Onycholyda

Taxonomy

Family: Pamphiliidae
Family common name: web-spinning and leaf-rolling sawflies
Subfamily: Pamphiliinae
Tribe: Pamphiliini
Genus: Onycholyda Takeuchi, 1938
Subgenera: none

Background

The Pamphiliidae are called the web-spinning and leaf-rolling sawflies because of their shelter-building behavior as larvae.

Onycholyda species are leaf-rollers. Larvae create rolled tubes of leaf matter and silk to live inside of for protection. The leaf rolls are fairly distinctive, and some species can be recognized by their tube morphology (Middlekauff 1964).

Diversity

There are 40 described species worldwide, all restricted to the Northern Hemisphere. Eight species occur in North America. Onycholyda is most diverse in East Asia (Shinohara and Byun 1993, Taeger et al. 2010).

A key to North American species of Onycholyda as "Pamphilius" is included in Middlekauff 1964.

Diagnostic characteristics

May be confused with

Pamphiliidae are recognized by a somewhat large quadrate head, elongate filform antennae, and tarsal claws often with inner teeth. Onycholyda can be distinguished from Pamphilius by the presence of hooked setae in the malar space, and from other genera by the presence of fore wing vein Sc1 and the tarsal claw (Goulet 1992).

Exotic pest species of concern

none

Host associations

Larvae in North America feed on foliage of Rubus sp. including Rubus parviflorus (thimbleberry), Rubus urninus (trailing blackberry), numerous Rubus cultivars, and also Siricidae sawflies; on tergite 10 in females, sternite 9 in males ">Cornus stolonifera (red-osier dogwood) (Middlekauff 1964, Shinohara 1985a).

Life history

Females oviposit eggs, singly or in groups of up to 12, on the underside of leaves alongside a vein. Eggs are slightly cylindrical and white. After hatching, the larva begins to roll the leaf into a tube-shaped nest. The leaf tube shape varies across species and may be cone-shaped, corkscrew-shaped, or comprising several leaves clumped together. In all cases, silk is used to cinch the leaf in the preferred position and hold the tube together. The larvae generally do not use thoracic legs for locomotion and instead use strands of silk to pull their body along a surface, or inch along like a worm. Mature larvae fall to the ground and burrow into the soil at a depth of 2–6 inches where they press surrounding soil into a cell and overwinter. Pupation and emergence occur in the spring (Middlekauff 1964, Shinohara and Byun 1993).

Adults fly on sunny days during the spring and summer. Onycholyda is generally univoltine, although there are records of an occasional two-year life cycle (Middlekauff 1964).

Distribution

World: The genus is widespread throughout northern Asia, including China, Korea, and Japan, west through Russia, and also occurs in Europe and North America (Shinohara 1985a, Shinohara and Byun 1993, Taeger et al. 2010).

North America: Onycholyda is mainly an eastern species with ranges as far south as Florida, north to Ontario, and west through the northern Midwest. One species, O. sitkensis, also occurs on the Northwest Coast north to Alaska (Middlekauff 1964).

Map data from: GBIF.org (26 June 2019) GBIF Occurrence Download Onycholyda

Details about data used for maps can be found here.

Oncholyda sp. female lateral habitus; photo by J. Orr, WSDA

Oncholyda sp. female lateral habitus; photo by J. Orr, WSDA

Oncholyda sitkensis female dorsal habitus; photo by J. Orr, WSDA

Oncholyda sitkensis female dorsal habitus; photo by J. Orr, WSDA

Oncholyda sitkensis female face; photo by J. Orr, WSDA

Oncholyda sitkensis female face; photo by J. Orr, WSDA

Oncholyda sitkensis wings; photo by J. Orr, WSDA

Oncholyda sitkensis wings; photo by J. Orr, WSDA

Oncholyda sp. malar space and setae; photo by Q. Baine, WSDA

Oncholyda sp. malar space and setae; photo by Q. Baine, WSDA