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Nymphs of Green Shield Backed Bug: Coleotichus costatus

Nymphs of Green Shield Backed Bug sitting on Red-Eyed Wattle. Note the seeds and the seed pods. Nymphs of Green Shield Backed Bug wit...

Tuesday, 14 February 2017

The Insect Diary featured on ABC South West

Please find my feature on ABC (Australian Broadcasting Corporation) South West. Many thanks to ABC for this.


Native Cockroaches of Australia

A beautiful cockroach is quite an oxymoron. True in case of Australian bush cockroaches. They are not only visually stunning, but also most of them are not regarded as pests and are not associated with disease like their American counterparts. They mostly live in the bush and seldom get indoors. They feed on various insects and are the food of various small reptiles and other insects which makes them an important part of the ecosystem. Below are some native bush cockroaches of South West Western Australia. 

Phylum: Arthropoda
 Class: Insecta 
Order: Dictyoptera 
Family: Blattidae

1. Mitchell's Diurnal Cockroach
Polyzosteria mitchelli
Also known as Mardi Gras cockroach
This was found in Kalbarri National Park, Geraldton, Western Australia. It was basking in the sun on a leaf on a very windy day. This is an adult which is wingless and doesn't have any remnants of vestigial wings. It has dorso-ventrally flattened body which is characteristic of cockroaches. Its body is steal blue in colour with yellow markings on the thorax. It is quite a pretty looking cockroach.It is extremely shy and hide under the foliage when disturbed. They are known to emit pungent defensive fluid as self defence. 

2.Ellipsidion Cockroach
Ellipsidion humerale

Ellipsidion is the most common and probably well known genus of Australian native cockroaches. They are winged and have beautiful golden lace like pattern on the wings. They are commonly found in woodland. They hide underneath the leaves and occasionally come up to sun themselves. They are very shy and rude away when disturbed. They are harmless, almost never live in houses and are not regarded as pests. Both the above photos are of Ellipsidion humerale. 

3. Gisborne Cockroach
Drymaplaneta semivitta
Gisborne Cockroach: Drymaplaneta semivitta
Drymaplaneta sp. at the mercy of a Carnaby's Wall Skink (Cryptoblepharus australis)
The genera Drymaplaneta is native to Australia. The two species of cockroaches in this genera are commonly found both in woodlands and sometimes indoors. Even though they are found in large numbers sometimes, they do not infest food and not regarded as pests. The two species D. semivitta, the Gisbourne cockroach and D. communis, are very similar. The Gisborne Cockroach is uniformly dark and the hind tibia of the male are expanded compared to the Common Shining Cockroach (as seen in the above photo). Both have absent vestigial wings, unlike many cockroaches.

Below: photos of cockroach nymphs, mostly Ellipsidion sp.

Reference: padil.gov.au

Tuesday, 20 September 2016

Gum Tree Hopper: Eurymeloides species

Location: Bunbury, Western Australia.
Season: Early spring 2016
Class: Insecta 
Order: Homoptera 
Suborder: Auchenorrhyncha 
Infraorder: Cicadomorpha 
Superfamily: Membracoidea 
Family: Cicadellidae 
Genus: Eurymeloides
Eurymelidae punctata

Eurymelidae is a genus of Gum Treehoppers which is found all over Australia. They mainly feed on eucalyptus trees. Both adults and nymphs have sucking moth parts that penetrate the tree and suck the sap. The excess sugar that the treehopper doesn't need is excreted which attracts the ants. In exchange for the sugar secretion, the ants provide protection for the nymphs and adults. Ants deter predators that could potentially attack the treehoppers. This symbiotic relationship is mutually beneficial to both ants and the treehoppers. The adults and the nymphs stay in groups, don't move far away from each other and hardly hop. They walk away to the nearest group and huddle up when spooked.

In the above photos, adult treehopper of Eurameloides sp is predominantly black with red ocelli. The tented wings have white and yellow patterned lines running through them. The nymphs at different stages have stark red on black pattern. This morphological feature is seen in Eurymelidae punctata according to this source.

Reference: http://www1.dpi.nsw.gov.au/keys/leafhop/eurymelinae/eurymel.htm

Thursday, 21 July 2016

Pittosporum Shield bug: Pseudapines geminata

3rd or 4th instar nymph of Pittosporum shield bug among the seeds in the pod of Karo plant.

