Eriophyes laevis

Bursifex alni
Phytoptus laevis
Phytoptus pustulatum

Hosts: Alnus glutinosa, incana, rugosa, tenuifolia, pubescens, rhombifolia, rubra, viridis. [Betula papyrifera and Salix nigra listed as likely mistakes reported in the literature]

Relationship: Numerous cephaloneon galls of various sizes, on both leaf surfaces (mostly upper); Cephaloneon pustulatum Bremi.

Range: Europe; CA, GA, KS, WA, WV

Notes:

Host associations on some plants are probably missidentifications, such as Betula papyrifera.

This may be a complex of very similar species, each restricted to one or two species of Alnus.

Amrine & Stasny (1994) mistakenly made laevis (Nalepa, 1889) a nomen nudum; they did not see the brief description on p. 132, which is sufficient according to the code.

These beadlike galls are particularly striking because they appear on both surfaces of the leaves. They are small, hemispherical, of variable size and are scattered singly or crowded alongside the midrib. The galls are firmly attached, with the exit holes on the underside. They are shiny externally and the interior contains fleshy tissue. They range from green to yellowish, to red, to reddish brown as they mature. A single leaf may carry numerous galls so that it becomes distorted and its growth inhibited. Although P. laevis is a common species on alder, little is known of its seasonal history and habits. Specimens were abundant in August. The hosts are Oregon or red alder, white alder, and mountain alder in California and hazel alder in Ohio and Georgia.