Hervé Koua

Publications (6) View all

• Article: [Histopathology of Anopheles gambiae s.l. Giles, 1902 (Diptera, Culicidae) subjected to the larvicidal activity of the aqueous extract of Persea americana Miller, 1768 (Lauraceae)].

  H K Koua, S H Han, M A d'Almeida
  [show abstract] [hide abstract]
  ABSTRACT: Larvae of Anopheles gambiae treated with an aqueous extract of Persea americana suffer important damages of the midgut. The first epithelial cells to be affected are those at the posterior part of the midgut which become hypertrophic after only 30 min. After one hour most of the cells in this part lyse. The cytoplasmic material is then rejected towards the lumen gut, between the peritrophic membrane and the midgut epithelium. Subsequently, an almost total cell degeneration is observed. Cells of gastric caeca and cells at the intermediary and anterior parts of the midgut undergo the same histopathology, albeit after a longer period.
  Bulletin de la Société de pathologie exotique 02/1998; 91(3):252-6.
• Article: Evaluation of the larvicide effect of an aqueous extract of Persea americana (Miller, 1768), Lauraceae, on Anopheles gambine (Giles, 1902), Diptera Culicidae

  KOUAKOU HERVÉ KOUA, SUN HEAT HAN
  Invertebrate Reproduction and Development 01/1998; 34(1):97-100. · 0.48 Impact Factor
• Article: Spatio-temporal distribution of the infestations of Coelaenomenodera lameensis Berti and Mariau (Coleoptera, Chrysomelidae) an oil palm tree (Elaeis guineensis Jacq.) pest in Toumanguié (Côte d’Ivoire).

  H. Koua, J. Mathieu, P.B. Seri-Kouassi, Y. Tano, P. Mora
  Sciences & Nature. 01/2010; 7(1):1-10.
• Article: Mouthpart Morphology, Anatomical and Histological Study of the Alimentary Canal of Coelaenomenodera lameensis (Coleoptera: Chrysomelidae), Leaf Miner of Oil Palm

  KOUA Kouakou Hervé, OUALI-N’GORAN San-Whouly Mauricette, D’ALMEIDA Marie-Anne, HAN Sun Heat
  [show abstract] [hide abstract]
  ABSTRACT: Coelaenomenodera lameensis Coleoptera, Chrysomelidae (Berti and Mariau, 1999) is a dangerous pest of oil palm in West Africa. In this study, we investigate for the first time, the mouthparts, the anatomy and histology of the alimentary canal of this leaf miner. Larvae mouthparts present parts size modifications from stage 1 to stage 4. Adult mouthparts are adapted for biting. The morphometric study of digestive tract showed that the midgut is the longest part whatever the stage of the insect. Histological study of the alimentary canal showed that it was divided into three main regions: stomodaeum, mesenteron and proctodaeum, both in larvae than in adult insects. Structure of these regions was particularly revealing in the foregut that the insect has anatomical structure to reduce the ingested plant.
  Asian Journal of Scientific Research 1(4):159-175.
• Article: Effect of Azadirachtin A systemic injection on Coelaenomenodera lameensis Berti and Mariau (Coleoptera: Chrysomelidae) an oil palm (Elaeis guineensis L) pest

  TANO Djé Kévin Christian, SERI-KOUASSI Badama Philomène, ABOUA Louis Roi Nondenot, KOUA Kouakou Hervé
  [show abstract] [hide abstract]
  ABSTRACT: Coelaenomenodera lameensis is the major pest of oil palm. The fight against this pest is achieved by using several methods including the injection of systemic insecticide in the trunk of the palm. The tests were conducted at the agro-industrial units of Toumanguié, located 90 km from Abidjan. Azadirachtin A was used in systemic treatment at four concentrations: 0.1, 0.2, 0.4 and 0.6 g/ml. Chiffon sleeves were placed on the palms to assess the effect of products on C. lameensis. Systemic injections were made during the dry and rainy seasons. The efficacy of azadirachtin was assessed by reference to thiamethoxam, an insecticide used in the fight against this pest. The effective minimal concentration was 0.4 g/ml of azadirachtin. This concentration generated the cumulated mortality rates of 38.92% in dry season and 19.28% in rainy season on the adults after 28 days of treatment. The percentages of efficiency achieved in the dry season on the larvae 7 days after treatment were 74.75% (stage 1), 57.23% (stage 2), 7.14% (stage 3) and 5.31 % (stage 4). In rainy season, the efficacy of azadirachtin on larvae was less than 29%. Azadirachtin can be used in dry season, at the beginning of the infestation period, to fight against C. lameensis.
  Asian Journal of Scientific Research 1(5):271-284.