- C D Eardley and M W Mansell
- Biosystematics Division, Plant Protection Research Institute, Private Bag X134, Pretoria 0001
- 1995
The farm Carpe Diem, near Ofcalaco, which is surrounded by indigenous vegetation, had a large complement of insects that visited the litchi blossoms. Most species were ineffectual as pollinators. These insects occurred in low numbers and simply robbed the flowers of nectar while passing through the orchard. There were, however, several bees, including the honeybee, and some flies which apparently contributed significantly towards pollination in the orchard. This differed from a similar study near Tzaneen, where very little indigenous vegetation was present, and only honey bees appeared to have any significance as pollinators.
Summary:
The study was conducted on the Carpe Diem farm near Ofcalaco, surrounded by indigenous vegetation, to assess natural insect pollinators during peak litchi flowering over a two-day period in September 1993.
The farm did not have introduced honey bees, making it ideal to study natural insect pollinator presence and activity.
Two transects in the orchard were monitored hourly from 8:00 to 16:00, with insect visitors to blossoms identified and recorded for relative abundance and potential pollination contribution.
Many different insect species visited litchi flowers, but most were ineffectual as pollinators and mainly robbed nectar.
Significant pollinator groups included several bee species (honey bees, mopani bees, small carpenter bees) and some flies that appeared to contribute substantially toward pollination.
The area surrounding the orchard was drought-stricken at the time, with no flowering plants nearby to divert pollinators.
The study noted differences from a previous survey near Tzaneen, where lack of indigenous vegetation resulted in honey bees being the only significant pollinators.
The diverse insect assemblage in the Carpe Diem orchard indicates that litchi flowers attract a wide range of pollinators in an area rich in natural vegetation.
The low numbers of alternate pollinators in more intensively cultivated areas are partly due to honeybee dominance and aggressive behavior towards other insects.
The findings provide valuable insight into natural litchi pollination ecology and recommend considering surrounding vegetation and pollinator diversity in orchard management.
Further monitoring will assess daily activity patterns of pollinators and their specific effects on litchi pollination.
The comprehensive insect list includes many Hymenoptera (various bees and wasps), Diptera (flies), and a few Coleoptera and other groups, with honey bees as the most abundant visitor species recorded.