Comparative study of egg-pod morphology in two genera of Oxyinae (Acrididae: Orthoptera)

Abstract

The egg-pods of 04 species viz: Oxya hyla hyla Serville, 1831, O. velox (Fabricius, 1787), O. fuscovittata (Marschall, 1836) of genus Oxya and Oxyina bidentata (Willemse, 1925) of Oxyina were examined under laboratory conditions. Significant differences were found in the sizes and shapes of the pods. Beside this, number of eggs in each egg pod, distribution pattern and weight, length and width of eggs in the pods were also noted. Eggs pods of Oxya species were cylindrically elongated, large, slightly bent in the middle and rounded at ends while egg pods of Oxyina bidentata are bean shaped. The weight, width and length of freshly laid egg pods of Oxya species was 46.82±5.28 mg, 15.56±9.56 mm, and 7.20±0.78 mm, 43.39±4.31 mg, 15.3±1.05 mm, 6.10±0.87mm, 33.73±7.28 mg, 13.4±1.1 mm, 6.73±0.56 mm for Oxya velox, Oxya fuscovittata and Oxya hyla hyla respectively while it was 37.59±6.28mg, 11.80±0.78 mm and 5.90±0.87 mm in Oxyina bidentata. Measurement and weight of these 4 species were also compared and it was noticed that the weight, length, and width of eggs of Oxya velox i-e 2.47±0.38 mg, 6.00±0.81 mm, and 3.31±0.30 mm respectively is significantly greater than that of Oxya fuscovittata, Oxya hyla hyla and Oxya bidentata. It was observed that the egg-pod is full of eggs without any empty space. There are more eggs at the base and their number decreased towards the top. The major hatching occur within few weeks i.e., 57.43 to 100% in Oxya velox from June to August but mostly in the month of June, 76.85% to 100% in O. hyla hyla from July to September but mostly in August, and 69.09% in O. fuscovitatta from July to August, mostly in mid-July then hatching stopped. Present study might be useful to forecast the exact hatching dates in near future.