Jonah’s worm
The biblical account of Jonah gives us wonderful examples of God’s mercy. First, mercy is given to a recalcitrant prophet, and then to the undeserving nation of Nineveh.
Jonah had to learn obedience the hard way. The account tells us that Jonah was called to preach to Nineveh, but instead he decided to flee across the ocean to a distant land.
However, God’s calling could not be evaded. Events led to Jonah being thrown overboard, where he was swallowed by a great fish prepared by God. His life was spared, and he then went to Nineveh to preach. Jonah was disappointed that the people repented, and so God showed Jonah his further wrong attitude through the object lesson of a plant and a ‘worm’:
Now the Lord God appointed a plant [qiqayon], and made it come up over Jonah, that it might be a shade over his head, to save him from his discomfort. So Jonah was exceedingly glad because of the plant. But when dawn came up the next day, God appointed a worm [tola] that attacked the plant, so that it withered (Jonah 4:6–7).
Over the years scholars have tried to identify the plant and worm. While a good candidate for Jonah’s plant has been proposed, the identity of the worm has proved elusive. Now, after more than 2,500 years, it seems scientists may have discovered this.
Jonah’s plant
The Hebrew word qiqayon for the plant has been variously rendered as vine, ivy, or gourd in English translations. None of these is accurate. But there is now general agreement that qiqayon refers to the castor oil plant, Ricinus communis, which gains support from Church and Hebrew tradition.1 In AD 404, the Church Father Jerome suggested the plant was then known to the Syriac people. It was fast-growing and could stand without support, being neither a gourd nor ivy.2
The identification of Jonah’s ‘vine’ as the castor oil plant Ricinus is of interest to Bible scholars and entomologists because it is highly toxic. The leaves and seeds are poisonous, and the leaf extract makes a potent insecticide—therefore very few insects can feed on the plant. It is also toxic to people and animals, and ricin has even been used as a chemical weapon! (But castor oil, made from the seeds, is safe. First, because ricin hardly dissolves in oil, and more importantly, the oil is heated to 80 °C (176 °F) which denatures ricin.) So, how could a worm (tola) feed on Jonah’s plant if it is so poisonous?
‘New’ moth species described in Israel
Despite this toxicity, in recent years a beautiful species of tiger moth has been discovered in Israel, which in its caterpillar stage can feed upon Ricinus without harm. The moth was at first thought to be new to science and described under the name Olepa schleini.3 However, it has since been found to be the same species as Olepa ricini, which is known in Bangladesh, China, India, Nepal, Sri Lanka, and Thailand.4 The caterpillars can cope with the toxins because they have very high activity of a detoxifying enzyme called glutathione S-transferase (GST).5
The habits of the caterpillars of O. ricini match the account given in the book of Jonah. They normally feed at night, and they can quickly destroy a Ricinus plant. (They also feed on useful plants such as cotton, maize, sweet potato, and banana.) The caterpillars usually leave the plant before sunrise, and hide from the heat among dry leaves nearby.
Supernatural supplementing the natural
Jonah 4:10 says that the plant “came into being in a night and perished in a night”. Supernatural action is obviously involved with several aspects of the Jonah account, but in such a way that much of it still happens ‘naturally’:
- Jonah could not naturally survive unharmed for three days inside the belly of any ocean creature. But it may well be natural for one of the marine monsters in creation’s catalogue to swallow such a mammalian morsel.
- A Ricinus plant would not normally reach a size large enough to shade a man within a night—but it is rather fast-growing. Similarly:
- The plant may well have succumbed faster than usual—but the natural destruction this caterpillar wreaks can be very rapid (fig. 3). And its attacks do take place at night, as the verse suggests.
It may appear surprising that an insect so destructive to Ricinus should have gone undocumented in the Middle East for so long, but the insect appears to be quite scarce there. While there are fears it may be on the verge of extinction, it has managed to survive for 2,500 years without anyone reporting on its behaviour.6
Summary and conclusion
This caterpillar’s feeding behaviour on Ricinus and its occurrence in the Middle East make it an extremely likely candidate for Jonah’s ‘worm’.1 Bible believers should not be surprised that the text of Scripture once again correlates with an aspect of observational science.
References and notes
- Hausmann, A. and Müller, G.C., The biblical worms on Jonah’s Ricinus were Olepa schleini larvae. Mitt. Münch. Ent. Ges. 95:5–9, 2006. Return to text.
- Letter from Jerome to Augustine (ad 404), 75.7, in Schaff, P. (ed.), Nicene and Post Nicene Fathers, T&T Clark, Edinburgh, 1886, “… the Hebrew Ms. has ‘ciceion,’ which in the Syriac tongue as now spoken is ‘ciceia.’ It is a kind of shrub having large leaves like a vine, and when planted it quickly springs up to the size of a small tree, standing upright by its own stem, without requiring any support of canes or poles …”. Return to text.
- Witt, T.J. and 5 others, A new Olepa species from Israel, NachrBl. bayer. Ent. 53:101–115, 2005. Return to text.
- Zhang, Y., Huang, S., Wang, M., First record of the genus Olepa Watson, 1980 from China (Lepidoptera, Erebidae, Arctiinae, Arctiini). Biodivers Data J. 14 Feb 2022. Return to text.
- Premachandran, K. and Srinivasan, T.J., Polyphagous insect Olepa sps. feeding on cardenolide rich Calotropis gigantea (L.) leaves and detoxification mechanism involving GST, Heliyon 8(9):E10596, 2022. Return to text.
- Müller, G.C. and 7 others, Distribution, phenology, ecology, behaviour and conservation issues of the new Israeli tiger moth Olepa schleini Witt et al., 2005, Mitt. Münch. Ent. Ges. 95: 19–29, 2006. Return to text.
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