode (Heterodera cruciferae) is not as prevalent but is also thought to not be native to the state.

It is thought that X. index and fanleaf virus have been moved on infested nursery stock, while cyst nematode movement has been largely through soil movement. As an example, in the Imperial Valley, it was at one time common practice for growers to utilize excess soil that would build up at processing plants to fill in low areas in fields. This practice followed by subsequent land leveling resulted in the star shaped pattern in this aerial photograph of a sugarbeet field.

Heterodera schachtii white female on root.
Heterodera schachtii on sugarbeet (infested plant on right)
Xiphinema index galls on grape roots
Xiphinema index on grape, two leaves on bottom with fanleaf virus
Xiphinema index on grape, leaf on right with fanleaf virus
Xiphinema index on grape, leaf with fanleaf virus
Xiphinema index on grape, top cluster of grapes with fanleaf virus
Xiphinema index on grape, two bottom canes with fanleaf virus

Click here if you want to review the biology of SUGARBEET CYST NEMATODE, HETERODERA SCHACHTII

Click here if you want to review the biology of DAGGER NEMATODE, XIPHINEMA INDEX

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