Some nematodes feed on plants. These species have hollow, needle-like structures that are used to puncture cell walls in plants thereby allowing the nematodes to be able to suck out the nutritious cell contents. Among nematodes, the ability to parasitize plants has been “invented” at least three times.
The one depicted here – Paratrichodorus – belongs to the most ancient group (this group is called Trichodoridae). Plant-eating nematodes are mostly known as pests in agriculture and some of these species can have large economic impacts. Paratrichodorus is a polyphagous, migratory ectoparasite of plants; it feeds on many plant species by puncturing with its spear the outer cell layer (‘rhizodermis’) of roots.