The Hoplolaiminae
15 The Hoplolaiminae RENAUD FORTUNEH Califurnia Department of Food ond Agricultute, Sacra- mento, Califurnia I. INTRODUCTION The Hoplolaiminae sezs.{ Fortuner (1987a) include eight genera: Porarotylenchus, Roÿlenchus, Scutellonema, Aorobimus, Hoplolaimus, Helicotylenchus, Antarctylus, ald Aphasmatylenchus. They belong to the family Hoplolaimidae together with the forms in the related subfamily Rotylenchulinae. Some Hoplolaiminae, and particularly some species in the Eenerc Sculellonema aîd Helicotÿlenchus, have a worldwide distribution and they are very common oD many cultivated plâDts. Other hoplolaimids are found in more rcstricted areas: Aphasmotylen càas in a few sites in \{est Africa, Para rotylenchus in cool loca I ities in the western United Stâtes and the Far East, A ntarctylus on at islald in Antarctica, etc. Host specificity varies from species to species. Most Hoplolaiminae are found in many differeot plânts: the list of hosts of Helicotylenchus ühysrer4 includes grasses, rice, com, soybean, sorghum, wheat, rye, sugarcane, Cyperaceae, potato, strawberry, peanut, cotton, vegetables, trees and bushes, tea, various orDamentals, and more. Hoplolaimids accomplish part or all oftheircycle in the soil. They are obligate plant parasiles, and they are closely associated vÿith plant roots. Some are migratory ectoparasites browsiog the surface of roots, sometimes attacking the outer layers. Some are migrâtory semiendoparasites. They p€notrate the cortex and remâin there for long periods as semien- doparasites, but they caD move out of the roots. A few species are true endoparasites, e.g., severul Hoploloimus srr'cies, Scutellonema bradys, etc. Members ofthis family are often considered as second-class parasites. In California, all Helicotylenchus, HoploLaimus, Roty lenchus, and S cuælloneaa are classified as parasites and organisms of little or no economic significance by the Câlifornia Departmeût of Food and Agriculture.
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