Friday, 31 October 2008

How to Catch a Moth

.....A Basic Introduction to Traps and Mothing

It's no secret that moths are drawn to light. As the saying goes one is drawn "like a moth to the flame". Anyone who has spent time around a camp fire may have literally seen moths plunge headlong into the flames. Shakespeare wrote in 1600, "Thus hath the candle singd the moath". He refers to this as already being an ancient saying in his day.

Of course we now know that the moths are not actually drawn by the light but they are confused by it. The moth navigates by means of that timeless luminary, the moon. As kids we would walk around and believe that the moon was following us. The same sensation occurs if you drive along a straight road. The trees and bushes by the side of the road seem to rush past us. The houses further back seem to move more slowly and the distant mountains move very slowly. The moon being at an extreme distance seems to be in a constant position in relation to ourselves and so it may appear to be following us. It is this relatively constant position which enables moths to navigate. Simply keep the moon at a constant angle to yourself and you will be traveling in a fairly straight line for the next hour or so. Flames, or these days artificial light sources, are much closer than the moon. If you try to travel with the artificial light at a set angle to yourself you will soon find yourself going in circles and spiraling in toward the light.


Kitchen Window / Back Porch Mothing

It is this navigational confusion which makes it easy to find moths for photography or study. The most simple method is to look for moths on the kitchen window or you might leave the light on at the back porch. In warmer areas this in itself may provide you with enough moths to satisfy your interest.


The Sheet Method

A step up from this is to hang a white sheet up on the clothes line or by a rope and shine a bright light onto the sheet. This will gives the moths a nice surface to settle on as well as making them easy to spot.


Moth Traps


One problem with the above methods is that you need to be in attendance the whole time or else you'll end up missing those moths that come and go. There are many designs of "moth traps" which will keep the moths happy and in good condition until you are ready to view them.

You can either make your own moth trap or you can purchase one. There are numerous plans on the Internet showing you how to build your own. Some commercial suppliers will sell you kits containing just the electronic components allowing you to design the trap itself. Unless you enjoy the DIY side of things then you may simply want to purchase one ready made.

So which design is the best? There will be many and varied opinions on this. Having said that the "Robinson Trap" is generally considered to be the most effective design. They will generally use a 125w mercury vapour (MV) bulb. These are extremely bright to us and even brighter to the moths as much of the light is in the ultraviolet spectrum and invisible to us. The moths fall down a funnel into the traps body. While very effective, they are also very expensive.


Robinson Trap
(Image courtesy of Anglian Lepidopterist Supplies)



The Skinner Trap is probably the most common design used by amateurs. They usually use the same lighting, that is a 125w MV bulb, but the trap is basically a box with two sheets of perspex sloping down into the top, with a gap where the moths can enter. It's very easy to lift the lid and check out your catch while the trap is still running.


Skinner Trap
(Image courtesy of Anglian Lepidopterist Supplies)


The Heath Trap uses an vertically positioned fluorescent tube surrounded by vanes. The moths hit the vanes and fall through a funnel into the trap. These are the least effective. However, they can be set up to run from a battery thus allowing you to take the trap well away from mains power. While catching fewer moths, many people have commented that some species come to the actinic light which rarely appear at the MV light.


Heath Trap
(Image courtesy of Anglian Lepidopterist Supplies)


There are many variations of the above. For example, for my own skinner trap I have a 125w MV bulb, however I also have 40w actinic flouro tube which I can use instead.

When to Put Your Trap Out

The obvious answer is at night. However, you will find that different species are on the wing at different times. For example some are crepuscular fliers meaning they only fly during the twilight period. Others will fly well after dark. Then there are the ones which only fly in the wee hours of the morning or even around dawn. The conclusion is obvious. For best results you want the trap to be running all night. Of course that is not always practical. I have recently had an external power point fitted to the shed so I can leave the trap on without having to leave the window open all night. There is another catch though. What if it rains? You can fit a protective cover over your bulb. This is something I need to do myself. At the moment I have to check the forecast as even light rain can potentially explode the hot MV bulb. If you have neighbours close by you will also need to consider whether the bright light is maybe shining through their windows and depriving them of sleep.


