Identification
Physical Characteristics
Size: The female's body length is about 8mm, but her width is more impressive. Males are tiny and rarely seen, measuring only 2-3mm long.
Coloration: The abdomen of the female is a stunning mosaic of colours. The upper surface is typically olive green and yellow, with white, red, and black markings. The two large spines are usually bright yellow or reddish. The underside of the abdomen is dark, often with red patches. The cephalothorax and legs are a uniform reddish-brown or dark brown. This vibrant colouring provides excellent camouflage among leaves during the day.
Key Features: The female is unmistakable due to her very wide abdomen featuring two large, pointed spines or 'horns'. This, combined with her bright colouration, makes her unique among Australian spiders. Her specialised method of hunting without a proper orb web is another key, though behavioural, distinguishing feature.
Biology & Lifecycle
Development & Reproduction
Reproduction Rate: Each female produces a single string of egg sacs in her lifetime, but this chain can contain several hundred eggs in total, ensuring a healthy next generation.
Lifecycle Details
Egg Stage
Mating occurs in late summer or autumn. The female then constructs a series of distinctive egg sacs. She produces up to seven sacs, which are joined together in a line, resembling a string of brown beads or tiny spindles. This 'necklace' of sacs is made of tough, brown silk and is suspended amongst foliage, often hanging from a twig. Each individual sac in the string contains numerous eggs. This unique, spindle-shaped, connected egg sac chain is a key identifier for the species, even when the spider isn't present.
Larval Stage
Inside the egg sacs, the eggs develop and hatch into spiderlings (there is no larval stage). They will spend the winter inside the protection of the tough, papery silk sacs. This is a critical period of development where they are shielded from predators and harsh weather. They undergo their first moult while still inside.
Pupal Stage
There is no pupal stage. The spiderlings emerge from the egg sacs in the spring when weather conditions become favourable. Upon emerging, the tiny spiders disperse, often by ballooning on silk threads, to find their own territories in the surrounding vegetation. They are independent hunters from the moment they leave the sac.
Adult Stage
The spiderlings grow throughout the spring and summer, moulting periodically. They reach maturity in late summer. The adult female's lifespan is about one year; after producing her egg sacs in autumn, she will die with the onset of winter. The male's lifespan is much shorter, likely lasting only a few weeks as an adult, during which his sole purpose is to find a mate.
Reproduction Rate
Each female produces a single string of egg sacs in her lifetime, but this chain can contain several hundred eggs in total, ensuring a healthy next generation.
Generations Per Year
There is a single, distinct generation per year. The adults seen in summer and autumn are the parents of the spiderlings that will emerge the following spring.
Development Time
The full lifecycle takes one year to complete, from egg to reproducing adult.
Seasonal Cycle
Adult females are present from mid-summer to late autumn. Hunting, mating, and egg-laying all occur during this period. The species exists only as eggs during the winter and as juveniles in the spring and early summer.
Environmental Factors
The presence of suitable foliage for hiding and hanging its egg sacs, along with a healthy population of nocturnal moths, are the key environmental factors for this spider's survival.
Habitat & Distribution
Preferred Habitats
- Coastal heathlands and woodlands.
- Suburban gardens, especially those with lush, dense shrubbery.
- Citrus orchards and other fruit trees.
- On the foliage of leafy plants like gardenias and lilly pillies.
- Any environment with dense vegetation providing daytime camouflage and nocturnal hunting space.
Distribution Patterns
Australian Distribution
Found along the coastal regions of Queensland, New South Wales, and Victoria. It is also found in parts of South Australia.
Climate Zones
- Subtropical
- Temperate
Urban vs Rural Distribution
Very common in suburban gardens that provide lush, leafy habitats. It has adapted well to urban environments, often being found in ornamental shrubs and fruit trees.
Native Range
Native to eastern and south-eastern Australia.
Introduced Range
Not known to be introduced outside its native range.
Introduction History
A native Australian species.
Current Spread
Its population is considered stable within its established range.
Limiting Factors
Its distribution is limited by cold, dry climates. It requires the warmth and humidity of the coastal belt and is absent from arid inland areas and colder southern regions like Tasmania.
Behavior & Diet
Activity Pattern
Strictly nocturnal. During the day, the female hangs motionless from a leaf or twig, tucking her legs in and relying on her cryptic colouration for camouflage. She looks remarkably like a bird dropping or a part of the plant. At night, she becomes active, moving to a more open position to begin hunting.
Dietary Preferences
Feeding Habits
A highly specialised insectivore that preys almost exclusively on male moths.
Health Risks
Always consult healthcare professionals for medical concerns related to pest exposure.
Disease Transmission
- Zero risk of disease transmission.
- It does not carry any pathogens harmful to humans.
- The spider is considered medically insignificant.
Allergens and Respiratory Issues
There are no known allergens associated with this spider.
Contamination Risk
None. It lives on plants and does not come into contact with human food or living spaces.
Vulnerable Populations
- No populations are vulnerable, as the spider poses no threat.
- The only 'risk' is startling someone unfamiliar with its strange appearance.
- Children may be curious about its appearance but are not in any danger.
