Trapping results from the 2015/16 season
The psyllid trapping program
for the 2015/16 season has been completed. Trapping is continuing with a small
number of traps currently being operated in Tasmania, Victoria and South
Australia during spring. Trap numbers will be increased again for the 2016/17
potato growing season when planting begins in each region.
A summary of the results is
given in Table 1.
- No tomato-potato psyllids (Bacticera cockerelli)
were detected on 325 traps placed in the field during the 2015/16 season.
- Over 1,753 native psyllids and 1,366 beneficial insects
- Captures of native psyllids were highest in South
Australia (average of 11.0 psyllids per trap) and lowest in eastern Tasmania
(3.1 psyllids per trap).
- None of the native psyllids caught are thought to feed
on potato plants but were attracted to the yellow colour of the sticky traps
from nearby vegetation, particularly Eucalyptus trees.
- Over all locations, only 0.6% of all native psyllids
caught belonged to the same family as the tomato-potato psyllid (Triozidae)
making differentiation rapid based on wing venation (see: Tomato –potato psyllid Identification Key).
- However, two triozids caught in north-western Tasmania
in January 2016 were very similar in appearance to the tomato-potato psyllid
and were later identified as a native species of Trioza.
- Captures of beneficial insects were highest in Victoria (8.9
per trap) and lowest in eastern Tasmania (3.1 per trap).
- Over 47% of beneficial insects caught were brown
lacewings, while ladybirds constituted 25% of captures and hoverflies 26%.
- As found in the 2014/15 season, there was no correlation
between the number of native psyllids caught and the number of beneficial
insects caught, as expected. The number of beneficial insects present in potato
crops is most likely affected by the density of other prey insects, in particular
aphids, and on agronomic practices (such as weed control and the number of
insecticide sprays applied).
For more details of the trapping results for individual regions see: northern Tasmania, south-eastern Tasmania, Victoria, South Australia, Queensland and NSW.
Table 1: Summary of 2015/16 trapping results
Total no. traps
Total no. psyllids
Mean no. psyllids/trap
Total no. beneficials
We thank industry partners
and Horticulture Innovation Australia for funding; all participating potato growers
for allowing us to conduct trapping on their farms; and Dr Gary Taylor
(University of Adelaide) for identifying the Trioza spp.