Every so often on the various nature programs we see examples of mammals and birds using tools to gain an advantage, usually having to to do with food.
This is an example of an insect using a "tool", in a sense, to amplify and/or direct its courtship song.
Quite often I discover male tree crickets of the genus Xabea with their heads stuck through the hole of a leaf. See another observation.
Xabea atalaia elderra Otte & Alexander male with its head protruding through the hole in a leaf.
Close-up of the same cricket.
This activity is not unusual in the Tree Cricket subfamily, Oecanthinae. Species in genera such as Oecanthus and Neoxabea have been observed performing a similar behaviour.
The heads and thoraxes of these crickets seem to be modified for this behaviour in that they are unusually elongated.
Elongated head and pronotum of male X. a. elderra.
There has been some question as to whether the cricket makes the hole in the leaf or uses or modifies holes that are already there. In this example made at the James Cook University Daintree Rainforest facility, the holes were ready-made by some other insect.
What is the reason for such behaviour? The cricket utilises the concave underside of the leaf to amplify and/or direct its song.
Underside of the leaf with singing cricket
Close-up of singing cricket
I have made a half dozen observations of this species and this behaviour and in every case, the cricket always sticks its head from the underside of the leaf. It does not make a mistake and approach the leaf from the top-side. So what clues does it use to avoid the mistake?
This species is associated with rainforest trees and shrubs and is not found in grasslands like Oecanthus species. The crickets seem to aggregate, perhaps in association with suitable leaves.
As an aside, captive males did not sing in jars where leaves were not provided.
Otte, D., Alexander. R.D. 1983. The Australian Crickets. Monograph 22. the Academy of Natural Sciences of Philadelphia. Pp. 1-477.
Every year about this time Little Bear Moths streak around the base of our oil palm (no, I did not plant it) around 9.30 am. Their flights are so rapid that they could easily be missed and certainly do not appear to be moths. Individuals dart back and forth and occasionally a "cloud" of a dozen or so moths hovers for a split second, then they are gone.
Oil palm with bromeliads at base.
Every so often a supposedly tired individual alights on the bromeliads that adorn the base of the palm allowing a photo if one is careful and lucky.
Little Bear moth, Synechodes coniophora Turner
The overall appearance of the moth suggests beetles or flies of the family Bibionidae, most notably Plecia ornaticornis, often associated with Mullerian Mimicry complexes of many insects.
The moths are apparently interested in the stumpy bases of old palm fronds.
Note the old bases of the palm fronds where the larvae apparently live
The Brachodidae is a small family related to both Clear-winged moths, Sesiidae, and Sun Moths, Castniidae. About 135 species have been named (Kallies 2004) distributed in all regions except the Nearctic. They are all day-flying but every so often, one turns up on the light sheet. I have seen another species at my place but it was not near the oil palm.
The moths are active for a few days, then they are gone.
Kallies, A. 2004 The Brachodidae of the Oriental Region and adjacent territories (Lepidoptera: Sesioidea). Tijdschrift voor Entomologie, Vol. 147: 1-19
Yesterday we had the sad news that Mrs Cassowary's body had been found on a property not far from our house. We had not seen her for about 3 weeks and have been wondering what has become of her. An autopsy may reveal the cause of her death.
This bird was unusually placid and often appeared with the male and with the chicks from time to time. This is the second adult female cassowary to die in this area in the past year. The other female was hit by a car on Black Mtn Road.
This leaves the male cassowary, and his sole chick, as the last adult in the area.
Cassowaries have been the subject of many entries on this blog. Simply search for "Cassowaries" and you can access all of them.
The autopsy reveals that the bird had a perforated bowel and died of blood poisoning. There was nothing in the gut to indicate what cause her malady. At least she was not shot nor attacked by dogs.
Warm, moist conditions seem to suit this odd fungus. Innocuous enough from a photo but it has a awful smell. For a couple of days I smelled what I thought might be escaping LPG gas, then I recalled the smell of flowering Amorphophallus bulbifera but it is the wrong time of the year for this plant. I searched the usual pots but could find no bulbifera.
Then I stumbled on the above-my first encounter with the Bridal Veil Fungus. The "veil" is usually intact, but after a couple of days with turkeys and birds about, the veil has become detached. This one measures about 10 cm.
The smell attracts flies, especially Blowflies (Calliphoridae) which feed on the juices of the plant.
In so doing the spores of the fungus attach to the fly and as it moves around the rainforest the spores detach and spread the fungus to additional habitats.
Blowflies are not the only flies that feed on the fungus. Here a Drosophila species has also been attracted to the food source.
