Diversity and Composition of Hymenoptera Around Tidal Swamp Rice In Indragiri Hilir District, Indonesia

Pest attacks on rice plants can cause a detrimental decrease in production. Hymenoptera has many important roles in ecosystems, including as parasitoids and predators of pests. The purpose of this study was to determine the presence of Hymenoptera around tidal swamp rice in Indragiri Hilir Regency, Indonesia. Sampling used four traps, namely: 1) swing net; 2) yellow pan trap; 3) malaise trap; and 4) pitfall traps. The analysis was carried out by calculating the Shannon-Wiener diversity index (H'), the Margalef species richness index (D), the Pielou species evenness index (J). Hymenoptera found around tidal swamp rice areas of Indragiri Hilir Regency were 15.253 Hymenoptera insects consisting of 11 superfamilies, 37 families, and 304 morphospecies. Hymenoptera parasitoid had the highest diversity index value (4,80), followed by Hymenoptera pollinator (3,13) and Hymenoptera predator (3,11). The number of species of Hymenoptera parasitoid, pollinator, and predator obtained was 243; 31 and 76 species. The high diversity of Hymenoptera around tidal agricultural land optimizes its ecological role in the rice plantation ecosystem.


INTRODUCTION
One of the main limiting factors for increasing rice productivity is pest attacks. Pest attacks on rice plants can cause a significant decrease in production. The emergence of pest attacks on rice plants makes farmers carry out control, both using insecticides and with integrated pest management strategies. This will automatically increase the cost of rice production.
Most pests come from the insect group. In terms of species richness, insects are the largest group of animal groups. 1,023,430 insect species have been found (IISE, 2012) . However, of the ± 1 million species, not more than 1% are potentially harmful to farmers. The rest are useful insects that can act as parasitoids, predators, pollinators, decomposers, and industrial insects (Buchori, 2014). One of the insect groups that are beneficial to farmers is the order Hymenoptera.
Hymenoptera is one of the four largest insect orders. The other three are the orders Coleoptera, Diptera, and Lepidoptera. Hymenoptera is divided into two suborders, namely Symphyta and Apocrita, and consists of 132 families, 9.108 genera, and 155.517 species that have been identified (Aguiar et al., 2013). A total of 32.410 species are found in Indonesia (Bappenas, 2016).
Hymenoptera has many important roles in ecosystems, namely as parasitoids, predators, pollinators, detritivores, and phytophages (Borror et al., 1996;Anderson et al., 2011). Hymenoptera is dominated by parasitoid species. About 80% of Hymenoptera are parasitoid (Quick, 1997;Saputra et al., 2017) . For example, several species from the family Braconidae are used as parasitoids to control various pests on agricultural crops (Lv, J., Wilson et al. , 2011;Tomanović et al,, 2013), several species from the family Ichneumonidae as parasitoids on larvae and pupae of Lepidoptera pests in the agroecosystems (Nelly et al., 2005;Mason, P. G., 2013), and some species from the family Trichogrammatidae as parasitoids to control pests in agroecosystems (Hidrayani et al., 2013;Sharma et al., 2019).
Hymenoptera is scattered in all agricultural vegetation, forests, or other places where there are food sources such as flowering plant vegetation and vegetable gardens. The diversity and abundance of Hymenoptera in an agricultural habitat can be influenced by the landscape structure and habitat conditions (Ikhsan et al., 2020;Susilawati, 2016). The existence of Hymenoptera around rice fields can provide benefits for rice plants. Based on this, research has been carried out on the diversity and composition of Hymenoptera around tidal swamp rice in Indragiri downstream district, Indonesia. The purpose of this study was to determine the presence of Hymenoptera around tidal swamp rice in Indragiri Hilir district, Indonesia.

EXPERIMENTAL SECTION
The research is in the form of a survey. Observation of the diversity and composition of Hymenoptera was carried out by trapping Hymenoptera around tidal swamp rice fields in the Indragiri Hilir district.
Trapping was carried out using four devices, namely malaise trap, yellow pan trap, swing net, and pitfall trap.

