Posted on homepage: 8 November 2010 (GMT+10)
Certain Acacia trees are well known for having resident ants. Ants eat the distinctive leaflet tips known as Beltian bodies—nubbins of protein and fat—and they drink the nectar that oozes from special nectaries on the leaf petioles (i.e. “little stalk” between stem and leaf). Often cited as a textbook example of a “mutually beneficial partnership” (or symbiosis), the resident ants fiercely defend their home trees against caterpillars and other invaders that might chew on the tree.
However, in Mexico, it seems the ants (Pseudomyrmex) are having to share their arboreal abode with a rival herbivore—namely, a spider.1 Bagheera kiplingi gets its name from a panther in a Rudyard Kipling story. Panthers are of course adept at leaping, and so is this spider—in fact a report in Science News says Bagheera kiplingi “belongs among the big-eyed, athletic predators in the family of jumping spiders”.2 Researchers have recently been surprised, however, to discover that a population of these spiders in Central America is “predominantly vegetarian”, dodging the ant guard patrols to forage on the fresh leaf tips, and to a lesser extent on petiolar nectar.1
In videos of 140 spider meals, the researchers observed the spiders feeding on the Acacia leaf Beltian bodies or nectar 136 times. On four occasions, spiders opportunistically snatched away ant larvae being carried by a passing ant nursemaid, and ate the larvae.
Despite the fact that “the tree is full of biting, vicious ant guards”, given that up to several hundred spiders are resident on some individual Acacia trees, the arachnids are obviously very effective at surviving despite the ants. As Science News quipped, “These arachnid herbivores are no wimps.”2 Yet they are indeed mostly vegetarian, based not only on the video observations but also on associated analysis of spider tissue for particular isotopes of nitrogen and carbon3—the results being typical of plant-eaters, not carnivores.
For some time now scientists have known that certain spider species occasionally taste vegetable matter. Male crab spiders have been observed to sip nectar from flowers, and some baby spiders eat pollen grains that have stuck to a web.2,4 But on hearing of this latest discovery of a “vegetarian spider”, one scientist’s reaction was typical: “I was absolutely floored.”2
This is not the first time that creatures thought of today as needing to eat other creatures to survive turn out to have a diet derived largely, or even exclusively, from plants instead.5,6,7,8,9,10 Such examples might be a surprise to people used to thinking our world is a product of “dog-eat-dog”, “nature-red-in-tooth-and-claw” processes over millions of years. But to Bible-believers, such instances of “unexpected” herbivory are readily understandable as legacies of a “very good” creation in which vegetarianism was a world-wide phenomenon,11 only around 6,000 years ago.
References and notes
- Meehan, C.J., Olson, E.J. and Curry, R.L., Exploitation of the Pseudomyrmex–Acacia mutualism by a predominantly vegetarian jumping spider (Bagheera kiplingi), 12th International Behavioral Ecology Congress, PS 62–107, Ithaca, New York, USA, 9–15 August 2008. Return to text.
- Milius, S., Vegetarian spider: Small jumping species steals lunch from ants, Science News 174(5), <www.sciencenews.org/view/generic/id/35121/title/Vegetarian_spider>, 30 August 2008. Return to text.
- I.e., 15N and 13C. Return to text.
- White, T., Pollen-eating spiders, Nature Australia 26(7):5, 1999–2000. (We reported on this in: Pollen-eating spiders, Creation 22(3):5, 2000; <creation.com/spiders_pollen>.) Return to text.
- Catchpoole, D., The lion that wouldn’t eat meat, Creation 22(2):22–23, 2000; <creation.com/lion>. (Refs 4b–10 can also be accessed via creation.com/carnivory.) Return to text.
- Catchpoole, D., Catching a kinkajou, Creation 26(3):42–43, 2004; <creation.com/kinkajou>. Return to text.
- Vegan dog, Creation 25(2):7, 2003. Return to text.
- Catchpoole, D., The “bird of prey” that’s not, Creation 23(1):24–25, 2000; <creation.com/vulture>. Return to text.
- Match the bat’s teeth, Creation 21(1):30, 1998; <creation.com/bats#batteeth>. Return to text.
- Catchpoole, D., Lea, the spaghetti lioness, Creation 29(4):44–45, 2007; <creation.com/spag>. Return to text.
- Genesis 1:29–31; see also Gurney, R., The carnivorous nature and suffering of animals, Journal of Creation 18(3):70–75, 2004; <creation.com/carniv>. Return to text.