The odour of this fungus is so strong that campers have been known to abandon campsites due to fetid smell.
For those bent on anthropomorphism, this is an appealing face.
It is actually the head of a female of Macleay's Spectre, Extatosoma tiaratum (Macleay), Phasmatidiae; Tropidoderinae, for those who are technically minded. Note the mouthparts on "top". This is the normal position for the insect hanging from the leaves and branches high in tree tops.
Females are large insects:
They measure 140 mm or more in length and can weigh 30-40 g. This species is known from a few populations along the east coast of Australia from central New South Wales to the Daintree of far north Queensland.
Females have short wings and are incapable of flight. Instead they spend their entire lives in tree tops where they feed on vegetation and rely on their protective coloration to avoid vertebrate predation.
Males, on the other hand, are mobile and have fully developed wings and can make flights at night.
Females, at least, are long-lived. Captive individuals have lived for more than 18 months and have produced more than 1000 eggs. The eggs are broadcast by flipping the abdomen. They may take 5-8 months to hatch and once they do, the first instar nymph looks and behaves much like an ant. It moves quickly from place to place until it detects a host plant that is suitable for its development. Once this happens, it ascends the plant and moulting occurs. It undergoes 6-7 moults, gaining in size after each. If several nymphs select a small tree or shrub, they can easily defoliate it and expose themselves to predation ending their progression to adulthood.
Females can produce eggs that hatch whether they are mated or not. Those eggs of unmated females become females; mated females produce eggs of both sexes. An interesting paper dealing with this topic if by Schneider and Elgar (2010). Among other things, mated females laid more eggs over a 7 day period than those that were unmated.
Eggs of this species were probably smuggled out of Australia. Because the insect is large, spectacular and easy to keep, and can be raised on a variety of non-Australian plants, it has made it into the pet trade in North America and Europe.
We have found males of Macleay's Spectre at lights from time to time during the wet season but have never discovered nymphs or females until recently. The above tattered female was found on our house. It was missing one wing and had a slightly damaged abdomen suggesting it had escaped predation. We attempted to keep it alive but it eventually died. The abdomen was mostly empty of contents--there were only a few eggs. So it must have been at the end of its life. This is just one of about 20 stick insect species found around Kuranda. Many have specific food preferences, others will eat a variety of plants.
Brock, P. D., Hasenpusche, J. 2009. The Complete Guide to Stick and Leaf Insects of Australia. 204 Pp. CSIRO Publishing Collingwood, Vic.,
Schnieder, A., Elgar, M. 2010. Facultative sex and reproductive strategies in response to male availability in the spiny stick insect, Extatosoma tiaratum. Australian Journal of Zoology, 2010, 58: 22-233.
Late autumn rains bring out the calls of many creatures in the Queensland rainforests. Crickets are contributors to many of the loud sounds we hear after dark. Mole Crickets commence calling on dusk from burrows in the ground. Their calling is low and guttural and continues for 10-15 minutes, then it ceases. They are followed by a number of other cricket species. Among them are the impressive burrowing crickets of the genus Cephalogryllus. At least 13 species occupy the eastern coastal eastern coastal forests of Australia. Each area or mountain range seems to have its own species, and there are some sympatric species. A single species has been described from Western Australia.
Cephalogryllus sp. probably tau Otte & Alexander is commonly heard around Kuranda. Further study is needed to establish its correct identity since a series of different-looking males have been dug from burrows in Kuranda.
This is a large cricket, some 25-27 mm in body length with very sturdy hind legs that are probably used in shaping the burrow. The wings are short and used solely in sound production; the crickets cannot fly. These crickets live in the ground and males sing from the entrance to their burrows on wet nights from February until August. There are many males per unit area in the rainforest but their calls are not synchronised. As a result the background is a continuous din of cricket calls. The ambient "din" can be heard in the recording presented here. The tape recorder was positioned about 16 cm from the entrance to the burrow.
Calling ceases at some stage late in the evening, probably as a result of decreasing ambient temperatures. Females have not been found wandering around after dark as one might expect. The purpose of the calling song supposedly is to attract females for mating. Perhaps, these crickets sing for other reasons, such as territoriality. By morning, the burrows are closed and the occupants remain underground during the day.
David and family moved to Kuranda, Queensland in 2002, following retirement from CSIRO Canberra, Australia. David, Barbara and an assortment of wildlife live in a rainforest setting. It is their first experience living in the tropics.
David's major interest is Entomology. He continues research in the Orthopteroid insects and is keenly interested in the biology of the rainforest.
This blog is a narrative of observations made in and around Kuranda.
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AND PROCEED TO THE "SETS"