scholarly journals Evaluation of Some Botanical Extracts Against Major Insect Pests (Leafminer, Armored scale and Woolly Whitefly) of Citrus Plants in Central Zone of Tigray, North Ethiopia

2020 ◽  
Vol 11 (2) ◽  
pp. 258-275
Author(s):  
Fitiwy Ibrahim ◽  
Tsehaye Hadush ◽  
Gebretsadkan Abraha ◽  
Araya Alemu

Citrus fruit production is suffering from various yield-limiting factors particularly the sucking pests viz, citrus leafminer Phyllocnistis citrella, woolly whitefly, Aleurothrixus floccosus and scale insects especially armored scales Aonidiella auriantii. The present paper tries to identify the effective botanical insecticides against these insect pests on citrus orange. An experiment was conducted in the established citrus orange farm in Kolla Temben at two farmer’s fields, Adiha and Agibe during the off-season of 2018 under irrigation growing condition in a randomized complete block design with six treatments and replicated thrice. The findings in both experimental sites showed that the neem seed extract had a significantly (P=0.001) lower leafminer infestation levels compared to the untreated control which is on par to the insecticide treatment of dimethoate. On the other hand, in both areas, whitefly mortality of more than 81% on average was recorded from neem seed extract followed by Tree tobacco (70%) (P=0.001). For scale insects however, in both experimental sites, the highest mean percent mortality was recorded from the insecticide dimethoate 40% EC (86.9%, 87.2 & 86.0%on average) followed by neem seed and tree tobacco extracts,70.1 and 65.4% respectively. The botanicals particularly the neem seed extracts followed by tree tobacco are as effective as the chemical insecticide, dimethoate 40% EC, even superior in some cases, in controlling the target pests. Therefore, these botanicals could be used as an IPM component for against the target pests.

2020 ◽  
Vol 1 (2) ◽  
pp. 55-63
Author(s):  
Isma Oktadiana ◽  
Venny Diah Ningsih

Plants that are currently being developed as botanical insecticides are those that produce essential oils. The largest active compound that is insecticidal in neem (Azadirachta indica) is azadirachtin, this compound belongs to the triterpenoid group. The purpose of this study was to determine the level of insect repellent activity of neem (Azadirachta indica) seed chlorophome extract against rice lice (Calandra oryzae). This research is an experimental study using a completely randomized design (CRD). Consisting of neem seed extract treatment with a concentration of 0.1% and 0.5% and a control in the form of distilled water each 10 times. The results of this study indicated that the concentration of 0.1% and 0.5% neem seed extract test increased the mortality of rice lice. The longer the application time, the higher the mortality rate of rice lice. In the treatment of 0.5% neem seed extract, it could cause 67% mortality compared to 0.1% neem seed extract treatment and control.   Keywords: Neem seeds, insect repellent, Calandra oryzae ABSTRAK   Tumbuhan yang saat ini sedang dikembangkan sebagai insektisida nabati yaitu tumbuhan yang menghasilkan minyak atsiri. Senyawa aktif terbesar yang bersifat insektisida pada tanaman mimba (Azadirachta indica) adalah azadirachtin, senyawa ini termasuk dalam kelompok triterpenoid. Tujuan dari penelitian ini yaitu untuk mengetahui tingkat aktivitas penolak serangga (insect repellent) ekstrak klorofom biji mimba (Azadirachta indica) terhadap kutu beras (Calandra oryzae). Penelitian ini merupakan penelitian eksperimental yang menggunakan Rancangan Acak Lengkap (RAL). Terdiri atas perlakuan ekstrak biji mimba konsentrasi 0.1% dan 0.5 % dan kontrol berupa akuades masing-masing 10 kali ulangan. Hasil penelitian ini menunjukkan bahwa Uji ekstrak biji mimba konsentrasi 0.1% dan 0.5% meningkatkan mortalitas kutu beras. Semakin lama waktu aplikasi maka semakin tinggi tingkat mortalitas kutu beras. Pada perlakuan  ekstrak biji mimba 0.5% dapat menyebabkan kematian sebesar 67% dibandingkan dengan perlakuan ekstrak biji mimba 0.1% dan kontrol.   Kata Kunci: Biji Nimba, penolak serangga, Calandra oryzae


