North Queensland Naturalist

Abstract

Field studies and laboratory trials show the Golden Leaf Beetle Lilioceris nigripes (Fabricius) (Criocerinae) feeds on the foliage of species in two families of cycads. The cycads consumed are species of Cycas L. (Cycadales: Cycadaceae) that form a continuum along 1000 kilometers of coastal Queensland, and the northern of two species of Bowenia Hook. ex Hook. (Cycadales: Zamiaceae) in the same areas but separated by the Burdekin Gap. Lilioceris nigripes browsed the foliage of Cycas ophiolitica, C. media subsp. banksii, C. cairnsiana and C. platyphylla, activity being restricted to young foliage produced in flushes prior to onset of the wet season or after fires when previous foliage had been burned away. Lilioceris nigripes also fed on leaflets of both nominate and putative B. spectabilis in north-east Queensland but not on the foliage of B. serrulata in central Queensland despite feeding on C. ophiolitica growing two kilometres away. Laboratory trials were conducted of L. nigripes feeding on different species of cycads without other food sources being available. Lilioceris nigripes previously feeding on nominate B. spectabilis did not eat the foliage of B. serrulata but did eat that of C. ophiolitica. Beetles collected from C. ophiolitica did not eat the foliage of B. serrulata but ate that of B. spectabilis. Adult and larvae L. nigripes collected from nominate B. spectabilis ate the foliage of C. media subsp. banksii and the reverse. The data presented in this paper extend the record of L. nigripes feeding on species and genera of cycads, and records of the chrysomelid genus Lilioceris (Criocerinae) piercing leaves and feeding on the sap in them.