Nematodes, figs and wasps.

Certain Ficus spp. are dependent on wasps for pollination. The invading wasps usually shed their wings on entering a fig through the ostiole; and during attempted or successful egg deposi t ion, transfer pollen to the female flowers and then die. A gall forms around each egg, and within the gall develops a male or a female wasp. Male wasps are the first to emerge from galls, and they then fertilize the female wasps b e f o r e the females emerge. After emergence from the galls, the female wasps escape from the fig via the ostiole and fly to developing figs where the cycle is repeated. Many spec ies of nematodes mature and reproduce within figs, and are transported to figs by pollinating wasps. The literature revealed no reference to nematodes within the fruit of fig trees, but Thorne (3) and Nickle (2) refer to the work of Gasparrini (1), who recorded a nematode Schistonchus caprifici (Gasparrini 1864) Cobb, 1927, carried by the fig-pollinating wasp Blastophaga psenes L. Many Ficus spp. grow in Rhodesia, and the majority are considered to be indigenous. Fruit has been examined from the following species: Ficus capensis Thumb.; F. sycomorus L.; F. burkei (Miq.) Miq.; F. ingens (Miq.) Miq.; F. sonderi Miq.; and F. welwitschii Warb. All are u n c u l t i v a t e d Af r i can figs indigenous to Rhodesia except for F. welwitschii. Nematodeand wasp-infested figs were present on every bearing tree examined, and in no case have nematodes been found in the absence of wasps or vice versa. Figs from seven non-African cultivated Ficus spp . , inc lud ing species grown as ornamentals, for shade and for fruit, did not reveal the presence of nematodes or wasps. Figs are not produced commercially in Rhodesia, but are grown in private gardens for home consumption. Several species of minute wasps were observed in many figs, and more than one