Panagaeus cruxmajor
Swamp Cross Runner
The bottom cross runner or runners Kreuzfleckige shyness ( Panagaeus cruxmajor ) is a beetle of the family of ground beetles ( Carabidae ). There are of the genus two very similar-looking species, which differ significantly from each other in their environmental claims.
Features
The beetles reach a body length of 7.5 to 9 millimeters. The black body is about two and a half times as long as wide, it reaches the maximum width in the final third of the elytra. He is only moderately arched and tight, bright and projecting finely hairy.
The head is stretched forward and much narrower than the pronotum. The eyes are hemispherical excellent ( Fig. 1). The eleven-membered antennae are filiform and finely hairy from the 4th member. They are dark, only the last links are brownish red. The sensors are turned in behind the base of the upper jaw before the eyes. The upper lip is short and rounded (Fig. 8a). The upper jaw is short, with bent tip and without tooth ( Fig. 8b). The jaws are elongated button, the end link beilförmig cut obliquely (Fig. 2, Fig 8c). The chin is tridentate, the middle tooth columns (Fig. 8d left). The end member of the lip button is also obliquely truncate (Fig. 8d).
The pronotum is rounded and margins on the side. It is wider than long, but narrower than the elytra. He is highly irregular structured and slightly wider than the more rounded neck plate of the two spot - Cross runners ( Panagaeus bipustulatus ) (Fig. 6, top ).
The elytra widen until the last third bit, then they are rounded in common. They carry longitudinal rows of pits point. They have four very large orange-red spots, so that the black ground color of the wing covers can be perceived as a dark cross. Since the marsh cross runner is on average slightly larger than the two- spot cross runners, explains the species name cruxmajor (Latin crux = cross, major = larger). Front and rear spots spots are separated by a broad wavy to serrated band side separates a narrow dark seam tape the spots from each other. The rear reach spots in contrast to P. bipustulatus the outer edge of the elytra (Fig. 6, below). The scutellum is triangular and clearly visible.
The abdomen has on the bottom 6 visible segments ( Abdominalsternite ). The first Abdominalsternit (Fig. 3, right green) is largely through the back hips ( Metacoxa, Fig.3, right yellow) covered. The rear hips are fixed to the lower breast (Fig. 3, right orange ) and the inside plate-shaped expanded. Where they project beyond the first segment of the abdomen addition. The legs are relatively weakly developed for ground beetles. The tarsi are all five-membered ( Tarsenformel 5-5-5 ). In the male the first two Tarsenglieder are extended. The leg ring ( trochanter ) of the hind legs (Fig. 3, right turquoise) is like beetles usual size and above. The center chest enclosing the Hüfthöhlen of the middle pair of legs laterally ( Pictured asterisks).
Similar Species
- Two spot - Cross runners ( Panagaeus bipustulatus )
Occurrence
The animals are found in the Palearctic. In the north of their range extends to the south of Norway, central Sweden and Finland. They occur also in England and Ireland. They live in moist habitats, such as on water banks or in damp forests and wet meadows. They are found under stones or amongst moss and foliage. They are rare.
Way of life
The adults emerge in the fall and winter. They have a life expectancy of about one year. Like all species of the subfamily Panagaeinae they can single out an unpleasant smell danger.