BIODIVERSITAS ISSN: 1412-033X Volume 19, Number 2, March 2018 E-ISSN: 2085-4722 Pages: 604-612 DOI: 10.13057/biodiv/d190231 The effect of understory plants on pollinators visitation in coffee plantations: Case study of coffee plantations in West Bandung District, West Java, Indonesia SUSANTI WITHANINGSIH 1,2,3,♥ , CLARISA DITY ANDARI 1 , PARIKESIT 1,2,3 , NURULLIA FITRIANI 1 1 Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran. Jl. Raya Bandung-Sumedang Km 21, Jatinangor, Sumedang 45363, Indonesia. Tel. +62-22-7796412 ext. 104, Fax. +62-22-7795545, ♥ email: susanti.withaningsih@unpad.ac.id 2 Center for Environment and Sustainability Science, Universitas Padjadjaran. Jl. Sekeloa Selatan I, Bandung 40213, West Java, Indonesia 3 Graduate Program on Sustainability Science, Universitas Padjadjaran. Jl. Dipatiukur No. 35 Bandung 40132, West Java Indonesia Manuscript received: 17 January 2017. Revision accepted: 16 March 2018. Abstract. Withaningsih S, Andari CD, Parikesit, Fitriani N. 2018. The effect of understory plants on pollinators visitation in coffee plantations: Case study of coffee plantations in West Bandung District, West Java, Indonesia. Biodiversitas 19: 604-612. West Java is one of the excellent producers of the most expensive coffee in the world (Kopi Luwak). Coffee (Coffea spp.) is one of the crops that require insect pollination for fruit formation. Coffee production in Indonesia is declining in recent years despite the expansion of coffee cultivation area that increases by 2-5 times. The decline in coffee production has been associated with fewer visitations of pollinator insects. Visitations of pollinator insects can improve the quality and quantity of coffee, mainly from the abundance and diversity of pollinator insect. Abundance and diversity of pollinator insects can be improved by to providing them with flowering plants such as understory plants. This study aimed to prove the effect of the existence of flowering plants on the visitation of pollinator insects. Pollinator insects visiting coffee flowers were observed with an observation method in two observation units. The first unit was the location with understory plants while the second was the location without understory plants. The results showed that the abundance of pollinator insects visiting coffee flowers in unit 1 was significantly (P<0.05) higher than that in unit 2. However, the diversity of pollinator insects between the two locations did not differ significantly (P> 0.05). Keywords: Abundance, coffee, insect pollinators, diversity, understory plants, visitation INTRODUCTION As the third largest coffee producing country in the world after Brazil and Vietnam (Hartono 2013), Indonesia has a one-of-a-kind coffee labeled as the unique and most expensive coffee in the world: Kopi Luwak. Coffee is one of the most important estate crops included as the world's most valuable export commodities (Ricketts et al. 2004). In developing countries, coffee is the second most traded commodity after oil (Munyuli 2014). Although coffee cultivation areas in Indonesia have increased by two to fivefold in the last 41 years, the coffee yield has fallen by 20-50% (Roubik 2002). The decrease of coffee yield, according to Roubik, is related to the decrease of pollinator insects visitation. More than 70% of angiosperms plants are pollinated by insects, including coffee (Hoffman 2005). The visits of pollinator insects on coffee flowers can influence the formation and duration of coffee and irregularities in coffee beans (Manrique and Thiman 2002; Klein et al. 2003; Ricketts et al. 2004; Olschewski et al. 2006; Veddeler et al. 2008; Classen et al. 2014; Tavares et al. 2014 ).The significant increase in the diversity and abundance of coffee flower visitor insects (<0) is associated with yield, gross weight, and net income of coffee (Manyuli 2014). Ebeling et al. (2008) found that pollinator insect visits increased linearly with the increase of abundance and species diversity of the flowering plants. The abundance of flowering plants will provide the resources for food, and their diversity will offer better pollen and nectar resources. Plantation land-use tends to have low abundance and diversity of plant species, especially for monoculture plantations. The types of plants that potentially can increase the abundance and diversity of large estates such as coffee plantations are flowering plants with understories commonly considered as weeds. These plants are generally in the forms of grasses, herbs, and shrubs, which are annual, biennial or perennial, with solitary or cluster life forms, upright, or vine-like form (Althorick 2005). According to Mustakim et al. (2004), the understory plants may serve as microhabitats to attract pollinator insects. This study aimed to see the effect of understory plants on the visitation of coffee flower insects. The number of pollinator insect visits in the two types of gardens (with or without understory plants) was recorded and compared in terms of abundance and variety of species. MATERIALS AND METHODS The research was carried out in one of the coffee plantations in West Java producing Kopi Luwak: coffee plantation under the management of Perhutani Resort Pemangkuan Hutan (RPH) Lembang, West Bandung