“…and today we’re talking about a sneaky spider. But more on that later.”
A cunning hunter weaves deceit in silken threads. Her artistry captures the eye, and it also snares her prey. But that’s not the only purpose for this cyclonic masquerade. It also hypnotizes hungry guests that would make a meal out of this patient little host. But the Cyclosa spider teaches careful observers an important lesson: Not everything is as it appears in Life, Death, and Taxonomy.
Description of the Cyclosa Spider
- Looks like a tiny armored tank crossed with a speck of existential dread
- Body is pale brown with dark brown spots, like it rolled through a coffee spill
- Abdomen is mottled, giving it a camouflage vibe that screams “I’m not worth eating”
- Legs are spindly, like they were designed by a minimalist architect
- Smaller than your average orb-weaver, about the size of a pencil eraser
Measure Up
Welcome to the beloved Measure Up segment. The official listener’s favorite part of the show! The part of the show when we present the animal’s size and dimension in relatable terms through a quiz that’s fun for the whole family. It’s also the part of the show that’s introduced by you when you send in audio of yourself saying, singing, or chittering the words Measure Up into ldtaxonomy at gmail dot com.
An American Tail: Fievel Goes West (1991) – The Flying Aaah! Scene (5/10) | Movieclips
Body Length of Cyclosa mulmeinensis
Cyclosa mulmeinensis has a body length of 4.7 mm (0.185 inches). How many objects fit into the spider’s body length (if the object is shorter) or how many spiders fit into the object’s length (if the object is longer)?
a) The length of a Philippine eagle feather
A tail feather from the Philippine eagle (Nisaetus philippensis), a national symbol, measures about 50 cm (500 mm or 19.7 inches) for an adult.
b) The length of a Thai water beetle
A Thai giant water beetle (Lethocerus indicus), used in local cuisine, measures about 7 cm (70 mm or 2.76 inches) long.
c) The diameter of a Myanmar sesame seed
A sesame seed (Sesamum indicum), a crop in Myanmar, measures about 3 mm (0.3 cm or 0.12 inches) long.
Question: How many fit into each body length comparison?
A) 104 Cyclosa mulmeinensis go into the length of a Philippine eagle feather
B) 14.9 Cyclosa mulmeinensis go into the length of a Thai water beetle
C) 1.4 Myanmar sesame seeds go into the body length of a Cyclosa mulmeinensis
Web Diameter of Cyclosa mulmeinensis
Cyclosa mulmeinensis has a web diameter of 10 to 30 cm (approximately 4 to 12 inches)
a) The length of a Philippine eagle feather
A tail feather from the Philippine eagle (Pithecophaga jefferyi), a critically endangered raptor, measures about 60 cm (600 mm or 23.6 inches) long for a large adult.
b) The diameter of a Thai mango seed
A mango seed (Mangifera indica) from Thailand, used in local cuisine, has a diameter of about 3 cm (30 mm or 1.18 inches) across its widest point.
c) The length of a Myanmar kammavaca manuscript page
A single page from a Myanmar kammavaca manuscript, a Buddhist palm-leaf text, measures about 10 cm (100 mm or 3.94 inches) long.
Question: How many fit into each body length comparison?
A) 14.0 Cyclosa mulmeinensis go into the length of a Philippine eagle feather
B) 4 Cyclosa mulmeinensis go into the diameter of a Thai mango seed
C) 21.3 Cyclosa mulmeinensis go into the length of a Myanmar kammavaca manuscript page
Fast Facts about the Cyclosa Spider
- Range: Spans from Africa to East Asia, with a notable presence on Orchid Island off Taiwan’s southeast coast.
- Habitat: Prefers rainforests and humid areas, building webs in low vegetation or near water.
- Mating Behavior: Males court females with cautious vibrations on the web, like sending a risky text and hoping for a reply.
- Diet: Feeds on small insects like flies and moths, caught in their orb-shaped webs.
- Hunting Behavior: Sits at the web’s hub, waiting for prey to blunder into sticky threads, then wraps them up like a burrito.
- Lifespan: Lives about a year, assuming it doesn’t get eaten or parasitized first.
- Social Behavior: Mostly solitary, only mingling during mating or when competing for prime web real estate.
- Predators: Targeted by wasps, birds, and jumping spiders, who aren’t fooled by its sneaky tricks.
Major Fact: Decoy Spider
Cyclosa mulmeinensis constructs small orb webs with linear web decorations, often composed of prey remains, silk, and other debris. These decorations are strategically arranged in the web to serve multiple purposes, including camouflage and predator deterrence.
The web decoration mimics the spider’s own size and appearance, effectively acting as “fake spiders” or decoys. This behavior has been studied in populations of C. mulmeinensis, especially on Orchid Island, Taiwan, where these decorations resemble the spider’s body, confusing predators like wasps.
The “fake spider” decoys are believed to enhance survival by diverting predator attention away from the actual spider. For example, studies have shown that wasps, a common predator, are less successful in attacking C. mulmeinensis when these decoys are present, as they may target the decorations instead.
This is part of a broader strategy among Cyclosa species, known as trashline orbweavers, where debris in the web (termed “trashline”) serves both as camouflage and a decoy.
Unlike most orb-weaver spiders that face downward in their webs, some Cyclosa species, including C. mulmeinensis, may face upward, potentially aligning with their decorations to further blend in.
Details of the Behavior
The decorations are made from materials like insect remains, plant matter, and silk, arranged in a linear pattern across the web. In C. mulmeinensis, these can be shaped to mimic the spider’s body size and coloration, creating a visual illusion of multiple spiders.
Research indicates that these decoys reduce predation success by creating uncertainty for predators. For instance, a wasp approaching the web may attack a decoration instead of the spider, giving the spider time to escape or remain undetected.
This behavior is particularly noted in populations on Orchid Island, where environmental pressures from predators like wasps may have driven the evolution of such sophisticated defenses. The decorations not only serve as decoys but may also obscure the spider’s outline, making it harder to spot against the web.
Other Cyclosa species, like Cyclosa confusa, also create similar decorations, but C. mulmeinensis is particularly noted for the lifelike quality of its decoys, which closely match its own appearance.
Ending
So put crop circles in your webs, surround yourself with copies of yourself, and put your trash out on Thursday nights so you don’t miss the Friday morning pickup and have to spend the next week smelling old garbage and trying to find a place to put the new garbage like the cyclosa spider here in LDT.