Three Arthropodean Visitors

..... a moth, a beetle, and a spider.

While I have not been actively searching for interesting spiders and insects, I have crossed paths with several over the last week or so..

1. Southern Old Lady Moth

Southern Old Lady Moth, Dasypodia selenophora - Close up showing labial palps and coiled proboscis

Southern Old Lady Moth, Dasypodia selenophora - Dorsal view

Southern Old Lady Moth, Dasypodia selenophora -  Detail of wing scales

 (click to enlarge)

The Southern Old Lady Moth, Dasypodia selenophora, can be found in the southern half of Australia, as well as Norfolk Island, New Zealand and Macquarie Island. One particular Southern Old Lady Moth can currently be found in my house. They like to hide in dark places by day and so they often come into houses or other buildings.  After taking the above photos, I wanted to coax it onto some glass so I could photograph the underside. However, the sprightly old lady made it's escape and has not been seen since.

Why is it called "Old Lady"?  Probably for the same reason as another moth of the same name in Britain. The pattern was said to be like that on an old lady's shawl. Another common name for this species, Golden Cloak Moth, suggests a similar meaning.

So how do the moths get down to Macquarie Island (1546 kilometres south of Hobart). Apparently they hitch a ride on prefrontal airflows (northerly winds) ahead of cold fronts.  In one such event it was estimated that the Old Ladies, flying at 300m asl, could have reached Macquarie Island in under 10 hours. A nocturnal temperature inversion kept the temperature at above 5C.  They would have been traveling at around 100 m.p.h. What a ride!

2. Fuller's Rose Weevil

Fuller's Rose Weevil - Asynonychus cervinus - Lateral View (Click to enlarge)

This 8mm long, beetle was found in the garden on the underside of our rhubarb leaves. Some one on the Bowerbird web site has identified it as Fuller's Rose Weevil (Asynonychus cervinus). It is an introduced pest in Australia and many other countries, probably originating from Central and South America.   It has a large number of host plants but is best known as a pest of citrus. So, you may wonder,  why is it named Rose Weevil? According to the University of Florida Entomology and Nematology Department, this weevil "caused considerable damage to winter roses when it was first reported in the United States from California in 1879."

The elytra (wing covers) are actually fused together rendering this evil wee weevil flightless.  Another interesting facet of this beetles life is that it reproduces parthenogenetically. (no male required). In fact only females have been recorded.

3. Cupboard Spider

 

Cupboard Spider, Steatoda grossa. -  Lateral View  - (click to enlarge)

Cupboard Spider, Steatoda grossa. - Oblique  Dorsal View  (click to  enlarge)

While sorting out a large wooden box full of old blacksmith's tools I came across a relative of the infamous Redback spider Latrodectus hasseltii. It's known as the Cupboard Spider, Steatoda grossa. Like the weevil above, this is a cosmopolitan species but it is considered to be a native of Europe, including Britain.

Are they dangerous to humans? There is at least one well documented case of a  22-year-old female bitten on the shoulder by a Cupboard spider. She developed nausea, vomiting, and severe local and regional pain; symptoms similar to that  caused by the bite of Latrodectus spiders such as the Redback..  In fact, the symptoms were succesfully treated with Redback spider antivenom.



References:

• Common I.F.B. (1990) Moths of Australia - Melbourne University Press
• Greenslade P., Farrow R. A., and Smith J. M. B. (1999). Long distance migration of insects to a subantarctic island. - Journal of Biogeography 26 , 1161–1167.
• Graudins, Andis; Gunja, Narendra; Broady, Kevin W.; Nicholson, Graham M. (June 2002). "Clinical and in vitro Evidence for the Efficacy of Australian Red-back Spider (Latrodectus hasselti) Antivenom in the Treatment of Envenomation by a Cupboard Spider (Steatoda grossa)". - Toxicon (Case report) 40 (6): 767–75.
• Gyeltshen, J. and A. Hodges. (2006, revised 2012) Fuller Rose Beetle, Naupactus godmanni (Crotch) (Insecta: Coleoptera: Curculionidae). - Entomology and Nematology. Florida Cooperative Extension Service. University of Florida IFAS. 

Sibling Cannibalism

.....Common Spotted Ladybird (Harmonia conformis )


The macabre practice of cannibalism is rife in Tasmania. It's been occurring since long before the days of convict Alexander Pearce and right up to the present day. It takes place not only in the remote wilderness areas but even in some of the more affluent suburbs of our cities and towns. Read on if you dare.

