Flooding Influences Ovipositional and Feeding Behavior of the Rice Water Weevil (Coleoptera: Curculionidae)

Abstract

The rice water weevil, Lissorhoptrus oryzophilus Kuschel, is the most destructive insect pest of rice in the United States. As part of an effort to develop strategies to manage this pest, the ovipositional and feeding habits of L. oryzophilus on rice plants subjected to different flooding treatments were characterized in greenhouse studies. Presence and depth of flood had a direct influence on the ovipositional behavior of weevils in no-choice studies. More eggs were found in flooded plants than in unflooded plants. Moreover, plants flooded to a depth of 5.1 cm received more eggs than plants flooded to depths of 1.3 or 10.2 cm. Presence and depth of flood influenced both the proportion of females that oviposited in plants and the number of eggs laid by those females that did oviposit. In choice studies, female weevils showed a marked ovipositional preference for plants flooded to a depth of 10.2 cm over unflooded plants and plants flooded to a depth of 1.3 cm. In separate choice experiments, adult rice water weevils fed more on flooded plants than on unflooded plants. In a third set of experiments, flooded plants were taller and had higher concentrations of 10 of 13 plant nutrients than unflooded plants. Thus, flooding may influence rice water weevil behavior both directly, by acting as a stimulus for feeding or oviposition, and indirectly, by inducing changes in the suitability of rice plants for feeding or oviposition. These data suggest that it may be possible to manipulate populations of weevils in rice by changing water management practices.

Impacts of Seeding Rate on Interactions Between Rice and Rice Water Weevils

“…Stout et al (2002b) demonstrated the effects of flood depth on ovipositional preference of L. oryzophilus under semi-controlled conditions in a greenhouse. In no-choice experiments, the proportion of females that oviposited and the number of eggs oviposited increased as soil moisture/flood depth increased from dry soil to 5.1 cm of flood.…”

“…Furthermore, free choice experiments showed that females had a stronger ovipositional preference for plants in a deep flood than for plants in saturated soil or a shallow flood. Stout et al (2002b) suggested the manipulation of flood depth as a possible means of suppressing rice water weevils; however, this concept has not been tested under field conditions. In this paper, several field experiments that investigated the impact of a shallow flood verses a deep flood on L. oryzophilus infestations in the field are described.…”

Analysis of junction site between T-DNA and plant genome in Lissorhoptrus oryzophilus resistance GM rice

“…벼물바구미 성충은 벼 잎의 엽육을 갉아먹어 어린 묘에 피해를 주고, 유충은 뿌 리로 이동하여 뿌리의 내부조직을 가해하여 초장과 뿌리 의 감소, 생육지연 등의 피해로 벼 수확량의 20% 이상을 감소시킨다고 알려져 있다 (Shang et al 2004;zou et al 2004;Saito et al 2005). 벼물바구미 방제는 대부분 유기살충제를 사용하고 있 으나, 살충제의 유해성과 비 목표인 무척추동물에 부정 적인 영향을 미치게 되는 문제점으로 인해 새로운 방제 전략으로 빠른 시기의 이앙, 이앙 후 논 전면에 수면처리 등의 방법이 이용되고 있고 (Stout et al 2002;Espino et al 2009;Stout et al 2011), 최근에는 효과적인 방제를 위한 생명공학기술을 이용한 저항성 작물 개발 연구가 이루어 지고 있다.…”

Photodegradation of clothianidin under simulated California rice field conditions

“…4 -7 Yield losses in excess of 20%, associated with early-season larval infestation and root pruning, have been reported in California. 5,6,8 Farmers rely on chemical agents to manage adult weevil populations; over 175 000 acres of rice fields were treated with pyrethroid insecticides in 2012. 4 The heavy use of this highly toxic and broad-spectrum class of insecticides increases the risk of development of resistance in the rice water weevil populations, and clothianidin has been marketed as an alternative to replace the pyrethroids.…”