Differences in Morphological and Physiological Characters between the Joetsu and Chikugo Green Rice Leafhopper Populations with Differential Reactions to Rice Varieties

Abstract

Morphological and physiological characteristics of the Joetsu and Chikugo populations of the green rice leafhopper, Nephotettix cincticeps UHLER, with differential reactions to rice varieties were comparatively studied. 1. Male adults with heavier black pigmentation on the face, lateral side of abdomen, and tip of tegmen occurred more frequently in the Joetsu population than in the Chikugo population. Width of head, and length of hind tibia and tegmen of the females in the Joetsu population were larger than those in the Chikugo population. 2. No clear difference in the non-diapausing nymphal development at 18-33°C under 16L:8D photoperiod, the diapausing development at 28°C under 12L:12D photoperiod, and the ability to overwinter was found between the two populations. 3. The females in the Chikugo population laid about 2.5 times more eggs than did those in the Joetsu population on an average. About 15 and 11 eggs were deposited daily by a female of the Chikugo and Joetsu populations, respectively. 4. The females of the Joetsu population excreted more honeydew on the three differential rice varieties than those of the Chikugo population. Optimum fluid uptake through a parafilm membrane by the females of the Joetsu and Chikugo populations was obtained in 10% and 14% sucrose solutions, respectively.