The Process And Mechanism Of Development, Degeneration And Regeneration Of Flight Muscle Of The Rice Water Weevil, Lissorhoptrus Oryzophilus Kuschel

The rice water weevil (RWW) Lissorhoptrus oryzophilus Kuschel, belongs to Erirhininae (Coleoptera: Curculionidae), and it is a dangerous quarantinable pest of rice. The development of flight muscles and ovary of RWW change with the seasons and show an obvious oogenesis-flight syndrome.A transmiting electron microscope study was conducted of RWW to illustrate the ultrastructural changes during flight muscle development and degeneration. The results demonstrate that the thick filaments (myosin filament) and thin filaments (actin filament) of flight muscle form a hexagonal lattice with the thin filaments midway between the adjacent thick filaments with a ratio of actin filament to myosin filament in 3:1. When the flight muscles are in the most strongest status, The myofibril is in the thickest in diameter, and the sarcomere is shortest, when the flight muscles start developing or degenerating, sarcomeres become longer, and the myofibril become thinner. The karyon and cellular wall do not break or disappear when the flight muscle development and degeneration. It showes that the flight muscle degeneration is just thick and thin filaments decrease in quantity.To understand the effects of host plant species, adulthood density, and their interactions on the survival and fecundity of the rice water weevil, a laboratory experiment was carried with rice and baryardgrass in high densities and low densities of adults. This experiment confirmed that RWW did exhibit better performance in barnyardgrass than in rice. When they were reared in former plants, the weevils fed more leaf tissue, lived longer and laid significant more eggs. However, the survivorship, of the first-generation adults in crowding condition is lower in early 50-60 days, but the extension of longevity and fecundity of the survivals is higher than that of low densities. It is obvious that crowding condition enhanced the survival and fecundity of the first-generation adults afterward.The flight muscle of the first-generation adults feeding on rice in higher adult density developed more quickly, while the flight muscle of the adults feeding on baryardgrass in lower adult density developed most slowly obviously, but the ovary...