Eucylodes buprestaria - I only ever get this moth by leaving the trap on overnight.


The warmer it is the more active the moths are. Also humid conditions seem to bring out more moths with many of them only emerging after periods of rain.. Another thing to look for is an overcast sky. On a clear night with the moon shining the moths are less likely to be tricked into approaching your trap. Windy conditions also seem to reduce the amount of moths. So, a calm cloudy, hot and humid night might give great results. Keep in mind though that some species may only be on the wing in winter so a variety of conditions will ultimately give you a wider variety of moths.


Keeping the Moths in the Trap.

Moths can and will escape from a Skinner trap. You need to encourage them to stay. The simplest way to do this is to place egg cartons inside the trap. This will give the moths a variety of nooks and crannies in which to settle. Sometimes the trap may look empty until you start turning over the egg cartons.

..... catch of the day hiding among the egg cartons


Predators too will quickly learn that your trap is full of potential prey. At my place, Kookaburras have been known to arrive at dusk and wait for the trap to go on. Sparrows and Fairywrens will actually get inside the trap and start helping themselves. Other birds will be waiting for you to release your moths each day. All you can do about this is to try and vary the position of the trap and the time of day you release the moths.

Another handy thing to have is a butterfly net. If you are outside watching the action around your moth trap you'll notice not only the odd escapee but also some large moths that will fly in and then actually head away again. With the net it's easy to sweep them up and place them into the trap for later inspection.

A Butterfly Net


Other Ways of Finding Moths

Sugaring and Wine Roping

Sugaring is another method used to attract moths. Usually it consists of a sticky mixture of ingredients such as treacle, brown sugar, rotting fruit, ale, wine, brandy etc etc. Everyone seems to have their own secret ingredient. This is painted onto a tree trunk or post. An alternative to this is Wine Roping where ropes are soaked in red wine and sugar. Short lengths are then hung in branches of trees. I have had only limited success with these methods when I was in Britain although I know they have worked well for others. I have read that these methods are not very successful on Australian moths but it is certainly something worth trying.

Searching

Not all moths will come to lights or sugar. Sometimes you will have to go to them. Try checking out flowering native plants at night with a torch. Also day flying moths such as Eutrichopidia latinus not likely to appear in a light trap. Then there are the Glyphipterigids (or just glyphips). These small moths are also active by day and are found on flowers.

Rearing

Sometime the only way you will see a particular moth is to rear it yourself from eggs or larvae. For example what hope have you got of a female Painted Apple moth appearing in your trap. These are completely wingless. The rearing of moths is whole other subject in itself which I really should do a blog post on. For now I shall merely mention it as another avenue of finding moths.

Assembling

This technique involves placing a virgin female moth in a net bag or cage upwind of the habitat where the males can be found. This can bring in males from some distance away depending on the species. In Britain it works particularly well with the Emperor Moth and I've been meaning to try it out with a Helena Gum Moth.


Well I hope this post has at least given an overview of the methods of mothing and maybe it will inspire someone to get away from the computer and the telly and have a go but I warn you - once you get started the hobby will draw you in like a moth to the flame.


My moth trap in action last night.


.....and some more of todays catch


Wednesday, 29 October 2008

A New Moth

Mothing - 29th October 2008
.....Culama australis


Not much in the trap tonight I thought to myself. There was a Helicoverpa sp and a Crexa Moth, Genduara punctigera both of which I posted photos of a couple of days ago. Then there was a Goat Moth which at first glance I thought was the Australian Goat Moth, Zyganisus caliginosus. Seen plenty of those I thought but as I hadn't shown one on the blog before I put it aside for photographing. Then I noticed the grey behind the head instead of the normal creamy buff colour. After closer inspection I found it was actually Culama australis which is a new species for my backyard moth list. For you birders out there that's every bit as exciting as any new bird tick.

You can see the similar looking Zyganisus caliginosus by clicking here which as it happens is one of my own photographs taken here in my backyard.

Apparently the larvae of this species bore just below the bark of Eucalypts whereas most Cossids are deep borers.

