Common Red-legged Robberfly
Size approx 15 mm. The front 2 pairs of legs are usually completely orange-red and the hind legs almost wholly black, though variants do occur (see image below). All Dioctria species have shiny patches on the side of thorax which in good light show as silvery patches or ‘shimmer stripes’.
D. rufipes has a particularly well-developed tubercle at the base of the antennae which helps to distinguish it from other Dioctria species.
Scrub and well wooded areas.
When to see it
May to July.
They are usually sluggish flies that perch on the foliage of mainly herbaceous plants, shrubs and trees waiting to launch attacks on insect prey. They have hard piercing mouthparts and often prey on parasitic wasps. The eggs are dropped whilst sitting on a leaf, one at a time.
Robber flies are impressive predators that typically specialize in flying insects, including wasps, bees, and dragonflies; the prey may be larger than the robber fly itself. Most robber flies frequent sunny, open areas and are active during the warmest parts of the day and year. They perch on branches, logs, stones, or the ground, and rush out to attack when suitable prey flies by. The robber fly uses its bristly legs to intercept the prey by grasping it around the head or back. Then, employing its needlelike mouthparts, the robber fly stabs the prey and injects a saliva that contains nerve toxins and digestive enzymes. This quickly paralyzes the prey and liquefies its tissues; the robber fly then sucks out the prey’s insides, much as spiders do. Some robber flies closely resemble certain species of bumblebees. This may provide the flies with protection against potential predators, and it may enable the robber flies to more easily approach and attack the bees themselves.
Stow-cum-Quy to Horningsea (Quy Fen Walk) Map and Information
Today I cycled and walked a path I hadn’t been before and what a gem it was , peaceful, full of wildlife from bees to woodpeckers to a weasel.
This walk takes you along the Lode , through fields and woodland a real good mix of habitats.