Pyrrhalta viburni (Paykull, 1799)

Female
With the possible exception of Cornwall, Pyrrhalta is a common species throughout England and eastern Wales. Joy gives southern Scotland as part of its distribution and this may be based on a pre 1900 record from Edinburgh (NBN), this record is mentioned by Cox but not included on his map. Hostplants are various species of Viburnum; V.lantana, V.tinus and V.opulus and, because these have for decades been widely utilized as garden and amenity ornamentals, the species is common, and in some years abundant throughout the area. On the continent it has also been recorded from Sambucus (Cox, 2007). Easiest observed by looking for the damage they cause as both adults and larvae feed on soft stems and leaves causing irregular holes and often extensive damage. Curiously some shrubs will host large populations of the beetle for years while others remain untouched, this is especially the case for V.tinus in Watford town centre gardens and shrub beds. On the other hand the extensive mature V.opulus planted around Radlett road are all affected, and usually severly so, year after year. Beating damaged shrubs during the summer will send adults and larvae falling to the ground as well as many adults taking flight. Locally the adults generally appear in small numbers from late May and increase in abundance through June, by July some shrubs are hosting large populations. They disappear quite suddenly with the onset of cold weather so the season may be extended, during the mild autumn of 2007 adults were beaten from V.tinus in a sheltered town centre garden during the first week of December. Eggs are laid in cavities eaten into the stems by the female which are then sealed with mucus and excrement or regurgitated food. Winter is spent in the egg stage. Mature larvae occur from May to July (Del Bene and Laudi, 1993) and pupation occurs within a cell near the soil surface (Cox, 2007)

4.5-6.5mm. Upper surface convex, dark yellow with darker markings. Head convex and transverse, aceoss eyes almost as wide as front margin of pronotum. Vertex black with fine, forwardly directed yellowish pubescence, strongly rugose and densely punctured, punctures longitudinally confluent along base. Antennae black with base of segments yellow, segment two small, 3 longer than others, 4-9 about as long as basal segment. Pronotum transverse (35:16) and finely bordered, sides strongly sinuate and broadest at middle, front and hind angles protruding, hind margin sinuate. Depressed along centreline and either side of disc, densely punctate with punctures much larger towards lateral margins. Pubescence dense and fine, perpendicular to centreline. Darkened medially and laterally. Elytra long, weakly dilated behind middle and with well developed humeral prominences, explanate lateral margins lighter and visible from above, finely and densely pubescence throughout, pubescence oblique to suture, fine and silky. Legs pubescent throughout, yellow or with upper surface darker. Tibiae with longitudinal furrows on upper surface. Claws split longitudinally.

Description from 10 Watford specimens at X20

Reference
Del Bene, G. and Laudi, S. 1993. Osservazioni su Pyrrhalta viburni in Toscana. Redia 1976:403-415.

Female

Male

Male

Male

Male

Male

Mature Larva on Viburnum tinus (Watford, June 2007)

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