The impact of bioinsecticide overdoses of Beauveria bassiana on species diversity and abundance of not targeted arthropods in South Sumatra (Indonesia) freshwater swamp paddy

Abstract

Abstract. Hanif KI, Herlinda S, Irsan C, Pujiastuti Y, Prabawati G, Hasbi, Karenina T. 2020. The impact of bioinsecticide overdoses of Beauveria bassiana on species diversity and abundance of not targeted arthropods in South Sumatra (Indonesia) freshwater swamp paddy. Biodiversitas 21: 2124-2136. Bioinsecticides have been shown to reduce insect pest populations, but it is necessary to monitor the effect of bioinsecticide overdoses on non-target arthropods because they are abundant in rice fields. This study aimed to analyze the impact of bioinsecticide overdoses of B. bassiana on species diversity and abundance of non-target arthropods. Bioinsecticides derived from Beauveria bassiana were sprayed on the paddy every two weeks until the ripening stage, at a dose of 1, 2, 3, 4 L.ha-1, control (without insecticide), and abamectin as prescribed. The abundance of spiders and predatory arthropods did not decrease when bioinsecticides were applied but the abundance of spiders, especially Lycosidae and Salticidae dropped significantly when abamectin was applied. The abundance of the parasitoid decreased significantly when abamectin was applied, but the abundance of parasitoids applied by bioinsecticide was not significantly different from those of control. The abundance of insect pests started to decrease when bioinsecticide was applied to 2, 3 or 4 L.ha-1. The diversity species of non-target arthropods (spiders, predatory arthropods, and parasitoids) tended to decrease when it was applied bioinsecticides 3 and 4 L.ha-1 or abamectin, but their abundance remained high and no species dominance was found. For this reason, the correct dosage for suppressing insect pests abundance by not decreasing the abundance and diversity of non-target species is 2 L.ha-1 and applied when herbivore abundance is high.

Arboreal Entomophagous Arthropods of Rice Insect Pests Inhabiting Adaptive Vegetables and Refugia in Freshwater Swamps of South Sumatra

“…Wetland in Indonesia generally consists of freshwater (non-tidal) swamp and tidal lowland. The freshwater swamp is a wetland that is flooded due to the flow of river water or rain, while the lowland tidal is inundated due to the tides (Hanif et al, 2020). According to Margono, Bwangoy, Potapov, & Hansen (2014), the wetland area in Indonesia is around 39.6 Mha of which 77% are spread in Sumatra Island (11.9 Mha), Kalimantan (12.2 Mha),and Papua (11.8 Mha).…”

Impact of mycoinsecticides and abamectin applications on species diversity and abundance of aquatic insects in rice fields of freshwater swamps of South Sumatra, Indonesia

“…Besides rice, chilies (Johari et al 2014(Johari et al , 2016, bitter melon, long beans, eggplants, pumpkins, and cucumbers are also cultivated (Siaga et al 2019). Rice is generally planted once a year (Hanif et al 2020). Currently, some farmers earn>100 ha land who start planting rice two to three times a year, and several smallholder farmers grow rice two times a year by utilizing the remaining ratoons of the previous season's rice harvest (Lakitan et al 2018b;Prabawati et al 2019).…”

“…Intensive rice cultivation in freshwater swamps will increase the use of insecticides due to the increasing insect population (Prabawati et al 2019). Commonly used insecticides are synthetic insecticides (Hanif et al 2020) and sometimes bioinsecticides (Karenina et al 2019;Prabawati et al 2019;Hanif et al 2020). Commonly insecticide used in rice fields in Indonesia is abamectin (Luo et al 2013).…”

“…and able to kill important insect pests such as brown planthopper, Nilaparvata lugens (Homoptera: Delphacidae) (Sumikarsih et al 2019) and Spodoptera litura (Lepidoptera: Noctuidae) (Ayudya et al 2019). Although the entomopathogenic fungi are generally reported to be host-specific (Hanif et al 2020), it is necessary to monitor the impact of these mycoinsecticides on the abundance of beneficial arthropods.…”

Community structure of arboreal and soil-dwelling arthropods in three different rice planting indexes in freshwater swamps of South Sumatra, Indonesia

“…Freshwater swamps are wetlands inundated by water from rivers or rain throughout the year (Hanif et al 2020). Freshwater swamps are generally submerged in the rainy season and drought in the dry season (Karenina et al 2020).…”