Amphibian parasites

This Myola tree frog (Litoria myola) is a regular visitor into our house. We actually had to move the frog outside on two occasions in recent weeks. We were sure we were dealing with the same individual as we noticed it had a couple of parasitic fly larvae under its skin. We generally don't interfere with wildlife, preferring to observe what we see and let nature take its course, but  in this case curiosity got the better of us, and decided to give the frog a hand and remove the parasites. The parasite is a fly in the genus Batrachomyia (Diptera: Chloropidae) and is apparently not life threatening to the frogs, however, having two large maggots feeding on body fluids beneath your skin cannot be comfortable. The larvae remain under the skin until they are sufficiently developed then crawl out in order to pupate underground.

The larvae maintain a breathing hole to obtain oxygen (marked with arrows in the image below). We were able to extract them through these holes quite easily. The larvae were bright yellow and 10mm long. This frog now has at least two less worries to contend with, although last night I we found it sitting on the driveway right behind the car when we were about to back out. Now it owes us three favours!

The parasite free frog which should heal completely in a matter of weeks.

One of the two Batrachomyia sp. larvae which were removed from beneath the frog's skin. The head has two hook-like appendages while the forked tail end remains close to the hole in the skin in order to breath.

Each larva remains under the skin until it is sufficiently developed then crawls out in order to pupate underground. Suprisingly, Hoskin, CJ and McCallum, HI (2007) found no evidence that Batrachomyia parasitism impacts on the body condition of these particular frogs, however, another study on several smaller species of frogs did show measurable impact on smaller specimens.

Christmas beetles arrive

Christmas beetles have made a welcome appearance to our lights over recent nights, the photos below are beetles that appeared tonight.

This attractive beetles belong to the Scarabaeidae family and are in the genus Anoplognathus. We have over thirty species of Christmas beetles in Australia, many are found along the east coast. In some regions they have become more abundant where land clearing has provided additional grasslands which host the beetles' larvae.

The life cycle of these beetles is the same basic cycle as most beetles. In this case, eggs are laid underground in grasslands adjacent to eucalypt trees or forests. The larvae feed upon grass roots and their growth is dependant on soil temperature. Those in warmer climates may emerge a year later, whilst those in cooler regions may spend two years underground. The larvae are crescent-shaped with a pale, reddish-brown head and three pairs of legs, but can be quite difficult to distinguish from other beetle larvae.

 

A green Christmas beetle, Anoplognathus smaragdinus

 

The face of Anoplognathus smaragdinus

After pupating, the adults time their emergence with warmer conditions and are also stimulated by rainfall. Different species will emerge at different times throughout the summer; perhaps to avoid direct competition. Other factors can influence the exact timing of their emergence, such as seasonal variations in weather patterns. Most Christmas beetles emerge from November to February, but as we know, many appear in late December.

 

Anoplognathus porosus 

Christmas beetles are good flyers and can cover distances of several kilometres. Many fly at dusk, but they are often attracted to lights after dark and can end up buzzing around the front porch.

Anoplognathus porosus about to take off

Anoplognathus porosus in flight

Colourful katydid nymph

This is Kurandoptera purpura, and older nymph of the katydid featured as a hatchling recently. This individual was found locally upon citrus, and although it has outgrown the ant mimicking phase of its lifecycle it still behaves quite unusually for a katydid. It vibrates its antennae in a rapid tapping-like motion, similar to the way many wasps do. Rather than moving in a 'swaying' leaf-like manner, it moves in faster erratic bursts, which is quite wasp-like also. This nymph was not hesitant at all about moving around during the day. Again this is relatively unusual for katydids. Nymphs of most species are quite inactive during the day, relying on their camouflage to protect them from visual predators such as birds.

Bug season is starting!

Although we still have not had any decent rain this season, there has been a noticeable increase in the abundance and diversity of invertebrates around Kuranda. Here is a selection of species photographed around our house recently.

Moth numbers are really on the increase. This one caught my eye, but I am yet to identify it.

One of  a multitude of green rainforest moths that have been visiting our light sheet (Comostola sp.)

Metallic darkling beetle (Tenebrionidae), feeding upon the trunk of a tree.

A small Raspy cricket (Gryllacrididae). The spines on the first two pairs of legs help the cricket to grasp small invertebrate prey.

Lacewing  Chrysopidae

The face of the Serrated-legged katydid, Paracaedicia serrata.

A Lynx spider, Oxyopes sp.. A nocturnal ambush hunter.

Irridescent Tachinid fly (Tachinidae).

Four-spined jewel spider, Gasteracantha quadrispinosa.

Ant-mimicking katydid

This small katydid nymph turned up in our yard earlier this month. It was on a plant frequented by Black rattle ants (Polyrhachis australis) which are about the same size as the nymph.

Not only does the nymph resemble the ants at a glance, its movements were very ant-like. Katydid specialist David Rentz thinks the nymph may be Kurandoptera purpura.

Peppermint twist

 

Megacrania batesii is known as the Peppermint stick insect for a very good reason. As a defence it sprays a dual-streamed blast of peppermint scented liquid at its predators. The defensive chemical is produced by glands in the thorax and liquid is stored in sacs which lead to ducts just behind the insect's head.  

Megacrania batesii discharging the defensive chemical from ducts just behind the head.

