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European Journal of Applied Sciences – Vol. 10, No. 5
Publication Date: October 25, 2022
DOI:10.14738/aivp.105.13041. Ibitoye, O., Ogundare, A. O., Ayangbemi, T. M., Ogungbemi, K., Oyewole, O. S., Abel, 0. O. (2022). Evaluation of Bay Leaf and
Onion Peel Ethanolic Extracts for the Management of Kola Weevils (Balanogastris kolae) (Coleoptera: Curculionidae) in Stored
Cola Nitida. European Journal of Applied Sciences, 10(5). 161-168.
Services for Science and Education – United Kingdom
Evaluation of Bay Leaf and Onion Peel Ethanolic Extracts for the
Management of Kola Weevils (Balanogastris kolae) (Coleoptera:
Curculionidae) in Stored Cola Nitida
Ibitoye O.
Durable Crops Research Department
Nigerian Stored Products Research Institute, P. M. B. 5044
Ibadan, Oyo State, Nigeria
Ogundare A. O.
Perishable Crops Research Department
Nigerian Stored Products Research Institute, P. M. B. 5044
Ibadan, Oyo State, Nigeria
Ayangbemi T. M.
Durable Crops Research Department
Nigerian Stored Products Research Institute, P. M. B. 5044
Ibadan, Oyo State, Nigeria
Ogungbemi K.
Perishable Crops Research Department
Nigerian Stored Products Research Institute, P. M. B. 5044
Ibadan, Oyo State, Nigeria
Oyewole O. S.
Postharvest Engineering Research Department
Nigerian Stored Products Research Institute, P. M. B. 5044
Ibadan, Oyo State, Nigeria
Abel O. O.
Durable Crops Research Department
Nigerian Stored Products Research Institute, P. M. B. 5044
Ibadan, Oyo State, Nigeria
ABSTRACT
Farmers subject cured kolanuts to chemical treatment for control of kola weevils,
kola nuts do not undergo any other additional form of post harvest processing
before storage and consumption, therefore, there is an urgent need to develop
new post harvest storage pest control strategies that are safe, of low cost,
convenient to use, and environmentally / user friendly. The objective of the study
is to assess the efficacy of Bay leaf and Onion peel ethanolic extracts on
Balanogastris kolae against the chemical control measures. Efficacy of ethanolic
extracts of Bay leaf and Onion Peels at concentrations of 20, 40, 60, 80 and 100
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European Journal of Applied Sciences (EJAS) Vol. 10, Issue 5, October-2022
Services for Science and Education – United Kingdom
%v/v, each as protectant in the control of the Kola weevil Balanogastris kolae,
were compared with a conventional insecticide, Cypermethrin at a rate of 5 ml /
100g Kolanut. Parameters evaluated include adult mortality, rate of adult
emergence and nut damage which were subjected to analysis of variance and
means between treatments were separated using LSD. Mortality of Balanogastris
kolae increased with increasing concentration of the extracts as well as days of
exposure, All the treatments were better than the control (P < 0.05) in reducing
the number of emerged adult B. kolae and grain damage. All treatments proved
superior to control (58.0%) with Cypermethrin and 90 %v/v Onion peel
outstanding.
Keywords: Bay leaf, Onion Peels, Cypermethrin and Balanogastris kolae
INTRODUCTION
Kola nut is a fruit of the kola tree which is native to Africa. it has social, cultural and religious
significance. (Oludemokun, 1982). Kolanut is known to suppress hunger and takes care of
hunger pranks, an important flavouring agent for soft drinks such as cocoa cola. (Odeyemi and
Daramola, 2000).
Kola nut is widely known in Western and Northern part of Nigeria as an economic crop and it
has a major active ingredient known as caffeine. Many Africans consume kolanuts regularly
for medicinal, stimulating and sustaining properties. kolanut had caffeine, medically known as
a bronchodilator which open up the air ways. People with asthma and other diseases that lead
to obstruction of the air ways might benefit from intake of kola nut to help in opening up of
the air ways (Asogwa et al, 2012).
Thus the role of insect pests, which are capable of destroying more than half of the little
produced fruits, cannot be overemphasized (Odeyemi and Daramola, 2000).These insect pests
include Balanogastris kolae, Sophrorhinus spp, Characoma stictigrapta, Phosphorous
virescens etc (Daramola, 1978).
