Schistonchus caprifici (Gasperrini, 1864) Cobb, 1927
Schistonchus caprifici is the earliest described
aphelenchid. It has a complex phoretic and parasitic realtionship with
the small wasp, Blastophaga psenes (L.), which pollinates the
Smyrna fig (see below).
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Feeds, grows and reproduces within inflorescences of caprifig, Ficus
The nematode parasitizes and reproduces on caprifig (Ficus carica
sylvestris) inflorescences and also in the haemocoel of the fig pollinator
wasp Blastophaga psenes. The process of caprification is the
managed pollination of figs that bear pistillate flowers by hanging male flowers
from branches to facilitate pollen transfe by wasps.
Staminate and pistillate florets of caprifig infected by S. caprifici
exhibited necrosis and cavities in the cortical parenchyma of floret
peduncles and stamen filaments.
Schistonchus caprifici is spread from infected to healthy
caprifig inflorescences through oviposition behaviour of the wasp,
Blastophaga psenes. Wasp development can occur in inflorescences that
are infected with nematodes. The nematodes colonize and reproduce in
the haemocoel of wasp larvae. The nematode persists in the pupae and winged
females that developed in the pistillate florets. Wingless male wasps are
not infected by the nematode.
Wasp development apparently does not occur in inflorescences of
commercial figs although they are visited by ovipositing wasps which vector
nematodes in their florets.
There is no evidence of adverse effect of S. caprifici on
B. psenes. However, the association is considered to be a
parasitic relationship because of nematode reproduction in the wasp's
haemocoel (Vovlas et al., 1992).
Schistonchus caprifici feeds om pistillate florets of commercial fig
(F. carica) as well as caprifig (Ficus carica sylvestris).
Population levels of the nematode were lower in commercial fig than
in caprifig (550 nematodes vs. 12,000 nematodes/g fresh floret tissues,
respectively) (Vovlas et al., 1992)..
Nematode infection may result in premature inflorescence decay.
Host Plant Resistance, Non-hosts and Crop Rotation alternatives:
Vovlas, N., R. N. Inserra and N. Greco. 1992. Schistonchus caprifici
parasitizing caprifig (Ficus carica sylvestris) florets and the relationship
with its fig wasp (Blastophaga psenes) vector. Nematologica 38:215-226.