Caterpillar with a Problem

On 11 April 2016 while doing some night photography in the bush on Clohesy Road, nr Koah, Queensland, we discovered a caterpillar with a problem.

This caterpillar, probably a lymantriid, Euproctis, perhaps lutea, had been parasitised by a small wasp early in its life history. The white pods are cocoons of the wasp, not eggs. The eggs had been laid internally by the wasp a couple of weeks before and the larvae developed within the caterpillar feeding on substances in the body fluids of the host.

 The unhatched cocoons with caps intact.

 Three days after collection of the caterpillar, the wasps emerged leaving the empty cocoons.  The parasites are wasps of the family Braconidae, probably in the genus Apanteles. The caterpillar remained active, moving around until 22 April, 2016 when it died. It had been doomed and would never have been able to form a cocoon and become an adult moth. This is an example of natural biological control

The caps indicate the hatching of the cocoons. There were 13 female  and 4 male Apanteles wasps.

The wasps. The female is in top. Note the short ovipositor that is used to insert eggs into the host caterpillar.

"Trump" Tower

Gotscha
Well we have all heard of Trump Tower. How about Cocks' Tower?

My friend Graeme Cocks drilled some holes in a block of wood and hung it outdoors to see what he could attract. Wasp and Bee "hotels" are not new. Naturalists have been doing this sort of thing for years. Books have been written on the subject. It is interesting and fun to see what shows up.

Before the uninitiated wonder why anyone would want to "attract" wasps and bees, it should be noted that these insects are "solitary". This is opposed to "social". Solitary bees and wasps are just that. They do not make communal nests with hundreds or thousands of individuals. The social bees, honey bees, for example, produce nests that should be kept well away from habitations etc.

Anyone can make a wasp or bee hotel. All you need is a drill. The one above measures about .5m in length and is about 65 mm deep. holes of different sizes will attract wasps and bees of different sizes.

All you have to do is hang one out and wait. Eventually someone will find it and begin to use it. If there is no interest on the part of the wasp and bee community, then move it to another location. These insects seem to like a bit of sunlight. Bee hotels kept in the shade seem to be ignored.

What can you attract? Well there is a great variety of these insects, perhaps more than you think. And with them come the wasp and bee parasites. But you have to keep on the lookout. That's why it is a good idea to have the hotel near a window or walkway where it can be more or less continually observed.

Here are a few examples that have shown up thusfar.

 This is a Potter Wasp checking out the facilities. The capped hole below is completed, the egg laid and eventually the adult will emerge--that is if it has not been parasitised by another wasp.

This wasp is adding a layer of mud that will form the sealed cap.

 Smoothing the edgesbefore sealing.

 Compare the wings of this wasp which is stationary, with the same wasp below which is in flight.

In the top photo, the wings first pair of wings are longitudinally folded on one another. When in flight in the one just above, they are fully expanded as is normal for wasps. All but one subfamily of the Vespidae have the wings longitudinally folded at rest. The one exception if the members of the subfamily Masarinae. Many hymenopterists regard the masarids as a separate family so in that case all vespids would have the wings folded longitudinally at rest. The most commonly known vespids are the Yellow Jackets, of which the European Wasp is an example. The European Wasp is an introduced and aggressive social wasp that can cause great pain through its stings if one stumbles upon a nest. It, fortunately, does not occur in the Australian tropics but is a great source of irritation in the southeast of the continent.

Usually the wasps provision their nests with paralysed insects. The most common prey is caterpillars.  Many wasps collect pollen and honey with which they stock their nests. In this instance I observed no prey being brought to the nest. Maybe next time.

Sorry bub.

Another wasp taking advantage of the "hotel" is this one. It is a member of the family Sphecidae. This is a diverse group of wasps and many its subfamilies are now transferred to another family, the Crabronidae. Whichever classification you choose, it is a very large group of wasps with species ranging greatly in size and biology. They are predatory and utilise a variety of insects and spiders to provision their nests.