(Click Photos to Enlarge)

#1 - Culama australis (Cossidae : Cossinae) - FW 23mm


#2 - Culama australis (Cossidae : Cossinae) - FW 23mm




Monday, 27 October 2008

Mothing - 27th October 2008

We had a very warm night last night. The temperature was still around 15 degrees at midnight. Unfortunately I couldn't leave the moth trap on all night as there was a risk of showers but a few did turn up before I hit the sack.

First up there were 3 Helena Gum moths which you can see below photographed on my assistants hand. These are all males so I won't be getting any eggs from these.


(Click to Enlarge all Photos)
.
#1. Helena Gum Moths - Opodiphthera helena (Saturniidae)


Next up is a small Pyralid. This family often sits high on it's front legs with the antennae straight back along the body. The wings often for a triangular shape.

#2 - Unknown Pyralid (Pyralidae)


The migratory Bogong Moths have been appearing over the last 2 weeks. These generally spend the warmer months in the mountains, particularly around the Bogong High Plains in Victoria. However, many of them overshoot their destination and end up in Tasmania.

#3 - Bogong Moth - Agrotis infusa (Noctuidae : Noctuinae)


Two other Noctuids were in the trap. Like the Bogongs, these are both known to be migratory species.
#4 - Southern Armyworm - Persectania ewingii (Noctuidae : Hadeninae)


#5 - Native Budworm - Helicoverpa sp. probably: punctigera (Noctuidae : Heliothinae)


.....and of course there were plenty of insects other than moths. Carious beetles, flies, wasps etc including the two shown below.

#6 - A Lacewing - (Neuroptera)


#7 - An Ichneumon Wasp - (Hymenoptera : Ichneumonidae)



Sunday, 26 October 2008

Mothing - 24th - 26th October 2008

The last few nights have produced a few moths although nothing new. I've included a few photos below.

The Psychid or Case Moth (Photos #2 & #3) is the most common member of this family that I see here but I'm still not sure on it's identity so if anyone has a suggestion please let me know.

The Hakea Moth, Oenochroma vinaria, had a damaged wing so wasn't much good for a dorsal view. This moth has more common names than most moths including:
  • Pink Bellied Moth
  • Hakea Moth
  • Grevillea Moth
  • Wine-coloured Moth
I'm sure there will be others.


(Click on Photos to Enlarge)
#1 - Rhapsa suscitatalis (Noctuidae : Catocalinae)


#2 - Ventral view - Unknown Case Moth (Psychidae)


#3 - Dorsal view - Unknown Case Moth (Psychidae)


#4 - Onycodes traumataria (Geometridae : Oenochrominae.)


#5 - Onycodes traumataria (Geometridae : Oenochrominae)


#6 - Hakea Moth - Oenochroma vinaria - (Geometridae : Oenochrominae)


#7 - Crexa Moth - Genduara punctigera (Lasiocampidae)




Thursday, 23 October 2008

An Anthelid Moth

.....Anthela repleta

I feel pretty certain this is Anthela repleta. For the sake of accuracy I'll mention that
A. repleta and A. acuta both seem to be quite variable and overlap a little in their appearance. It's a male as can can be seen from the broadly bipectinate (feathery) antennae.

This one was found in the moth trap two nights ago. The adults of the suborder Anthelinae only have vestigal mouthparts and thus cannot feed or drink. They therefore have to rely fully on the fat reserves which were built up during the larval stage. The larvae of both the above mentioned species feed on Acacia spp.



(Click on Photos to Enlarge)
#1 - Anthela repleta - Dorsal view


#2 - Anthela repleta - Frontal view



Monday, 20 October 2008

Helena Gum Moth

.....Opodiphthera helena

I found a gravid female Helena Gum Moth last night. Australia has 14 members of the Saturniidae family and some of them can look rather similar. Thus the Helena Gum Moth is sometimes confused with the Emperor Gum Moth (Opodiphthera eucalypti). In Tasmania it's really quite simple as Opodiphthera helena is the only one we get here. The one shown below is the first I've seen this season. As is often the case this female was found flailing about on the ground looking half dead. The problem is she is full of eggs. Once they land they seem to have a real hard time getting air borne again and even then they will often only flutter a few metres away. If you pick them up they will happily sit on your hand after first giving a few warning signals. That is to say they open and close their wings in order to reveal the large eyespot on the underwings. You can see this in the small video I've included below.

