Trite is a genus of jumping spiders found across New Zealand, New Caledonia, and a handful of nearby islands, with the black-headed jumping spider, Trite planiceps, being the most studied and commonly encountered species. These small, active predators have attracted outsized scientific attention for their sharp eyesight, flexible hunting strategies, and surprisingly sophisticated spatial reasoning. If you have noticed a compact, alert spider peering at you from a window frame or a flax bush anywhere in New Zealand, there is a good chance it was a Trite.
Life Inside a Rolled-Up Leaf
What makes Trite planiceps unusual among jumping spiders is not just what it does, but where it lives. This spider’s preferred home is the curled, dead leaves of New Zealand flax (Phormium tenax) and similar plants. The dried leaves roll into tight tubes as they age, and these natural cylinders serve as nests, shelters, and even communication channels for the spiders living inside them. While many jumping spiders build silk retreats in crevices or under bark, Trite planiceps has developed a relationship with a specific plant structure that shapes nearly every aspect of its biology.
Inside these rolled-up leaves, spiders are shielded from weather and many predators. Males and females both use the leaf surface itself to send vibratory signals, tapping with their front legs and vibrating their abdomens against the interior wall of the tube. Researchers observing spiders in glass tubes under infrared light found that both sexes produce these vibratory displays even when no other spider is nearby, suggesting the behavior functions partly as a way of announcing presence or probing the environment rather than being triggered solely by encounters with mates or rivals.1New Zealand Journal of Zoology. Habitat‐adapted communication in Trite planiceps, a New Zealand jumping spider (Araneae, Salticidae) The flax leaf, in other words, is not just a shelter. It doubles as a signaling medium.
How Trite Spiders See
Jumping spiders as a family are famous for their vision, and Trite is no exception. Like all salticids, Trite planiceps has eight eyes arranged in rows, but the two large, forward-facing anterior-median eyes do the heavy lifting. These principal eyes are camera-type eyes with a layered retina, making jumping spiders one of the only invertebrate groups to possess this kind of optical architecture. They are also the only invertebrate group whose eyes include a fovea, the small, densely packed region of photoreceptors that allows fine detail discrimination at the center of the visual field.2PubMed Central. A Comparative Analysis of the Camera-like Eyes of Jumping Spiders and Humans
The principal eyes have a narrow field of view but outstanding spatial resolution for an animal this size. To compensate for that narrow window, jumping spiders can move the retinal tubes behind the lenses, effectively scanning across a scene without moving their heads. The secondary eyes, particularly the anterior-lateral pair flanking the principal eyes, have a much wider field of view and excel at detecting motion. This division of labor between the eye pairs is not just anatomical trivia; it directly shapes how Trite hunts.
Two Ways to Catch Prey
Research on Trite planiceps revealed that it uses two distinct hunting strategies depending on whether the target is moving or still. When prey is in motion, the spider relies primarily on its anterior-lateral eyes to track and chase the target. When prey is stationary, the spider switches to a controlled stalk driven by its anterior-median (principal) eyes. These are not just variations on the same approach; they involve different motor sequences and different visual systems, and the spider transitions smoothly between them as conditions change.3New Zealand Journal of Zoology. Visual mechanisms of hunting behaviour in Trite planiceps, a jumping spider (Araneae: Salticidae)
The full hunting sequence, as documented across salticid species including Trite, follows a surprisingly organized chain of behaviors. It begins with orientation: the spider alerts to something in its visual field, swivels its body to face the stimulus, and aligns itself with the target. Then comes pursuit, which takes different forms depending on the prey. If the target moves, the spider may follow at a measured pace or break into a run. If the target is still, the spider stalks, moving slowly and deliberately. Finally, there is the capture phase, where the spider crouches low, tenses, and leaps.4New Zealand Journal of Zoology. A qualitative analysis of hunting behaviour in jumping spiders (Araneae: Salticidae) Each of these stages consists of discrete motor elements, meaning the spider is not simply running at food. It is cycling through a structured behavioral program, adjusting its approach at each step based on what its eyes tell it.
