This document summarizes the life stages of the migratory endoparasite Radopholus similis, or burrowing nematode. It affects important crops like banana and black pepper. The nematode completes its life cycle in roots in 24-30 days. Females lay eggs within infested root tissues. Eggs hatch and juveniles develop, completing the cycle. Symptoms in banana include stunting, reduced leaves and fruit, and root lesions. Management includes crop rotation, hot water treatment of planting material, and nematicides. In black pepper, the nematode causes yellowing, defoliation and reduced berry production.

1. Study of Life Stages of Migratory
Endoparasites
Burrowing Nematode - Radopholus similis
Prepared by
R MOHANAPRIYA
Assisstant Professor (Plant Pathology)
JSA College of Agriculture and Technology,
Ma. Podaiyur, Cuddalore district, Tamilnadu

2. Systematic position
Phylum : Nematoda
Class : Secernentea
Order : Tylenchida
Suborder : Tylenchina
Super family : Tylenchoidea
Family : Pratylenchidae
Sub-family : Pratylenchinae
Genus : Radopholus
Species : similis
Major hosts : Black pepper (pepper yellows) &
Banana (Fusarial wilt)
Type of parasitism : Migratory Endoparasite
• (Gr. Radix-root, phelien-loving) denotes endoparasitic mode of life,
• Common name ‘burrowing nematode’ is coined beacause it causes
extensive cavity formation in roots due to migratory behaviour.
• 1st observed by Cobb in 1890-91 in banana disease in Fiji

3. Female
• Vermiform
• 0.5-0.8 mm long
• Lip region low, set off, spear
strong with well developed
basal knobs
• Oesophageal glands
overlapping intestine dorsally
• Ovary – didelphic
• Vulva median
• Tail conoid to blunt with
rounded terminus
Female anterior region

4. Male
• Spear very slender with tiny
knobs
• Oesopagus reduced
• Bursa extending upto 2/3 of
the tail
Male anterior region

5. Economically important species
• R. similis (now known as R. citrophilus) is considered as
economically very important species in tropical and
subtropical areas of the throughout the world
• In India introduced into Kerala by banana suckers from other
countries
• It occurs in TN, AP, MP, Goa, Maharastra, Gujarat, Karnataka
• Serious problem in Banana, Pepper, Coffee, Tea, Cocoa,
Coconut, Arecanut, Sugarcane, Turmeric, Ginger

6. Life cycle
• Females and all juvenile stages are infective.
• Males are non-parasitic and morphologically degenerate (without stylet).
• Penetration occurs mostly near the root tip. The nematode penetrates
within 24 hours and the cells around the site of penetration become
brown.
• After entering the roots, the nematodes occupy intercellular position in
the cortical parenchyma where they feed on the cytoplasm of nearby cells
causing cavities which coalesce to form tunnels.
• Nematodes do not enter the stellar portions of the root.

7. • The nematode completes its life cycle within 24-30 days at a temperature
range of 21-32°C.
• Females lay eggs within infested tissues with an average of 4-5 eggs for
two weeks.
• Eggs hatch after 8-10 days and the juvenile stages are completed in 10-13
days.
• A low soil temperature, adequate soil moisture and availability of fresh
tender roots help in the build up of population.

10. Spread of necrotic lesions from roots to rhizome in banana infected with
Radopholus similis

11. Symptoms
Fusarial wilt of Banana
F. Oxysporum f.sp. cubense
 Stunting of plants
 Reduction in size and number of
leaves and in bunch weight.
 Appearance of dark red lesion on
roots.
 Toppling of plants in windstorms
or heavy rains
Management
• Fallowing for a period of six
months or longer.
• Crop rotation with non-host
crops.
• Use of disease free planting
material.
• Storage of large corms in the sun
for two weeks prior to planting.
• Use of cover crop Calapogonium.
• Removal of infested portions of
corm before planting.
• Hotwater treatment at 55o C for
15-25min.
• Paring and Pralinage
• Carbofuran 3 g @40g/ plant at
90 days after planting.
• Application of neem cake

13. Black pepper
Yellow disease
• Yellowing of leaves
• Complete defoliation
• Reduces the berry production
• Vines become unproductive
• Roots are devoid of laterals, extensive
necrosis on the main roots
Management
Apply Fensulfothion @ 4-8kg a.i./ha at nursery
stage is effective to control nematode infection