New Zealand Journal of Crop and Horticultural Science abstracts
Timing of insecticide applications for control of soft wax scale
(Homoptera: Coccidae) on citrus
R. H. BLANK
M. H. OLSON
G. S. C. GILL
The Horticulture and Food Research
Institute of New Zealand
Whangarei Research Centre
Private Bag 9003
Whangarei, New Zealand
B. W. DOW
The Horticulture and Food Research
Institute of New Zealand
Whangarei Research Centre
Private Bag 3123
Hamilton, New Zealand
Abstract The efficacy of four insecticide
treatments--buprofezin, chlorpyrifos, 1 and 2% mineral oil, applied at four
single, and a double application time, was evaluated against soft wax scale,
Ceroplastes destructor Newstead, on `Seminole' tangelo (Citrus
paradisi (Macfadyen) x C. reticulata (Blanco)) in Kerikeri, New
Zealand. Settlement of the insecticide-sensitive ray stage (1st instar and 2nd
instar) onto leaves, and the later dispersal of rays onto the wood to form the
wax-protected peak stage (3rd instar), was monitored. Spray application times
on 15 and 25 January, 12 February, and 2 March 1993 corresponded to 64, 96,
100, and 50% of total ray abundance on leaves in untreated trees. Maximum ray
abundance, after correcting for natural mortality, was estimated to occur on 4
February. There was no significant difference between chlorpyrifos and both
mineral oil treatments which resulted in 71 and 90% control of rays, when
averaged over all single and double applications, respectively. The highest
level of control was achieved about the time of maximum ray settlement and
insecticides should be applied during the period, 18 days before and 28 days
after maximum settlement. A longer-term evaluation of the success of treatments
showed that all treatments significantly reduced peak stages in April by 71%,
averaged over all times of application. The 1% mineral oil treatment was the
preferred choice in an integrated pest management programme.
Keywords Ceroplastes destructor, soft wax scale;
citrus; timing; control; insecticides
New Zealand Journal of Crop and Horticultural Science, 1997, Vol. 25:
311-317
0114-0671/97/2504-0311 $7.00/0 (c) The Royal Society of New Zealand
1997
PDF file of entire paper: medium quality (546K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
