Category Archives: Bees and Wasps

Thread-waisted Wasp – Sceliphron spirifex – Sceliphron

Sporting the colours yellow and black of a normal wasp, this flying insect looks strangely disconnected in flight. The overall length is from 19 to 25mm with part of that made up of a yellow “thread” or pedicel. The body is mainly black with yellow bands on the long legs which hang down in flight. They can be found in Southern Europe and Africa.

Thread-waisted Wasp – Sceliphron spirifex – Sceliphron are solitary wasps and are not aggressive, they do not sting unless threatened or mishandled. The sexes look very similar with the female being slightly larger and with a visible sting.

Thread-waisted Wasp - Sceliphron spirifex - Sceliphron
Thread-waisted Wasp – Sceliphron spirifex – Sceliphron

The female searches out an ideal shelter to create a mud daub nest, by flying repeatedly around an area and finally walking around to be thoroughly sure in her choice. Shade from the sun and shelter from the rain are a priority and this wasp favours old derelict buildings. Fine particles of mud are collected, balled up and flown back to the chosen site. They will search out a damp patch from an irrigation system, pond or puddle, returning frequently during the day to collect more.

Thread-waisted Wasp - Sceliphron spirifex - Sceliphron
Thread-waisted Wasp – Sceliphron spirifex – Sceliphron Collecting mud.
Thread-waisted Wasp - Sceliphron spirifex - Sceliphron
Thread-waisted Wasp – Sceliphron spirifex – Sceliphron Individual cells with larvae inside.

Several cells are connected along side each other, sharing the mud walls, but when finished they are individual, sealed tubes. Small spiders (mostly crab or jumping spiders) are hunted, paralysed by a sting and placed into the mud tube with between 6 and 14 spiders in each cell. Once the female is happy with the amount of food supply she will lay one egg and cap the tube with a layer of mud sealing the spiders and the egg inside. When the egg hatches into a larvae it proceeds to devour the spiders.


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Mammoth Wasp (Megascolia (Regiscolia) maculata flavifrons) Avispa parasita de cuatro puntas

This is a very large solitary wasp, the female reaching up to 4.5cm whereas the male is a little smaller. This species appears in warm weather during late May, June, July and August. They hold no danger to humans despite their size and black / yellow warning colours. (Above image Megascolia bidens)

They feed eagerly on flower nectar and this is the best time to view them.

Megascolia flavifrons male and female examples

Mammoth Wasp (Megascolia (Regiscolia) maculata flavifrons) Avispa parasita de cuatro puntas
Mammoth Wasp (Megascolia (Regiscolia) maculata flavifrons) Avispa parasita de cuatro puntas

Left: Female showing yellow head Right: Male, note long antennae

The larger female can be told apart by her yellow face and short antennae. The male has a black head and longer antennae. Both have two yellow bands on their abdomens which can sometimes be divided to form 4 spots, which is more evident on the female in these pictures.

You may see several of these wasps flying around decaying tree stumps, they have a purpose here. They are searching for larvae of a particular beetle.

Inside the rotten wood may be young of the Rhinoceros beetle (Oryctes nasicornis). The female Mammoth wasp, once she has discovered the huge larvae, will sting one to paralyze it and then lay her egg on the outer skin.

Mammoth Wasp (Megascolia (Regiscolia) maculata flavifrons) Avispa parasita de cuatro puntas
The rhino beetle larvae is the food supply for the larvae of the mammoth wasp. Left: Rhinoceros beetle (Oryctes nasicornis) Right: Rhinoceros beetle Larva.

On hatching, the larvae of the Mammoth wasp will eat into its host thereby killing it. The larva of the wasp then creates a cocoon near to the meal remains. It will stay in this cocoon over winter and hatch out once the spring weather warms sufficiently.


Family: Scoliidae

  • Scientific name: Megascolia (Regiscolia) maculata flavifrons (Fabricius 1775)
  • Also accepted as Scolia flavifrons

There are several very similar species within Iberia, including:

Megascolia bidens
Megascolia bidens showing yellow antennae
  • Megascolia bidens – always has coloured antennae, either reddish or yellow.

Other mammoth wasps

  • Scolia erythrocephala – has more than two yellow bands
  • Scolia hirta – two yellow bands and a violet tinge on wings
  • Scolia hortorum
  • Scolia sexmaculata – has six yellow spots

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