Essentials Oils (Ocimum gratissimum and Cymbopogon citratus) Against Pseudotheraptus devastans in Coconut Plantations at Marc-Delorme Station in Ivory Coast
Akpesse Akpa Alexandre Moise,
Ochou Germain Elisabeth Cynthia,
Diabate Dohouonan,
Kedja Bossoma Agnes Monique,
Koua Kouakou Herve
Issue:
Volume 6, Issue 4, December 2022
Pages:
94-101
Received:
13 September 2022
Accepted:
14 October 2022
Published:
18 October 2022
DOI:
10.11648/j.aje.20220604.11
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Abstract: The bug Pseudotheraptus devastans is one of main insect pests in Ivory Coast. The objective of this study was firstly to evaluate the incidence of Pseudotheraptus devastans attacks on coconut palm plants of two varieties (GOA and NJM), and secondly to study the insecticidal activity of essential oils (Ocimum gratissimum and Cymbopogon citratus) on adults of Pseudotheraptus devastans. Bunches of nuts aged 2 to 4 months showed the highest attack rate in the GOA variety. On other hand, all the nuts aged 1 to 7 months were all attacked in the NJM variety. As for the drop rates, bunches aged 1 to 4 months recorded the highest drop rates for both varieties. It appears that the NJM variety is more sensitive to bites unlike that of GOA which was more tolerant. Mortality rates varied with applied concentrations and observation time. Thus, the essential oils extracted from the two aromatic plants Ocimum gratissimum and Cymbopogon citratus have insecticidal properties on the adults of Pseudotheraptus devastans. This insecticidal effect was highlighted by the LC50, therefore determining the essential oil of Ocimum gratissimum as the most toxic with an LC50 of 1.41% unlike Cymbopognon citratus which recorded a value of 7.76%. These biopesticides can be used to protect coconut palms against insect pests.
Abstract: The bug Pseudotheraptus devastans is one of main insect pests in Ivory Coast. The objective of this study was firstly to evaluate the incidence of Pseudotheraptus devastans attacks on coconut palm plants of two varieties (GOA and NJM), and secondly to study the insecticidal activity of essential oils (Ocimum gratissimum and Cymbopogon citratus) on ...
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The Jumping Plant-Louse Colophorina baphiosis sp. nov. (Hemiptera: Psyllidae) Associated with Baphiosis parvifolia (Fabaceae) in Cameroon
Wenceslas Yana,
Victor Joly Dzokou,
Yves Patrick Mveyo Ndankeu,
Joseph Lebel Tamesse
Issue:
Volume 6, Issue 4, December 2022
Pages:
102-109
Received:
15 September 2022
Accepted:
13 October 2022
Published:
29 October 2022
DOI:
10.11648/j.aje.20220604.12
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Abstract: Psyllids are sap-sucking insects commonly called Jumping plant lice. Many psyllid species of Cameroon remain not described. Recent field works carried out in some localities of Cameroon, permitted to collect a non described psyllid species Colophorina baphiopsis sp. nov. associated with Baphiopsis parvifolia a valuable timber tree. The aim of this survey was to describe and identify psyllid of B. parvifolia which is a contribution of the study of psyllid biodiversity of Cameroon fauna. The psyllid induces damages on the host plant, such as rolling and distortion of leaves and stunted growth of buds. The diagnostic characters of Colophorina baphiopsis are: the fifth instar immature with 1+1 pointed sectasetae on terminal abdominal margin; anus in terminal position, circumanal consisting of a single row of pores; additional pore fields developed, convulted, extending much onto abdominal dorsum and consisting of a single row of wax pores; adult genal processes short and broad with divergent relatively pointed apices; forewing pattern in which surface covered by large brown band with light white area; Female terminalia with triangular proctiger ending by rounded large apex, circumanal ring ovoidal with two rows of elongate pores, subgenital plate triangular with broad proximal part and the third apical part tapering with pointed apex. According to above discriminative characters and comparison with previously described species, Colophorina baphiopsis, can be considered as new afrotropical psyllid species in Colophorina genus.
