A Beltian body is a structure found on the leaves of some species of Acacia

Acacia

Acacia is a genus of shrubs and trees belonging to the subfamily Mimosoideae of the family Fabaceae, first described in Africa by the Swedish botanist Carl Linnaeus in 1773. Many non-Australian species tend to be thorny, whereas the majority of Australian acacias are not...

. Beltian bodies, named after Thomas Belt

Thomas Belt

Thomas Belt , an English geologist and naturalist, was born at Newcastle-on-Tyne in 1832, and educated in that city. He is remembered for his work on the geology of gold bearing minerals, glacial geology, and for his description of the mutualistic relationship between certain bullthorn Acacia...

, are found on the tips of each leaflet and are rich in lipids and proteins and often red in colour. They are believed to have evolved in a symbiotic relationship with ants. The ants live inside special plant structures (Domatia

Domatia

Domatia are tiny chambers produced by plants that house arthropods.Domatia differ from galls in that they are produced by the plant rather than being induced by their inhabitants...

) or near the plant and keep away herbivore

Herbivore

Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...

s.

Other ant-mutualism related plant structures include Beccarian, Mullerian and pearl bodies.

Unique among spiders for its predominantly vegetarian diet, Bagheera kiplingi

Bagheera kiplingi

Bagheera kiplingi is a species of jumping spider found in Central America including Mexico, Costa Rica and Guatemala. It is the type species of the genus Bagheera, which includes one other species, B. prosper. B. kiplingi is notable for its peculiar diet, which, uniquely for a spider, is mostly...

feeds almost exclusively on Beltian bodies.