Bursaphelenchus cocophilus. Rhadinaphelenchus was designated a junior synonym of Bursaphelenchus by Baujard Revue Nematol , as it has all the same characters including a subterminal bursa; but differs only in having a greater length to width ratio 'a' ratio , being very long and slender. Naturally infects coconut and oil palms, can be artificially inoculated into cabbage palm and a few others. Nematode has a 10 day life cycle, and can migrate and survive in soil, especially moist areas, but tree to tree spread seems minimal. Nematodes can be transmitted by putting infected tissue in soil near healthy trees, but nematode survives free in soil only days.
|Country:||Trinidad & Tobago|
|Published (Last):||5 October 2012|
|PDF File Size:||17.46 Mb|
|ePub File Size:||10.60 Mb|
|Price:||Free* [*Free Regsitration Required]|
Bursaphelenchus cocophilus nematodes infect palm trees and cause the red ring disease that is fatal to palm, coconut and other fruit trees. Chlorosis leaf discoloration first appears at the tips of the oldest leaves and spreads towards their bases.
The brown lower leaves may break across the petiole of the lower part of the rachis, or they may become partly dislodged at the base and hang down. Nuts are shed prematurely, either simultaneously with the development of leaf symptoms, or slightly before.
About weeks after symptoms first appear the crown often topples over from the internal damage caused by the palm weevil larvae; but, the trunk remains standing in the field for several months until it decays. However, the outward yellow appearance of the nematode infection is sometimes indistinguishable from those of trees growing under conditions of poor drainage or during intense drought The name Red Ring Disease comes from the internal lesions these nematodes cause and they appear as an orange to brick-red colored ring, cm wide, and at a distance of cm from the periphery.
In longitudinal section, the reddened tissue may appear as two united bands joined in the bole forming a U-shape or full circle. To view an adult Bursaphelenchus cocophilus click here. Bursaphelenchus 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. There is a serious economic threat if the red ring disease comes to the United States; especially since it could then be vectored by native Rhincophorus cruentatus.
If the nematode is able to utilize the native weevils it would expand the range of threat from just California and Texas, where the South American Palm Weevil is present, to all states where palm trees grow or are imported. This nematode poses a great risk to the ornamental palm industry of the U. For more information on the South American Palm Weevil click here. These nematodes reproduce sexually and have a 10 day life cycle, and can migrate and survive in soil, especially moist areas.
This nematode can be transmitted by putting infected tissue in soil near healthy trees, but nematode survives free in soil only days. Bursaphelenchus cocophilus adults are carried on body surface and also enter body through spiracles and mouth of the South American Palm Weevil Rhynchophorus palmarum. Transmission to leaf axils occurs as beetle feeds. Nematodes also aggregate around ovipositor and are injected into soft tissue as beetle deposits eggs.
Beetle larvae hatch and tunnel into tissues, pupate, emerge, become infected and spread nematodes. There is some evidence to suggest that nematodes may persist in beetle larvae through molts, but this is unclear. It was thought to be brought in on an imported palm tree or an ornamental plant. The vector is present in the United States but there is no presence of Bursaphelenchus cocophilus yet. Also, Bursaphelenchus cocophilus adults survive best in wet, swampy areas, in clay rather than sandy soil.
In the Caribbean, Traps or guard baskets are designed to protect plantations from frequent outbreaks of Bursaphelenchus cocophilus. They do so by attracting and killing palm weevils which may enter the plantations from nearby diseased trees. Guard baskets are cylindrical, 1 m high and 0. There are no simple means of controlling this nematode and limited and expensive effective measures are available for control of it in living palms.
Control is based on prevention rather than cure either by the destruction of infested palm material by cutting and burning, or by the injection of nematocides and burning, or by trapping and killing of the weevil vectors before they spread the nematodes. Esser, R. Red ring nematode. Gainesville, FL. Gerber, K.
Association of the red ring nematode, Rhadinaphelenchus cocophilus , and other nematode species with Rhynchophorus palmarum Coleoptera: Curculionidae. Hagley, E. The role of the palm weevil, Rhynchophorus palmarum , as a vector of red ring disease of coconuts.
Results of preliminary investigations. Journal of Economic entomology, 56 3 About Facilities Contact. Texas Invasive Species Institute. Red Ring Nematode. Bursaphelenchus cocophilus. Description Bursaphelenchus cocophilus nematodes infect palm trees and cause the red ring disease that is fatal to palm, coconut and other fruit trees.
To view an adult Bursaphelenchus cocophilus click here Ecological Threat Bursaphelenchus cocophilus causes serious damage to coconut palms in the Neotropic region and also in Brazil where it is vectored by the weevil Rhincophorus palmarum. Biology These nematodes reproduce sexually and have a 10 day life cycle, and can migrate and survive in soil, especially moist areas.
References Text References Esser, R. Griffith, R. Red ring disease of coconut palm. Plant Disease
EPPO Global Database
Bursaphelenchus cocophilus causes red ring disease of palms. Symptoms of red ring disease were first described on Trinidad coconut palms in Red ring disease can appear in several species of tropical palms, including date, Canary Island date and Cuban royal, but is most common in oil and coconut palms. The red ring nematode parasitizes the palm weevil Rhynchophorus palmarum L. Vincent, Surinam, Tobago, Trinidad and Venezuela. In some areas, mainly from Mexico to South America and in the lower Antilles, Bursaphelenchus cocophilus is co-distributed with its primary vector, Rhynchophorus palmarum.
Texas Invasive Species Institute
The red ring disease of coconuts and African oil palms is caused by the nematode Bursaphelenchus cocophilus. It is also identified in literature with an alternative scientific name Rhadinaphelenchus cocophilus. The common name, the red ring nematode, is derived from its distinguishing symptom. This nematode is distributed in Central and South America, and some of the islands in the Caribbean. Females have the vulva located two-thirds body length and have a vulval flap.