Very hungry caterpillars

Madonna Lily
Bud and flowers (some moth-eaten) of a Madonna Lily

We have quite a few pots of Madonna Lilies (aka Peace Lilies, Spathiphyllum spp.) around the house; they do well until they are eaten, which happens with some regularity. Looking down into a pot yesterday, I saw a couple of the usual suspects lying on the dirt as though they were sleeping off their gluttony.

Continue reading “Very hungry caterpillars”

Clear-winged Hawk Moth

Clear-winged Hawk Moth on cupboard
Clear-winged Hawk Moth

Most of us know hawk moths quite well, since they are plenty big enough to notice and they are common right around the country. Australia has about 65 species and most of them are brown, as demonstrated by this visual index to the family on the site created by Don Herbison-Evans and Stella Crossley.

The moth which appeared on my kitchen cupboard one evening recently is obviously a hawk moth by size and shape, but what happened to the brown wings?

The wings of moths and butterflies are covered in scales, as close-up photos (not mine!) show, but a few species lose nearly all of those scales immediately after emergence from the pupa, leaving clear wings outlined by the dark veins and a few small patches of scales. The Clearwing Swallowtail and Glasswing (my photos on Flickr) are the best local examples of butterflies which do this. Others lose just a few scales in well-defined patches to leave ‘windows’ in coloured wings, as seen in this moth.

The one genus of hawk moth which does it is Cephonodes. There are four Australian species; they are all quite similar but I believe mine in Cephonodes hylas. The clear wings highlight the size difference between the large, powerful fore wings and and the tiny hind wings, and the mass of the body – especially obvious in side view.

side view of hawkmoth
Side view of the same moth

The common name for the clear-winged hawk moths is apparently “Bee Hawk Moth” but I don’t think it is particularly appropriate. How about “Cicada Hawk Moth”, since cicadas are at least comparable in size and weight?

Whatever we decide to call it, this moth brings my total hawk moth species count (just in my own garden) to nine. Typing “hawk moth” into the search box in the side-bar will show you some of the others, while this link will take you to all my hawk moth photos on Flickr, including the large and often colourful caterpillars.

The very hungry caterpillar

black caterpillar
Caterpillar of Impatiens Hawk Moth on a well-eaten twig of Pentas. Its head is at the right.

Hawk Moths (Sphingidae) are a family of large, heavy-bodied moths whose caterpillars are similarly large and heavy-bodied, and they get that way by eating voraciously.

The Australian Museum says:

The caterpillar of the Impatiens Hawk Moth, Theretra oldenlandiae, is a common visitor to suburban Sydney gardens. It is most frequently found on Balsams, Impatiens balsamina, I. oliveri and I. wallerana, often eating all the leaves. Some other larval food plants include:

  • Arum Lily – Zantedeschia aethiopica
  • Fuchsia (any of the garden varieties)
  • Grape – Vitis vinifera

The caterpillars are black with yellow spots and strips, and have a thin spine at the end of the abdomen that has a white tip. Mature larvae can reach a length of 7 cm. The larvae pupate in a loosely woven cocoon, which they construct within leaf litter.

… Although they may eat your plants as caterpillars, hawk moths are not considered pests. The adults have an important role as pollinators of many plant species and are the most significant pollinator of papaya (pawpaw) crops.

Hawk moth caterpillars regularly attack just two species of plants in our garden, the Pentas and Madonna Lily, and one or two caterpillars can, and do, strip a plant in a matter of days. The one in my photo was evicted from a white-flowering pentas to give it (the plant!) a chance of survival.

The same site notes that Australia has 65 species of hawk moth (all the adults are shown here, with links to the caterpillars) of the 850 known worldwide. I’m not sure how many of them we have around Townsville but I have photographed adults of seven species and caterpillars of about six in my garden. (Caterpillars are hard to be sure about because each species can have two or three colour forms.)

I only have caterpillar-adult pairs of four species, however, so we have at least eight species altogether: Convolvulus Hawk Moth, Agrius convolvuliEupanacra splendens; Grapevine Hawk Moth, Hyppotion celerioHippotion rosettaDaphnis protrudens; White-brow Hawk Moth, Gnathothlibus erotus; Impatiens Hawk Moth, Theretra oldenlandiae; and Macroglossum micacea. Note that most of them don’t even have ‘common’ (i.e. English-language) names but have to get by, somehow, with Latin. I don’t think it bothers them.