Open AccessEGG AND LARVAL ABUNDANCES OF HELICOVERPA HARDWICK (LEPIDOPTERA: NOCTUIDAE) ON CHRISTMAS BELLS
Author(s) -
Coombs M.,
Ramsey M.
Publication year - 1991
Publication title -
australian journal of entomology
Language(s) - English
Resource type - Journals
eISSN - 1440-6055
pISSN - 1326-6756
DOI - 10.1111/j.1440-6055.1991.tb00420.x
Subject(s) - biology , larva , lepidoptera genitalia , noctuidae , helicoverpa armigera , botany , instar , population , abundance (ecology) , horticulture , ecology , demography , sociology
A population of the native monocot Christmas bells was examined for eggs and larvae of Helicoverpa spp. throughout the 1989–1990 flowering season. H. armigera (Hübner), but no H. punctigera (Wallengren), were found. Eggs were found only on floral buds or recently‐opened flowers. On plants with eggs, individual buds carried only a single egg. On such plants the mean number of eggs was 1.2 ± 0.6, although plants had 6.5 ± 2.0 buds. During peak flowering 21% of plants carried eggs. Larvae were found on plants with buds, flowers and/or fruits. Late instar larvae that fed predominately on buds and flowers of Christmas bells produced fertile offspring, suggesting that this plant was suitable as a host. Egg and larval abundances were both correlated positively with the numbers of plants with buds. Abundance of larvae, but not eggs, was also correlated positively with the numbers of plants with flowers. During peak flowering, egg and larval abundances were estimated at 1.5 and 0.5 million per 100 ha respectively.