She has laid 55 eggs since last night although I have no way of knowing how many she laid prior to my finding her.

Update: The following night she laid another 53 eggs bring the total t 108 eggs.

(Click on Photos to Enlarge)
#1 - Opodiphthera helena - Helena Gum Moth


#2 - Opodiphthera helena - Helena Gum Moth


#3 - Opodiphthera helena - Eggs of the Helena Gum Moth
- No I did not use baked beans for this shot :-)






#4 - Notice it reveals the large eyespots when I shake my hand



Sunday, 19 October 2008

Don't Count Your Chickens 'til They've..........

..... Oh 'ang on... they've hatched - all 5 of them!

Well it it's not nature in the 'wild' sense but it's certainly natural. We have chooks and ducks nesting all over the place in the backyard at the moment. These ones just hatched this morning.

All but one of these are Silkies. The last shot is an Old English Game bantam. The bantam has been sneaking eggs into other chook nests. Perhaps there are some Cuckoo genes in there somewhere :-) In any case it is the best looking bird of the lot but unfortunately it is also the weakest and seems to be having trouble standing. Time will tell.


(Click on Photos to Enlarge)

#1 - Hatchlings


#2 - Hatchlings


#3 - 'Old English Game' bantam


Friday, 17 October 2008

Mothing - 16th - 17th October 2008

..... or "A Sparrows Breakfast Party"

Last night was quite warm at about 13 degrees with only a light breeze blowing and reasonable amount of cloud cover. Great conditions for mothing I thought so I decided to leave the light trap on overnight. Off I went to bed, jaw still aching from last weeks dental appointment at the local butcher shop but with my head filled with pleasant thoughts of wonderful new species of moth which would be spiraling around my moth light and would be waiting for me in the morning. (Can you tell I've had too many pain killers :-)

Morning came and it seems my hunch was right. Yes it must have been a great night judging by the two fat sparrows that were caught in the trap this morning. Unconcerned about their predicament they simply continued on eating the few remaining morsels left strewn among the diverse collection of moth wings and legs. This is not the first time this has happened as I've had sparrows in the trap on several other occasions.

Predators are quick at spotting new opportunities for an easy feed. In the past I've had Kookaburras regularly arriving at dusk to feed on the beetles and moths coming to the light. My domestic chickens and ducks also quickly learned that when I lift the lid on the trap there would be some easy pickings. I would have to literally fight them off. Fortunately I now have them fenced off into another part of the yard. In Britain I had cats coming to the trap and I've known of other people with foxes regularly coming to moth traps too. Even the Pipistrelle bats used to hang around the lamp post outside my house for the same reason. I guess there's not a lot you can do to stop this other than varying the time of day that you check your trap and not always placing it in the same location.

Wednesday night did not offer such great conditions but at least the few moths I did catch survived the experience. The most interesting was the Geometrid I've shown below that is a new one for my site. I don't yet have an ID for it so feel free to offer suggestions if you recognise it.

As of 2pm it's 18 degrees outside - the hottest day we've had this side of winter so hopefully another good mothing night tonight. The sparrows are already chirping and tweeting in anticipation.

Edit: I was way of the mark with this one but thanks to some outside help I now have an ID. It is Praxis porphyretica a Noctuid of the subfamily Catocalinae.



(Click on Photos to Enlarge)
#1 - Praxis porphyretica - Dorsal view - Forewing 20mm


#2 - Praxis porphyretica - Ventral view (Unfortunately through a dirty jar)


Wednesday, 15 October 2008

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


Tuesday, 14 October 2008

A Nesting Earwig

.....Order: Dermaptera

You might not think of female Earwig as being a nurturing mother but that is exactly what they are. Whereas most insects aside from the Hymenopterans will just lay their eggs and fly (or crawl) off, the earwig actually makes a nest. The other day, after moving a rock, I noticed a nesting earwig. With the roof of her burrow mostly gone she went about moving the eggs one by one into the far end of the burrow which was still a little bit more enclosed. We have a least six species on Tasmania. This one appears to be the introduced European Earwig, Forficula auricularia. In any case I replaced the rock and will keep an eye on them. Maybe I'll have a chance at photographing the hatchlings.