Symptoms of Exposure
- A bite from this spider has never been reliably recorded in medical literature, as it is non-aggressive and its fangs are tiny.
- If a bite were to occur, it is predicted that it would be completely trivial, with no symptoms beyond a possible faint pinprick sensation.
- No pain, swelling, or any other symptoms would be expected.
- It poses less of a threat than a mosquito.
Transmission Methods
- A bite is theoretically possible but practically unheard of. The spider would need to be physically forced against the skin.
- It has no other way of causing harm.
Risk Severity
Low. This species is completely harmless to humans.
Economic Impact
Treatment Costs
Professional Treatment
Not applicable. No one would ever require professional treatment for this species.
Prevention Costs
Zero.
Diy Treatment
Zero.
Property Damage
Structural Damage
None.
Garden Damage
None. It does not harm plants.
Food Contamination
None.
Equipment Damage
None.
Business Impact
Restaurant Issues
None.
Retail Impact
None.
Reputation Damage
None.
Operational Disruption
None.
Agricultural Impact
Crop Damage
None. Does not eat plants.
Yield Loss
None.
Beneficial Aspects
It is a predator of certain species of moths. Some of these moths may be agricultural pests in their larval (caterpillar) stage. Therefore, the Two-spined Spider can be considered a minor beneficial insect in an agricultural or horticultural setting.
Economic Loss
None. It may provide a small, localised economic benefit through natural pest control.
Indirect Costs
Healthcare Costs
Zero.
Cleanup Costs
Zero.
Replacement Costs
Zero.
Preventive Maintenance
Zero.
Detection & Signs
Visual Signs
- The most definitive sign is finding the unique string of brown, spindle-shaped egg sacs hanging in a shrub.
- Sighting the female spider at night. She is brightly coloured and hangs in open space to hunt.
- Finding a dead, dried-out female in late autumn or winter.
- It is very difficult to spot during the day due to its excellent camouflage.
Physical Evidence
- The chain of egg sacs is the primary physical evidence.
- The spider itself.
- There is no web, so that cannot be used as a sign.
- Discarded remains of moths may be found on leaves below its hunting perch.
Behavioral Signs
- Observing the spider swinging its bolas at night (requires patience and luck).
- Seeing a spider that is perfectly still on a leaf during the day.
- Its presence is very subtle, and behavioural signs are hard to spot.
Seasonal Indicators
- The spiders themselves are only seen in mid-summer to late autumn.
- The egg sacs can be found from autumn through to the next spring.
- Emergence of tiny spiderlings occurs in spring.
- If you see one, you know it's the warm season.
Early Warning Signals
- 'Infestation' is not a relevant term. An early sign of their presence in your garden is finding a single egg sac chain from the previous year, indicating the habitat is suitable.
- A high number of moths around your property may attract them.
- They are not a pest, so warnings are not needed.
Prevention
Sanitation Measures
- Not applicable. This spider is not a pest and requires no sanitation measures.
Exclusion Methods
- Not applicable. They do not enter homes, so no exclusion is necessary.
Landscaping Tips
- To encourage their presence (as they are fascinating and beneficial), plant a variety of dense, leafy native shrubs like lilly pilly or bottlebrush.
- Avoid the use of broad-spectrum pesticides, which will kill them and their food source.
- Creating a diverse garden habitat will support these spiders.
- If you must prune a shrub where they are living, try to do so in winter or spring when the adult females are not present.
Monitoring Strategies
- Monitoring is done for interest, not for control.
- Go into the garden on a warm summer night with a torch and scan the foliage of leafy shrubs.
- Look for the characteristic string of egg sacs during the day.
- Checking citrus trees is often a good strategy, as they are a favoured habitat.
Environmental Modification
- No modification is needed to prevent them. To encourage them, create a healthy garden ecosystem free of pesticides.
Control Methods
Professional Treatment Methods
Chemical Control
Absolutely not recommended, necessary, or justifiable for this harmless, beneficial, and fascinating native species.
Biological Control
Not applicable.
Physical Control
The only physical interaction should be to gently relocate a spider if it's on a plant you need to move, but it's best to leave them undisturbed.
Integrated Approach
The only IPM approach is to appreciate and conserve them.
DIY Treatment Options
Natural Remedies
The best remedy is to leave them alone.
Home Made Traps
Not applicable.
Deterrent Methods
Not applicable.
Mechanical Control
Not applicable.
Treatment Effectiveness
Success Rate
Not applicable.
Timeframe
Not applicable.
Follow Up Required
Not applicable.
Seasonal Considerations
Not applicable.
Application Techniques
- The best technique is observation with a camera.
Professional Services
Professional Treatment Services
Chemical Control
Absolutely not recommended, necessary, or justifiable for this harmless, beneficial, and fascinating native species.
Biological Control
Not applicable.
Physical Control
The only physical interaction should be to gently relocate a spider if it's on a plant you need to move, but it's best to leave them undisturbed.
Integrated Approach
The only IPM approach is to appreciate and conserve them.
Professional Treatment Costs
Not applicable. No one would ever require professional treatment for this species.
Treatment Success Rates
Not applicable.
