Entomofauna of Oil Palm Tree Inflorescences at La Mé Experimental Station (Côte d’Ivoire)

Abstract

Pollination of oil palm tree is mainly entomophilous. The inflorescences of this plant lodge many insects. The identification and quantification of these insects have proven ability to hold their pollination. The entomofauna of female and male inflorescences was inventoried and quantified at La Mé, a station of CNRA, the National Center of Agronomic Research of Côte d'Ivoire (West Africa) for a period of 2 years. The insects of the male inflorescences were listed at the beginning, the full and the end of anthesis on 1536 spikelets of 384 male inflorescences. For the insects of female inflorescences, 96 inflorescences were covered with a muslin sheath. The insects arriving on these inflorescences were captured in 2 days corresponding to anthesis length, during 10 minutes per hour, from 6 am to 6 pm. Species Elaeidobius sp., Microporum sp., Prosoestus sp. and Atheta burgeoni were common and regular present regardless of inflorescence type. Species Gabrius sp., Thrips sp., Anthocoride sp., Lithargus sp. and the bees (Nomia sp. and Apis mellifera) were rarely observed in female inflorescences. Elaeidobius kamerunicus and Prosoestus sp. were more abundant on the female than on the male inflorescences. The higher level of insects was observed in full anthesis on male inflorescences whereas among female inflorescences it was noted at the first day of flowering. Knowledge of the insect fauna of oil palm inflorescences according to different stages of flowering allows better management of pollination.

Pollination Activity ofElaeidobius kamerunicus(Coleoptera: Curculionoidea) on Oil Palm on Hainan Island

“…Elaeidobius kamerunicus was more abundant on male inflorescences than female inflorescences, and this is similar to the results of Hala et al (2012). Our examinations were more detailed than those of Tuo et al (2011).…”

“…We demonstrated that adult weevils were most abundant on the female flowers on the 2nd day of anthesis. This finding is similar to that of Hala et al (2012) but differs from the results of Syed (1979Syed ( , 1982, who reported that the adult weevil population increased to a maximum on the female inflorescences during the 2nd and 3rd days of anthesis. The differences between our observations and those reported by Syed (1979Syed ( , 1982 could perhaps be due to differences in climate and location.…”

FLOWER DEVELOPMENT OF MALE AND FEMALE INFLORESCENCE OF OIL PALM, Elaeis guineensis Jacq.

“…Visitation of weevils increases due to opened flowers during the anthesis period (Yue et al, 2015). Visitations of weevils are high on the first day of anthesis of female inflorescence, but this observation is differed from Hala et al (2012) and Yue et al (2015). They reported that the visitations of weevils are higher on the second and third days of anthesis.…”

Efficacité De La Pollinisation Entomophile Du Palmier A Huile Dans Les Plantations Du Sud-Ouest Et Du Sud-Est De La Côte d’Ivoire

“…Cette identification a été faite à l'aide d'une loupe binoculaire en se servant de la collection des insectes des inflorescences du palmier à huile disponible sur cette station. Les travaux antérieurs ont également été consultés pour cette identification (Hala et al, 2012).…”

“…L'absence de certains de ces insectes pollinisateurs ou la diminution de leurs populations dans les palmeraies entraîne systématiquement une diminution du taux de fruits fécondés (Syed et al, 1982 ;Mariau et Genty, 1988;Mariau et al, 1991 (Syed, 1979 ;Desmier de Chenon, 1981, Mariau et Genty, 1988Mariau et al, 1991). L'espèce E. kamerunicus transporte plus de grains de pollen et s'est montré plus efficace dans la pollinisation (Kouakou et al, 2014) Les travaux récents sur l'entomofaune des inflorescences du palmier à huile en Côte d'Ivoire ont révélé des fluctuations spatio-temporelles importantes et une diminution de la densité de ces principaux pollinisateurs (Hala et al, 2012 ;Koua et al, 2013). L'influence de ces fluctuations sur le taux de nouaison n'a pas été clairement établie.…”