Bombylius Major - part 2 - Eating, laying eggs, flight 

Nature - Wild Life - Insect Life . Bombylius major (commonly named the large bee-fly, the dark-edged bee-fly or the greater bee fly) is a parasitic bee mimic fly. Bombylius major is the most common type of fly within the Bombylius genus. The fly derives its name from its close resemblance to bumblebees and are often mistaken for them.
Bombylius major exhibits a unique flight behavior known as "yawing" and plays a role in general pollination, without preference of flower types.The fly does not bite, sting, or spread disease. However, the fly uses this mimicry of bumblebees to its own advantage, allowing close access to host solitary bee and wasp nests in order to deposit its eggs. After hatching, the larvae find their way into the nests to parasitically feed on the grubs.
Bombylius major has several host species, including the brood of solitary wasps and bees, particularly digging bees such as Andrena. Egg deposition takes place by the female hovering above the entrance of a host insect nest, usually a solitary bee, and throwing down her eggs using a flicking movement. The larvae are hypermetamorphic parasitoids which then feed on the food stored, as well as the young solitary bees or wasps. If the female is unable to flick her eggs near the nest, she plants them on flowers visited by the host insects. The developing larvae then make their way to the host nest or attach themselves to the bees or wasps to then be carried to the nest.
The parasitic eggs of B. major are produced in large numbers, however few will make it to the host insect burrow entrance. The female fly will dip down and coat her rear abdomen with dust that covers the eggs as they leave the female.
The species acts as a nectar robber; this foraging behavior allows the species to feed on floral nectar and is an essential part of adult fly diets. This is facilitated by the characterizable long proboscis of the fly, which is horizontally inserted into the flower.This occurs as the fly continues to buzz in the air, without touching either the anthers or stigma of the flower. The fly also consumes pollen as part of its diet, with considerable differences between the sexes. Males and females visit the same range of flowers as a food source.