This one seems to be adding some fluffy plant material to the nest. Beyond that I did not see her provision the nest. It was promptly sealed up.

Then this appeared. Any suggestions?

National Moth Week

What is National Moth Week you say. Well the idea comes from the US where it was started as a sort of "moth and insect appreciation" scheme to introduce the public to the world of moths during the summer. After a couple of years, it took on an international scope with countries on several continents "celebrating" nocturnal insects. Even in our winter, we find a variety of moths on any given night. Nights without a moon are most effective.

"Mothing" as it has been called, is a fairly simple activity. On needs a source of light. Strong electric bulb will do but a Mercury Vapour Light or the lights used to attract insect to commercial insect traps are also very effective. The large local hardware stores sell these lights.

Not every light sheet will look like this! This was a recent "evening with moths" experienced by Michael Braby and his friends.

WATCH THIS SPACE FOR A LOCAL MOTHING NIGHT

In the meantime, this is what you might see if you put a light and sheet in a natural area.

Click for enlarged view. Also see http://www.leapfrogoz.com.au/LeapFrogOz/Moth_Identification.html

for more Queensland moths

Crambidae; Pyraustinae; Agathodes ostentalis 

 Crambidae; Pyraustinae; Dichrocis clytusalis

 Aganaidae: Digama marmorea

 Noctuidae; Catocalinae; Grammodes oculata

Drepanidae; Hypsidia erythropsalis

 Crambidae; Pyraustinae; Notarcha polytimeta

 Saturnidae; Saturniinae; Syntherata janetta

 Crambidae; Acentropine; Tetrernia terminitis

 Geometridae; Ennominae; Bracca rotundata

 Noctuidae; Catacolinae; Sympis rufibasis

 Lacturidae; Eustixis leucophthalma

 Geometridae; Geometrinae; Prasinocyma caniola

Thyrididae; Striglininae; Aglaopus gemmulosa

Arctidae; Arctiinae; Paralacydes maculifsciata

Noctuidae; Catocalinae; Buzara latizona

 Geometridae; Geometrinae; Agathia pisina female

 Noctuidae; Catocalinae; Donuca rubropicta

Geomtridae; Ennominae; Milionia queenslandica

Another pesky Ant

Residents of the Far North of Queensland have to put up with a number of invasive species ranging from Cane Toads to Feral Cats. Ants seem to head the list these days with Yellow Crazy Ants, Anopolepsis gracilipes, among the worst and with a ability to do terrific damage to local animals, large and small.

Yellow Crazy Ant from the web

The ecological destructiveness of these ants is documented in the recent edition of the Kuranda Newspaper. And their potential disaster to northern forests is discussed in an article by Steve Turton on the threat of invasive ants to the Wet Tropics. 

Several other ants have dangerous potential. The Electric Ant, Wasmannia auropunctata, are a tiny ants. They are under 1.5 mm in length and establish colonies everywhere. They attack ground dwelling animals and seem to head for the eyes of the victim. They both sting as well as bite and they are notable because they can occur in the thousands. They have been found in several localities and there is a big push to exterminate them before they "get away". 

Electric Ant biting a human from the web

But the reason for this blog is to report on another ant with which every resident of Kuranda, at least, is familiar. The are the "little black ants" that show up from out of nowhere in the kitchen where they seem to eat most foods. A knife left on the sink with some peanut butter, a sugar bowl, a dish with bread crumbs or a dinner plate with odd bits left and these ants will appear and, if left to their own devices, they will accumulate by the hundreds.

 They don't seem to be particularly distinctive. But my colleague Dr Lori Lach identified them as the imported African Big-headed Ant, Pheidole megacephala.

The "Big-headed" comes from the large-headed soldiers that usually accompany groups of the ants. It is thought that the large muscles inside the head are used to crush seeds or dismember tough-bodied insects. These ants build small colonies that can be identified by bits of wood and frass that accumulate on widow sills, breaks in concrete and the like.

