Reading: Assessment of the egg parasitoid guild of rice leaf folder, Cnaphalocrocis medinalis (Guenee...

Download

A- A+
dyslexia friendly

Research Articles

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

Authors:

KS Hemachandra ,

LK
About KS
Department of Agricultural Biology, Faculty of Agriculture, University of Peradeniya, Peradeniya.
X close

MCD Perera

LK
About MCD
Postgraduate Institute of Agriculture, University of Peradeniya, Peradeniya.
X close

Abstract

Biological control of rice leaf folder (RLF), Cnaphlocrocis medinalis by augmentative release of egg parasitoids has been suggested. This study was conducted to assess the egg parasitoid guild associated with the RLF and to determine their parasitism levels under local conditions. A survey was conducted in three districts at 14 sites using 16 fields where rice was cultivated under conventional, pesticide free and organic farming practices. RLF eggs were collected and incubated at room temperature with 60 % RH under natural daylight in the laboratory. The emerging parasitoids were identified and their parasitism levels were calculated. 

Four egg parasitoid species: Troichogrammatoidea bactrae, Troichogrammatoidea nana, Trichogramma sp. and Lithromeromyia sp. (Hymenoptera: Trichogrammatidae) were found parasitising RLF eggs. These species collectively parasitised 17 % of RLF eggs and the level of parasitism significantly varied between 0 and 57 % among sampling sites. Mean parasitism in conventional and pesticide free fields were 1.62 ± 0.81 % and 24.39 ± 16.8 %, respectively, which was significantly different. T. bactrae was the most prevalent parasitoid species, which was found in nine sites, while T. nana and Lithromeromyia sp. were found only in one site. Trichogramma sp. was found in four sites. Mean parasitism caused by T. bactrae, T. nana, Trichogramma sp. and Lithromeromyia sp. were 8.2 ± 5.7 %, 15.2 %, 3.7 ± 1.3 % and 2.5 %, respectively. The parasitoids did not affect beneficial arthropods such as spiders and coccinellids. The results suggest that T. bactrae is a potential egg parasitoid of RLF to manage RLF populations in local rice fields through augmentative release.

How to Cite: Hemachandra, K. & Perera, M., (2016). Assessment of the egg parasitoid guild of rice leaf folder, Cnaphalocrocis medinalis (Guenee): a search for biocontrol agents. Journal of the National Science Foundation of Sri Lanka. 44(2), pp.185–192. DOI: http://doi.org/10.4038/jnsfsr.v44i2.7999
Published on 30 Jun 2016.
Peer Reviewed

Downloads

  • PDF (EN)

    comments powered by Disqus