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Although some authors refer to the "fruit-like" structures on wild fig trees (Ficus) as galls, they are actually specialized structures called syconia bearing minute male and female flowers on the inside. A tiny female wasp enters an opening (ostiole) on the syconium to pollinate the flowers and lay her eggs inside the short-style female flowers. She inserts her ovipositor down the stylar canal and deposits an egg inside the ovary of each short-style flower. According to I.J. Condit (The Fig, 1947), oviposition injures the stylar canal, thus inhibiting pollen tube growth and fertilization in short-style flowers. Because her ovipositor is too short, the fig wasp is unable to oviposit inside the long-style flowers. The latter flowers each develop a seed (with an embryo and endosperm) by normal pollination and double fertilization. Although there is considerable disagreement in the literature, many authors continue to describe the short-style flowers as "gall flowers," presumably because they are commonly occupied by a developing male or female fig wasp; however, they are fully capable of producing normal seed-bearing drupelets, and in this respect are no different from long-style flowers. In 2-3 months a new crop of male and female wasps emerge from the short-style flowers. After insemination by males, the fertile female wasps pack their pollen baskets (corbiculae) with pollen and exit the syconium. These syconia serve as "wasp condos" for populations of wasps that pollinate the fig flowers in one of nature's most remarkable and complex symbiotic cycles. They also produce seeds inside long-style flowers that provide the vital genetic diversity and perpetuation of fig trees.

The "gall controversy" of fig flowers is complicated because food tissue (endosperm) for the developing larva may be initiated parthenogenetically (without pollination and fertilization), possibly by a mechanical or chemical stimulus during oviposition. In this case the flower functions like a minute gall, except there is no apparent tissue malformation as in typical insect galls. Functional male caprifigs of Ficus carica produce three crops of syconia per year: the summer profichi, fall mammoni and overwintering mamme that mature the following spring. Only the profichi crop produces pollen, and this is used to pollinate the Calimyrna orchards of California's Central Valley. The receptive mamme and profichi syconia are not pollinated, so endosperm tissue to nourish the wasp larvae in these crops must be initiated parthenogenetically. Whether they contain a mature seed or a wasp, the short-style flowers of caprifigs appear virtually identical in structure, and do not fit the definition of a typical gall. However, proponents of gall flower terminology argue that when the wasp induces the formation of nutritive endosperm tissue, the ovary interior is literally transformed into a minute gall.

Another case for wasp-induced "gall-like" endosperm tissue is the sycomore fig (Ficus sycomorus) of the Near and Middle East. According to J. Galil (Endeavor, Vol 1, 1977), oviposition by the nonpollinator wasp Sycophaga sycomori results in the development of parthenogenetic endosperm tissue which the larva feeds upon. The galled endosperm tissue develops through proliferation of nucellar cells surrounding the embryo sac. Since there is no pollination, the syconia are seedless. However, in its native habitat of eastern Central Africa and Yemen, F. sycomorus is pollinated by the symbiotic wasp Ceratosolen arabicus, and the long-style flowers produce seeds. The story is even more complicated because without pollination the sycomore fig typically drops its immature syconia. Oviposition and the presence of nonpollinator wasp larvae not only initiate the development of endosperm tissue, but also the enlargement and ripening of the syconium containing wasp-bearing drupelets without pollination--a condition known as parthenocarpy. Since the normal course of events is to abort unpollinated syconia, the entire syconium could be viewed as a gall occupied by nonpollinator wasps.

The sycomore fig was carried north to Egypt by 3000 B.C., and on to Israel, Lebanon and Cyprus. Early farmers in these regions learned how to induce parthenocarpy in sycomore figs by gashing them with a knife. Within 3-4 days the hard, green syconia enlarge and become sweet and fleshy, long before any possible wasp inhabitants are sufficiently developed to damage the crop. In fact, some biblical scholars think the phrase "gatherer of sycomore fruit" (Amos 7:14) actually means "piercer of sycomore fruit." According to J. Galil (Economic Botany Vol. 22, 1968), gashed figs produce ethylene gas which hastens the ripening process. It is interesting to note that in Israel today there is a fully parthenocarpic variety of sycomore fig that does not require gashing or wasps. The syconia ripen on the tree without any external stimulus, as in the popular black mission, kadota and brown turkey varieties of F. carica.

The presence of remarkably specific pollinator wasps probably accounts for the lack of hybridization between many tropical fig species, even though they grow close together in the rain forest. With an abundant supply of specific pollinators for each tree, several species of figs can coexist side-by-side, a phenomenon known as "species packing." Fig wasps apparently do not enter the "wrong" syconium, possibly due to a special chemical attractant for each species of wasp. As with most complex biological phenomena, there are always exceptions. Some syconia may contain more than one species of wasp, including "bogus" fig wasps of the families Torymidae and Eurytomidae, which have very long ovipositors. Some torymid wasps can even oviposit through the syconium wall without ever entering or pollinating the fig. Other bogus fig wasps may simply insert their long ovipositors into long-style flowers which are normally reserved for fig seeds and not fig wasps. The torymid larvae may be seed predators, parasites of fig wasp (agaonid) larvae, or inquilines coexisting with, but not necessarily harmful to the fig or its symbiotic wasp. With its very long ovipositor, the bogus fig wasp is essentially beating the system of long-style female flowers which prohibit egg laying (oviposition) by typical symbiotic pollinator wasps. The presence of nonpollinator, bogus fig wasps and natural pollinator wasps in the same syconium is a complex and perplexing coevolutionary problem in fig biology.

Bogus fig wasps (family Torymidae and Eurytomidae) have an unusually long ovipositor. It can easily penetrate the long-style flowers which are too long for true female fig wasps. Thus bogus fig wasps can lay eggs in long-style fig flowers reserved for fig seeds. Consequently no seeds are produced in these flowers. In addition, the bogus fig wasps do not pollinate fig flowers. Although they do not benefit the fig tree, torymid and eurytomid wasps are common inhabitants of New World fig syconia. Their coexistence with natural fig pollinator wasps is a complex and perplexing coevolutionary problem in fig biology.