Autumn fruits — Life in a Southern Forest

Autumn is the season when, according to John Keats, things come to fruition.

A moth emerges from its pupal case to complete its life cycle. A late-maturing plant produces berries or other fruits. Fungi thrust up their fruiting bodies - mushrooms - from networks of soil hyphae.

But autumn can also mark the start of new life.

Many insects mate at this time of the year. In some cases, their larval offspring hunker down for the coming winter in an inactive form. In others, the larva continues feeding - particularly if it’s a herbivore. Many parasitic wasps select active larvae as hosts in which to deposit their eggs.

A few plants flower, using alternative modes of pollination as insects have become scarce. But most just slow down their growth, waiting for longer days, warmer temperatures and the return of their insect pollinators in spring.

This gallery showcases examples of the many sides of autumn life in the forest.

The developmental journey of two moths

The Batwing Moth - autumn marks the end of a 9 month lifecycle

Featured

30th May, 2022

This story began last autumn when we attracted 17 male Batwing Moths (Chelepteryx collesi: family Anthelidae) to our May lightsheet …

30th May, 2022

… together with 2 females of the same species. As you can see, she is a large, beautiful insect. She had apparently met up with one of those 17 males (or perhaps another one) shortly before she came to our attention. The evidence? On the lightsheet she deposited …

30th May, 2022

… this elegant string of eggs. The lightsheet wasn’t the optimal environment for their continued development, so we moved them to our moth (and other insect) rearing cage.

So development starts now!

29th July, 2022

Pretty soon we had around a dozen caterpillars to care for. They readily accepted Eucalypus leaves and grew apace. They were around 17mm long at this stage. Quite striking creatures, but watch those long hairs! They can break off if you handle the caterpillar carelessly and cause severe skin irritation.

25th September, 2022

4 months later, the caterpillars had grown to a length of 58mm, passing through a series of moults - like the one shown here with its former skin.

7th November, 2022

6 weeks later, the caterpillars had grown to around 100mm long. While much larger, they were otherwise little changed in appearance. They became restless soon after, wandering around the cage. Apparently, they are often seen walking along suburban footpaths in Canberra at this stage. In early December, ours started to pupate, building a white, silky cocoon around their bodies.

6th March, 2023

Then 3 months later, a new adult female emerged from one of the pupal cases. You can see the remnant hairs from the larval body protruding from the surface of the cocoon. So from egg to adult takes a full 9 months in this moth species.

6th March, 2023

We carefully moved this female outside and placed her on a bush while she was preparing for her first flight. A half hour later she was gone. Perhaps she’ll appear on our May lightsheet this year!

19th May, 2023

And the cycle starts again! Two male Chelepteryx collesi moths have been attracted to our light sheet tonight - almost exactly 12 months since we last sighted this species.

The Mottled Cup Moth - autumn marks the start of a paused, overwintering stage of development

Featured

Kerri spotted a caterpillar of this species (Doratifera vulnerans; family Limacodidae) wandering in the undergrowth on 24th March. It was probably blown out of the crown of a eucalypt during a windy period. Unlike many moth larvae, it has a distinctive enough appearance to determine its species identity with confidence. But we decided to rear it through to the adult stage in our buddy tank anyway.

Fed on a diet of eucalyptus leaves, the caterpillar - shown here on 10th April - grew rapidly. This photo shows the rosettes of stinging hairs which the larva everts when disturbed. These release a cocktail of toxins when touched, producing a stinging sensation (ref. 1). Doratifera vulnerans means “bearer of painful gifts” - an apt name! The caterpillar gives due warning of its toxicity with its bright colouration. Most birds give it a wide berth, although fan-tailed cuckoos and rosellas have developed ways of dealing with this toxicity as they include it in their diet.

This caterpillar lacks the prolegs found on the rear body segments of almost all other lepidopteran larvae. These are replaced by suckers, which the caterpillar uses to glide around on the leaf. This front-on view shows that the head is almost completely withdrawn into the thorax.

