Parasitizations Levels and Temperature Tolerance of Rice Bug (Leptocorisa oratorius Fabricius) Egg Parasitoids: Mass Rearing for Biological Control

Abstract

Abstract-The rice bug is a significant pest that attacks wet rice fields Rice bug egg parasitoids can be used as a biological control for this pest in the field. Successful parasitoid mass rearing in the laboratory depends on optimum temperatures to ensure the fitness of the adults that are introduced into the field. The objectives of this research were to determine the parasitization levels of rice bug egg parasitoids from two areas in West Pasaman Regency; one in the lowlands (Kinali 56 m asl) and the one at a higher altitude in the foothills (Talamau 47 m asl). Then the best temperature for parasitoid rearing was determined for the dominant parasitoid. A purposive sampling method was used for collecting the rice bug egg samples which were collected along 1 km transect lines in the rice fields. A descriptive method was used to report the parasitization levels. Rearing temperature treatments for the dominant rice bug egg parasitoids in the laboratory were 20 o C, 25 o C, 30 o C and one batch raised as a control with no temperature regulation. 20 replications were conducted for each treatment. The data were analyzed using Completely Randomized Design (Statistics 8). The main species of rice bug egg parasitoids found were Hadronotus leptocorisae and Ooencyrtus malayensis with parasitization levels in the lowlands of 6.4% and 2.2% and the foothills of 28.4 % and 3.1% respectively. The best temperature for mass rearing parasitoid in the laboratory was 25 o C, and they had the longevity of 22.6 ± 5.4 days.

The Species of Rice Bug (Leptocorisa oratorius Fabricius) Egg Parasitoids in Rice Field in West Sumatera, Indonesia

“…Distinguish between parasitoidswere observed in number of segments and antenna color, hair in thoracic dorsal, leg color and body size (Figure2). Both parasitoids were previously reported in rice field in Tanah Datar regency and West Pasaman, West Sumatra(Maulina et al, 2016);(Maulina et al, 2018).…”

“…leptocorisae to survive at cooler temperature. Parasitoid H. leptocorisae survive at low temperatures and the best temperature to longevity in laboratory test is 25 o C (Maulina et al, 2018). However, the ideal or optimum temperature for the longevity of adult parasitoids depends on the species of parasitoids or variability among individuals (Régnière et al, 2012) such as longevities of Aphelinus varipes were 27.0 days at 20 o C and 20.6 days at 25 o C (Yashima & Murai, 2013).…”

“…The presence of parasitoids in West Sumatra food crops has been reported with different levels of parasitization, species diversity and population abundance (Susiawan & Yuliarti, 2006)., (Maulina et al, 2018), but its application as a biological control agent has not been widely studied yet. Rice bug eggs are one of the main pests of rice plants have been reported to be attacked by parasitoids (Maulina et al, 2018), but the use of parasitoids as biological control agent of rice bug in rice cultivation needs a thorough review. Based on these descriptions, the study of egg parasitoids on the pest is important to do.…”

DISTRIBUSI PARASITOID Ooencyrtus malayensis DI PERTANAMAN PADI SUMATERA BARAT: KANDIDAT PENGENDALI HAYATI WALANG SANGIT (Leptocorisa oratorius F.)

“…Salah satu jenis agens hayati adalah parasitoid yang merupakan musuh alami yang penting dalam konsep pengendalian hayati. Parasitoid dapat melumpuhkan inangnya secara perlahan (Maulina et al, 2018) dan memiliki keunggulan karena mengendalikan pada stadia awal perkembangan hama (Hidrayani et al, 2013). Ooencyrtus merupakan parasitoid telur polipag (Tunca et al, 2016) yang dapat memparasiti telur serangga hama pertanian dan kehutanan, antara lain walang sangit (Winasa et al, 1997;Jamili dan Anggraeni, 2012;Maulina et al , 2018), dan kepik buah lada (Alwi dan Soetopo, 2000).…”

“…Hal ini akan memudahkan dalam usaha ISSN 1412ISSN -1948 https://doi.org/10.32530/lumbung.v19i2.206 60 perbanyakannya di laboratorium sehingga dapat digunakan sebagai agens pengendali hayati hama walang sangit di lapangan. Kebanyakan kegagalan penggunaan agens hayati parasitoid yang berkaitan dengan kurangnya kesesuaian hidup dan pemahaman tentang biologi dari parasitoid (Ilacer et al, 2006;Nelly et al, 2011;Maulina et al, 2018). Oleh karena itu informasi distribusi dan adaptasi parasitoid O. malayensis di topografi Sumatera Barat perlu dilakukan.…”