WASPS & FIGS

A Delicious Example of Symbiosis


One of the tastiest treats grown in California is the Calimyrna Fig. You could call it the fig of figs! But when growers first attempted to cultivate this treat in the United States, they were puzzled as to why their trees wouldn't produce figs. Finally, in the late 1800's they discoverd that their orchards were lacking a crucial element - a tiny female wasp, no more than 2 millimeters long that comes from Asia Minor! It turns out these tasty "fruits" are really an inside-out cluster of small flowers called a syconium. Without pollination the syconia fail to ripen. Here's where the wasps come into play...a female wasp will work her way into the caprifig through an opening called the ostiole. She then attempts to lay her eggs inside the ovary of all of the female flowers on the inside of the caprifig. Some of these flowers have short styles, and prove to be a successful home for the eggs, other flowers (the ones that eventually grow into figs) have longer styles. The female's ovipositor isn't long enough to pollinate the syconia with long-stlyes. The female desperately attempts to lay her eggs in these long styles until she dies of exhaustion. Her reproductive failure equals reproductive success for the ficus tree since the female's futile attempts end up pollinating the long-styled syconia. Therefore, the fig tree and the wasp have developed a functional symbiotic relationship where some caprifigs serve as a breeding and feeding ground for new wasps, and others are pollinated by the unsuccessful attempts of unlucky wasps!
A wasp developing inside the ovary of a fig flower!
A close-up view of the inside of a syconium that is impenetrable to a wasp's ovipositor.

website created by Leiana Leon Guerrero 4/2004