The spider, the bamboo, and the frog

We are probably quite used to reading stories about humans exploiting plant resources in ways that don’t cover some of the obvious examples such as food or medicines. Not so familiar, I suspect, are instances of non-human animals doing the same.

By way of extending the range of such interactions, here is the true tale of a tarantula that makes its home in the stems of bamboo in Thailand (Becki Robins). Newly discovered and described by Chaowalit Songsangchote et al., Taksinus bambus [nicknamed ‘bambootula’], was found inside the stalks [more technically called culms] of Asian bamboo (Gigantochloa sp.). Not only is this a species of arachnid new to science, but it’s sufficiently distinct from other described spiders to be recognised as a new genus.

Although tarantulas are famously fiercely-‘fanged’, the researchers point out that the spider doesn’t use them to break through the tough tissues of the bamboo’s stem to create entry [unlike say a woodpecker that physically hammers out its home in a tree trunk (Laura Erickson)]. Rather, the opportunistic arachnid makes use of existing breeches in the bamboo’s culm made by other animals to gain entry. In keeping with the true spirit of scientific enquiry, particularly its predictive power, Chaowalit Songsangchote et al. hypothesize that the tarantula might occupy the empty nest of insects, such as the bamboo-nesting carpenter bee Xylocopa, which creates a large hole. Irrespective of how the spiders come to be inside the plants, this is now an additional use of bamboo (Swapna Dutta; Fred Hornaday), which extends the utility of that grass beyond 1001 [or 1002..?] uses [as tallied here].

Recognising that no Botany One item worthy of being categorised as a Plant Cutting* would be complete without a link to another story, here’s news of another spider that “may sew leaves into fake shelters to lure frogs to their doom” (Jake Buehler), which remarkable behaviour is reported by Thio Rosin Fulgence et al. Entitled ‘Spider traps amphibian in northeastern Madagascar’, this reads more like an attention-grabbing headline in a sensationalist newspaper than one suited to a serious, sober, scientific study, but, it certainly grabbed my attention(!). In that work, Fulgence et al. speculate [note the scientists’ care and caution in word choice] that the shelter, called a ‘retreat’**, acts as a “targeted trap that deceives frogs seeking shelter during daytime”. The retreats are made by spiders of the genus Damastes which use their silk (Jason Bittel) to weave together two green leaves that are still attached to the tree [two spp. were involved, Phyllarthron madagascariensis, and Tambourissa sp.]. You’d need to read the full paper for all of the evidence, but it is primarily based upon a single observation of a spider eating a specimen of Heterixalus andrakata [a frog] inside a retreat, and three observations of spiders “hiding at the rear end of the retreat” [slightly less-than-cautious wording here]. So, there we have two nice examples*** of non-human animals exploiting the plant resource in ways not too dissimilar to human examples of using plants for shelter (e.g. a baobab tree used as a house), and as an aid in catching animals for food (e.g. a fish trap fashioned from willow). It’s always good to see animals appreciating plants.

* Astute readers of this piece might recognise the term Plant Cuttings (e.g. p. 6 here). That is the name of my monthly column carried by the Annals of Botany, an international academic journal of plant science managed by the Annals of Botany Company, which organisation also publishes the Botany One web log. Although the journal stopped publishing those items early in 2019, I’m very pleased to say that Botany One has now offered a home – a retreat you might say – for Plant Cuttings items.

** Any suggestion that the trap is called a retreat because that is what the hapless amphibian wishes it could do – before falling prey to the spider – is probably just coincidence.

*** Or three, if you include the notion of amphibians using a leaf-crafted ‘retreat’ as a daytime hiding place.

READ THE PAPERS

Fulgence, T.R., Martin, D.A., Kreft, H., Ratsoavina, F.M. and Andrianarimisa, A. (2021) “Spider traps amphibian in northeastern Madagascar,” Ecology and Evolution, 11(2), pp. 682–687. Available at: https://doi.org/10.1002/ece3.7102.

Hurd, P.D. (1978) “Bamboo-Nesting Carpenter Bees (Genus Xylocopa Latreille) of the Subgenus Stenoxylocopa Hurd and Moure (Hymenoptera: Anthophoridae),” Journal of the Kansas Entomological Society, 51(4), pp. 746–764. Available at: http://www.jstor.org/stable/25083865.

Songsangchote, C., Sippawat, Z., Khaikaew, W. and Chomphuphuang, N. (2022) “A new genus of bamboo culm tarantula from Thailand (Araneae, Mygalomorphae, Theraphosidae),” ZooKeys, 1080, pp. 1–19. Available at: https://doi.org/10.3897/zookeys.1080.76876.