A week later, Kerri noticed that the caterpillar had stopped feeding and had attached itself to this twig. It had woven a spherical mesh of silk around its body, rolling around inside this ball as it did so.

This photo, taken 20 minutes later, shows another view of the caterpillar’s body inside its silk ball.

45 minutes later the weave on the silk ball was finer. The larva continued to rotate inside as it wove its housing.

Five hours later the thickened silk sheath completely hid the caterpillar inside.

24 days later the larva now looks like a gumnut on the twig - hidden in plain sight! The caterpillar will soon enter the pupal stage, during which its body becomes transformed into an adult moth. The emerging moth will escape from the cocoon by pushing against the circular end cap, popping it off. It’s clear where the “cup moth” name comes from.

Kim Sinclair has produced a great YouTube video of the whole process of cocoon formation by Doratifera vulnerans.

We’ll have to wait till next spring to see the emergence of the adult moth from the cocoon. Collett and Fagg (ref. 2) state that in East Gippsland, pupae develop throughout winter and emerge as adults in September to recommence the lifecycle. Our larva has probably paused development at the prepupal stage within the cocoon.

Other moths and some butterflies

Featured

NOCTUOIDEA, Agaristinae

whistling moth caterpillar

NOCTUOIDEA, Agaristinae

Hecatesia fenestrata - the larva of the Whistling Moth, featured in our Summer Sightings blog. Seen here feeding on Dodder Laurel (Cassytha pubescens), on which it will continue to graze over winter. The adults have been reported to emerge in early spring.

NOCTUOIDEA, Agaristinae

PAPILIONOIDEA, Nymphalidae

Banks' Brown

PAPILIONOIDEA, Nymphalidae

Heteronympha banksii - a male defending its territory at the top of a bush. This butterfly only appears in autumn, when it is regularly sighted patrolling sunlit patches around the forest. It lays its eggs on grasses, which the larvae feed on through winter.

PAPILIONOIDEA, Nymphalidae

GEOMETRIDAE, Oenochrominae

geometer moth

GEOMETRIDAE, Oenochrominae

Parepisparis lutosaria - sighted on our April lightsheet. Its larvae feed on Eucalyptus. Moths in the genus often lie with their abdomens twisted to the side, resembling dead or yellowing leaves.

GEOMETRIDAE, Oenochrominae

YPONOMEUTOIDEA, Glyphipterigidae

gem moth

YPONOMEUTOIDEA, Glyphipterigidae

Glyphipteryx gemmipunctella - a rather small but beautiful moth with a very long name. We see this moth during the day in early/mid autumn resting on leaves of sedges, flicking its wings open and closed. Sadly, nothing is known about its life cycle. So I can’t tell you what its caterpillar looks like, what it feeds on or the duration of its larval stage.

YPONOMEUTOIDEA, Glyphipterigidae

NOCTUOIDEA, Erebidae

Amphiongia chordophoides - another April lightsheet moth. This is the first time we’ve sighted this species in our forest. We appear to be at the southern limit of its distribution.

NOCTUOIDEA, Erebidae

PAPILIONOIDEA, Nymphalidae

Common Brown

PAPILIONOIDEA, Nymphalidae

Heteronympha merope - a female resting on the forest floor. The females mate in the spring, but aestivate over the hot summer months, hiding out in the cool gullies. They re-emerge in autumn when they lay eggs on a range of plants, including Themeda and Poa. Their larvae emerge as adults in spring.

PAPILIONOIDEA, Nymphalidae

NOCTUOIDEA, Oenosandridae

Boisduval's Autumn Moth

NOCTUOIDEA, Oenosandridae

Oenosandra boisduvali - the male of this species, shown here, has an interesting speckled pattern on the forewings. It is a sexually dimorphic species - the female has white forewings with a narrow longitudinal stripe of the same pattern as the male’s wings. As befits its name, the adults make their first appearance in early autumn and are gone by the start of winter. The larva feeds at night on Eucalyptus leaves, hiding beneath the bark of the tree during the day.