Materials
The materials used in this study were label paper, photo paper, detergent, water, insect glue, gauze, 96% alcohol, and plastic.

Instrumentation
The tools used in this research are swing net, yellow pan trap, malaise trap, pitfall trap, drone, boots, collection box, tissue rolls, water container, magnifying glass, tweezers, knife, rope, collection bottle, 2 ml Eppendorf tube, binocular microscope, small brush, rubber band, filter, hand counter, stationery, camera, and applications for measuring altitude and coordinate points.

Determination of location and sample points
Research in the form of surveys and sampling was carried out using the purposive sampling method.
The study was conducted in four sub-districts in the tidal swamp rice of Indragiri Hilir Regency. At each And. Int. J. Agric. Nat. Sci. study site, two-line transects were made with a length of ± 1.000 m. Along the transect line, ten sampling points were determined, ± 100 m apart. So, there are 20 sample plots at each research location.

Sample Collection
Insect sampling in each sample plot on the line transect was carried out using pitfall trap, yellow pan trap, swing nets, and malaise trap. Insects caught in each trap are cleaned of dirt. Furthermore, it is stored in a collection bottle containing 96% alcohol to be identified in the laboratory.

Identification of Hymenoptera
Identification was carried out on imago. All insects obtained were separated according to their order.
Insects of the order Hymenoptera were further identified to the family and species level (coded).
Identification was carried out using a microscope at the Insect Bioecology Laboratory, Faculty of Agriculture, Andalas University, Ecology Laboratory, Faculty of Mathematics and Natural Sciences, Padang State University, and the Zoology Laboratory of the Cibinong Biology Research Center-LIPI.

Data Analysis
The identification data is tabulated in a pivot table in Microsoft Excel software to become a database.
Data processing was carried out to see the diversity of Hymenoptera based on their classification and ecological function. The diversity observed in this study was the Shannon-Wiener diversity index (H'), the Margalef species richness index (D), the Pielou species evenness index (J). Calculations and data analysis were carried out using the V5.2 Primary and the EcoMethods V7.2 Application (Colwell et al., 1994;Colwell et al., 2014).

RESULTS AND DISCUSSION
Indragiri Hilir Regency is located between 00 36' North Latitude and 10 07' South Latitude, and between 1040 10'-1020 32' East Longitude (BPS, 2020). The study was conducted on four fields in four subdistricts in the tidal swamp rice of Indragiri Hilir Regency. Two fields have monoculture farming systems and two polycultures. The description of the research location can be seen in Table 1. The results of this study revealed that tidal swamp rice at four study areas in Indragiri Hilir District had a high Hymenoptera parasitoid diversity index, while Hymenoptera pollinators and predators were had moderate diversity index ( Table 2). The high diversity of Hymenoptera parasitoid is a potential that must be maintained in order to suppress pest attacks on tidal swamp rice. Based on the literature, Hymenoptera insects are dominated by parasitoid species. About 80% of Hymenoptera are parasitic (Quick, 1997;Saputra et al., 2017). Therefore, Hymenoptera parasitoid plays an important role in sustainable agriculture through its ability to control pest populations. In this study, Braconidae, Ichneumonidae, Scelionidae and Formicidae were Hymenoptera family with the highest number of morphospecies ( Figure 1). In addition, Formicidae, Scelionidae, Sphecidae, and Braconidae were Hymenoptera family with the highest number of individuals (Figure 2). Ichneumonidae and Braconidae are the families with the largest and most abundant members found worldwide. These two families have the highest number of species compared to other families and almost dominate the entire ecosystem (Goulet et al., 1993). In other studies, monoculture and polyculture agroecosystems, Ichneumonidae and Braconidae are families that have the highest relative abundance (> 15%) (Hariyanti et al., 2017). Another study also found that Braconidae and Ichneumonidae were the dominant parasitoid Hymenoptera families in vegetable agriculture ecosystems in West Sumatra (Yaherwandi, 2012).