A few weeks ago I posted a photo of some ladybird eggs on my nectarine tree. Well the tree is now covered in all stages of the ladybird life cycle.

(Click on photos to enlarge)

Newly hatched ladybirds - Harmonia conformis

After hatching, many insects feed on their own egg shells for their first meal. In the photo above you can see newly hatched larvae feeding on the eggs. I knew something was wrong with this photo but it took a few moments for it to dawn on me that the eggs in the photo have not hatched.

Note the empty (white) egg shells on the left

A few centimetres away you can see the empty eggs shells where the larvae have come from. They have then moved along to feed on their unhatched siblings.

Sibling cannibalism among ladybirds is not unusual. In fact it can be quite common, particularly if there is a shortage of food. It's a mechanism which appears to allow at least some of the ladybirds to get a good start in life as opposed to them all going hungry and dying off.

Larval Moult

This one is doing well. It has shed it's skin and entered another stage in it's development. You have to wonder how many siblings and cousins have helped it to get to this stage.

A larger (probably final instar) larva.

A pupa which looks ready to emerge

A newly emerged adult.

Adult Harmonia conformis

References:

* Osawa, N. 1992.
Sibling cannibalism in the ladybird beetle Harmonia axyridis - Fitness consequences for mother and offspring.
Researches on Population Ecology 34, 45-55.

* Nakamura, K.; Miura, K.; Jong, P.W. de; Ueno, H. (2006)
Comparison of the incidence of sibling cannibalism between male-killing Spiroplasma infected and uninfected clutches of a predatory ladybird beetle, Harmonia axyridis (Coleoptera: Coccinellidae)
European Journal of Entomology 103 . - p. 323 - 326.

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The Fab Four

.... The Beatles Beetles

Here are four beetles that I have come across in the last week or so.

(Click on photos to enlarge)



Soldier Beetle - Chauliognathus lugubris





Nectar Scarab - Phyllotocus rufipennis
Feeding on the nectar of Manuka





Leaf Beetle - Paropsis sp





Common Spotted Ladybird - Harmonia conformis and eggs

The eggs were laid in batches on the bark of my Nectarine tree.

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The Resplendent Leaf Beetle

Aside from moths, there are many other visitors drawn in by a light trap including flies, wasps, bees, and birds. In the course of a week there will always be something new and unusual that I have not seen before. This morning it was the magnificently coloured leaf beetle, Chrysophtharta nobilitata. It doesn't appear to have a common name so, given it's shining and dazzling appearance, I'll put my vote in for the Resplendent Leaf Beetle :-)

Chrysomelidae (Leaf beetles, or Tortoise beetles) is quite an extensive family with at least 153 named species in Tasmania. Many a very difficult to separate so I don't usually try to name them. I'll make an exception with this one as it is so brightly coloured and distinctively marked that it's hard to imagine it being confused with anything else.

For comparison I've also posted a photo of another leaf beetle which came to the trap last week. Note the much more subdued pattern and colouration.

Please forgive the poor quality photos. These beetles are only around 5mm (if that) in length and I'm usually photographing them while I'm still waking up.

(Click to view larger photos)

Chrysophtharta nobilitata

Chrysophtharta nobilitata

A Chrysomelid beetle (Leaf Beetle)

A Chrysomelid beetle (Leaf Beetle)

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Ladybirds

.....or Lady Beetles (or for the Americans, Ladybugs)

I was happy to find a species of Ladybird a couple of day ago that I haven't seen before. It's not uncommon or anything, it's just that I don't seem to get them at my place. In fact the only reason I found this one is because it was on a lettuce that I bought at the shops. It was said to be locally grown so I will assume that at least places it's origin within the confines of Tasmania.

Speaking of ladybirds you may have seen the Ladybird segment on ABC's Catalyst this week. If not you can always watch it online by clicking here. The show reported on the Ladybirds of Australia website. This is a fantastic resource for anyone interested in these fascinating little beetles with photographs of hundreds of Australian species as well as a wealth of information.

There is also a "Ladybirds of Australia" book. Coincidentally, I placed an order for this book last week before becoming aware of the web site.

