Global patterns of arthropod herbivory on an invasive plant, the physic nut (Jatropha curcas L.)

The physic nut (Jatropha curcas L.) is a multipurpose and oil-producing shrub of Central and South American origin. Since the 15th century, this shrub has existed across tropical regions. Despite its presumed resistance to herbivores, reports show that arthropod herbivores infest it. However, no comprehensive account of arthropod herbivores, which consume the physic nut, exists. Here, we conducted a literature review that provides a comprehensive account of arthropod herbivores of the physic nut. Based on the co-evolutionary hypothesis, we expected to find a higher herbivore of species richness and a larger proportion of native herbivores within the native range than elsewhere. As physic nut is a well-defended plant chemically, we expected to find evidence for highest herbivory levels in plant parts that are the least defended. By the literatures review, we compiled 78 arthropod herbivores representing nine orders and from 31 families that feed on physic nut across the globe. As expected, the highest numbers of herbivores (34 species) were documented within the native range of the J.curcas and the lowest species number (21 species) in Africa. Of the 34 species in Central and South America, 94% were of native origin. Nine species were found feeding on J.curcas on more than one continent. Origins of 49% of species were from the native range of J.curcas. The highest percentage (54%) of species belonged to Hemiptera. With regard to feeding guilds, 59% of the herbivores belonged to sucking and 41% to chewing species. Forty-one per cent of species were flower or fruit feeders, and 36% foliage feeders. We conclude that J.curcas is, despite its toxicity, vulnerable to herbivory, mainly to foliage, flower and fruit feeders.