honeyeater (Lichmera indistincta), New Holland honeyeater (Phylidonyris novaehollandiae), white-cheeked honeyeater (P. nigra), singing honeyeater, (Lichenostomus virescens), as well as the twenty-eight parrot (Barnardius zonarius semitorquatus) two species of native bee of the genus Leioproctus, a beetle of the genus Liparetrus, and ant species Iridomyrmex conifer. The yellow flowerheads are also the ones that bear the most nectar, and are greatly preferred by red wattlebirds. An analysis of the invertebrate population in the canopy of Banksia woodland found that mites and ticks (Acari), beetles (Coleoptera) and ants, bees and wasps (Hymenoptera) predominated overall, with the three orders also common on B. ilicifolia, although outnumbered by thrips (Thysanoptera). More arthropods on B. ilicifolia might be related to a higher nutrient (potassium) level in the leaves. Lower overall numbers of invertebrates on Banksia species were thought to be related to the presence of insectivorous birds. Hand-pollination experiments on wild populations near Perth showed that Banksia ilicifolia is self-compatible, although progeny produced have less vigour and seed production is reduced. Further experiments show that seedlings of outcrossing with plants greater than apart are more vigorous and adaptable, suggesting that plants breeding within small fragmented populations are subject to reduced vigour and genetic inbreeding. Banksia ilicifolia regenerates after bushfire by regrowing from epicormic shoots under its bark. Follicles open and release seeds after several years. It is weakly serotinous, like eight other Banksia species, all of which tend to occur in Western Australia's southwestern corner. The other two species of the subgenus Isostylis are killed by fire and regenerate by seed. All banksias have developed proteoid or cluster roots in response to the nutrient-poor conditions of Australian soils (particularly lacking in phosphorus). The plant develops masses of fine lateral roots which form a mat-like structure underneath the soil surface. These enable it to extract nutrients as efficiently possible out of the soil. A study of three co-occurring species in Banksia woodland in southwestern Australia—Banksia menziesii, B. attenuata and B. ilicifolia—found that all three develop fresh roots in September after winter rainfall, and that the bacteria populations associated with the root systems of B. menziesii differ from the other two, and that they also change depending on the age of the roots. Along with its shallow lateral roots, Banksia ilicifolia sinks one or more deep taproots seeking the water table. It is an obligate phreatophyte, that is, it is reliant upon accessing groundwater for its survival;