Adult Pittosporum shield bug

Nymph of Pittosporum Shield Bug

Early instar nymph of pittosporum shield bug
Class: Insecta
Order: Hemiptera 
Suborder: Heteroptera
 Infraorder: Pentamomorpha
 Superfamily: Pentatomoidea 
Family: Pentatomidae
Genus: Pseudapines 
Pseudapines geminata 

Pittasporum is a genus of shrub native to New Zealand, Australia and parts of Asia and Africa. Whereas some Pittosporum plants such as Sweet Pittasorum, Pittasporum undulatum, are common in East coast, many Pittasporum plant species are introduced to Western Australia. Along with the plant, the shield bug that is specific to the host plant is also introduced. The above plant that grows in my garden in Bunbury, WA is P. crassifolium, commonly known as Karo in New Zealand, with different stages of the corresponding shield bug on it.

The nymphs of Pittosporum Shield Bug: The early instar nymphs are about 2 to 3 mm in size and circular in shape. The black body has symmetrical white spots. They lack wings, as any nymphs of hemiptera. The antennae are orange in colour, the last segment is black. They are shy and hide behind the leaves when disturbed.

The adults of the Pittosporum Shield Bug: The adults have wings. The shield shaped body is dull black with white spots. The outer edges of wings, thorax and the abdomen are orange in colour.  The first two segments of the antennae are orange in colour, followed by alternating black and orange segments.

The relationship between the Pittosporum plant and the shield bug is that of symbiosis based on mimicry complex. The seed pods are three valved capsules which split to expose black sticky seeds with in. The nymphs and the adults of Pittosporum Shield Bug are black in colour with white spots which make them look very similar, almost indistinguishable from the seeds. The seeds serve as food for the shield bug. The shield bugs use their piercing mouth parts to suck the nutrients through the hard outer layer of the seed. When birds and other insects predate on the shield bug, they also carry the sticky seeds with them which helps in dispersion of the seed and propagation of the plant. The shield bugs protect themselves by releasing an alkaloid cocktail which can cause an allergic reaction to the predators (and to humans who handle the insect). These shield bugs are widely regarded as pests of this garden decorative plant, which itself is not native to the region.

reference: Guide To Wildlife of Perth And South West

Wednesday, 9 December 2015

Nymphs of Green Shield Backed Bug: Coleotichus costatus

Nymphs of Green Shield Backed Bug sitting on Red-Eyed Wattle. Note the seeds and the seed pods.
Nymphs of Green Shield Backed Bug with the Red-Eyed Wattle pods.
Location: Bunbury
Season: Early Summer 
Class: Insecta 
Order: Hemiptera 
Suborder: Heteroptera 
Infraorder: Pentatomomorpha 
Superfamily: Pentatomoidea 
Family: Scutelleridae
Coleotichus costatus

These colourful nymphs were found on Red-Eyed Wattle (Acacia cyclops).

Relationship between Red-Eyed Wattle and Green Shield Backed Bug
Red-Eyed Wattle has dry twisted pods within which lie glossy black seeds encircled by two folds of a large orange to bright red fleshy stalk-like structure. The black seed looks like an eye and the surrounding orange-red aril looks like a stalk, giving it the name Red-Eyed Acacia and the botanical name cyclops (stalk eyed).The seeds attract ants and birds. Birds like Honey-eaters and Wattle Birds feed on the seed, digesting the red aril and excreting the black seed which helps in dispersion of the seed and propagation of the plant. The interaction with ants is one of the most important mutualistic mechanisms for seed dispersal. Ants carry the seed with the encircling aril into their underground nests. The aril is nutritious but the ant cannot pierce the hard seed. The seeds are cast away, sometimes burst out of the nests during bush fires, helping the dispersal of the seed and propagation of the plant. This process is called Myrmecochory.

Red-Eyed Wattle is one of the known host plants for Green Shield Backed Bug. The nymphs and adults feed on the plant. Their piercing mouth parts are strong enough to penetrate the hard seed. The nymphs of the Green Shield Backed Bug resemble the seed and almost indistinguishable from the seeds unless examined closely. This a mimicry model. The insect nymph is at risk of predation from birds due to its bright colour. This has probably been exploited by the plant which mimics the insect to get the attention of birds for seed dispersal. Hence, the nymph may be the model and the seed may be the mimic.

