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Dr. Pia Addison
Dr Pia Addison joined the
Department during July 2004, after having worked for the Agricultural
Research Council (ARC Infruitec-Nietvoorbij) in Stellenbosch for nine
years as a researcher in the Pest Management Division. Research focuses
primarily on the following:
- Ant management in vineyards
- Grain chinch bug, a phytosanitary
pest of Deciduous fruit
Ant
management in vineyards
Ants (Hymenoptera:
Formicidae) feed on the honeydew excreted by homopterans, such as
aphids, scales and mealybugs and thereby prevent small predators
and parasitoids from attacking these pests. They therefore do no
direct damage to the crop, but rather hinder biological control.
In South Africa, four species of ants have been found to be of economic
significance in preventing biological control against the vine mealybug
Planococcus ficus: the invasive Argentine ant Linepithema humile,
the pugnacious ants Anoplolepis custodiens and A. steingroeveri
and the cocktail ant Crematogaster peringueyi. The following projects
are being carried out: |
- Toxic baits to
control ants in vineyards
- The development
of an action threshold for ants in vineyards
- Quantifying the
impact of ants on vine mealybug and its parasitoids
|
The Argentine Ant Linepithema
humile |
Grain
chinch bug, a phytosanitary pest of Deciduous fruit
The grain chinch bug Macchiademus diplopterus (Hemiptera: Lygaeidae)
is an indigenous bug feeding on wild grasses and grain crops, primarily
wheat. During spring, when the wheat is harvested and the grasses
start drying out, they move to shelters, such as under the bark of
bluegum trees, where they become quiescent until the following winter.
In areas where wheat is grown together with fruit, these bugs seek
shelter in orchards. They crawl into the calyx end of pears and nectarines
as well as citrus fruit. Due to their limited distribution, the winter
rainfall area of the Western Cape, they are classified as a quarantine
pest. The following projects are being carried out: |
- A survey of grain
chinch bug in fruit orchards of the Western Cape
- Investigating
the chemical ecology of grain chinch bug (with the assistance
of Rothamsted Research, United Kingdom)
- Preliminary trials
on possible mitigation treatments against grain chinch bug
The grain chinch bug Macchiademus diplopterus, adult at right
with four immature stages |
The grain chinch bug
Macchiademus diplopterus, adult at right with four immature stages |
| List
of Scientific publications |
| 1. ADDISON,
P. & SAMWAYS, M.J. 2000. A survey of ants (Hymenoptera: Formicidae)
foraging in Western Cape vineyards of South Africa. African Entomology
8 (2): 251 – 260. |
| 2. ADDISON,
P. 2002. Chemical stem barriers for the control of ants (Hymenoptera:
Formicidae) in vineyards. South African Journal of Enology and Viticulture
23 (1): 1 – 8. |
| 3. ADDISON,
P. 2005. Post-harvest control of the grain chinch bug Macchiademus
diplopterus (Heteroptera: Lygaiedae) on pears in the Western Cape
Province, South Africa. (ISHS) Acta Horticulturae 671: 549 –
554. |
| 4. ADDISON,
P. & SAMWAYS, M.J. 2006. Surrogate habitats demonstrate the invasion
potential of the African pugnacious ant. Biodiversity and Conservation 15: 411-428. |
| List
of selected popular publications |
| 1. ADDISON,
P. 2001. Ants foraging in vineyards in the Western Cape Province.
Wynboer No 141: 95 – 98. |
| 2. ADDISON,
P. 2004. Seasonal occurrence and monitoring of grain chinch bug on
pears. South African Fruit Journal, Oct/Nov: 16 – 21. |
| Congress
contributions |
| 1. ADDISON,
P. The distribution of ant species in Western Cape Vineyards. Conference:
South African Society of Enology and Viticulture Congress, Somerset
West, 1999. |
| 2. ADDISON,
P. & SAMWAYS, M.J. The distribution and control of ants in vineyards
in the major grape-growing regions of South Africa. XXI International
Congress of Entomology, Brazil, 2000. |
| 3. ADDISON,
P. Preliminary trials of grain chinch bug in Ceres. Cape Pomological
Association Symposium, Stellenbosch, 2001. |
| 4.
ADDISON, P. Ant management in South African vineyards. South African
Society of Enology and Viticulture Congress, Somerset West, 2001. |
| 5. ADDISON,
P., SAMWAYS, M.J. & WALTON, V.M. An integrated approach towards
ant management in vineyards. 14th Congress of the Entomological Society
of South Africa, Pretoria, 2003. |
| 6. ADDISON,
P. Post-harvest control of the grain chinch bug Macchiademus diplopterus
(Heteroptera: Lygaiedae) on pears in the Western Cape Province, South
Africa. 9th International Pear Symposium, Stellenbosch, 2004. |
| 7. ADDISON,
P. Seasonal occurrence and monitoring of the grain chinch bug, Macchiademus
diplopterus (Heteroptera: Lygaeidae), on pears in the Western Cape
province. Proceedings of the 15th Entomological Congress of Southern
Africa, Grahamstown, July 2005. |
| 8.
ADDISON, P., CHAMBERLAIN, K., DUFOUR, S., WADHAMS, L. & WOODCOCK,
C. Preliminary investigation into the chemical ecology of the grain
chinch bug, Macchiademus diplopterus (Heteroptera: Lygaeidae). Proceedings
of the 15th Entomological Congress of Southern Africa, Grahamstown,
July 2005. |
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