Life cycle
Adult female weevils which are internally infested with B. cocophilus
disperse to a healthy coconut palm and deposit the juvenile stage of the
nematode during oviposition. Nematodes enter the wounds, feed, and
reproduce in the palm tissues, causing the death of the infected trees.
The weevil larvae are parasitized by juveniles of B. cocophilus
which persist in the insect through metamorphosis and appear to aggregate
around the genital capsule of the adult weevil. The adult weevils emerge
from their cocoons in the rotted palm and disperse to apparently healthy
or stressed and dying palms, completeing the life cycle
Geographic distribution and dissemination
B. cocophilus infects coconut palms in many areas of South and
Central America, Mexico, and the Carribean. The nematodes principally
reach noninfected palm trees in or on the bodies or feces of the palm weevil.
They also may be carried on seeds, seedlings, tools, vehicles, animals,
or move by natural migration from infected to noninfected roots.
Wood chippings from axes or machetes used to fell infected palms, as well
as the felled infected palms themsevles also serve as infective material.
B.
cocophilus does not survive in soil for more than 2-3 days, but it
lives in decomposing tissue of dead palms up to 90 days. Inside its
weevil vector, B. cocophilus can survive 10 days, while on the body
ot its vector, it can survive only 2-3 days. Live B. cocophilus
have
been recovered from decaying roots a year after removal of the top portion
of the palm.
Habitat
Highest incidence of Red ring disease caused by B. cocophilus occurs
in low, poorly drained areas. B. cocophilus are susceptible
to desiccation, and drought conditions keep the disease in check. B.
cocophilus survive best in wet, swampy areas, in clay rather than sandy
soil.
Regulatory considerations
B. cocophilus causes serious damage to coconut palms in the
Neotropic region and also in Brazil where it is vectored by the weevil
Rhincophorus
palmarum. The nematode can be introduced with infected weevils
or infected coconut palm material. If introduced into the United
States this pest may be vectored by native Rhincophorus species.
This nematode poses a great risk to the ornamental palm industry of the
U.S.
Information taken from Florida Dept. of Agriculture and Consumer
Service, Plant Industry Div.
Nematology Circulars # 181 and 141, Sept. 1990 and May 1987.
To order copies of these or other circulars, contact them at: http://doacs.state.fl.us/