The dune grass stems showed larger, hard, dark brown galls, which on opening them contained insect larvae and showed small exit holes of wasps. Nematode galls sometimes situated on top of, or next to the insects’ galls, were always brown to dark brown in colour, and appeared harder and drier than those found on grass stems and leaves.

Larger, harder galls varying from beige to dark brown in colour, apparently caused by insects, were also found on the stems of dune grass at Blouberg Beach and Langebaan Nature Reserve.

Insect galls [from Langebaan, Western Cape] were light to dark brown in colour, about 5 mm in width and 10 mm in length), oval in shape and rough on the outside (Fig. 5d, e and f) The galls were very hard to cut through and the inside was cream in colour (Fig. 11d). The hardness of the galls extended to the grass stalk surface. The galls were traversed by tunnels that ended with a cavity containing the larval stage of the wasp (Fig. 5d and e). On close inspection of the insect gall, the aperture of another, small tunnel was observed (Fig. 5d).

Insect galls from Blouberg Beach were beige to light brown in colour. The galls were oval, 5 mm wide and 10 mm long and smooth on the outside. They were traversed by tunnels that ended with a cavity containing the larval stage of an insect, probably a gall-forming fly of the family Chloropidae. Wasp exit apertures were visible on the surface of some galls (Fig. 5d and e).