Pollination services of the local insect community of Oil palm (Elaeis guineensis) in Sumatra, Indonesia

Abstract
Oil palm is a major crop in Indonesia, but production can come at the cost of biodiversity loss and ecological degradation, making it a critical issue to conservation. Despite oil palm’s economic significance and ecological impact, little is known about biotic factors in its production, in particular how the ecosystem service of pollination from insects contributes to yield. Using size-based insect exclusion, we plan to investigate the contributions of different insect groups in pollinating oil palm flowers. Using passive insect sampling methods, we will also investigate the effect of neighboring land use type and distance to neighboring forest on pollinating insect diversity. We hypothesize that greater pollinator diversity will improve measures of oil palm yield, and that more natural neighboring land use types (i.e. more similar to forest) and locations closer to forests will be associated with higher pollinator diversity. Understanding these relationships could improve our knowledge of how oil palm may fit into a diversified agroecological landscape and the role of pollination in yield gaps in palm oil production.

Objectives

1. We will identify the role different pollinators play in determining various metrics of yield in oil palm production. Pollinator groups will be separated by size using exclusion netting to enclose flowering oil palm trees. Critically, netting mesh size will allow us to isolate the pollinating visits by the small (< 5mm) weevil Elaeidobius kamerunicus, which was introduced to Indonesia for this purpose, from larger insect pollinators and compare differences in yield. These results will also be compared to complete pollinator exclusion and complete (human-assisted) pollination benchmark treatments. The identity of visiting pollinators will be identified using methods such as pan traps or sticky traps

2. We will examine variation in pollinator diversity in oil palm plantations as a function of distance to neighboring land use and type of neighboring land use. Using passive insect sampling methods (e.g. pan traps, vane traps, or sticky traps), we will collect insects within oil palm plantations at different distances from neighboring forest or other common land use types, such as shrubland, rubber plantation, or other oil palm plantation.