Theretra tryoni

Theretra tryoni (Miskin, 1891)
Tryon's Hawkmoth
(one synonym : Theretra herrichii Kirby, 1892)
MACROGLOSSINAE, SPHINGIDAE, BOMBYCOIDEA

Don Herbison-Evans,
(donherbisonevans@yahoo.com)
and
Stella Crossley

Theretra tryoni
early instar,
(Photo: courtesy of Tom and David Sleep, Queensland)

This Caterpillar is initially green with a black straight tail spike.

(Photo: courtesy of Jenny Whiting, Sydney, New South Wales)

Later instars develop four blue-green eyespots, each ringed with yellow, and outlined in brown, one on each side of each of the first and of the second abdominal segments. The tail spike becomes reddish-brown.

tail
(Photo: courtesy of Rhiannon Kuchel, Sydney, New South Wales)

Mature instars often become brown, and the tail spike becomes black with a pale tip and curved backwards.

(Photo: courtesy of Rhiannon Kuchel, Sydney, New South Wales)

This species is the only one in SPHINGIDAE with caterpillars that have two equally sized eye spots on each side of the abdomen.

head, close-up
(Photo: courtesy of Rhiannon Kuchel, Sydney, New South Wales)

The caterpillars have been found feeding on various species of ARACEAE, including :

Cunjevoi ( Alocasia brisbanensis ),

Elephants Ear ( Alocasia macrorrhizos ),

Taro ( Colocasia esculenta ), and

Arum Lily ( Zantedeschia aethiopica ).

The caterpillars feed at night, and hide during the day. By day: early instars rest lying along the midrib under a leaf. Late instars rest along a stem by a leaf axil with the head pointing downwards. The caterpillars grow to a length of about 9 cms.

(Photo: courtesy of Tom and David Sleep, Queensland)

The pupa is rather slender, with a length of about 6 cms. It is mottled brown with dark rings around the abdominal segments. Pupation occurs in a camouflaged cocoon amongst the surface leaf litter.

(Photo: courtesy of Tom and David Sleep, Queensland)

The adult moths of this species have plain brown forewings, each with some faint darker lines, a submarginal line of faint dark dots, and a single black dot near the middle of the costa. The moths have a wingspan of about 7 cms.

(Specimen: courtesy of the Macleay Museum, University of Sydney)

The abdomen of the adult moths has hardly any lateral striation which distinguishes them from the very similar species Theretra latreillii. The adults may be nearly indistinguishable, but the caterpillars are easily distinguished, having two eyespots each side, whereas Theretra latreillii caterpillars have only one.

(Photo: courtesy of Tom and David Sleep, Queensland)

The eggs are oval and off-white, with a length of about 1.6 mm. They are laid singly on the under surface of leaves of a foodplant.

The species may be found in:

New Guinea,

Solomons,

and also in Australia through

Queensland, and

New South Wales.

showing undersides
(Photo :courtesy of Rhiannon Kuchel, Sydney, New South Wales)