Killer parasitic wasp Melittobia acasta and bumblebees

The life cycle of Melittobia acasta.

Melittobia is wingless insects from the family Eulophidae belonging to the superfamily chalcides. It is primarily parasite of solitary bees, Vosick až sekundárně bumblebees, and, where applicable, other organisms.
The honey bee can effectively defend itself against it.

This is more heat-loving species, flies at temperatures of 20°C and above.

Her chucks at temperatures at 15°C they fall into hibernation.

It spreads successfully mainly in warmer regions and during warmer weather. 

Female after birth and mating it flies away and It searches for its host by smell.. As soon as it smells his scent, it lands and doesn't leave the spot., I'm trapped”and seeks access to the host's fruit.
Her goal is to produce new offspring and, like the female wax moth (Aphomia sociella), she wants penetrate to the found nest of the found host At all costs. Her time is also limited, so it's „all or nothing“ for her.

Is capable overcome the caps of solitary bee nesting cavities and a to of solid and mud-built. They often attack in larger numbers of siblings, and cooperation in drilling a hole has also been documented. Biting through a cork stopper has also been documented in the laboratory. 

Female must found food within approximately 2 weeks of hatchingotherwise it dies of hunger. Thanks to its size and the need to find food quickly, its spread may not be rapid. It spreads well where it canhop from host to host.

Mother if feeds on pupae, which it pierces with its stinger and sucks their juices.

It then lays eggs on other larvae. Its larvae, after hatching live on the surface of the host larva, until they have completely drained it.

After pupating, they hatch nfemale lambs and a few males. The first generation of females do not have fully developed wings and cannot fly., pairs with “brothers” and help the mother lay eggs and attack other cocoons. Development from penetration of the cocoon to the hatching of new individuals It's quick, takes about 14 days.

If the first female is not fertilised, she is capable of laying unfertilised eggs from which the necessary male will hatch. This is called parthenogenesis.

Note
Parthenogenesis (also called virgin birth or self-impregnation) means the development of a new individual from a female egg cell that has not been fertilised by a male sex cell. 

The mother with her daughters are then able to To exterminate the whole family of bumblebees, who breed ever more host cocoons – for the growing colony of Melittobia.
Similarly, this is done in a colony of solitary bees.

The next generation again contains a prevalence of females, they have already developed wings and after pairing with its “brothers” They are looking for a quick way out, the cycle then repeats.

The attack is taking place secretly and mostly they manifest fully only when the new mothers appear on the surface of the nest and look for a way out, where they search for a new host's nest.

The larvae overwinter in the cocoons of their hosts. The host larva is paralysed and preserved for later consumption.

At temperatures below 15°C, Melittobia larvae enter hibernation and will wake up only when the temperature rises above 20°C. 

You can read details about the life of Melittobia acasta and their activity in bumblebee nests HERE

The image depicts Lifecycle Melittobia