Arge ochropus
A rose brushes Horn wasp from above
The rose brushes Horn wasp ( Argentina ochropus (synonym: Arge rosae ) ) is a plant from the family of wasp brushes Horn sawflies. She is one of 29 Arge species in Germany.
Features
The animals are seven to ten millimeters long. They have an abdomen, which exceeds the width of the front limbs. The thorax of the animals has two colors, mostly black with yellow sides, because the type of all other Central European Arge species is distinguishable. The abdomen is colored bright yellow. In the male the cerci are offset in black and sharp against the yellow abdomen. The legs are black, the second and third segment of Hintertarsen are yellow colored with a black ring at the rear end. The rose brushes Horn wasp has no sting and thus can not stand. However, the female has a ovipositor with which she deposits 16 to 18 eggs in a row.
Way of life
The larva of Arge ochropus lives on rose species. As food crops are: Rosa canina, R. gallica, R rubiginosa, R. majalis, R. pimpinellifolia and Turkey also Rosa damascena. The adults are flower visitors without being tied to roses, they occur eg often on the flowers of umbelliferous plants on. Argentina ochropus regarded as something warmth. They often come together with related species such as Argentina before pagana. Flight time of the imagos is the summer (April / May to August). The species forms in Central Europe of two or three overlapping generations. The green-colored, relatively densely hairy larvae live socially ( gregär ) on rose bushes and can cause defoliation. Pupation occurs in the soil beneath the plant. The last larval stage spins to a rigid, two-layered cocoon of silk.
The larva of Arge ochropus is like all the studied species against predators such as Ants protected by toxins. When approaching an ant larva bends her abdomen in its upward direction. From glands on the ventral side leaking secretion, but also the blood ( hemolymph ) of the larva had eaten inflammatory and toxic to ants. The rather strikingly colored larvae were spurned by singing birds ( blackbirds ).
The species occurs Europe, in West and Central Asia and the Mediterranean. In Central Europe it is widespread and not rare, it occurs also in home gardens. It is considered agricultural pest in commercial cultivation of roses.