Parasitoids of the rice leaffolder Cnaphalocrocis medinalis and prospects for enhancing biological control with nectar plants

Abstract

1 The rice leaffolder Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae) is a serious rice pest in Asia. The conspicuous foliar damage caused by C. medinalis larvae leads to early-season insecticide applications that disrupt the biological control of this and other pest species. 2 Despite the often dramatic impact of C. medinalis, rice plants can tolerate severe defoliation with no impact on grain yield, although persuading farmers to withhold insecticide application has proven very difficult. 3 The present review assesses the prevention of damage caused by C. medinalis via biological control using parasitoids. Information on the indigenous parasitoids of C. medinalis is drawn together for the first time from the non-English literature published in Asia. This is integrated with the wider English language literature to provide a comprehensive analysis of the parasitoid fauna. 4 Survey studies have been conducted in many Asian countries in recent decades, showing that parasitoids of rice pests can achieve high rates of parasitism but are far from consistent as a mortality factor. There is much less work available on the biology of leaffolder parasitoids in rice and there is an unexpected dearth of studies regarding increasing their performance by providing nectar sources, which is a widely explored approach for other crop systems. 5 It is concluded that the recently reported work in which nectar plants are established on rice bunds to support planthopper parasitoids may have significant benefit for leaffolder parasitoids. The use of plant species, however, that are selective in not allowing adult moths to feed will be essential.

Assessment of the egg parasitoid guild of rice leaf folder, Cnaphalocrocis medinalis (Guenee): a search for biocontrol agents

“…have been reported as egg parasitoids of RLF (Vreden & Ahmadzabidi, 1986;Gurr et al, 2012). Of these species, Trichogramma chilonis and Trichogramma japonicum (Bentur et al, 1994;Kumar & Khan, 2005) have been found in Indian rice fields, which are similar to Sri Lankan rice fields.…”

Selectivity of pesticides used in rice crop on Telenomus podisi and Trichogramma pretiosum

“…Some of the hosts are the eggs of the Asiatic rice borer Chilo suppressalis (Walker) (Lepidoptera: Crambidae) (Chen et al 2010, Ko et al 2014, the rice leafroller Cnaphalocrocis medinalis (Guenee) (Lepidoptera: Pyralidae) (Gurr et al 2012) and the rice yellow stem borer Scirpophaga incertulas (Walker) (Lepidoptera: Crambidae) (Guo et al 2002), among others. In Brazil, several species of Trichogramma have been described (Querino & Zucchi 2003), and Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) is one of the most used for controlling Lepidoptera pests (Brugger et al 2010, Stefanello Júnior et al 2012.…”

Identification and expression profiles of putative cytochrome P450 monooxygenase genes from Cnaphalocrocis medinalis (Lepidoptera: Pyralidae)

“…Outbreaks occur frequently throughout eastern Asia (Gurr et al . ). For a long time, the pest has been controlled mainly through spraying of insecticides.…”