This documentary covers important aspects of the life of a Sphex argentatus solitary wasp recorded in Noida, India.
Wasps play a very crucial role in the ecosystem. Wasps are the apex predators of the insect world. And just like bees, wasps play an important role in pollination of the flowering plants.
Sphex is a cosmopolitan genus with 148 currently recognized species as per Catalog of Sphecidae, The California Academy of Sciences. Sphex genus is scarcely reported from India with only nine recorded species till date. Taxonomic study of Sphex species remains scarce and limited in India (Anagha et al. 2021).
Female wasps of the genus are powerful predators. Female Sphex argentatus hunts for the long-horned grass hoppers (katydids) of the family Tettigoniidae (Orthoptera) as provision for their larvae.
Sphex argentatus, a solitary wasp, forages alone and the nest she builds is occupied solely by herself and her offspring. Numerous female Sphex argentatus wasps nest in very close proximity to each other but still work independently. This is in contrast to the life of social wasps.
They sometime fight with other females of the congregation. Some even try to steal the prey brought by the other females. Some even try to usurp the owner of the nest and take control of the already built nest.
Why “Accessory Burrows”?
Sphex argentatus builds accessory burrows in addition to the main burrow.
It is hypothesized that accessory burrows function to distract parasitoids from the real nest entrance(O’Neill 2001).
Several persons working with species that build such accessory burrows have independently concluded that they serve to divert parasites into ovipositing in inappropriate places or at least into spending much time exploring blind tunnels (Howard E. Evans 1966).
THE HUNT. Hunting for the bush crickets.
The wasp delivered the first sting in the head (throat) of the prey corresponding to the subesophageal ganglion of the ventral nerve cord. This resulted in the total paralysis of the mouth parts and general reduction in the activities and resistance offered by the prey. Stings are delivered in the vicinity of ventral ganglia of the central nervous system that control movement of legs and mouthparts (O’Neill 2001). Subsequent stings to achieve C4SP (complete, four-sting pattern) possibly followed (H, T1, T2, T3) pattern as described by (Steiner 1981).
Stizoides are obligate brood parasites (Evans & O’Neill, 2007). Available evidences shows that all species of Stizoides are kleptoparasites on orthoptera hunting sphecid wasps (Ohl, 1999). All Stizoides are brood parasites of digger wasps (Howard Ensign Evans & O’Neill 2007).
Kleptoparasitism is "parasitism by theft"
Species and groups of species that do not make or provision their own nests. They put their eggs on prey supplied by other species of wasps. Those forms are considered cleptoparasites (Ohl 2008).
There is both behavioral and morphological evidence that all species of Stizoides are cleptoparasites on Orthoptera-hunting Sphecidae(Ohl 2008).
Stizoides blandinus (F. Smith, 1856)
Conocephalus sp. (Orthoptera: Tettigonidae). bush cricket.