This flexibility matters because Trite planiceps is a generalist predator. It takes a range of small invertebrates rather than specializing in one prey type. A spider that hunts flies on a sun-warmed window needs to chase; one hunting a motionless moth larva inside a flax tube needs to stalk carefully in near-darkness. Having two visual systems tuned to different tasks lets the spider handle both situations.
Courtship That Depends on Context
Trite planiceps males face a problem that most jumping spider males do not: their preferred mate might be out in the open or hidden inside an opaque leaf tube. The male’s solution is to have two entirely different courtship modes. In the light, where visual signals work, the male performs a vision-based display and mates in the open. At a nest inside a rolled-up leaf, where neither spider can see the other, the male switches to vibratory courtship, drumming on the leaf surface and vibrating his abdomen. Mating then happens inside the leaf tube.5New Zealand Journal of Zoology. Habitat‐adapted communication in Trite planiceps, a New Zealand jumping spider (Araneae, Salticidae)
This dual system is rare among jumping spiders. Most salticids are famous for their elaborate visual dances, with males waving decorated legs or flashing iridescent body parts. Those displays are useless in a dark tube. By relying on the leaf itself as a vibration-conducting surface, Trite planiceps has essentially repurposed its home into a communication device. The vibratory signals are not a fallback or a degraded version of the visual display; they are a parallel channel adapted to a specific habitat.
Males also show a remarkable patience when it comes to timing. If a male encounters a female who is immature but within roughly ten days of her final molt, he will cohabit with her inside the rolled-up leaf, waiting until she matures before mating. This cohabitation strategy likely functions as mate guarding, preventing rival males from accessing the female during the final stretch before she becomes reproductive.
How Males Settle Fights
When two Trite planiceps males encounter each other, the outcome of the dispute depends on two interacting factors: body size and physical condition, specifically whether a spider has lost any of its front legs. Foreleg loss turns out to be common in wild jumping spiders and plays a significant role in determining contest outcomes.
In laboratory experiments, when both rivals were intact, the larger spider won more reliably as the size difference between them increased. When rivals were matched in size, injury state became the dominant predictor. An intact spider beat one missing a single foreleg, and a spider missing one foreleg beat one missing both. When size and injury both varied, the two factors combined. A larger spider still tended to win, but if the larger spider was also the more injured one, its size advantage shrank or disappeared.6Animal Behaviour. Interacting effects of size and prior injury in jumping spider conflicts
This matters because male jumping spiders use their forelegs prominently in threat displays, raising and spreading them to look larger. A spider missing a leg cannot produce the same visual signal, and it may also be physically weaker in a grapple. The fact that both rivals appear to assess each other’s condition and adjust their behavior accordingly suggests these contests are not simple tests of brute strength. They involve mutual evaluation, and the spiders are integrating multiple pieces of information about their opponent before deciding whether to press or retreat.
Planning Routes and Taking Detours
One of the more striking findings about Trite planiceps is its ability to plan spatial detours. Jumping spiders often need to take indirect routes to reach prey or return to a nest, especially in the three-dimensional tangle of branches and leaves where they live. Getting to a visible target sometimes means walking away from it first, which requires holding a goal in memory while navigating a path that temporarily takes you in the wrong direction.
In controlled experiments testing whether Trite planiceps could evaluate the length of alternative routes, spiders consistently chose shorter paths over longer ones. When presented with two routes of different lengths to a goal, Trite selected the shorter option at rates above chance. Interestingly, the presence of a lure (something attractive at the endpoint) did not change this preference; spiders did not favor a lured route over a control route, but they reliably preferred short routes regardless.7PubMed Central. Distance assessment of detours by jumping spiders This suggests that route-length assessment is a genuine spatial ability in these spiders, not simply a side effect of being attracted toward a visible reward.
Researchers have also tested whether Trite planiceps can evaluate route riskiness alongside route length. In complex environments, salticids rely on a combination of visual cues and spatial memory to orient in three-dimensional space. When given the option of different routes that varied not just in distance but in associated risk, both Trite planiceps and the notoriously clever Portia fimbriata demonstrated the ability to factor in multiple variables when choosing a path.8Behavioral Ecology. Risk assessment and the use of novel shortcuts in spatial detouring tasks in jumping spiders The fact that Trite holds its own alongside Portia, a genus considered among the most cognitively sophisticated of all spiders, is notable. It suggests that the spatial reasoning skills seen in Portia are not limited to a single extraordinary lineage but may be more broadly distributed across jumping spiders.
