Biological Studies on Paddy Earhead Bug, Leptocorisa oratorius Fabricius (Hemiptera:Alydidae)

Abstract

Studies on biology and morphometric studies of Paddy earhead bug, Leptocorisa oratorius Fabricius (Hemiptera:Alydidae) revealed that eggs had an incubation period of 7 and 6.98 days under field and greenhouse conditions respectively. The nymphs were observed to pass through five instars and the duration of each instar was 3.98, 3.30, 3.48, 3.83 and 4.15 days for I,II,III,IV and V instars respectively. The nymphal period averaged 18.9 and 18.7 days under field and greenhouse conditions respectively. The average fecundity was recorded to be 50-135 and 75-137 eggs per female under greenhouse and field conditions respectively. The total development period was seen to be 25.76 and 26 days under greenhouse and field conditions. Only a little variation was noticed in its biology under both conditions. The length and width of the eggs was ranged from 1.00 to 1.20 mm (1.10±0.07), 0.80 to 0.86 mm (0.83 to±0.02) respectively. The length of adult females was measured to be 17.50 to 18.50mm (18.00±0.37) in length and 2.40 to 3.00 mm (2.63±0.21) in width and that males length was varied from 18.00 to 19.00 mm (18.49 to 0.42) and width from 1.95 to 2.50 mm (2.19±0.22) respectively.