Fumigant and Repellence Potentials of Oils from Four Plant species Against Sitophilus zeamais Motschulsky (Coleóptera: Curculionidae)

NJE Vol. 41: 125-141, 2025

DOI.10.36108/NJE/5202/14.0190

Boniface Effiong Archibong¹, Simon Idoko Okweche², Idorenyin Asukwo Udo¹ and Sylvia Bassey Umoetok¹

¹Department of Crop Science, University of Calabar, Calabar, Cross River State, Nigeria

²Department of Forestry and Wildlife Resources Management, University of Calabar, Calabar, Cross River State Nigeria

Abstract

Insect pests infestation is one the major problems associated with the production of maize in many Sub-Saharan Africa including Nigeria. Control of these pests by farmers has been vastly through the use of synthethic chemical pesticide which possesses lots of threats to human health and environments. A study was conducted at the University of Calabar, Nigeria, to assess the effectiveness of essential oils (EOs) derived from four plant species against Sitophilus zeamais Motschulsky, commonly known as the maize weevil. The EOs were applied in varying concentrations (2.5, 5, 7.5, and 10 µl/l) arranged in Caompletely Randomized Design four replications. Parameters assessed included adult mortality, LC₅₀, and seed damage. The results showed that EOs from Dennitia tripetala, Physostigma venenosum, Xylopia aethiopica, and Senna hirsuta were effective in repelling and fumigating the maize weevil. The repellence ranged from 41.7% (X. aethiopica), 75.00% (D. tripetala), 75. 67% (P. venenosum) and 51.14% (S. hirsuta) applied at 2.5 µl/l while at 10, it recorded a repellence of 92.00 (X. aethiopica) 88.00 (D. tripetala), 90.0 (P. venenosum) and 89.14 (S. hirsuta). Mortality ranged from 45% to 90% at 2.5 µl/l and 90 to 100% at 10 µl/l  when applied as fumigant. The median lethal concentrations showed that X. aethiopica, D. tripetala, P. venenosum and S. alata EOs were effective against S. zeamais. Therefore, the study recommends the use of X. aethiopica, D. tripetala, P. venenosum and S. hirsuta EOs at 20% to effectively manage maize weevil infestations during storage.

 

Keywords: Sitophilus zeamais, essential oils,  mortality, repellence, fumigant, Median lethal concentration.

 

 

Download PDF