Bees tend to have a high species diversity in arid areas, particularly those with a mediterranean climate. South Africa, being a largely arid country, has its fair share of bee species, but when there are no rains and consequently no flowers, they cannot be found. As with most insects, solitary bees breed through the summer and their progeny emerge during the following summer to reproduce. Therefore, productive bee collecting has much to do with the previous summer’s weather.
During 21 November to 1 December 2016 the bee team began fieldwork. The team consisted of Elisabeth Khumo Mwase and Connal Eardley, who spent a day collecting at each site. One day is adequate to sample a square kilometre for bees.
The trip focussed on the East Karoo BioGaps sites. The area was dry, with some sites being very dry, except for the Black Hill farm that had received rain. Surprisingly, bee collecting was not much better on Black Hill than on the other farms, but the results were different because we collected many more small carpenter bees than elsewhere. With one or two exceptions, bee collecting was average. A few sites were very dry and bee collecting was poor.
The second BioGaps bee trip took place in the Central Karoo during 30 January to 4 February 2017. The team consisted of Reinette Swanepoel and Connal Eardley. . Although flowers were plentiful near Victoria West, bees were scarce in that area. We had sampled bees there during the previous summer and had found the area very dry with few flowers; hence the knock-on effect described above. The other sites, near Beaufort West, Fraserburg and Loxton were devastatingly dry and bees were non-existent (because we could not find any bees we sampled more than one site per day). This was disappointing as we now have no bee records from those areas. It will be interesting to see how long it takes after good rains have fallen for the bee populations to recover. Let’s hope that the rains come soon and that long-term sampling can be undertaken.
Near the BioGaps site on Chris Hayward’s farm