Hybrid onion seed are produced mainly in
the Klein Karoo and partly in some areas in the greater Karoo in the Western Cape
province. The seed companies are mostly
situated in Oudtshoorn.
The Klein Karoo is a longitudinal area of
about 23 500 km2 situated between two mountain ranges parallel to
the southern coastal shores of South Africa (the Langeberg-Outeniqua mountain
range in the south and the Witteberg-Swartberg mountain range in the north). The soils of the lowlands are generally
clayey and nutrient-rich while the mountains typically have sandy,
nutrient-poor soils. Soil surfaces in
the lowland areas are dependent on a living soil crust, formed by small
organisms like lichens, mosses, fungi and bacteria, to insure water
infiltration, erosion control and nutrient cycling. The Klein Karoo has a semi-desert climate
with higher rainfall in the mountainous areas.
The diversity of environmental factors merging in the Klein Karoo is the
reason for the very rich plant diversity.
About 3 200 plants have been identified in the region with 400 of them being
endemic to the region. Four vegetation
types are recognized namely, subtropical thicket, succulent karoo, transitional
shrubland and fynbos (Vlok & Schutte-Vlok, 2010).
The ecosystems in the mountain ranges,
which also serve as water catchment areas, are largely protected and unaltered
in protected areas. However, the lowland
landscapes have been altered considerably over the years by agricultural
practices. One of the main farming
practices in the region is ostrich farming that started between 1857 and 1860, which
also impelled the cultivation of lucerne as ostrich fodder (Beyleveld, 1967).
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| Ostrich farming in the Klein Karoo, near Calitzdorp |
The topology of the Klein Karoo landscape
where hybrid onion seed are produced, is largely characterized by undulating
hills interchanged with historical floodplains along rivers and streams. These floodplain areas is
suitable for crop cultivation, while the hilly areas are mostly used for livestock
grazing.
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| View of the Swartberg mountain range from the
Klein Karoo, showing the hilly landscape in the foreground with a historical riverine
floodplain in between. |
Not much work has been done on the insect
diversity found in the Klein Karoo. Some
work has been done on the occurrence and diversity of pollen wasps in the
region and elsewhere by Fred and Sarah Gess from the Albany Museum in Grahamstown. But the area remains largely under-sampled in
terms of insect, and especially pollinator insect diversity, says Jonathan
Colville, my promoter and entomologist at SANBI. Thus, my work will be a valuable contribution
to the knowledge base of pollinator insect diversity and distribution within the
area covered in the study.
Even the casual collection of insects can bring about new species being discovered. Jonathan is particularly interested in monkey beetles, members of the family Scarabaeidae, which are largely endemic to southern Africa and important pollinators of many flowers. He asked me to be on the look-out for them and collect them if I find some. So, while we were busy data capturing on a site in the greater Karoo, a rather large monkey beetle came landing on the ground in front of me. I picked it up, and pickled it in some alcohol. It turned out to be a new species! Needless to say, the monkey beetle specialists were ecstatic about the new discovery. The trick is to be on the right place at the right time.
