Micro-coevolution in insect-plant relationships Back :  Forward
male Anthophora pauperata & Alkanna orientalis
We are interested in the possibility of micro-coevolution in insect-plant relationships, using behavioural, ecological, biochemical and molecular approaches, studying the pollination in spring of Alkanna orientalis by the solitary bee Anthophora pauperata. Females are the main pollinators, visiting the flowers for pollen before they have really opened properly, and then later in the female phase of the flowers for nectar.

Males are either territory holders, non-territorial wanderers, or sit-and-wait sneakers. They cannot defend a territory unless the sun is warm enough (it is very cold in March-April without it!), and begin small, defending just one or two plants, and gradually expand the territory to a maximum size by the early afternoon. In the wadis the mountain shadow returns early, causing the cessation of territoriality. Females forage over larger non-exclusive home ranges that contain their individual and isolated nest dug into the sand among the rocks.

The highly localized patterns of bee movements create the preconditions for localized pollen movement, and hence restricted plant gene flow. From RAPD genetic data, there is genetic differentiation among the Alkanna plants of adjacent wadis. Wadi populations are genetically distinct, with a pattern of genetic relationships consistent with gene flow via the rare event of seed transport by flash floods.

Again from RAPD data, there is also evidence of genetic differentiation among wadis in bee populations, but plant and bee patterns of genes do not match, falsifying a coevolutionary process.

Currently a PhD student, Rayan AlAnsari from Saudi Arabia, is studying the genetic differentiation of Alkanna orientalis and Anthophora populations from Sinai and Saudi Arabia, and comparing them with other samples from across the entire Middle East.

Selected publications:

Mahmoud MAM, Zalat SM, El-Akkad SS & Gilbert F (2008) Genetic variability in the endemic bee Anthophora pauperata among wadis in the St Katherine Protectorate. Egyptian Journal of Biology 10: 77-86 [PDF]
Semida FMM (2000) Nesting behaviour of Anthophora pauperata (Hymenoptera: Anthophoridae) in the St Katherine ecosystem, Sinai. Egyptian Journal of Biology 2: 118-124 [PDF]
Gilbert F (1999) Insect-plant coevolution in the mountains of Sinai. Central Association of Bee-Keepers, London. 8 pp. [PDF]
Stone GN, Gilbert F, Willmer P, Potts S, Semida F & Zalat S (1999) Windows of opportunity and the temporal structuring of foraging activity in a desert solitary bee. Ecological Entomology 24: 208-221 [PDF]
Wolff K, El-Akkad S & Abbott RJ(1997) Population substructure in Alkanna orientalis L. Boiss. (Boraginaceae) in the Sinai desert, in relation to its pollinator behaviour. Molecular Ecology 6: 365-372 [PDF]
Gilbert F, Willmer PG, Semida F, Ghazoul J & Zalat S (1996) Spatial variation in selection in a plant-pollinator system in the wadis of Sinai, Egypt. Oecologia 108: 479-487 [PDF]
Willmer PG, Gilbert F, Ghazoul J, Semida F & Zalat S (1993) A novel form of territoriality: daily paternal investment in Anthophorid bees. Animal Behaviour 46: 535-549 [PDF]