America's Crop Heritage


Smyrna fig depended upon the Blastophaga psenes. The female
of this species of wasp somehow transferred the pollen of the wild,
inedible caprifig to the blossoms of the Smyrna fig, thus bringing
about fertilization and ripening of the fruit. (2)
 This discovery made the agriculturists realize that there was
some significance in the ritual associating the caprifig with the
ripening of the Smyrna variety. The missing link-the wasp which
acted as a fertilizing agent between the two plants-had been
found. In confirmation of this discovery, George Roeding ferti-
lized young Smyrna figs with pollen from the caprifig by trans-
ferring the pollen with a toothpick. He also tried blowing in the
pollen with a small glass tube. Eisen, too, sealed pollen from
caprifigs in a glass container and with it pollinated young figs
200 miles away. However, discovery of the procedure of fertiliz-
ing the Smyra figs was not enough. A quantity of the Blastophaga
wasps had to be imported if fig cultivation was to succeed com-
mercially.
 Importing the Wasps-California growers made a number of
unsuccessful attempts to import the live wasps by bringing in
caprifigs containing the insects. They appealed to the Secretary
of Agriculture, James Wilson, for assistance, suggesting that the
insects be imported in figs on living branches instead of detached
fruits. A young scientist connected with the Department of Agri-
culture, the same Walter T. Swingle mentioned previously, was
studying in Naples at the time. Swingle was commissioned as an
agricultural explorer and given the task of securing a supply of
Blastophaga.
 Swingle's second shipment of Algerian figs in 1899 was success-
ful. He had wrapped the insect-filled figs in tinfoil, sealed them
with wax, and then packed the figs in cotton.
 The figs were opened upon their arrival in California and
hung on two trees which were covered with tents to ward off the
frost. Successful acclimatization of the wasps the following summer
was assured when an employee in the orchard noticed what he
thought were seeds in an unusual-looking hard, green, plump
caprifig. An inspection of the figs growing on the trees showed
that many of them were filled with the wasps.
 How Figs Are Fertilized-Previous shipments of the Blasto-
phaga had failed to survive because the importers did not under-
stand the life cycle of the wasp. In order to ship the wasps success-
fully they had to be obtained during their hibernating stage,