When the female European Earwig nests, it will form a little burrow under a rock or log where it will lay from 20 - 90 eggs. It will stay with the eggs to protect them and will even lick them clean to keep them moist and also to prevent fungal attack. After hatching, the first instar nymphs will stay with the mother. By the first moult (2nd instar) the young will start to forage but will still return to the nest. By the third instar they will be independent.

The cerci of an earwig are quite large and act like forceps. These can be used to tell male from female as the male cerci are much more curved. (See diagram)


(Click on Photos to Enlarge)

#1 - Forficula auricularia -European Earwig
Moving eggs after disturbance


#2 - Forficula auricularia -European Earwig
One to go


#3 - Forficula auricularia -European Earwig
All eggs present an accounted for
.


#4 -Sexual dimorphism in Dermapteran cerci (or forceps)


According to the "Catalogue of the Insects of Tasmania", the following species occur in Tassie:

Aanisolabidae
Aanisolabinae
  • Anisolabis sp
  • Gonolabis pacifica
Isolabellinae
  • Euborellia tasmanica
Forficulidae
Forficulinae
  • Forficula auricularia
Labiduradae
  • Labidura riparia
Spongiphoridae
Nesogastrinae
  • Nesogaster ruficeps





Blotched blue-tongue Lizard

.....Tiliqua nigrolutea

On Sunday my wife came across a Blotched Bluetongue Lizard on the road so she brought it back home where we released it in the bush up behind our house. Of course I first took the opportunity to get some photos.

The Blotched blue-tongue is found in the south-east of Australia and Tasmania. On the mainland it is usually found at higher elevations but here in Tassie it is found from sea level up to around 750m. They are omnivorous, feeding on insects, snails, flowers, and fruit. In a backyard situation they will be attracted by pet food and your strawberry patch.

These are the largest lizards in Tasmania. Head to vent they grow to around 30cm or up to about 45cm including the tail. This one was 42cm. I had one in the yard last year which I reckon would have been at least half a metre. I didn't realise at the time that it was above average so I wish I had measured it more accurately.

You may see from the photos that this one has an injured rear right foot, perhaps from a previous close shave with the traffic. At least if this one appears on my block again in future I'll be able to recognise it.

(Click on Photos to Enlarge)


#1 - Tiliqua nigrolutea - Blotched blue-tongue


#2 - Tiliqua nigrolutea - Blotched blue-tongue


#3 - Tiliqua nigrolutea - Blotched blue-tongue


#4 - Tiliqua nigrolutea - Blotched blue-tongue


#5 - Tiliqua nigrolutea - Blotched blue-tongue - Note the scaly eye lids


#6 - Tiliqua nigrolutea - Blotched blue-tongue - Head Scales


#7 - Tiliqua nigrolutea - Blotched blue-tongue - Previous injury



Monday, 13 October 2008

Mothing - 13th October 2008

.....or should that be butterflying?

The weather has been a little bit milder so I put the moth trap out last night. It attracted several large Click beetles and half a dozen large Black Scarab beetles. It also pulled in a Yellow Admiral Butterfly at about 10:30pm. This is not that unusual as I've had butterflies in the trap before. In Scotland I occasionally found Red Admirals in the trap. Surprisingly, a few moths also made an appearance.

Edit: I originally had the white Lymantriid shown below listed as Acyphas semiochrea. I received an email explaining why it is in fact Euproctis melanosoma. Thanks for the correction.

All up, aside from the beetles I had:

Lymantriidae
  • Euproctis melanosoma
Geometridae
  • Melanodes anthracitaria - Black Geometrid (yellow form)
Noctuidae
  • Agrotis munda
  • Praxis edwardsii
Nymphalidae
  • Vanessa itea - Yellow Admiral

(Click Photos to Enlarge)

#1 - Vanessa itea - Yellow Admiral


#2 - Euproctis melanosoma - Vental view showing orange/brown anal tuft


#3 - Euproctis melanosoma