The bugs have evolved to protect themselves. In order to deter the predators, these shield bugs emit toxic alkaloids. These alkaloids can be emitted when the bug is handled by humans as well. These chemicals are also responsible to the 'stinkiness' of the stink bug. They also have strength in numbers. They line up resembling a longer insect (like a caterpillar) to confuse the predators. The adult has the colouring of the seed pod. It camouflages itself from the predators, contrary to the nymphs which stand out.

Description of Green Shield Backed Bug
Life Cycle of Coleotichus costatus
Top left: Eggs hatched
Top right: Early instar nymphs
Bottom left: 4 or 5th instar nymph
Bottom centre: ecdysis nymph to an adult
Bottom right: adult nymph
Eggs: These hatched eggs are typical of hemiptera eggs. They have pearlescent shine and a neatly cut circular cap from which the nymph has emerged. It was found on the pod of the Red-Eyed Wattle.
Early Instar nymphs: These are tiny, about 2 cms in length. They closely resemble the red eyed wattle seeds. They have dark dark centre with an encircling red pattern. They are highly iridescent.
4 to 5th Instar nymphs: (given the progression of the wing bud and the 3 segment antennae). These nymphs are 2 - 3 cms in length, much bigger than the seed. They have a red and green iridescent pattern.
Just hatched adult: Immdediately after ecdysis, the adult is pink in colour. It has a smooth body and doesn't use its wings. It was noticed that the adult crawled out of the shell, rather than flying out. As they grow, the colour of the adult body changes. The pink gradually becomes brown. It develops green metallic patches on the body which shine with the light. The colour is very similar to the seed pod of the red-eyed wattle, offering it camouflage and protection from predators. The adults are shy, slow moving and were not seen flying at all.
The adults have a simple eye, one red dot above each of the compound eyes.

The family Scutelleridae is a family of Jewel Shield Bugs. Most Shield Bugs of this family have bright colours and metallic sheen making them one of the most attractive bugs of the Hemipterans. The famous Cotton Harlequin Bug belongs to this family. It is only found in East Coast of Australia. The West Coast has Red Jewel Bug which has different markings on the abdomen than the Green Backed Jewel Bug. 

These Shield Bugs are True Bugs. They often confused with beetles (Coleoptera), which are essentially very different to the Hemipterans. A few general features of Hemiptera can be seen here.

Different stages of the Coleotichus costatus showing the Red Eyed Wattle seeds and seed pods.
Fully grown adult
Ecdysis, 5th instar nymph and adult
exoskeleton after ecdysis

Friday, 27 November 2015

Black Faced Percher: Diplacodes melanopsis

Location: seasonal swamp, still water,
Bunbury, Western Australia
Season: Spring/Summer
Class: Insecta 
Order: Odonata 
Family: Libellulidae 
Genus: Diplacodes
Diplacodes melanopsis

Black Faced Percher is a medium sized dragonfly measuring about 5 cms in length. It has a bright scarlet red body. The eyes, head and the thorax are dark red to black, hence the name Black Faced Percher. The abdomen has black markings on each segment on the bright red background. It can be (easily) distinguished from the other red coloured dragonflies, the Scarlet Percher and Wandering Percher by the markings on the abdomen. While the Black Faced Percher has dark (heart shaped) markings on each abdominal segments, the Wandering Percher has smaller less prominent markings and the Scarlet Percher has no markings at all. The Black Faced Percher, of course, has a black head and thorax which are red in the other two.

This Black Faced Percher's perching pattern is parallel to the long grass but perpendicular to ground. The Scarlet Perchers perch mostly parallel to the ground. One other difference is the wings of the Scarlet Percher has red patch at the base of the hind wings. The Black Faced Percher has clear wings with black pterostigma and a small area of red patch very close to the border of both hind and the fore wings.