NOCTUOIDEA, Oenosandridae

GEOMETRIDAE, Oenochrominae

Pink-bellied Moth

GEOMETRIDAE, Oenochrominae

Oenochroma vinaria - a striking caterpillar, larva of an equally attractive moth, seen here on one of our window screens in November. The larva is seen feeding on Hakea macraeana, which will support its development through to the spring, when it will transform into the adult moth.

GEOMETRIDAE, Oenochrominae

NOCTUOIDEA, Notodontidae

Black Spot Moth

NOCTUOIDEA, Notodontidae

Epicoma melanospila - these caterpillars feed gregariously during the day. We found this large cluster in an Acacia longifolia bush. They disappeared suddenly in late autumn. Later stage larvae are reported to be solitary feeders and are widely scattered. The earliest sightings of the adults on iNaturalist are in late spring, so the larvae apparently feed right through winter. We often see the adults from early summer onwards on our lightsheets, displaying its eponymous wing pattern.

NOCTUOIDEA, Notodontidae

PAPILIONOIDEA, Nymphalidae

Brown Ringlet

PAPILIONOIDEA, Nymphalidae

Hypocysta metirius - probably our most common butterfly. It is seen throughout the forest in large numbers from mid spring to mid autumn. Their larvae spend the winter feeding on grasses.

PAPILIONOIDEA, Nymphalidae

ZYGAENOIDEA, Zygaenidae

Cunning Forester

ZYGAENOIDEA, Zygaenidae

Pollanisus subdolosa - a small, but striking moth often seen flying slowly in the forest in early-mid autumn. It can afford to be both conspicuous and slow moving because its body contains cyanide, a product of its own metabolism.

ZYGAENOIDEA, Zygaenidae

A grab bag of other autumn insects (plus a couple of other arthropods)

Featured

ICHNEUMONIDAE, Pimplinae

White-spotted Ichneumonid Wasp

ICHNEUMONIDAE, Pimplinae

Echthromorpha intricatoria - there are many, many ichneumonid wasps in the forest. They become one of the most active groups of insects in autumn, flying here and there searching for a host for their eggs. This one is after lepidopteran pupae.

ICHNEUMONIDAE, Pimplinae

Ichneumonid wasp

ICHNEUMONIDAE, Pimplinae

Xanthopimpla sp. - a small parasitic wasp, often seen in the last month, patrolling the vegetation low in the undergrowth. Like the White-spotted Ichneumonid Wasp, it is searching for a lepidopteran pupa in which to deposit its eggs. Wasps in this genus have been used as a biological control agent for the Light Brown Apple Moth.

ICHNEUMONIDAE, Pimplinae

ICHNEUMONIDAE, Ophioninae

Short-tailed Ichneumonid Wasp

ICHNEUMONIDAE, Ophioninae

Enicospilus sp. or Netelia sp. - we’re not sure which one but it’s definitely in the subfamily Ophioninae of the Ichneumonidae. This wasp often comes to our lightsheets. Species in this subfamily inject their eggs into larval lepidopterans. It includes some of the only parasitoid wasps that can use their ovipositors to sting humans.

ICHNEUMONIDAE, Ophioninae

COLEOPTERA, Belidae

belid weevil

COLEOPTERA, Belidae

Rhinotia lineata - a common but striking weevil, often seen in the forest. Little is known about the biology of the genus Rhinotia but adult weevils in the family Belidae feed on pollen and some are important pollinators. The larvae of some species bore into the wood of Acacia, so it’s probably no coincidence that we saw this adult on a wattle stem.

COLEOPTERA, Belidae

COLEOPTERA, Curculionidae

Botany Bay Diamond Weevil

COLEOPTERA, Curculionidae

Chrysolopus spectabilis - indeed a spectacular beetle! We often see it feeding, as here, on Acacia stems and leaves. This was one of the first Australian insects to be described, having been collected by Joseph Banks and Daniel Solander on Cook’s first voyage.