Among these pests, the kola weevils Balanogastris kolae and Sophrorhinus spp happen to be
the most serious pests of kola in Nigeria, they are referred to as “field – to – store” pests as
their infestation is initiated in the field and persists in storage (Odeyemi and Daramola, 2000)
The females lay eggs 1cm deep in the kola nuts or in other parts of the fruit through wounds
and holes made by other insects such as Ceratitis colae or through cracks on the husk, which
occurs when the follicles dehisce before harvest (Daramola, 1978).
These weevils are robust dark brown 3-4mm long. They are found in kola growing areas of
southern Nigeria. Both the adult and larvae attack nuts. The larvae are small and usually white
in colour. Larvae are commonly seen in ripe kola pods, often in tunnels within the cotyledon
of the seeds (Odeyemi and Daramola, 2000).
Onion (Allium cepa) is an herbaceous biennial plant of the family Amaryllidaceae (Cantrell et
al; 2020). It is grown for its edible bulb. Onion is the most common vegetable used in
preparation of different dishes (Marefati et al; 2018). Onion peel is usually trashed out. Onion
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Ibitoye, O., Ogundare, A. O., Ayangbemi, T. M., Ogungbemi, K., Oyewole, O. S., Abel, O. O. (2022). Evaluation of Bay Leaf and Onion Peel Ethanolic
Extracts for the Management of Kola Weevils (Balanogastris kolae) (Coleoptera: Curculionidae) in Stored Cola Nitida. European Journal of Applied
Sciences, 10(5). 161-168.
URL: http://dx.doi.org/10.14738/aivp.105.13041
bulbs are safe to consume hence their skin may have promising insecticidal potentials if
screened.
Bay leaf (Laurus nobilis) is a perennial shrub which belongs to the family Lauraceae (Sayyah et
al, 2002) Ground bay leaf is safe when taken by mouth in medicinal amounts (Ferreira et al
2006). Bay leaf is used as condiment in the preparation of different delicacies
MATERIALS AND METHODS
The study was carried out in the Entomology Laboratory, Nigerian Stored products Research
Institute, NSPRI Ibadan Zonal office. Kola nut was purchased from Badeku Village, Egbeda
local Government, Oyo State. The kolanuts were manually sorted to obtain clean, healthy and
uninfested nuts and thereafter kept in a refrigerator in the laboratory until needed for the
experiments. Infested nuts from the lot were used to raise pure culture.
Balanogastris kolae culture
Initial culture of adult B. kolae was raised from infested kolanut sorted from the purchased lot.
Fifty pairs of adult B. kolae, sexed following the reports of Odeyemi and Daramola (2000),
were introduced into 2 litre Kilner jar containing 500g kolanut. The jar was covered with wire
mesh lid to allow for aeration and replicated 4 times for availability of insects throughout the
experiment. Jars were placed on a table whose stands were dipped in plastic bowls containing
oil to prevent ants from contaminating the culture.
Onion peels was sourced from Onion Seller at Bodija market, Ibadan and Bay leaf was
purchased from Dugbe Market, Ibadan Oyo State.
Preparation of Bay Leaf and Onion peel Powder
Bay Leaves and Onion peels were spread on trays and dried further in Parabolic Solar Tent
Dryer (PSTD) to make it crispy for easy milling. 500g of each of the leaves were milled using
warren blender. Milled samples were sieved using 0.5mm mesh. Powder of Bay leaf and Onion
peel were labeled and kept in the Ziplock bag.
Extraction of oils from plant materials
Two hundred grammes (200 g) each of Bay leaf and Onion peel powder was transferred into
the soxhlet extractor using 95 % ethanol as the solvent. The oil extracts were further
concentrated in a rotary evaporator under reduced pressure until a semi-liquid oil extract
was obtained. Crude extracts of Bay leaf and Onion peel were later diluted with 95 % ethanol
to obtain five different concentrations of 10, 20, 30, 40 and 50 % v/v with a control (0 %v/v)
containing only ethanol.
Effects of Bay leaf and Onion peel extracts and Cypermethrin on the mortality of B.
kolae
100 g of kola nut was weighed into kilner jars. Using a micro-pipette, 0.5ml of the
concentrations (10, 20, 30 and 40 % v/v) of each of the extracts and Cypermethrin was
applied to the kola nuts and shaken to allow for coverage. Nuts in the control jar were treated
with ethanol only. Consequently, there were five treatments in four replications. The nuts
were infested with ten adult B. kolae per jar and jars covered with a lid of fine mesh to allow