5
Rice Brown Planthopper
caudolaterally.
Host plant:
Rice; Economic importance: High; Distribution: Australia, Bangladesh,
Cambodia, China, East Timor, Fiji, India, Indonesia, Japan, Korea, Laos, Malaysia,
Myanmar, New Guinea, Pakistan, Palau, Philippines, Taiwan, Thailand, Vietnam, and Yap
Island.
Morphological description given above for the genus Nilaparvata , and the species
Nilaparvata lugens (Stål,1854) refers to the type specimen described originally 1854
by Stål and later by so many authors in different situations published in various
instances are regarding the insect which we will henceforth be calling as rice brown
planthopper or simply BPH for the sake of convenience. One most important thing all
rice entomologists have to keep in mind is that, there can be a slight morphological
variation in many of the above characters described when a total population of BPH is
considered in a given area and in a given situation. There can be many physiological
variants with regard to each of the physiological characters.
Damage to Rice Crop:
All the three species of hoppers possess typical piercing and
sucking type of mouth parts usually called stylets. Stylets have a provision to insert into plant
system particularly vascular bindles and drain enormous quantities of plant sap. As phloem
contains nutrients like carbohydrates, amino acids and peptides plant hoppers mainly derive
their nutrition from phloem. Those occasionally feed on xylem vessels carrying inorganic
nutrients like nitrates, potash, phosphates, calcium, magnesium, zinc etc. This probably is
essential to satisfy their excess water requirement. Typical structures called stylet-sheaths are
formed around the stylets at the time of feeding but remain inside the plant system or mainly
vascular system. The stylet-sheaths cause serious obstruction to normal vascular flow in both
phloem and also to some extent xylem. However these plant hoppers have not been recorded
injecting any known toxins into rice plants that adversely affect normal plant physiology.
At genetic level it has been reported that planthopperfeedingup-regulates the genes
responsible for senescence and down regulates normal functioning. As a result affected
plants start showing slight wilting symptoms at first followed by severe wilting
and drying-up. The damage by BPH and WBPH spreads in a circular fashion and
istechnically termed as “hopper-burn”. If timely control measures are not taken up
against the plant hoppers, the entire field could be hopper burnt in a span of 15-20 days