Abstract: Psyllids are sap-sucking insects commonly called Jumping plant lice. Many psyllid species of Cameroon remain not described. Recent field works carried out in some localities of Cameroon, permitted to collect a non described psyllid species Colophorina baphiopsis sp. nov. associated with Baphiopsis parvifolia a valuable timber tree. The aim of this ...
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Comparative Study of Red Palm Weevil (RPW), Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) Reproduction Reared Using Different Diets
Nor Ahya Mahadi,
Tajul Ariffin Aziz Yusof,
Wan Khairul Anuar Wan Ali,
Amiran Ngah,
Mazidah Mat,
Anuar Abdullah,
Mohd Hafizudin Zakaria,
Noor Azlina Masdor
Issue:
Volume 6, Issue 4, December 2022
Pages:
110-115
Received:
26 September 2022
Accepted:
14 October 2022
Published:
29 October 2022
DOI:
10.11648/j.aje.20220604.13
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Abstract: Rhynchophorus ferrugineus or known as red palm weevil (RPW) is a damaging pest of coconut and many other palms. Due to its damaging nature to palms, many efforts have been taken to develop control methods of the pest which originated from laboratory studies. The use of wild-captured RPW from the field for laboratory trials would cause inconsistencies due to many factors. Thus, rearing them under laboratory condition is a must. Rearing techniques used by previous workers are laborious, requires frequent maintenance and sometime produced insufficient samples for testing. Some of the ingredients used also could not be acquired easily. Therefore, a study was conducted to compare RPW reproduction using different alternative diets in order to produce better technique for continuous rearing as preparation before laboratory studies. This study was done by preparing two types of alternative diets, namely Diet A using cassava+chicken feed+young coconut husks as the main ingredients and Diet B using sugarcane, for rearing the weevil. Two pairs of RPW were used on each diet and observations were done daily. Numbers of RPW were recorded for every stage until adult emergence. Development time and adult longevity were also recorded. The experiment was done for two generations and replicated five times. Results of the study revealed that Diet A increased RPW fertility per female (P<0.0001), shortened the developmental time (P<0.05), and requires less maintenance as compared to Diet B. However, RPW longevity was the same in both diets (P>0.05) as it could have been dependent on the freshness of the diets over time. Thus, the results of this study suggested that Diet A is a better option as compared to Diet B for RPW rearing under laboratory condition.
Abstract: Rhynchophorus ferrugineus or known as red palm weevil (RPW) is a damaging pest of coconut and many other palms. Due to its damaging nature to palms, many efforts have been taken to develop control methods of the pest which originated from laboratory studies. The use of wild-captured RPW from the field for laboratory trials would cause inconsistenci...
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Survey of the Distribution and Severity of White Mango Scale in Mango Production in Eastern Ethiopia
Gelana Keno,
Mulatu Wakgari
Issue:
Volume 6, Issue 4, December 2022
Pages:
116-123
Received:
2 November 2022
Accepted:
24 November 2022
Published:
27 December 2022
DOI:
10.11648/j.aje.20220604.14
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Abstract: Mango production in Ethiopia is harmed by a number of arthropod pests particularly the White Mango Scales (WMS) is major pest of grave concern to mango growers. The main objective of this study was to assess the current status of WMS insect pest in Mango production and farmers’ knowledge about the pest in eastern Ethiopia. WMS distribution and severity specifically in the major mango growing areas East Hararghe, Harari regional state, and Dire Dawa were surveyed. The survey result indicated that WMS is distributed across most of the mango growing districts of the surveyed zones with the exception of few areas which were found to be WMS free. A total of forty-seven mango grower fields infested with WMS and 470 mango plant leaf samples within altitudinal gradients ranging from 1166 to 2170 meters above sea level were checked for WMS infestation. Severity and abundance of WMS wаs highest аt Dire Dawa followed by Babile, then Haramaya and Harari sub districts. The comparative means of both male and females’ number of WMS showed that the severity was significantly different across the districts (p values <.0001) for number of males, number of females and for both males and females of WMS.