Controlling African Big-headed ants is a real problem. They seem to "delight" in the various ant baits that are available in local shops. Nothing seems to work. If any readers have suggestions, please offer them. 

A Most Unusual Grasshopper

Rehn (1952) in his classic work on Australian grasshoppers stated that "No considerable area of Australia seems to be without one or more representatives of the Eumastacidae...." Sixty years and more than 250 described species later, this statement is true. [Current classification of these insects
places them in their own family, the Morabidae] No other orthopteroid group seems to have radiated more than the members of the Australian endemic subfamily Morabinae. The "Matchstick Grasshoppers" have been successful in adapting to most habitats from the arid deserts to grasslands. They occur on plants near the ground and in trees like Acacia and Eucalyptus.

But one place you don't find morabine grasshoppers is in the tropical rainforest. They can be found on shrubs bordering rainforests but not within. 

In the rainforests, members of the Biroellinae occur on shrubs and in treetops. They are not frequently encountered. They may be rare or just very difficult to observe. One genus is known: Biroella comprises many species from New Guinea but only two have been described from Australia. One is winged, the other wingless. But several undescribed species have been recognised. In about 14 years collecting in the Queensland tropical rainforest, I have only found a few Biroella.

Recently while night collecting along the Clohesy River, not far from Kuranda, a male of the wingless species was sighted on a leaf after dark. This is tentatively identified as B. tardigrada Sjostedt. With the highly localised nature of other morabid species, it seems that this could be an undescribed species as B. tardigrada was described from Malanda, Qld. from quite a different habitat from the rainforests along the Clohesy River. The species was described from a female and no males were recorded. This makes the task of determining whether the Clohesy River species is the same without having females for comparison.

The splayed hind legs is very typical of most eumastacids and the biroellines, but not necessarily of morabines. This is an adult male.

But the interesting point about this discovery is the odd green flanges protruding from the sides of the abdomen.

These structures remain rigid after the death of the grasshopper. I have not seen anything of a similar nature on any other grasshopper. Certainly they do not occur on any morabine. What function they have, if any, remains to be discovered. 

The cerci (claspers) at the end of the abdomen are also odd and a bit difficult to interpret unless viewed carefully. 

At first they appear to be C-shaped but the sharp corners at the base to the left are part of the supra-anal plate and not the cerci. The cerci are the erect slender structures with the dark, ovoid base.

This little observation highlights that there is so much about the Australian insect fauna that remains to be studied.

Literature

Rehn, J.A.G. 1952. Grasshoppers and Locusts (Acridoidea) of Australia. Vol. 1 Tetrigidae and Eumastacidae. Pp. 1-326. CSIRO, Melbourne.

Giant Robbers!

This has been a strange year in the northern tropics. There has been no wet season at all. A few showers here and there but nothing approaching a normal wet. To the west, there has been a few good showers that have greened up the outback but no monsoonal drops at all.

Insect populations seem to be unusual as well. A recent few nights in the Daintree resulted in huge hauls of insects at the light sheets. But these were of a few species represented hundreds of individuals. Daintree lightsheets are usually quite sparse.

A lightsheet in the Daintree. Most of the moths represent a couple of species. B Richardson photo

This summer has seen large numbers of the very large robberfly (ca. 40 mm) identified by Greg Daniels as probably Dolopus genitalis (Hardy).

Robberflies are predaceous insects. They catch other insects, including robberflies, on the wing. Most species are diurnal, but a few Australian ones are active at night. These big fellows seem to prefer dark areas and will enter houses if doors and windows are left open. Their buzzing attracts attention but being a good Samaritan can result in a painful bite. The mouthparts are an effective syringe which conveys a concoction of painful chemicals. If they have to be handled, the flies can be dealt with effectively if grasped from the side, thereby, avoiding the beak coming into contact with the finger.