Where the Genus Comes From
The genus Trite contains species split into two groups. The planiceps-group is found across New Zealand, New Caledonia, Lord Howe Island, and Norfolk Island, while the incognita-group is restricted to New Zealand. Molecular data places Trite within the Australasian Astioida clade, a broader grouping that arose roughly 30 million years ago. The genus Trite itself is estimated to be about 10 million years old.9PubMed Central. A new species of Trite Simon, 1885 (Araneae: Salticidae) from New Zealand, with remarks on Trite relationships and radiation
Where the genus actually originated is an open question with three competing scenarios. New Caledonia is one candidate, supported by the presence of several related genera there and the planiceps-group’s distribution. Under this model, Trite arose in New Caledonia and later spread to New Zealand. New Zealand itself is another possibility, backed by the sheer number of species found there and the fact that the incognita-group is entirely endemic. A third scenario points to Australia as the ancestral source, since some Australian jumping spider genera share genitalic structures with the planiceps-group. None of these hypotheses has been definitively settled, and the geographic history of the southwestern Pacific, with its complex pattern of island emergence, submersion, and reconnection, makes disentangling dispersal routes genuinely difficult.
What is clear is that the genus has diversified considerably within New Zealand. The country harbors the majority of known Trite species, and new ones continue to be described. The two species groups differ enough in their anatomy that they may eventually be recognized as separate lineages, though for now they remain under one genus.
Jumping in Wind
Jumping spiders do not use webs to catch prey; they leap. That makes every jump a biomechanical calculation involving distance, trajectory angle, and whatever forces are acting on the spider mid-flight. For a tiny animal, wind is one of those forces, and it can easily push a spider off course or cause a jump to fail entirely.
Research on how salticids handle wind found that Trite planiceps and Portia fimbriata both adjust their behavior in response to airflow. When exposed to wind, spiders changed the horizontal direction of their jumps so that the wind would favor the trajectory rather than fight it. Both species also preferred to jump during calm intervals when exposed to intermittent wind, waiting for a pause before launching. However, the two genera differed in an interesting way: in Portia, the vertical angle of the jump strongly predicted whether the landing succeeded or failed, while in Trite this relationship was weaker. The difference may reflect different jumping styles or different body proportions, since Portia has longer legs relative to body size and a different center of gravity.
The broader point is that these spiders are not leaping blindly. They integrate visual information about distance with mechanical information about wind conditions before committing to a jump. For an animal whose entire predatory strategy depends on precision leaping, this kind of multi-sensory integration is not a luxury; it is a survival requirement. And for Trite planiceps, which often hunts on exposed flax leaves swaying in New Zealand’s coastal breezes, the ability to time and aim jumps around gusts of wind is especially relevant to daily life.
Why Trite Matters to Spider Science
Trite planiceps is not the most famous jumping spider. That distinction usually goes to the peacock spiders of Australia, with their viral courtship dances, or to Portia, the celebrated “genius” spider. But Trite has become a quiet workhorse of salticid research, partly because it is abundant and easy to collect in New Zealand, and partly because it is genuinely interesting in its own right. Its habitat-adapted communication, with the rolled-up leaf acting as both a home and a signaling substrate, is uncommon among salticids. Its performance in spatial reasoning tasks challenges the assumption that high-level navigation is limited to Portia. And its dual courtship system, switching between visual and vibratory channels depending on context, illustrates how a single species can evolve parallel communication strategies when its environment demands them.
For anyone encountering these spiders in person, they are among the most watchable of New Zealand’s invertebrates. Their large forward-facing eyes give them an attentive, almost curious appearance, and they are one of the few spiders that will turn to face you and track your movements. They are harmless to people, beneficial as pest controllers in gardens and homes, and small enough to go entirely unnoticed unless you know where to look. The rolled-up leaves of a flax bush are a good place to start.