Rice earhead bug Or Gandhy (Leptocorisa acuta)

Rice earhead bug Or Gandhy

Common name :

    The Rice Gandhy Bug Or Rice earhead bug

Scientific name:

    Leptocorisa acuta

Order :

    Hemiptera

Family :

    Coreidae

Distribution:

    Bhutan, Burma, New Caledor.ia, Sri Lanka, China, Hong Kong, India, Bangladesh, West Iran, Indonesia, New Hebrides, Northern Australia, Malaysia, New Guinea, Papua, Pakistan, Philippipes, Somoa, Sarawak, Solomons, Taiwan, Tonga, Thailand, Queensland and Vietnam.

Host:

    Rice, bajra, fingermillets, sugarcane and some grasses.

    The newly hatched nymph is about 2 mm long and is pale green. However, as it grows, the green colour deepens. The grown-up nymphs are very similar to the adults in colour and size, but they are wingless. The adults are slender, about 20 mm long and greenish brown. They have long legs and antennae with four joints.

Life-cycle:

    In absence of paddy crop in the field, the bugs breed on other alternate hosts and grasses, hence, the activity of this bug is noticed throughout the year. The bug appears in paddy fields sometimes in August and remains active till November. The females deposit 24-30 round yellow eggs in rows on the leaves. The incubation period is 6 or 7 days. The nymphs transform into adult bugs after passing in six stages within 2 or 3 weeks. The longevity of bug is 33-35 days. The pest is diurnal in habit and is most active in the morning and in the evening. During the hotter parts of the day, it seeks shelter in the paddy fields. A number of generations are completed in a year. After harvest of rice, the insect over winters in the millets and wild grasses,

Damage:

    The nymphs and adults suck sap from the peduncle, tender stems and milky grains. They suck milky sap from developing grains by inserting the probosis at the vulnerable point, the place at which the glums meet and due to exudation at the site of feeding whitish spots appear frequently. Its presence in the field is made out with a repugnant smell which gives to this pest the name 'Gandhy bug'

Control:

    When the grains are in milky stage and at least 10 bugs/100 heads of rice or reaches more than 1/m2, dust 5% malathion or 4% endosulfan @ 25 kg/ha.