COLEOPTERA, Curculionidae

DIPTERA, Tipulidae

large crane fly

DIPTERA, Tipulidae

Leptotarsus igniceps - this is one of many crane fly species we see in the forest. They are often seen hanging from vegetation with their enormously long legs. This appears to be a southern species - we are close to the northern limit of its reported distribution on iNaturalist.

DIPTERA, Tipulidae

DIPTERA, Heleomyzidae

fungus fly

DIPTERA, Heleomyzidae

Tapeigaster brunneifrons - a new species for us of a familiar group of flies. These plucky little males take up residence on the cap of a mushroom. I’ve seen other species defending that territory from intrusions by other males, but on one occasion I saw three males of this species sharing a mushroom cap. They mate with females seeking to lay eggs on the gills of the mushroom, which represent a rich food source for their larvae.

DIPTERA, Heleomyzidae

fungus fly

DIPTERA, Heleomyzidae

Here is an overview shot of the male in position on its chosen Amanita sp. fungus.

DIPTERA, Heleomyzidae

DIPTERA, Asilidae

goggle-eyed robber flies

DIPTERA, Asilidae

Bromotheres australis - these rather small flies are, like other robber flies in the family Asilidae, predators. They impale their prey - other insects - with their needlelike hypopharynx and immobilise and liquefy it by injecting a mix of neurotoxins and enzymes. Nice! They are easiest to spot when still and mating, like this pair.

DIPTERA, Asilidae

ORTHOPTERA, Phaneropterinae

Giant Torbia

ORTHOPTERA, Phaneropterinae

Torbia perficita - a large katydid which is a frequent visitor to lightsheets in mid autumn. We reared this species from the egg right through to adulthood on eucalypt foliage. You can read the full story in our blog Growing Up.

The adults lay their eggs in a row on a eucalypt stem in autumn and probably die soon thereafter. The eggs overwinter in a state of arrested development, called diapause, and hatch in late October. They reach the adult stage in mid-late January.

ORTHOPTERA, Phaneropterinae

ORTHOPTERA, Trigonidiidae

Trigonidium cricket

ORTHOPTERA, Trigonidiidae

Trigonidium sp., close to Trigonidium marroo - a very pleasing little cricket, which became increasingly common in mid autumn. This one is a male. Little is known about their biology, apart from their preferred habitat, which is amongst grasses and forbs.

ORTHOPTERA, Trigonidiidae

Southern Pygmy Cricket

ORTHOPTERA, Trigonidiidae

Bobilla sp. - we always seem to get a burst of these small, ground-dwelling crickets in early autumn and this year was no exception. The male, shown here, produces his mating call by rubbing the tiny teeth on a vein of one of the forewings over the other wing.

ORTHOPTERA, Trigonidiidae

PHASMATIDAE, Tropidoderinae

Spur Legged Phasmid

PHASMATIDAE, Tropidoderinae

Didymuria violescens - our visitor Janet discovered this impressive female stick insect in a low bush. She was probably blown out of the forest canopy in the strong winds. After we collected her to take close-up photographs, she began to drop eggs. We released her, but she will not live for much longer as adults are reported to have only a 2-3 month life span after appearing in late summer.

PHASMATIDAE, Tropidoderinae

stick insect egg

PHASMATIDAE, Tropidoderinae

Here is one of the phasmid’s eggs. She will lay around 200 eggs, which typically hatch in November-December. The nymphs take 2-3 months to develop to the adult stage.

PHASMATIDAE, Tropidoderinae

ISOPODA, Porcellionidae

Woodlouse

ISOPODA, Porcellionidae

Porcellio sp. - we don’t get many crustaceans in the forest, so it was a surprise to find this one in a rotten eucalypt log.

ISOPODA, Porcellionidae

ARANEIDAE, Argiopinae

Saint Andrew's Cross Spider

ARANEIDAE, Argiopinae

Argiope keyserlingi - It’s always nice to see one of these in her web with an egg sac.

