Black Slip Wasp

Pimpla rufipes can reach a length of about 15 mm (0.59 in) with a rather slender body. These wasps are generally black with bright orange legs. The hind legs are larger than the other pairs. The ovipositor is straight, quite short and thick, however the male Pimpla rufipes does not have an ovipositor. These wasps are often mistaken for Apechthis compunctor due to having similar size, and the males of both of the species are indistinguishable from photographs. The main key difference between these two species is the ovipositor: Pimpla rufipes females have a straight ovipositor while Apechthis compunctor females have curved ovipositors. The front wing of Pimpla rufipes is 5.5 to 15 mm long. Its hind tibia is without a pale submedian band and the abdomen is finely mat to subpolished, usually rather closely dotted with tiny holes. Its first tergite is long, with a prominent dorsal hump centered just beyond the middle. The upper valve of ovipositor is also not or only weakly flattened.

This species can be found in the following countries: Afghanistan, Albania, Algeria, Armenia, Australia, Austria, Azerbaijan, Azores, Belarus, Belgium, Bulgaria, China, Croatia, Cyprus, Czech Republic, Denmark, Egypt, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, India, Iran, Ireland, Italy, Japan, Kazakhstan, Korea, Kyrgyzstan, Latvia, Libya, Lithuania, Macedonia, Madeira Islands, Malta, Moldova, Mongolia, Morocco, Netherlands, Norway, Poland, Romania, Russia, Serbia & Montenegro , Slovakia, Spain, Sri Lanka, Sweden, Switzerland, Tajikistan, Tunisia, Turkey, Turkmenistan, Ukraine, United Kingdom, and Uzbekistan. These wasps mainly inhabit hedgerows and vegetated areas.

A parasitoid of butterfly and moth larvae and pupae, laying an egg in each one. Pimpla rufipes have preferences in choosing their hosts that are affected by various factors. Research was conducted on cylinders which represent the hosts Pimpla rufipes would normally puncture. The first factor is the texture of the host; smooth cylinders were punctured more often than cylinders that had been roughened with sandpaper. The second factor is colour; the wasps discriminated between yellow and blue cylinders and could remember to associate the colours as a presence of a host, where blue was inherently preferred over yellow. The last known factor is whether or not a cylinder/host is open or closed ended, where only cylinders that were close ended were frequently punctured. These factors are tested by the female wasp using its antennae which send vibrations to make the object resonate before determining if the host will make for a suitable oviposition site. It is still unknown how these vibrations are created from the antennae, and the antennae are not utilized as drumsticks. However it is known that the wasp does not use a stridulatory organ to generate these noises. This is all part of Pimpla rufipes exploratory behaviour, and acoustic probing allow the females to find and locate prey.