Fabulous green sphinx moth (Tinostoma smaragditis)

GenusTinostoma (1)

The fabulous green sphinx moth is classified as Endangered (EN) on the IUCN Red List (1).

Aptly known as the fabulous green sphinx moth, Tinostoma smaragditis has captivated and eluded scientists for over a century (2). Bestowed with vibrant green wings and thorax, pale brown hind wings and orange antennae (2), this exquisite moth was thought to be extinct until 1998 (1).

The male and female fabulous green sphinx moth can be distinguished by the underside of the wings, which are pale green on the female and pinkish-brown on the male (2). Most strikingly, however, the male displays a black collar around its thorax and a black spot on each forewing. The distinctive larva of the fabulous green sphinx moth has a reddish caudal horn which measures around half the length of the body (2).

The fabulous green sphinx moth has an incredibly restricted range, being found in only a few areas of native forest on Kaua’i (1), one of the Hawaiian Islands. In 110 years of searching, the fabulous green sphinx moth has been recorded just 15 times. Experts conclude that either the moth is restricted to an extremely small range and so is hard to find, or that it is exceptionally rare (1).

The scarce sightings of the fabulous green sphinx moth have been concentrated in lowland mesic forest (1). This type of habitat is thought to cover around 800 square kilometres of Kaua’i Island and is the most likely home of this mysterious species (1).

Little is known about the biology of the fabulous green sphinx moth. Like all Lepidoptera (moths and butterflies), it has a long, coiled proboscis, which is most likely used for feeding on nectar (3).

Records show that the fabulous green sphinx moth may lay around 15 eggs at a time but, after nine days, just a few of these will hatch into caterpillars (2). These caterpillars then feed, probably on plants, until they undergo a full metamorphosis into an adult (3). Efforts to identify the plant on which this species feeds have, to date, been unsuccessful (2).

The fabulous green sphinx mothhas been captured repeatedly near light sources suggesting it may have a strong attraction to light (2).

The fabulous green sphinx moth resides on an island containing the highest diversity of threatened plants of all the Hawaiian Islands (1). The host plant of the fabulous green sphinx moth has not yet been identified but it is possible that it is as rare as the moth itself (1) (2). In 1992 Hurricane Iniki damaged large parts of forest on the moth’s island and resulted in an increase in non-native invasive plant species, which could have affected the host plant (1). The unknown host plant also faces destruction by feral animals such as pigs and goats, which decimate native vegetation (1).

Certain butterflies and moths are threatened simply due to their rare nature. Collectors across the globe will pay large sums of money for a sphinx moth to add to their collection, particularly one as elusive as the fabulous green sphinx moth (1).

The fabulous green sphinx moth was thought to be extinct until, astonishingly, it was re-discovered in 1998 (1). It is now considered to be Endangered but unfortunately there are no protection measures in place to conserve it (1). Despite attempts to have it listed on the U.S. Endangered Species Act, the lack of information about the fabulous green sphinx moth has so far prevented it from making the list (1).

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  1. IUCN Red List (January, 2011)
  2. Heddle, M.L., Wood, K.R., Asquith, A. and Gillespie, R.G. (2000) Conservation status and research on the fabulous green sphinx of Kaua’i, Tinostoma smaragditis (Lepidoptera: Sphingidae), including checklists of the vascular plants of the diverse mesic forests of Kaua’i, Hawai’i. Pacific Science, 54(1): 1-9.
  3. Thain, M. and Hickman, M. (2004) Dictionary of Biology. 11th Edition. Penguin Books, London.