ARANEIDAE, Argiopinae

Birds and other vertebrates

Featured

Eastern Yellow Robin

Eopsaltria australis - it took a while for the Yellow Robins to recover after the fire, but they’re now back in good numbers.

Rufous Fantail

Rhipidura rufifrons - this is a regular autumn visitor

Grey Fantail

Rhipidura albiscapa - an everpresent inhabitant of the forest. We never tire of watching it doing its back and forth dance on tree branches.

White-faced Heron

Egretta novaehollandiae - this year for the first time, we’ve seen this heron wandering around the block on several occasions. It visits the frog pond but also searches for prey in the forest proper.

White-faced Heron

Egretta novaehollandiae

White-faced Heron

Egretta novaehollandiae - it seems to quite like roosting in the dead wattle trees behind the frog pond

Agile Antechinus

Antechinus agilis - these guys often keep Kerri awake at night as they run back and forth over the flyscreens on our bedroom window hunting insects. I took this photo from my bed on my back looking upwards - hence the rather strange perspective.

Agile Antechinus

Antechinus agilis - Is this one looking at me?

Southern Brown Bandicoot

Isoodon obesulus - this guy is definitely a resident! We often catch sight of it racing away into the bushes when disturbed. But on this occasion it was nonchalantly digging for worms in broad daylight in front of our kitchen window.

Common Eastern Froglet

Crinia signifera - the frog pond has been extremely busy this summer and autumn. Lots of tadpoles and loud mating calls of several species. I managed to catch this pair of Crinia signifera in amplexus.

Common Eastern Froglet

Crinia signifera - very obligingly the pair rolled over to give me a shot of their bellies.

Plants

Featured

RUTACEAE

Common Correa

RUTACEAE

Correa reflexa speciosa - one of the very few low growing plants in flower at this time of the year.

RUTACEAE

FABACEAE, Mimosoideae

Sunshine Wattle

FABACEAE, Mimosoideae

Acacia terminalis - this wattle has been in full bloom for over a month now and is still going strong.

FABACEAE, Mimosoideae

Sunshine Wattle

FABACEAE, Mimosoideae

Acacia terminalis - some bushes are overloaded with blossom!

FABACEAE, Mimosoideae

ROSALES, Cannabaceae

Poison Peach

ROSALES, Cannabaceae

Trema tomentosa - we have two bushes of this plant and this one currently bears a heavy crop of berries. They turn black as they ripen but should not be eaten as they are reported to be toxic to stock.

ROSALES, Cannabaceae

PINALES, Cupressaceae

Port Jackson Pine

PINALES, Cupressaceae

Callitris rhomboidea - We lost all of the trees and bushes of this native pine in the January 2020 fire. Their regeneration from seed has been a relatively slow process but some plants are now over a metre tall. This shot shows the mini-forest of seedlings growing from seed dropped by the single killed bush just behind them.

PINALES, Cupressaceae

ERICALES, Ericaceae

Prickly Broom-Heath

ERICALES, Ericaceae

Monotoca scoparia - these low bushes with their sharp leaf tips bloomed in early autumn.

ERICALES, Ericaceae

Fungi (note: these identifications are very provisional at this point)

Featured

Webcap

Cortinarius sp.

Ocher-gilled Barefoot Lepidella

Amanita ochrophylla

Basidiomycete fungus

Basidiomycota - unidentified at this time

Bonnet

Mycena sp.

Pinkgill

Entoloma sp.

Agaric mushroom

Leucoagaricus

Webcap

Cortinarius sp.

Bracket fungus

Trametes sp.

Bracket Fungus

Trametes sp.

References:

A.A. Walker et al. (2021) Production, composition, and mode of action of the painful defensive venom produced by a limacodid caterpillar, Doratifera vulnerans. Proc. Natl. Acad. Sci. U.S.A. 118 (18) e2023815118.
N.G. Collett & P.C. Fagg (2010) Insect defoliation of mixed-species eucalypts in East Gippsland. Australian Forestry 73:2, 81-90.