Re: Record Holders (with Quiz)
Posted: Sat Nov 07, 2020 11:17 pm
Has the longest proboscis of any fly. 
... of any insect
Moegistorhynchus longirostris has the longest proboscis relative to body size of all known insects. Proboscis length ranges from 32 to 83 mm.
It is a keystone species along the west coast of South Africa, where it pollinates, partly or exclusively, the long-tubed flowers of at least 20 species of Iridaceae, Geraniaceae and Orchidaceae. It has been widely discussed in the pollination biology literature and the interest in M. longirostris from a suggested co-evolutionary process between it and the long-tubed flowers it pollinates. This form of interaction was described as an arms race between long-tubed flowers and pollinating insects — a process driving the evolution of increasing flower depth and further increases in proboscis length.
A pollination guild of at least 20 late spring or early summer-flowering species of Iridaceae, Geraniaceae and Orchidaceae centred on M. longirostris, is established in the literature. Unusual features shared by these flowers include a very narrow floral tube (length 45 to 90 mm), and unscented flowers which are white through pink to salmon, with contrasted markings usually in red.
As hypothesized by Darwin, the benefits derived by pollinator and plant from their interaction depended on their relative position in a race for elongation. On average, the fly is able to consume little or none of the nectar when its proboscis is shorter than the floral tube with which it is interacting, but it is able to consume all the nectar when its proboscis is longer than the floral tube. The plant, on average, receives few or no pollen grains when its tube is shorter than the proboscis of the foraging fly, but it is well pollinated when its tube is longer than the proboscis of the fly. Thus, long‐proboscid individuals in the fly population can select for even longer‐tubed plants by parasitizing plants with tubes that are shorter than their proboscides; simultaneously, long‐tubed plants in the population can select for flies with yet longer proboscides by parasitizing flies with proboscides that are shorter than their floral tubes. In this pair of naturally interacting populations, the interacting traits have the potential to impose directional, reciprocal selection on each other, and, as such, a necessary condition for coevolution is met.
Which record does it hold?
