Journal article
Population dynamics of the chrysomelid leaf beetle Chrysophtharta agricola (Chapuis), a pest of Eucalyptus nitens plantations in Tasmania
TasForests, Vol.15, pp.67-84
2004
Abstract
The phenology of the southern eucalypt leaf beetle, Chrysophtharta agricola, was assessed at three Eucalyptus nitens plantations in Tasmania: Florentine Valley, Frankford and Blue Gum Knob. Five branches were sampled from each of 20 trees at each site every two weeks for three summer seasons between November 1999 and March 2000, between October 2000 and March 2001, and at two of these sites between October 2001 and March 2002. On each occasion, the numbers of egg batches, larvae of each instar, and adults were recorded from each branch. Adults were collected and dissected in the laboratory to ascertain their reproductive maturity, mated status and sex ratio. Egg-to-fi nal instar mortality was estimated, and natural enemies present in the plantations were recorded. Beetles fi rst appeared in the fi eld in mid to late October and laid eggs between early November and February. Overall, larval populations peaked in December, and egg-to-fourth instar mortality ranged from 85 to 100%. Newly emerged adults were present in plantations between January and March/April. Sex ratios of parent and new generation adults were rarely female biased. Peak defoliation scores coincided with late larval instars at Florentine Valley and with newly emerged adults at Frankford. Defoliation at Florentine Valley peaked at about 30% of current season's growth removed, while at Frankford the average peak defoliation represented about 50% of current season's growth removed. Spatial analyses indicated that C. agricola life stages were randomly distributed throughout plantations.
Details
- Title
- Population dynamics of the chrysomelid leaf beetle Chrysophtharta agricola (Chapuis), a pest of Eucalyptus nitens plantations in Tasmania
- Authors
- Helen F Nahrung (Author) - University of TasmaniaG R Allen (Author) - University of Tasmania
- Publication details
- TasForests, Vol.15, pp.67-84
- Publisher
- Forestry Commission of Tasmania
- Date published
- 2004
- ISSN
- 1033-8306
- Organisation Unit
- University of the Sunshine Coast, Queensland; Forest Industries Research Centre; Forest Research Institute
- Language
- English
- Record Identifier
- 99450507502621
- Output Type
- Journal article
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