Mammoth Wasp

• It parasitises the large larvae of the rhinoceros beetle: it paralyses them with a sting and lays a single egg on them.
• Despite its six centimetres and its menacing look, it is a solitary and very peaceable wasp that rarely stings people.
• Its presence indicates ecosystems with dead wood and decaying organic matter, which is where its prey lives.
• It is the largest hymenopteran in Europe: the female reaches 6 cm and the male is considerably smaller.
• It depends entirely on the European rhinoceros beetle: the female seeks out its larvae in dead wood, paralyses them with a sting and lays a single egg on each.
• The wasp larva devours the beetle larva leaving only the skin, spins a cocoon and overwinters there until it emerges in spring.
• It has been recorded in southern Britain, but cannot establish there because its prey does not live on the islands.
• The adult is harmless and feeds only on nectar.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Warm Mediterranean areas with dead wood and compost

Sexual maturity

The adults appear in late May, are active by day, feed on nectar and pollen during daylight and spend the night buried in the leaf litter

Gestation / incubation

The wasp larva consumes the beetle larva first from the outside and then from within, leaving only the skin; once it has reached a sufficient size it spins a cocoon and waits inside until the following spring to emerge as an adult

Litter / clutch size

A single egg per parasitised beetle larva

Sources consulted: Wikipedia (es): Regiscolia maculata · Invertebrados de Huesca · Museu Virtual da Biodiversidade (Universidade de Evora) · Invertebrados de Huesca, ficha Megascolia maculata flavifrons · Ficha de especie de Megascolia maculata (Wikipedia ES) · Fichas de especie de Megascolia maculata · iNaturalist, ficha Mammoth Scoliid Wasp

Best time: Flies in warm areas between May and September, in holm oak woods, maquis and Mediterranean garrigue; it only turns up where its prey, the European rhinoceros beetle, lives