Laboratory rearing of root grubs

The root grubs Holotrichia serrata Fabricius, Holotrichia consanguinea Blanchard, Holotrichia reynaudi Blanchard, Leucopholis lepidophora Burmeister and Anomala dimidiata Hope ,were reared on sliced carrots under laabortory conditions. Ambient temperature of 26+10C and 65% RH with food availability ad-libitum provided for successful rearing of the grubs. Biological attributes varied among the different species and the grub stage had three instars irrespective of the species. The average life cycle of L.lepidophora and A.dimidiata was completed in 291.8 and 301.9 days, respectively as compared to the Holotrichia species, where the duration ranged between 110.2 to 218.3 days. H.consanguinea had the highest average longevity of 38.6 days followed by H.reynaudi with 32.4 days. Fecundity of the root grubs ranged from 30-56 eggs/female. The benefit of laboratory rearing for taxonomic delineation of grub species and bioassay studies are discussed.