Thomson Reuters provide Endnote style downloads for some journals at the following link.
However, I was unable to find Journal of Helminthology(JHL) when I searched so I don’t think you have a style for JHL. Is there any possibility of developing endnote styles for Journal of Helminthology? Here is the link that has format for reference,
Please let me know when you have developed the endnote style for JHL.
(Although, there is a feature in Endnote where the user can build their own custom Endnote style)