#1 - Transverse Ladybird - Coccinella transversalis - 5.3mm

#2 - Transverse Ladybird - Coccinella transversalis - 5.3mm

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The Elaterid Clicking Mechanism

..... or How Click Beetles Click

We all know Click beetles (family: Elateridae) click and jump but how do they do it? These beetles will jump to confuse a predator and the technique is also pretty handy for righting themselves if they end up on their back. I have tried to photograph the clicking mechanism in the past without success but a deceased Click beetle made the job a little easier.

How it works

The first segment of the thorax (prothorax) is loosely hinged to the middle segment (mesothorax). Now lets looks at the underside of these two segments. The plate on the underside of the prothorax is known as the prosternum. It has a backward pointing, spine-like process (prosternal process). It slots neatly into a corresponding cavity on the mesosternum (mesosternal cavty)

OK so you've got all that, theres a pointy bit and a corresponding groove or cavity :-) Now think about what happens click your fingers. You put your finger and thumb together and apply pressure until your finger suddenly slips away from your thumb with quite some force. Likewise, the beetle inserts this process (pointy bit) into the cavity and then arches back putting pressure on the process until it suddenly releases from the cavity, springing the beetle into the air.

So just how good are they at righting themselves? One study ran several thousand tests on four species of Elaterids which showed a success ratio of 2 to 1 if the beetle was initially lying flat on it's back. The success was shown not to be through the beetles selecting a particular path through the air but by the body shape having a disposition toward attaining an upright position. Randomly dropping dead or live click beetles on the floor gave a similar success rate in landing in an upright position. On an inclined surface the success rate was as high as 85% to 90%. Thus it seems that the increased chance of rolling or bouncing also increases the success rate in landing upright.

(Click Photos to Enlarge)

#1 - The clicking mechanism of an Elaterid beetle

#2 - Ventral view of an Elaterid beetle highlighting the region shown in image #1

References:

• Program and Abstracts of Scientific Papers Presented at the Marine Biological Laboratory, Summer of 1944 - Biol Bull 1944 87: 153-166

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Leaf Beetle

.....family Chrysomelidae

Well Mosura has just had an extremely traumatic experience with a dental surgeon. One and a half hours to remove a problematic wisdom tooth and quite a bit of jaw bone along with it. Thus, todays offering is is one that involves minimal effort on my part. It is a Leaf Beetle and a reasonably large one at 12mm. It was found in the backyard a few days back under some loose bark of a Eucalypt.

(Click Photo to Enlarge)

A Leaf Beetle - 12mm long

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Mimicry in Longicorn Beetles

.....Macrones sp. and an unknown

I spotted an interesting insect while up the backyard today. It had me fooled for a moment. I initially thought it was a scorpion fly until I looked closer. It seems it is actually a Longicorn beetle, Macrones sp, from the family Cerambycidae. It was around 25mm in length. In the photograph you might notice it is on a Blackwood sapling but it crawled it's way into a flowering Spike Beardheath, Leucopogon australis, no doubt looking for a feed. The adults of these beetles feed on nectar while the larvae are borers in Eucalytus trees. Apparently the Genus Macrones are considered wasp mimicks. As mentioned above I actually thought it was a Scorpion fly but I'm sure it doesn't care what I think as long as the birds reckon it's a wasp :-)

My attention was then diverted by an ant, about 7-8mm in length, crawling up a stem which I was holding away from the camera. Not wanting to be bitten I decided to photograph the ant instead. I took several photos of it side on. Then when it turned on a different angle, I realised it wasn't an ant at all but another Longicorn beetle. Unfortunately the lateral shots did not turn out which is a shame. I've included a blurry shot anyhow just to show how "ant like" it was. The third and fourth photo below shows this beetle.

While watching this one through the lens it came face to face with the original beetle. A wasp mimick meets an ant mimick - You have to wonder if they recognise themselves as beetles :-) Both seemed a little startled but the larger beetle (Macrones sp.) dropped from the branch into the undergrowth.

(Click on Photos to Enlarge)

Macrones sp.

Macrones sp.

Unknown Longicorn beetle - Pos. Ochrya coarctata - about 8mm.(excluding antennae)


Unknown Longicorn beetle - Blurry but you may see how it resembles an ant.