Abstract: Mango production in Ethiopia is harmed by a number of arthropod pests particularly the White Mango Scales (WMS) is major pest of grave concern to mango growers. The main objective of this study was to assess the current status of WMS insect pest in Mango production and farmers’ knowledge about the pest in eastern Ethiopia. WMS distribution and seve...
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Populations Variations and Impacts of Bemisia tabaci (Genn.) and Aphis gossypii Glov. (Hemiptera), Two Sap-sucking Insects of Pepper Capsicum annuum L. 1753
Pierre Stephan Elono Azang,
Cyril Romeo Heumou,
Desiree Chantal Alene,
Dounia,
Vanessa Kemgang Danemo,
Pierre Ngassam,
Joseph Lebel Tamesse,
Champlain Djieto-Lordon
Issue:
Volume 6, Issue 4, December 2022
Pages:
124-138
Received:
17 February 2020
Accepted:
13 March 2020
Published:
29 December 2022
DOI:
10.11648/j.aje.20220604.15
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Abstract: From April to August 2018, seasonal variation of the populations and the damage due to Aphis gossypii (Aphididae) and Bemisia tabaci (Aleyrodidae), two sap-sucking pests on Pepper (Capsicum annuum L.), was carried out in a forestry region of Cameroon with bimodal rainfall. This study focused on 133 days after transplanting (DAT). Populations were counted by 5 leaves per plant during 19 weeks, 02 seasons and 03 phenological phases of plant. Average number of individuals and attacked leaves due to these pests were correlated with total rainfall, mean temperature and mean relative humidity. The study showed that the average number of A. gossypii and B. tabaci per 5 leaves per plant varied significantly with sampling weeks (df=18, F=8.50, p<0.001 and df=18, F=4.87, p<0.001 respectively), seasons (df=1, F=2.99, p<0.01 and df=1, F=12.58, p<0.001 respectively) and with phenological phases of C. annuum (df=2, F=111.07, p<0.01 and df=2, F=132.74, p<0.01 respectively). The highest population were recorded at the 13th sampling week corresponding to 91 days after transplanting (91 DAT) with 5.30±0.8 individuals/5 leaves for A. gossypii and 2.30±0.42 individuals/5 leaves for B. tabaci. Average number of A. gossypii and B. tabaci were highest in the short dry season with 3.49±0.17 individuals/5 leaves and 0.83±0.07 individuals/5 leaves respectively. The study also showed that damage due to A. gossypii / B. tabaci complex varied significantly with sampling weeks (df=18, F=3.02, p<0.004), with seasons (df=1, F=9.69, p<0.001) and with phenological phases of C. annuum (df=2, F=20.31, p<0.005). These damage were higher in the first sampling week corresponding to 7 days after transplanting (7 DAT) with an average attack rate of 31.25±5.56%, during the short rainy season with an average attack rate of 20.57±1.48% and during the pre-flowering phase with an average attack rate of 20.85±1.10%. Average number of A. gossypii and B. tabaci individuals showed negative and non-significant correlations with total rainfall (r=-0.80, p<0.104 and r=-0.60, p<0.284 respectively) and mean temperature (r=-0.86, p<0.057 and r=-0.29, p<0.637 respectively), then positive and significant for A. gossypii (r=0.89, p<0.040) and positive and non-significant for B. tabaci (r=0.11, p<0.857) with relative humidity. Damage due to hemipteran complex showed positive and non-significant correlations with total rainfall (r=0.60, p<0.285) and mean temperatures (r=0.87, p<0.058) and negative and significant correlations with relative humidity (r=-0.86, p<0.041). The present study provided baseline data for integrated pest management strategies against A. gossypii and B. tabaci on C. annuum in forestry region of Southern Cameroon.
Abstract: From April to August 2018, seasonal variation of the populations and the damage due to Aphis gossypii (Aphididae) and Bemisia tabaci (Aleyrodidae), two sap-sucking pests on Pepper (Capsicum annuum L.), was carried out in a forestry region of Cameroon with bimodal rainfall. This study focused on 133 days after transplanting (DAT). Populations were c...
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