''Synanthedon flaviventris'', the sallow clearwing, is a moth of the family

Sesiidae The Sesiidae or clearwing moths are a diurnality, diurnal moth family (biology), family in the order Lepidoptera known for their Batesian mimicry in both appearance and behaviour of various Hymenoptera. The family consists of 165 genus, genera ...

. The larvae form pear-shaped

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or war ...

s on sallows (''Salix'' spp).

Description

The eggs are laid in the

axils A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, f ...

on slender shoots (<10 mm diameter) of sallows, and the first year larva excavates a tunnel which shows no external signs of the larva. In the spring of the following year the larva can be as long as 17–18 mm and tunnels deeper into the tissue of the stem, excavating a vertical tunnel 50–75 mm long and 3 mm in diameter. By the second autumn the frass is pressed into cavities between the bark and wood, and the pear-shaped gall is noticeable. The larva feeds on sallows and their hybrids; eared willow (''

Salix aurita Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known ...

''), goat willow ('' S. caprea''), creeping willow ('' S. repens''), grey willow ('' S. cinerea''), white willow ('' S. alba''), crack willow ( ''Salix'' × ''fragilis''), European violet willow ('' S. daphnoides'') and rosemary-leaved willow ('' S. rosmarinifolia''). Before pupation, the larva makes an exit hole and the

pupa A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...

(11–13 mm long) is yellowish and formed head down in a chamber above the gall. There is no cocoon. Adults have a

wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the opposite wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingsp ...

of 17–20 mm and are on the wing in June and July. The species has a two-year life cycle, with adults present mostly in even years.

Distribution

It is found in most of

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

(except

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

, the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

, the

Iberian Peninsula The Iberian Peninsula ( ), also known as Iberia, is a peninsula in south-western Europe. Mostly separated from the rest of the European landmass by the Pyrenees, it includes the territories of peninsular Spain and Continental Portugal, comprisin ...

, most of the

Balkan Peninsula The Balkans ( , ), corresponding partially with the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throug ...

and

Ukraine Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the nor ...

). and

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

(southern Siberia, Baikal, Irkutsk, Chaborowsk, Ussuri).

Notes

References

{{Taxonbar, from=Q2283130 Sesiidae Gall-inducing insects Moths described in 1883 Moths of Asia Moths of Europe Taxa named by Otto Staudinger Willow galls