The First Report of the Diversity of Ensifera (Insecta: Orthoptera) From Rokan Hulu District, Riau Province

The objective of this study was to determine the diversity of the suborder Ensifera in Dusun 3, Rambah Hilir Tengah, Rambah Hilir Sub-District, Rokan Hulu District, Riau Province, Indonesia. The study was conducted from September 2015 to January 2016 at six sampling locations by sweep net and hand picking at day and night hours. We recorded 17 species of the Ensifera belonging to 12 genera, 2 families, and 10 subfamilies. The diversity comprised of Conochepalus maculatus, Conochepalus melaenus, Conochepalus sp., Elbenia sp., Elimaea sp., Euscyrtus concinnus, Hexacentrus unicolor, Loxoblemus parabolicus, Mecopoda elongate, Mecopoda sp., Nisitrus vittatus, Orthelimaea sp., Podoscirtinae species 1 (unidentified), Teleogryllus emma, Teleogryllus sp., Trellius sp. and Xabea sp. The C. maculatus and E. concinnus were the predominant species in this study.


I N T R O D U C T I O N
Indonesia is a mega-biodiversity country which endowed rich and unique biodiversity in the tropical belt between Indomalaya dan Australasia (FWI/GFW, 2001;Rhee et al., 2004). The insect is one of the most diverse groups of animals found in Indonesia (Darnaedi & Noerdjito, 2007). This group is one of the most success organism due to its abundance of more than 25 orders and one million species (Fried & Hademenos, 2006) and also has a worldwide distribution, from terrestrial to aquatic. One of the insect groups we can find easily in our environment is the Ensifera (Resh & Cardé, 2003).
Crickets and katydids (bush crickets, long-horned grasshoppers, and their relatives) constitute the suborder Ensifera. Their multisegmented antennae (more than 30 segments) characterize members of this suborder that, with few exceptions, are as long as or longer than the body. Tympanal organs, when present, are located on the fore tibiae. The ovipositor is long and used to place eggs in crevices, soft ground, or plant tissues. Eggs are laid singly or in small groups in or on stems or leaves, or in loose soil or humus. The cerci are unsegmented, and in most species of Ensifera (especially Grylloidea) they are rather long and flexible, and in males individuals of many species (especially Tettigonioidea), they are modified to form clasping structures to be used during copulation. A single spermatheca is usual, and accessory glands occur either as tubules opening at the base of the ovipositor. Most species are nocturnal and omnivorous (Resh & Cardé, 2003;Gillot, 2005;Tan & Kamaruddin, 2014).
The Ensifera live in virtually all terrestrial habitats from treetops to a meter or more beneath the ground; in or near treetops and in bushes, grasses, and other herbaceous plants; on the soil surface; in caves and shallow or deep burrows Some excavate burrows in logs or standing trees. Some beach-dwelling species run and jump readily on the water. Females of different groups lay eggs in stems or twigs, in wood, under bark, in the ground, or in burrows (Resh & Cardé, 2003;Gillot, 2005).
This group plays an ecological role, especially in the food web, health indicators of the terrestrial ecosystem and also for the human being. Some species are prey for larger animals such as birds while others are predators of smaller insects. Some are known to be keystone species while others may serve as good indicators of ecosystem health (Samways, 1997;Erawati et al., 2004;Rentz, 2010). Some are reared and sold in large numbers as fish bait and food for laboratory animals in many parts of the world. Some act as pests and plant diseases. In Indonesia these group attacks various crops like rice, sugar cane, tobacco, tea, soy, corn, banana, bamboo, lemon grass, sugar cane, pineapple, young plant roots, beans, castor, potatoes, dadap, cassava, areca, mimosoid îlamtoroï and other crops (OPETE, 2010).
However, data about the occurrence of the Ensifera species in Indonesia still poorly known and not up to date. Most data, mainly discuss the potential of this fauna as a pest of crops. Furthermore, data of this particular group found in Sumatra is still lacking. The early information about this fauna in Sumatra was reported by Karny (1926) and followed Ebner (1929). However, they did not provide the information from Riau Province, especially, in Dusun 3, Rambah Hilir Tengah, Rambah Hilir Sub-District, Rokan Hulu District. Information on the Ensifera species from this specific area will allow a better understanding of the overall biodiversity of this species not only to this highland area, but also Indonesia.

M E T H O D S
This study was conducted from September 2015 to January 2016 in six sampling sites of Dusun 3, Rambah Hilir Tengah, Rambah Hilir Sub-District, Rokan Hulu District, Riau Province, Indonesia (Figure 1). Table 1 presented the descriptions of each sampling site. Samples were collected by using sweep net and hand picking during the day and night hours and preserved in ice box which containing ice.
We transported all collected samples to the Laboratory of Biology, University of Pasir Pengaraian, Rokan Hulu District, Indonesia, photographed, identified and drymounted. The photographs of specimens were taken using a Nikon D3100 digital camera. After taking the picture, all specimens were identified based on Tan  We mounted the specimens using insect pin number 1 on the insect mounting board. A long, rust-proof pin goes through the middle of the thorax of the Ensifera and put on the mounting board. Then, all specimens stored inside the MERMET oven with 25°C temperature for two days and deposited in insect specimen box.
The most predominant species in this study were Conochepalus maculatus and Euscyrtus concinnus. C. maculatus is also known as one of the abundant species elsewhere and able to inhabit in all habitats which possess lowland grass Bazelet & Naskrecki, 2014). Meanwhile, E. concinnus has long time been known to be widely distributed and act as a pest in a rice field (Barrion & Litsinger, 1980;Pathak & Dhaliwal, 1981;IRPI, 1983). We hope, our study could contribute to the knowledge of the biological diversity of Ensifera species in Indonesia, especially in Rokan Hulu District, Riau Province, which is relatively poorly known.

C O N C L U S I O N
We recorded 17 species of Ensifera belonging to 2 families and 10 subfamilies.      Lateral view, scale bar = 10 mm.

A C K N O W L E D G E M E N T
We would like to express our deep gratitude to Mr. Tan Ming Kai of the Department of Biological Sciences, the National University of Singapore for his valuable support and help in identification of the Ensifera species.