Treatment Timeframe
Not applicable.
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Browse All ProvidersSeasonal Patterns
Spring Activity
Spiderlings emerge from the egg sacs and disperse. They are tiny and spend their time hunting small insects and growing.
Summer Activity
Spiders continue to grow, reaching maturity by mid-to-late summer. Adult females begin their nocturnal hunting for moths using their bolas.
Autumn Activity
This is the peak season for adult females. They are at their largest, hunt actively on warm nights, mate, and then produce their characteristic strings of egg sacs.
Winter Activity
The adult spiders die off with the cold weather. The entire population exists only as eggs, safely dormant inside the well-insulated egg sacs.
Breeding Season
Mating and egg-laying occur in autumn.
Peak Activity Period
Not a pest. Peak visibility of adult females is from late summer to mid-autumn.
Environmental Factors
Temperature Effects
Warm nights are required for the spider and its moth prey to be active. Cold weather is lethal to the adults.
Humidity Effects
They are found in humid coastal regions, suggesting humidity is important for their survival and that of their prey.
Photoperiod Effects
The shortening days of autumn trigger the final stages of reproduction and egg-laying.
Weather Patterns
Calm, warm nights are the best for hunting. Heavy wind or rain will inhibit their activity.
Legal Considerations
Pest Status
It has no pest status whatsoever. It is a benign and beneficial native animal.
Control Regulations
There are no regulations for its control as it is not a pest. Regulations are focused on its protection (i.e., not harming native wildlife unnecessarily).
Professional Requirements
Not applicable.
Environmental Considerations
This spider should be conserved. Its presence indicates a healthy garden ecosystem. The use of pesticides should be avoided in areas where they are found.
Compliance Requirements
- Compliance with wildlife protection principles by not harming them.
- Avoiding indiscriminate pesticide use.
Frequently Asked Questions
I found a weird spider that looks like a spaceship, what is it?
You've likely encountered the incredible female Two-spined Spider, *Poecilopachys australasia*. Her appearance is certainly out of this world! The 'spaceship' look comes from her abdomen, which is exceptionally wide and features two large, horn-like projections, one on each side. This, combined with her vibrant colour scheme of greens, yellows, and reds, makes her one of Australia's most unique-looking spiders. She is a type of orb-weaver but has evolved a very different lifestyle. Instead of building a net, she hunts at night using a silk line with a sticky ball on the end, like a bolas. You'll find her in the foliage of garden shrubs, particularly in eastern Australia. Despite looking fierce, she is tiny, timid, and totally harmless, so there's no need for alarm.
Does the Two-spined Spider build a web?
No, it does not build a conventional web for catching prey. While it is related to orb-weavers, the Two-spined Spider belongs to a specialised group known as bolas spiders. Instead of spinning a large, circular net, the female constructs a simple, single strand of silk. At the end of this strand, she creates a globule of extremely sticky silk, often weighted with other droplets. This structure is called a 'bolas'. At night, she hangs from foliage and dangles this bolas, swinging it at any prey that comes near. This is a much more targeted and active form of hunting than passively waiting for an insect to fly into a large web. The only other silk structures she makes are the distinctive chains of spindle-shaped egg sacs she creates in autumn.
How does the Two-spined Spider catch its food?
The hunting method of the Two-spined Spider is a masterpiece of evolution. It's not just about the silk bolas; it's about chemical warfare. The spider's primary food is male moths of certain species. To attract them, she releases a complex chemical cocktail of pheromones into the air. This scent is an almost perfect imitation of the sex pheromone released by a female moth ready to mate. Lured by this irresistible promise, unsuspecting male moths fly in towards the source of the scent. As the moth gets close, the spider detects the vibrations from its wing beats and begins to whirl the sticky bolas in the air, striking the moth and instantly trapping it. She then hauls her meal in to eat. It's an incredibly specialised and effective method of ambush.
Are Two-spined Spiders dangerous to people or pets?
Absolutely not. The Two-spined Spider is completely harmless to both people and pets. Her startling appearance with the large spines is purely for show and defence against her natural predators, like birds, not for aggression. Her fangs are minute, and her venom is weak, formulated specifically for moths. There are no records of anyone being bitten by one, as they are extremely placid and non-aggressive. You would have to physically grab and squeeze one to even have a chance of being bitten, and even then, it's unlikely to break the skin or cause any reaction. They are a 'look but don't touch' creature simply because it's best to leave wildlife undisturbed, not because they pose any danger.
Why can I only find these spiders in summer and autumn?
The Two-spined Spider has a strict annual lifecycle, which is why you only see the conspicuous adult females during the warmer months. The spiderlings hatch in spring and spend the next few months growing and maturing. By mid-summer, they have become adults. This is when they are at their largest and most active, hunting, mating, and, for the females, developing eggs. In autumn, after mating, the female lays her chain of egg sacs and her lifecycle comes to an end. The adult spiders cannot survive the cold of winter. The entire species spends the winter dormant, existing only as eggs safely protected within the tough, silk sacs. The cycle begins anew the following spring when the next generation hatches. So, their appearance is a reliable marker of the summer and autumn seasons.
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Image Gallery
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