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Rice Brown Planthopper
Summary and conclusions
Among Sixty-five species of plant hoppers recorded to be associated with
Rice ecosystem, Brown Planthopper, Nilaparvata lugens (Stal) (BPH), White-
backed Planthopper, Sogatellafurcifera (Horvath) (WBPH) and Small Brown
Planthopper Laodelphax striatellus Fallen (SBPH) are the most economically
important insect pests causing damage to rice crop.
These plant hoppers are small insects where the adults measure about 4-6 mm in
length and 3-4 mm in width.
Based on the host range and other ecological requirements, it could be said that
BPH and WBPH appeared to have co-evolved in tropics along with rice plant,
while SBPH is a temperate species in its evolutionary cycle.
These hoppers possess typical piercing and sucking type of mouth parts and
suck enormous quantities of plant sap from vascular bundles of rice plant. As a
result the plants get wilted and die. Under field conditions, the damage spreads
in circular patches and if unchecked may spread to whole field causing total
“hopper-burn”. Distribution of BPH in the field is patchy or clumped and is
termed as “negative binomial distribution”.
Among different life stages in BPH, third and fourth instar nymphs have been
reported to be more devastating than younger nymphs or adults.
Two morphologically distinct forms exist in BPH adults in both males and
females. 1) Those with long or fully developed wings or “macropterous” adults
and 2) those with short or half developed wings called “brachypterous” adults.
(Plates 1&2 Page 2)
Adversity in food quality or adverse environment like high or low temperatures
induces more of macroptery. First instar is the most sensitive stage for these.
Exposure of nutritionally rich food or optimum environmental conditions in the
first instar are the most important determining factors that fixes the individual’s
probability of becoming a brachypterous adult or otherwise to a macropterous
adult.
