Pollen load and distribution on the body of Elaeidobius kamerunicus Faust. (Coleoptera: Curculionidae) within oil palm plantations

Abstract

<p>The African oil palm weevil,<strong> </strong><em>Elaeidobius kamerunicus</em> is an effective pollinator of oil palm. Each individual palm produces exclusively male or female inflorescence so that the success of pollination depends on the ability of the pollinator to transfer pollen from male to female flowers. The objective of this research was to study the amount of pollen carried by <em>E. kamerunicus</em> between male and female inflorescences (pollen load) and the amount of pollen carried on each part of the weevil’s body (pollen distribution). Fifty each of male and female <em>E. kamerunicus</em> individuals were collected from male and female flowers on trees in 3 locations: Siantar (North Sumatra), Dramaga (West Java), and Morowali (Central Sulawesi). Data on pollen load and pollen distribution on the weevil’s body were analyzed using <em>ImageJ</em> software. Results show that <em>E. kamerunicus</em> individuals collected more pollen from male flowers than from female flowers. In addition, male insects carried more pollen on their bodies than female insects. Pollen distribution on weevil body parts was highest on the elytra, followed by the thorax, abdomen, legs, and head respectively.</p>

Factors Affecting Pollination and Pollinators in Oil Palm Plantations: A Review with an Emphasis on the Elaeidobius kamerunicus Weevil (Coleoptera: Curculionidae)

“…Adult weevils of this species carry the highest average number of pollen grains [ 18 , 33 , 52 , 53 , 54 , 55 ]. On average, E. kamerunicus can carry an average of 80,000 to 100,000 pollen grains per visit to the female inflorescence of oil palm [ 55 ]. Ref.…”

“…Ref. [ 55 ] observed that the amount of pollen carried by E. kamerunicus is positively correlated with their body size, with larger weevils carrying higher pollen loads. Bristles or hairs on the body surface also contribute to higher pollen loads, as reported by studies, such as [ 17 , 18 ].…”

“…Male weevils have been found to carry more pollen than females, and the pollen is primarily found on their elytra, thorax, and abdomen [ 55 ]. Male weevils have a body size ranging from 3–4 mm and possess more fine hairs or bristles on their abdomen, which aid in enhancing pollen transfer.…”

“…For example, ref. [ 55 ] reported that E. kamerunicus showed a preference for fresh pollen, which is known to contain higher levels of viable pollen grains. The study also found that the weevils avoided inflorescences with stale or aged pollen.…”

“…kamerunicus is recognized as one of the most efficient pollinators in the oil palm landscape, as it has the highest capacity for pollen cartage. Adult weevils of this species carry the highest average number of pollen grains [18,33,[52][53][54][55]. On average, E. kamerunicus can carry an average of 80,000 to 100,000 pollen grains per visit to the female inflorescence of oil palm [55].…”