Sphecodes monilicornis, a species of sweat bee, is known for its distinctive red and black coloration. This solitary bee inhabits diverse environments, from urban gardens to open fields. Unlike social bees, it parasitizes other bee nests, particularly of the Halictidae family. It plays a crucial role in pollination, despite its parasitic nature.

Sphecodes monilicornis, commonly known as a species of cuckoo bee, is native to parts of Europe and North Africa. It is commonly found across countries such as the United Kingdom, France, Germany, and extending into regions of the Mediterranean.

Sphecodes monilicornis typically inhabits a variety of environments that include meadows, grasslands, and areas with loose, sandy soil. These areas provide suitable conditions for the nesting of host bee species, which Sphecodes monilicornis parasitizes. The climate in these regions is usually temperate, with variations depending on the specific geographical area.

As a parasitic bee, Sphecodes monilicornis occupies a unique ecological niche. It does not build its own nests but instead lays its eggs in the nests of other solitary bees, particularly those in the genus Halictus and Lasioglossum. The larvae of Sphecodes monilicornis consume the host bee's provisions, which is why its presence is closely tied to the distribution and availability of host species.