Tropical Topics A n i n t e r p r e t i v e n e w s l e t t e r f o r t h e t o u r i s m i n d u s t r y Butterflies and moths No. 54 April 1999 Not a butterfly Notes from the “What is this butterfly?” This query is often directed at Queensland Parks and Wildlife staff. Invariably the insect in Editor question (right) has large wings patterned with bands of Throngs of birdwing butterflies are black and pale blue which is often tinged with a to be seen at the moment in the coppery blush. It has been seen fluttering around vicinity of Aristolochia vines*, the flowers but cannot be found in any of the Australian bright green male and the enormous butterfly books or butterfly posters. female (Australia’s largest butterfly) often flying in mesmerising The reason is simple; it is not a innocuous. Indeed, many are synchronicity. Anyone who has butterfly, but a moth — the important plant pollinators and a few taken the simple step of planting appropriately-named day-flying (or have been put to good use, one these vines* in their garden or resort zodiac) moth. So what makes this species having devastated weedy is likely to be treated to this sight — insect, which looks and acts like a invasions of prickly pears and another one which visitors may well count as swallowtail butterfly, a moth? being used (along with weevils) in the a highlight of their visit to the fight against water hyacinths. Tropical North of Australia. There are two main distinctions. All butterflies have antennae with club- Of the estimated 22 000 Lepidopteran Growing the food plants of shaped ends while those of most species in Australia, only 385 are butterflies and moths is a particularly moths are feathery or pointed — butterflies, leaving about 21 615 rewarding pursuit (see page 7). Not although some moths with clubbed moths! They range from the huge only does it attract the colourful antennae break this rule. In addition, Hercules moth to the thousands of adults, but provides opportunities while many moths possess a device tiny ‘microlepidoptera’, most of which for watching the growth and (frenulum) to lock the wings together have not yet received names. A glance development of the caterpillars — in flight, with one exception* this is at a moth book (see Bookshelf) will and the antics of their enemies. not found in any butterflies. reveal how diverse and how lovely Pupae, if handled carefully, can be Butterflies, therefore, have clubbed these insects can be. They are brought inside so that the adult can antennae and lack frenulums. certainly worthy of the sort of be admired as it emerges. Simply appreciation which butterflies receive. hang the pupa out of direct sunlight, The similarities between moths and spray from time to time to moisten it butterflies, however, are more striking and when the adult has emerged than their differences, the name of leave windows open so that it can their order — Lepidoptera — which find its way outside when ready to means ‘scale wings’, describing a fly. unique characteristic common to all members of the group. In fact *Only native birdwing vines will butterflies are just one of many groups allow the birdwing butterflies to within the order, just as owls and reproduce — imported South parrots are all birds. Nevertheless, American Dutchman's pipe vines many people who consider butterflies The four o’clock moth (above) is attract the female butterflies to lay a delightful asset to the garden, view another bright day-flying moth, eggs, but kill the caterpillars. moths as pests, to be exterminated. frequently mistaken for a butterfly. It Plant Aristolochia tagala, or While a few species certainly are a has a fat yellow body and attractive Pararistolochia deltantha NOT nuisance, their larvae feeding on Aristolochia elegans A. ringens very dark purple wings interspersed or . clothes, stored grains and crops, the with scaleless, transparent ‘windows’ vast majority of moths are completely and bright yellow spots on I would like to thank Mike hindwings. Trenerry, EPA, and Sue and Jack Hasenpusch, Australian Insect *The male regent skipper (found in the Wet Tropics) is the only butterfly to lock Farm, for their valuable help with its fore and hindwings together during flight — which makes it the most this issue. primitive of the world’s butterflies. The females, however, are more advanced — they have lost their frenulums! Life stages The life cycle of the butterfly is a miracle of nature which is introduced to us all early on in our primary school careers — but details of the transformations involved still puzzle scientists. Crawling eating machines Fussy feeders Change of life Before she lays her eggs, When the caterpillar is ready to pupate it usually spins a silken pad the female butterfly or moth for support. This is a particularly vulnerable time from the point of must