36 Nilaparvata lugens [EIF

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This leaflet is produced by the Ministry of Agriculture & Livestock, Solomon Islands, with support from IPPSI:
Improved Plant Protection in Solomon Islands, a project financed by ACIAR, the Australian Centre for
International Agricultural Research, Canberra. Authors: Helen Tsatsia, MAL & Grahame Jackson, TerraCircle
Inc. Photos: above -

http://ricehoppers.net/

(IRRI); below - Natasha Wright, Florida Department of Agriculture

and Consumer Services, Bugwood.org

Extension Fact Sheet 64:

Nilaparvata lugens

Common name: Brown planthopper

Scientific name: Nilaparvata lugens

Hosts: Rice and wild grasses.

Damage

Both adults (photo, below right) and nymphs (photo, left) do the damage. They have piercing
mouthparts that they insert into the leaf blades and leaf sheaths (‘stems’) of rice plants to
suck the sap. Also, egg laying blocks the water and food channels inside the plant.

Symptoms depend on variety, number of planthoppers, and plant age: tiller and panicle
number, and plant height, are reduced; grains are unfilled; injury from feeding and egg laying
allows entry of fungi and bacteria, and sooty mould fungi blacken stems. Severe infestations
cause plants in the ‘milk’ or ‘dough’ stages to gradually yellow from the tip, brown, dry out
and collapse (a wilt, known as ‘hopperburn’; photo, above right). The most susceptible time
is from tillering to flowering. Hopperburn is more common in paddy than dryland rice.

Biology and Life Cycle

Eggs are laid in the midrib of the leaf blades, 4-10 in an egg mass; they are cylindrical,
slightly curved, 1 mm long, white at first, darker when about to hatch, with two spots - the
eyes of the nymph. The eggs hatch in 4-8 days. Nymphs are creamy white with a pale brown
tinge, later becoming dark brown. There are four to five moults. The final nymphs are nearly
3 mm long, with a line from the top of the head to the middle part of the body where it is
widest. Adults are brownish black with a yellowish-brown body. There are two forms, long
winged (photo, above) and short winged.

___________________________________________________________________________

http://ricehoppers.net/

(IRRI); below - Natasha Wright, Florida Department of Agriculture

and Consumer Services, Bugwood.org

Infestations start with the arrival of the winged form, which then produce wingless types.
Winged form develops when numbers are high; females are about 4 mm and males 4.5 mm;
wingless forms are smaller. After harvest, the planthoppers migrate to grasses, or spread to
new crops of rice. Brown planthoppers live for up to 20 days.

Detection and Inspection

Look at the base of the plants, where it is shady and humidity is high, for the nymphs and
winged and wingless adults. Look for the sooty mould fungi that often accompany large
numbers of the insects. More than 3-5 insects per tiller is considered high, needing more
intensive observation and possibly insecticide treatment.

Management

Over use of insecticides is the main cause of outbreaks of Brown planthopper. IPM programs
stress the need to main biological control – natural enemies – and also include resistant
varieties. The routine use of insecticides should be avoided.

Natural enemies:

There are a number of natural predators of the Brown planthopper: spiders eat the nymphs
and adults, as do coccinellid beetles, dragonflies and damselflies. There are two species of
mired egg-sucking bugs - Cyrtorhinus chinensis and C lividipennis – in Solomon Islands, and
there are likely to be wasp parasitoids that attack eggs, as well as fungal pathogens and mites.

Cultural control:

•  Drain the paddies for 3-4 days during the early stage of infestation;
•  Split applications (three times) of nitrogen fertilizer;
•  Avoid staggered planting, preventing planthoppers moving from older to younger crops;
•  Remove volunteer plants;
•  Rotate rice with other crops.

Resistant varieties:

Egg laying and survival of nymphs differs between rice varieties. Many varieties have been
bred for resistance to Brown planthopper; unfortunately, there are many cases when changes
in the insect have overcome the resistance.

Chemical control:

Insecticides should only be used when plantshopper populations are likely to reach an
economic injury level; otherwise natural enemies will be destroyed and planthopper
populations will return greater than before. The systemic insecticide, Orthene (acephate), has
been used for many years against the Brown planthopper in Solomon Islands. Check for
current recommendations from MAL Research/Extension officers, as well as the timing and
method of application. READ THE INSTRUCTIONS BEFORE USING ANY PESTICIDE.