Reference: Brisbane Insects

Sacrlet Percher: Diplacodes haematodes

Class: Insecta 
Order: Odonata 
Family: Libellulidae 
Genus: Diplacodes
Diplacodes haematodes

Scarlet Percher is a completely red coloured dragonfly with bright red eyes, head, thorax and abdomen. The abdomen lacks markings which distinguishes it from other red dragonflies, the Black Faced Percher and the Wandering percher. The wings are clear with red patch at the base of hind wings, red costa and red pterostigma. The above is a picture of a male. The females are paler red to yellow in colour. The female has black marking on the abdomen. There is a yellowish brown coloration to the wing tips of the female.

The Scarlet Perchers tend to perch parallel to the ground around water bodies, appearing to sun themselves. They often compete with each other and with much larger Blue Skimmers for perching spots.

Wednesday, 25 November 2015

Tick Tock Cicada: Physeema quadricincta

Class: Insecta 
Order: Hemiptera 
Suborder: Auchenorrhyncha 
Infraorder: Cicadomorpha 
Superfamily: Cicadoidea
Physeema quadricincta
(previously known as Cicadetta quadricincta)

Tick Tock Cicada is the most common cicada seen (mostly heard) around Bunbury during early summer. These cicadas have a classic calling song which is soft clicking, more clip-clop than tick-tock. They are mostly found in low lying grasses of the heath. They are as big as a bee in size, much smaller than the other common Red Bandit Cicada. With some perseverance they are easy to spot if the call is followed. They tend to have a weak flight when disturbed. They more or less jump to the nearest grass straw. They don't look particularly remarkable at the first sight but when the sunlight hits, they dazzle. The black body has olive green to yellow pattern on it, that shimmers with a golden shine. The abdomen has paler rings. The wings are clear with a brown costa. The underside is pale green. This species is endemic to the South West of Western Australia. 

References: http://www.mapress.com/zootaxa/2012/f/zt03287p262.pdf

Friday, 11 September 2015

Black And White Tiger Moth: Spilosoma glatignyi

Macro image of caterpillar 

Class: Insecta 
Order: Lepidoptera 
Family: Arctiidae 
Ardices glatignyi
(Formerly Spilosoma glatignyi)

This Black And White Tiger Moth is an Australian moth that is easily identified by the black/brown pattern in white wings. The abdomen has black and orange horizontal stripes. Thorax is covered in white hairs. It has black eyes with variable orange pattern on the head. 

The above photos were taken during different times. The first photo was in Summer 2014. The second and the third photos were taken in Autumn 2015 which show the eggs laid by the female. The caterpillars (at a late instar phase) are black and orange. They are very hairy. The mandibles and thoracic legs are bright red. I have seen the caterpilars voraciously feed on African Daisy.


Angled Satin Moth: Thalaina angulosa

Angled Satin Moth, Underside

Class: Insecta 
Order: Lepidoptera: 
Family: Geometridae
Thalaina angulosa

This beautiful moth was attracted to my kitchen window light on an autumn evening. This moth has satin-like white wings. The forewing has a stark orange line pattern on it. The orange lines have a black margin, making the pattern stand out on the white background. The hindwing is mostly white with a black wavy patch on it.
The pattern of the orange line is specific to this moth. It can be easily confused with Thalania clara. The orange line of T. angulosa runs from almost parallel to the margin of the forewing (base to the centre of the margin) T. clara can be seen here 

Reference: butterflyhouse.com.au/

Heliotrope Moth: Utetheisa pulchelloides

Class: Insecta 
Order: Lepidoptera 
Family: Arctiidae 
Subfamily: Arctiinae 
Utetheisa pulchelloides

This pretty moth was my nighttime kitchen window visitor on a fine spring evening. This moth is small with a wingspan of about 4 cms. It has white wings with beautiful orange and black spots. The costal margin of the forewing has a broken orange line, the fringe has dark spots. The underside of the moth also has black and orange pattern. 

Trichoplusia lectula

Location: Bunbury
Season Winter
Class: Insecta 
Order: Lepidoptera 
Family: Noctuidae 
Trichoplusia lectula

This unglamourous drab moth was found on our window one sunny afternoon. This moth has dark brown forewings and pale hind wings. When the moth rests, the folded forewings have a pattern resembling horns. It looks like the moth has horns on its back. There is a cream line from the base to the edge of the forewing.