Source of nectar - Leucopogon australis - Spike Beardheath

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A Darkling Beetle

.....Saragus costatus

Whilst in hot pursuit of a small but agile skink, I was removing a few rocks among which it had crawled. My attention was then shifted to the interesting looking beetle you see photographed below. It is 15mm in length and I believe it to be Saragus costatus, one of the Darkling beetles of the Tenebrionidae family. As was the case with this one, these beetles are often found under rocks or among leaf litter. Most likely, it was laying low, waiting to come out at night to feed. Most of the Tenebrionids feed on rotting plant and fungal material although the larvae of this particular genus are root feeders. Along with several other genera they are listed among the False Wireworms which, coincidentally, I mentioned here just a couple of days ago. Another coincidence is that I last saw this species almost a year ago to the day and only a few feet from where this one was located.

Tenebrionidae is a very large family with over 1500 species in Australia. "The Catalogue of the Insects of Tasmania" lists 82 species here in Tasmania including the well known pest of stored grain, the Mealworm. My first post on this blog showed the full life cycle of the Mealworm Tenebrio molitor. It can be viewed here.

(Click Photos to Enlarge)

Saragus costatus - Dorsal View

Saragus costatus - Frontal view

Saragus costatus - Ventral view

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Wireworms

.....The Larval Stage of the Click Beetle

These slender, hard coated, ground dwelling insects are the larvae of Click beetles (Elateridae). Many of them feed on roots and thus a few are considered agricultural pests. Some of the Elaterids are even carnivorous although I'm not aware of whether any of the Tasmanian species are in this category. The "Catalogue of the Insects of Tasmania" lists 38 species from 4 subfamilies. They are slow to mature and some species spend many years in the soil before pupating and emerging (usually Jan/Feb).

The Wireworm in the photographs below was found in my backyard yesterday. While I did not measure it, I would estimate it to be around 12mm - 15mm in length.

(Click on Photo to Enlarge)

A Wireworm

True or False?

The larvae of the Tenebrionidae are also rather wiry and are often referred to as False Wireworms. So how can you tell if you have a true or false wireworm? For one thing, False Wireworms are more cylindrical and are fast moving. The ones I've seen have wriggled quite vigorously when disturbed. There are a few features that will help to identify a True Wireworm. The head will be dark brown. They have a single proleg under the last segment. This segment also has a flattened shield, known as the anal plate, with serrated edges.

(Click on Photos to Enlarge)

Detail of anal segment

Ventral View

Detail of head and thorax - ventral view

A typical adult Click beetle

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Blue Metallic Flea Beetle

.....Altica pagana

These small Leaf Beetles (family: Chrysomellidae) are brilliant in colour, like little iridescent jewels. They are only around 5mm in length. There common name, flea beetle, alludes to their ability to jump. This morning I saw at least 150 of them all within a half metre of each other. They were mostly in 3 large groups as can be seen in the photos but with a few individuals scattered here and there. They were on a piece of treated pine which forms the edge of a pathway.

The larvae of these leaf beetles will feed on plants of the Rosacea family. The adults are on the wing from spring through to autumn.

(Click Photos to Enlarge)

Blue Metallic Flea Beetle - Altica pagana

Blue Metallic Flea Beetle - Altica pagana

Blue Metallic Flea Beetle - Altica pagana

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A Weevil

An interesting Weevil (family: Curculionidae) found while walking along the Emu River at Fern Glade last Friday. Notice the small processes/projections on the elytra. Total length 13.5mm

(Click on Photos to Enlarge)

Weevil - Unidentified

Weevil - Unidentified

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Pitfall Trap

...watch your step

Yesterday at dusk, I set up a pitfall trap. No I'm not hunting stray tigers, not even Tasmanian tigers. The use of pitfall traps is a common way surveying for ground dwelling beetles. I've had some success with them in Scotland and for some time now I've been meaning to place a few up the hill in the backyard.

While there are all sorts of interesting designs out their I have simply used the humble baked been tin. It was buried so that the rim is at ground level. It is placed alongside a log, the theory being a beetle will be merrily walking along following the edge of the log and whistling 'The Road to Gundagai' until suddenly it stumbles into the trap.

The Pitfall Trap

Was it a success? Well there was one one beetle in the trap this morning. So, on current averages one could speculate that 5 traps might produce 5 beetles a night or 150 beetles per month :-) Of course you wouldn't want to put the trap out on a rainy night as the beetles will surely drown.

I will definitely set up another couple of traps, maybe just once a week or so. The main thing that may hold me up is the thought of eating more beans.

The beetle from last night belongs to the family Carabidae, known as Ground Beetles. These are the most likely catch in such a trap. The Catalogue of the Insects of Tasmania list 223 Carabids from 20 subfamilies.

Ground Beetle - family Carabidae (10mm)

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