receive the correct view of parasites, when it has slowed down but still has a soft skin chemical cues from the plants she lands on and instead of the harder pupa. Many are stung by wasps, their young uses receptors in her antennae, legs and the tip of developing inside the pupa and eventually emerging instead of the her abdomen to test for them. Some females respond to adult butterfly or moth. a green surface by drumming with their feet. This is thought to abrade the Unusual foods Although some butterflies (and moths) pupate leaf enough for the essential oils to be While living plants are the most normal in underground chambers most hang from released and its suitability for egg-laying caterpillar food, some species twigs or leaves. Two types of pupa (or assessed. Temperature, colour, light, shade (particularly moths) eat dead wood, chrysalis) are produced. Some species and leaf texture may also be important while (swallowtails, whites, yellows, girdle leaves and bark, stored seeds and cereal, * low or high air pressure are known to animal dung, wool, hair, feathers, other blues, coppers, and some influence egg-laying. Numbers of eggs laid insects and each other. Among the skippers) produce a girdle by individuals vary from 120 to several plants, fungi, lichens mosses, cycads and which is looped around the hundred. even certain ferns* are targeted by a few upper part of the caterpillar species. Many caterpillars eat their own and provides support as its split Most butterflies are very limited in the eggshells as their first meal although, skin is cast off. Special claspers variety of plants which they consider since the proteins are indigestible, the (cremaster) or anal hooks at the end vine and birdwing caterpillar illustrations courtesy Queensland Museum suitable for their offspring, and the few benefit of this is not fully understood. of the abdomen are then hooked into chosen by each butterfly species are likely the silken pad, to hold the pupa to be related. This is why some introduced *Ferns are generally avoided by secure. Other species simply hang plants, which apparently give the correct caterpillars — possibly because they upside down from the cremaster (which signals, are rapidly adopted (for example, the contain a chemical similar to the moulting requires some fancy footwork when the skin orchard butterfly on citrus, the common hormones of insects which could is slipped off). A number of moths enclose Australian crow on oleander and rubber interfere with their development. their pupa in silken cocoons — the silk moth Aristolochia tagala vine). This can lead to some unfortunate taking this to extremes. cremaster mistakes, however. Blue triangle butterflies sometimes deposit cremaster eggs on young shoots of avocado, Eichhorn’s crow on frangipani Within the pupa great changes are taking place, Native and birdwings on non-native Aristolochia vines — but their * out of sight. When the caterpillar was originally caterpillars do not survive. On the other hand, the orchard forming inside the egg, two types of cells swallowtail has been tricked, experimentally, into laying on developed. Some formed clusters and ceased parsley, celery and camphor laurel instead of citrus trees developing, while the others divided normally to and their caterpillars have thrived — even growing more produce the body of the caterpillar. After it hatched, rapidly on the parsley. It appears that the female’s these cells grew and enlarged as the caterpillar did, instincts are not always correct. growing to many times their original size, while the cell clusters remained unchanged and unfunctioning. Whether the ‘wrong’ plants poison the caterpillars is not When pupation starts, however, the distended caterpillar cells break certain. The caterpillars themselves are fussy eaters, down and the cluster cells come to life. Nourished by the soup having an inbuilt preference for certain types of food — formed by the breakdown of the other cells, they divide rapidly to to the point where paper treated with the appropriate form the adult body. plant juices will be consumed. They appear to be able to test the plants with antennae and certain parts of their When the adult butterfly or moth is ready to emerge, the pupa may mouths and if they detect the wrong food they refuse to become darker or transparent, the insect eventually appearing eat it. However, when these mouthparts and antennae usually during the hours of darkness. Following a shaking of the were removed experimentally, some caterpillars ate, and pupa, the head pushes its way out of the end. Gradually the entire developed successfully, on plants they normally reject. body emerges, the wings folded and crumpled. The adult must then Many chosen foodplants are extremely toxic, but the hang as blood pumps along veins in the wings and they unfold.