Elaeidobius

Kuschel, 1952

palm-pollinating weevil

Species Guides

1

Elaeidobius is a of Afrotropical weevils (Curculionidae: Derelomini) comprising eight recognized , all associated with male inflorescences of oil palm (Elaeis guineensis). The genus was revised in 2020 using integrative combining morphological and molecular data (COI and COII). Species in this genus are critical of oil palm, with E. kamerunicus being the most economically important and widely introduced throughout Southeast Asian and Latin American oil palm regions.

Pronunciation

How to pronounce Elaeidobius: /ˈe.laɪ.doʊ.bi.əs/

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Identification

Elaeidobius are distinguished from other Derelomini by their association with oil palm male inflorescences and can be separated from each other using morphological characters of habitus and male genitalia; an illustrated key to all eight species was provided by Haran & Kuschel (2020). The includes species transferred from other genera (Prosoestus, Derelomus) based on phylogenetic and morphological evidence. Two new species (E. pilimargo and E. piliventris) were described in the 2020 revision.

Habitat

Oil palm plantations and natural stands of Elaeis guineensis; occurs in both lowland and highland areas where oil palm is grown.

Distribution

Afrotropical in origin; E. kamerunicus and other have been introduced to Southeast Asia (Indonesia, Malaysia) and Latin America (Colombia) for oil palm pollination. Documented occur in North Sumatra, West and Central Sulawesi, West Sumatra, and Central Kalimantan in Indonesia.

Host Associations

  • Elaeis guineensis - primary All in the are associated with male inflorescences of oil palm; critical for pollen transportation and fruit set.

Ecological Role

Primary of oil palm (Elaeis guineensis); pollen transportation by these weevils is critical for fruit set of this economically important palm. The increasing of these pollinators directly impacts oil palm pollination success and productivity.

Human Relevance

Essential for oil palm production; E. kamerunicus was deliberately introduced to Malaysia in 1981 and subsequently to Indonesia and other oil palm-growing regions to improve pollination and fruit set. education programs in Indonesia train smallholder farmers to conserve and reduce use that harms these insects. The demographic parameters of E. kamerunicus (net reproductive rate Ro=4.88, intrinsic growth rate rm=0.084, time T=19 days in lowland conditions) are used to predict population growth and manage pollination services in plantations.

Similar Taxa

  • ProsoestusOne Elaeidobius (E. spatulifer) was transferred from this based on integrative taxonomic revision; previously confused due to convergent associated with palm pollination .
  • DerelomusE. singularis was previously placed in Derelomus as D. uelensis, now synonymized; both belong to Derelomini and share palm-associated but differ in specificity and morphological details.

More Details

Taxonomic revision

The was comprehensively revised in 2020 (Haran & Kuschel, European Journal of 684), increasing recognized from five to eight through new combinations and species descriptions. The revision used both traditional and mitochondrial gene sequences (COI, COII).

Environmental sensitivity

including temperature, humidity, wind speed, and light intensity significantly affect weevil and . Highland in North Sumatra showed markedly different demographic parameters compared to lowland populations: extended from 12.25 days to 29.5 days, and lifetime production reduced from ~198 to ~20 eggs per female.

Sources and further reading