POLLINATOR PROFILE – LONG-TONGUED FLIES (!!!!!)
Written by Wayne L. Handlos, based on an article in the March 2005 issue of Natural History.
“Extreme Pollinators” was the catchy caption on the cover of the Natural History magazine for March 2005.
The article was titled “The Flower and the Fly” and a 1/2 page picture (See 1/2 a pagebelow.) in the article showed a mega-nosed fly visiting
a flower of Pelargonium suburbanum – a nice candidate for a hanging basket.
The mega-nosed fly has a very long proboscis (not really a nose despite the
common name) up to 4” long – on a body less than an inch long
Long-tongued flies seek nectar in the long floral tubes of certain geraniums
(Pelargonium includingP. cortusifolium, P. crassicaule, P. echinatum,
P. incrassatum, P. magenteum, and P. sericifolium) in South Africa. In attempting
to suck the nectar from deep within the flower – the insect inadvertently picks up
pollen which may be transferred to another flower as the insect searches for its next
drink of nectar. In their natural habitat, these flies have also been found to visit other
plants with long floral tubes. These other plants nclude species of Lapeirousia (an iris relative), Ixia (a South African bulb which is widely
available and easily grown here), and Disa (a terrestrial orchid).
The plants pollinated by the long-nosed flies (about 12 species in two families – the tangle-veined flies and the tabanids or horse/deer flies)
form a “guild.” A guild is a group of unrelated plants pollinated by the same pollinators. These plants are all characterized by “long straight
floral tubes or spurs; brightly colored flowers that are open during the day; and no scent.” This sets them apart from the moth pollinated
flowers which are typically heavily scented at night (i.e. jasmine, etc.).
The article did not consider other interesting geranium flowers like the night scented species with differently
colored flowers (P. gibbosum, P. x rutaceum, P. x glaucifolium, P. bowkeri and others), nor the day
scented but dark colored flowers as seen in P. sidoides.
(Illustration from Natural History Magazine of March 2005).