Taxonomy
Gyrostigma rhinocerontis larva - lateral view of third instar larva © Natural History Museum, London
The species was first described by Hope in 1840, originally as Oestrus rhinocerontis.
Species name synonyms are:
- pavesii (described as Spathicera pavesii by Corti, 1895)
- meruensis (described as Spathicera meruensis by Sjostedt, 1908)
The genus name, Gyrostigma was given by Brauer (1885) when he described Gyrostigma sumatrensis.
Morphology
The larvae of Gyrostigma rhinocerontis vary in colour from dirty-white through pink to yellow, darkening as they age, with mature larvae having irregular dark brown markings.
All larvae have 12 segments and the third to eleventh segments of the mature third instar possess bands with 3–4 rows of impressive spines.
The 3 slits in the posterior breathing spiracles of the third instar larva are long and tortuous, distinguishing them from larvae of the other 2 species of Gyrostigma, which have less tortuous slits.
Male and female adults have a very similar morphology, with:
- red/orange to dark brown head
- dark brown to black thorax with a lighter median strip of variable width
- abdomen, similar in colour to the thorax, with a lighter, reddish tip
- wings that are shaded dark brown to black and are long, so that if folded they would reach beyond the tip of the abdomen
- legs that are long and slender and a reddish/orange colour
The adults resemble large spider wasps (Pompilidae; Hymenoptera) and have a noisy flight.
Look-alikes
There are 2 other species in the genus, Gyrostigma conjungens (Africa) and Gyrostigma sumatrensis (Sumatra). Both are extremely rare if not extinct, and:
- Gyrostigma conjungens was last seen in 1961
- Gyrostigma sumatrensis has only been recorded once, in 1884, as larvae recovered from an Asiatic 2-horned or Sumatran rhinoceros (Dicerorhinus sumatrensis) in the Zoological Gardens of Hamburg - the adult of Gyrostigma sumatrensis is unknown
