Blómsveifa býr til göng ofaní harðann sandinn og verpir þar. Episyrphus is a genus of hoverflies in the subfamily Syrphinae. Larvae are predatory, often on aphids. One species, E. balteatus is very cosmopolitan. Hoverflies, sometimes called flower flies or syrphid flies, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, while the larvae (maggots) eat a wide range of foods. In some species, the larvae are saprotrophs, eating decaying plant and animal matter in the soil or in ponds and streams. In other species, the larvae are insectivores and prey on aphids, thrips, and other plant-sucking insects. Aphids alone cause tens of millions of dollars of damage to crops worldwide every year; because of this, aphidophagous hoverflies are being recognized as important natural enemies of pests, and potential agents for use in biological control. Some adult syrphid flies are important pollinators. : http://en.wikipedia.org/wiki/Syrphidae Eristalis pertinax is one of the larger hoverflies (family Syrphidae). Hoverflies are classic Batesian mimics, harmless but closely resembling bees or wasps (order Hymenoptera), and E. pertinax is one that closely resembles the Honey Bee, Apis mellifera, not only in appearance but also in behaviour as it visits flowers. However, as a true fly it has just a single pair of wings, the hind wings having been modified into the tiny, drumstick-like halteres, which provide balance in flight. The males commonly hover in woodland clearings, aggressively defending small territories. Hoverflies are unusual amongst flies in having two outer cross veins close to the wing margin, with most other flies having only one such cross vein or none at all. E. pertinax is a common and fairly easily recognised species, though it can be confused with the Drone Fly, E. tenax. The latter has a broader facial stripe between the eyes and little or no yellow on the legs - specifically the tibiae of the hind legs are dark in E. tenax whereas they are distinctly bicoloured in E. pertinax and the front tarsi (sequences of lower leg joints) of E. pertinax are orange. Whereas the abdomen is tapering in E. pertinax, causing it to resemble a worker Honey Bee, the abdomen is more nearly cylindrical and "chunkier" in E. tenax, so it is more like the drone. A common but smaller species otherwise resembling E. pertinax in general appearance is E. interruptus, which has black front tarsi. : http://bioref.lastdragon.org/Diptera/Eristalis_pertinax.html The Bembicini, or Sand wasps, are a large tribe of crabronid wasps, comprising 20 genera. Bembicines are predators on various groups of insects. : http://en.wikipedia.org/wiki/Sand_wasp

• published: 22 Aug 2013
• views: 3