  

 Like all phasmids, Megacrania batesii sheds its exoskeleton in order to grow. The process is practically the same at the sequence pictured in the previous post featuring Phyllium monteithi. The exuvia left behind is typical with one exception; it contains the sacs in which the peppermint scented defensive fluid is found. The result is that the insect is not only soft and vulnerable immediately after moulting, but has to replenish the chemical before being able to defend itself fully. This period is obviously one of hightened risk for this species, and perhaps there are some behavioural modifications during this period to reduce the risk of predation. Species such as the Peruvian stick insect Oreophoetes peruana have a similar defence yet do not shed the lining to the sacs, hence retaining their defensive ability post moult.
 

The entire exuvia with the two white sacs present at the left near the head.

The sacs can be clearly seen filled with the white peppermint scented chemical.


If you are interested in keeping these or other fascinating stick and leaf insects visit Minibeast Wildlife's site.

 

Moulting Phyllium monteithi

Last February an adult pair of Phyllium monteithi (Leaf insects) were found in Kuranda by an invertebrate enthusiast from Cairns. They were found upon Cape Ironwood (Gossia floribunda).  Females of this species have proved to be extremely elusive until now, but it was only a matter of time before one turned up. The many eggs laid by the female were collected and incubated. By mid-year some had hatched.

We acquired some 1st instar nymphs and some eggs about 3 weeks ago to begin our own captive population of these amazing insects.

Today the first of our hatchling (1st instar) nymphs has moulted. Here are some images of the moulting process.

Several minutes into the moulting process and the insect is pumping itself steadily out of the old exoskeleton. The initial emergence point through a split that forms just behing the head

All the legs are now free.

The insect hanging by the end of its abdomen while the new exoskeleton hardens.

All complete, and now a 2nd instar nymph.

The moulting process (ecdysis) is how arthropods achieve growth. Insects such as phasmids need to have a secure hold on a leaf or branch in order to extract themselves effectively from their old exoskeleton. If something goes wrong it can result in limb loss or even death. It is also a period where they are extremely vulnerable to predators.

This specimen moulted at 7am this morning. The temperature was 16.5°C and the process took around 20 minutes for the insect to completely free its limbs and the majority of its body. It then hung from the exuvia via the end of its abdomen for a further 20 minutes before pulling completely free and climbing back onto the leaf. Like most phasmids, it then proceeded to eat the exuvia.

If you are interested in keeping stick and leaf insects yourself, visit our comprehensive site.

Mt Baldy

A recent trip to Mt Baldy near Atherton on a cold night revealed very little, particularly within the foliage. On the ground, however, there was a bit of activity, and a few interesting species moving around. Here's a selection.

Chrysomelid leaf beetles mating on acacia.

More Chrysomelid beetles. Probably the same species as above and are obviously highly variable.

Whistling frog, Austrochaperina sp.

Stony creek frog, Litoria jungguy

Leeches were very active. Many on the ground and some lurking in the lower foliage like this one.

Semi-slugs were very active. This is most likely Fastosarion brazeri

A semi-slug has a small shell which is concealed by a soft mantle.

Hercules update

We are currently raising some Hercules Moth caterpillars. They hatched out on the 26th of May and one has pupated today, a larval period of 81 days. The growth rate of the caterpillars has been relatively slow given the cooler conditions we have experienced over the recent months. 

A caterpillar emerging from the egg on the 26th May.

24 hours after hatching and the larvae are feeding voraciously and already filling out.

At 24 days old the larvae are substantially larger, but still white in colour.

By 40 days they are pale green in colour and becoming very large caterpillars.

Day 74 – what a whopper!

Silken weaponry

A drama unfolded on our ceiling recently which highlighted the power of silk that some spiders use. A Red House Spider (Nesticodes rufipes) capture and killed an Asian House Gecko (Hemidactylus frenatus) much larger than itself, and it did so using silk as its major tool.

A Red House Spider (Nesticodes rufipes) in the process of capturing an Asian House Gecko (Hemidactylus frenatus)

Several hours later and the gecko has seccumbed to the spider's venom and the spider has begun feeding.

This spider belongs to the family Therididae, which also includes well known species such as the Redback and Black Widow. Many of the spiders in this family utilise a particular snare system that enables them to capture very large prey. One of the key parts of the snare is high tension trip lines that are beaded with blobs of liquid silk. When prey makes contact with these lines it is bound by the glue-like silk and becomes tethered. Any struggles often result in it making contact with more lines, and subsequently in more trouble. At this point the spider descends from the scaffold of silken threads which support the trip lines, and using its long rear legs begins to bind the prey with lines coated with the glue-like silk. For most animals, there is little chance of escape from here on. Only when the prey is safely manacled with dozens of silken lines does the spider venture close enough to bite its victim, which begins the chemical onslaught inside its body.



A Redback (Latrodectus hasselti) in the process of binding a large Tenebrionid beetle.

A Redback with a bound up huntsman, over 10 times its own body weight.

Evening...Brown

This is an Evening Brown Butterfly, Melanitis leda, a species most active in the early morning and late afternoon. We have seen many of these butterflies around, but this one ended up inside so I decided to take a few photos. I was quite taken by the comical appearance of the face in particular.

The species has excellent camouflage while sitting within dry leaf litter, usually spending periods of inactivity sitting motionless on the forest floor. It has a distinct wet-season and dry season colour form, this is obviously the dry-season form.