Relative size matters: Eyespots on large insect prey deter small arthropod predators
Data files
Apr 11, 2025 version files 35.80 KB
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Jumping_spider_binary_choice.xlsx
9.72 KB
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Mantis_eyespot_attack_latency.xlsx
14 KB
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Mantis_eyespot_binary_choice.xlsx
10.05 KB
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README.md
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Abstract
Circular chromatic patterns that appear to resemble vertebrate eyes (“eyespots”) are commonplace in the animal kingdom and are widely believed to have evolved as an anti-predator defence. For example, experiments have shown that eyespots on caterpillar-like pastry baits can deter predation by domestic chicks. However, little is known about the extent to which eyespots deter (or promote) attack by arthropod predators. Here we describe two separate experiments in which salticid spiders (Salticus scenicus) and Chinese mantids (Tenodera sinensis) were presented with a choice of mealworm (Tenibrio molitor) larvae with or without eyespots. In a complementary experiment we observed the time taken for adult Chinese mantids to attack hawkmoth (Manduca quinquemaculata) larvae of two different sizes, with and without eyespots. All three experiments indicate that eyespots on insect larvae can deter predation, so long as the larvae with eyespots are sufficiently large compared to the size of the arthropod predator. In smaller caterpillars the selective benefit of eyespots may diminish and may even be selected against. Our results suggest that small arthropods can show an aversion to large prey with eyespots and help explain the presence of eyespots in medium-sized caterpillars, since these traits are unlikely to deter avian predators.
Three separate experiments were conducted to assess whether eyespots on insect larvae detered predation by arthropod predators.
Experiment 1 presented mealworms with and without eyespots to zebra jumping spiders (Salticus scenicus) of different sizes in a binary choice experiment.
The variable names in the spider binary choice dataset are as follows:
- spider: spider ID (1-50)
- size: the spider’s total body length in mm
- Neither0Eye1NoEye2: code for the type of mealworm attacked by the spider in its binary choice (0 - neither, 1 - eyespotted, not eyespotted)
Experiment 2 presented mealworms with and without eyespots to Chinese mantis (Tenodera sinensis) of different sizes in a binary choice experiment.
The variable names in the spider binary choice dataset are as follows:
- Individual: the individual mantis (1-80)
- Instar: its instar (3-6)
- Neither0Eye1NoEye2: code for the type of mealworm attacked by the mantis in its binary choice (0 - neither, 1 - eyespotted, not eyespotted)
Experiment 3 presented hawkmoth larvae (Manduca quinquemaculata) of two size classes to adult Chinese mantis (Tenodera sinensis) and evaluated the time taken for the mantis to approach and attack these larvae.
The variable names in the mantis attack latency dataset are as follows:
- Day: Experimental day (1-4)
- Individual: Mantis ID (1-12)
- Order: Order of presentation of the 4 treatments (1-4); see SI for the exact sequences
- Treatment: 0 - mealworm; 1 - large, eyespot; 2 - large, no eyespot; 3 - small, eyespot; 4 - small, no eyespot
- Eyespot: 0 - no, 1 - yes
- Size: 1 - small, 2 - big
- First: time to first base or end of observation (in seconds)
- Attacked: time to attack or end of observation (in seconds)
- Status1: 1 - event (passing first base) occurred, 0 - event did not occur in observation period
- StatusA: 1 - event (attack) occurred, 0 - event did not occur in observation period.