Phyllobius

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Phyllobius
Mating of green weevils

Mating of green weevils

Systematics
Order : Beetle (Coleoptera)
Superfamily : Curculionoidea
Family : Weevil (Curculionidae)
Subfamily : Entiminae
Tribe : Phyllobiini
Genre : Phyllobius
Scientific name
Phyllobius
Germar , 1824

The Grünrüssler ( Phyllobius ) are a species of beetles from the family of the weevils (Curculionidae).

The name green weevil comes from the fact that many species of the genus Phyllobius appear green due to their scaling. There is often a great variety of colors towards olive tones. However, if the scales are worn off over time, the dark color of the chitin appears first in places, then over a large area. A brown animal can therefore also belong to a green weevil species. There are also brown species of the genus.

anatomy

Most species are smaller than one centimeter and appear greenish due to their scaling.

Seen from above, the short trunk looks rectangular and is only slightly narrower than the rest of the head. The pronotum is only slightly wider and bell-shaped. the elytra, on the other hand, are significantly wider and their pronounced shoulders are clearly separated from the pronotum. The label between the base of the wing covers is clearly visible and triangular. The wing covers widen slightly backwards to the last third and then converge almost in a straight line to a point.

Phyllobius species have no tongue, the two pairs of jaws are exposed. The feeler pit is oval, visible from above, and has only a weak margin. The antennae are remarkably long and thin, the first antennae (the shaft) reaches at least the front edge of the eyes, the angled hostage consists of seven clearly visible members and the final club consists of 4 members. The eyes are round and lateral.

The legs are strong, the claws grown together at the base. The fore legs are slightly bent inwards, and there is usually a clearly visible thorn on the inside.

Fig. 1: Phyllobius sensor pit
Fig. 2:
Polydrusus sensor pit
Phyllobius oblongus
Phyllobius glaucus
Phyllobius glaucus
Phyllobius pomaceus
Phyllobius pyri
Phyllobius virideaeris in copula

Possibility of confusion

Phyllobius species are often confused with species of Polydrusus or consciously grouped together because of their ecological equality. The major systematic difference lies in the shape of the feeler pit. The feeler pit is the recess in the trunk into which the feeler is pivoted. So that the beetles can place the feelers on the body to protect them, the feeler pit often ends in a groove in which the stem of the feeler comes to rest. In Phyllobius this groove is only indicated by a bulge in the antennae on the upper side of the trunk (Fig. 1), in Poydrusus it runs clearly on the side of the proboscis in the direction under the eyes (Fig. 2). Therefore Phyllobius and Polydrusus not only form different genera, but they even belong to different subfamilies of the weevils.

Systematics

The individual species differ in the hairiness and color and shape of the scales. The interest in this group of beetles, which emerged only slowly, is reflected in the fact that only 6 Central European species are listed in CG Calwer 's Käferbuch Hoffmannsche Buchdruckerei in Stuttgart 1876, E. Reitter 1916 already lists 18 species for the German Empire and in Joy- Harde-Lohse are given 25 species for Central Europe.

Today the genus Phyllobius is represented in Europe with 86 species and subspecies. 15 species occur in Germany.

biology

The beetles ( imagines ) feed on leaves of various trees , shrubs and herbaceous plants . The adults appear in spring and early summer, then often en masse. Since some species also gnaw the buds of the fruit trees, they can be harmful. Almost all species are not fixed in their choice of food plants ( polyphagous ). Some species prefer willows and poplars, others rose plants. This subheading includes those species which can be harmful to apricot or plum plantations. In one species, grass is given as a food crop. No information is given for other species. The green weevil larvae develop in the soil, the larvae feed on plant roots.

Individual evidence

  1. Fauna Europaea Web Service (2005) Fauna Europaea version 1.2 (March 7, 2005), online: https://fauna-eu.org/cdm_dataportal/taxon/c6e168c0-cc3a-4581-b343-d29c4b5f8354 (accessed September 15 2006).

Web links

Commons : Phyllobius  - album with pictures, videos and audio files