2018 ◽  
Vol 36 (3) ◽  
pp. 353-356 ◽  
Author(s):  
Ewerton M Costa ◽  
Francisco EL Silva ◽  
Elton L Araujo

ABSTRACT The leafminer [Liriomyza sativae (Diptera: Agromyzidae)] is one of the main pests of melon crop (Cucumis melo) in the states of Rio Grande do Norte and Ceará. Thus, adopting strategies to control this destructive insect is essential. The aim of this study was to evaluate the effect of aqueous neem seed extract, applied to soil via irrigation, on leafminer larvae, in the melon crop. An experiment was conducted in greenhouse, in completely randomized design, consisting of five treatments (four doses of aqueous neem seed extract: 1; 3; 5 and 10 g/100 mL) and the control consisting only of distilled water and 10 replicates (melon plants). The treatments were applied in a single dose, via soil irrigation. In the first stage of the evaluation, 24 hours after application, the number of dead larvae per plant was counted. In the second step, pupal mortality was recorded. The total mortality was also calculated considering the number of larvae and the number of emerged adults. We verified that, increasing the concentration of aqueous neem seed extract, an increase in the larval and pupal mortality of the leafminer in melon crop was noticed. The concentration 10 g/100 mL presented the best results, resulting in 36.4% of larval mortality, 96.5% of pupal mortality and 96.8% of total mortality.


2012 ◽  
Vol 5 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Daniel Antonio Villamil Montero ◽  
Natalia Naranjo ◽  
Mario Andres Van Strahlen

El presente trabajo se desarrollo con el objetivo de evaluar o efeito insecticida del extracto etanólico de semillas de Neem (Azadirachta indica A. Juss) sobre ninfas de la chinche de los pastos Collaria scenica Stal. Para eso, se elaboró un extracto a partir de frutos inmaduros de Neem mediante rotaevaporación. El extracto fue diluido en tres concentraciones de ppm que corresponden a los tratamientos. Por medio de cromatografías en capa delgada se determinó la presencia de Azaridactina. Se realizó un experimento DCA de 4 tratamientos y 5 repeticiones que incluyó las tres concentraciones del extracto y un control. En cada repeticion se usaron 15 ninfas, colocadas aleatoriamente en cajas plásticas herméticas con alimento y la concentración correspondiente. Diariamente se realizó una aplicación del extracto y se registró porcentaje de mortalidad, número de exuvia y número de individuos que llegaron al estado adulto en cada tratamiento. Los resultados fueron analizados con prueba Kruskal-wallis y Games-Howell para cada variable. Las tres concentraciones del extracto de semillas de Neem presentaron un efecto negativo sobre el desarrollo de las chinches. El tratamiento más concentrado (250ppm) fue el más eficaz presentando una mortalidad del 97%, menor número de exubias y menor número adultos al final del ensayo. Insecticide Effect of Neem (Azadirachta indica A. Juss) Seed Extract against Collaria scenica Stal (Hemiptera: Miridae) Abstract. This work was developed with the objetive to evaluate the insecticidal effect of the Neem (Azadirachta indica A. Juss) seeds against grass bug nymphs Collaria scenica Stal. For that, an extract was prepared from green fruits of Neem by rotaevaporación. The extract was diluted in three ppm concentrations corresponding to treatments. Using thin-layer chromatography we identified the presence of Azaridactina. DCA essay was carried out with 4 treatments and 5 repetitions that included the three extract concentrations and a control. In each repetition were used 15 nymphs, randomly placed in plastic boxes with food and the corresponding concentration. Every day an extract application was made and recorded mortality percentage, number of exuviae and number of individuals who came to adulthood in each treatment. The results were analyzed using Kruskal-Wallis and Games-Howell for each variable. The three concentrations of Neem seed extract had a negative effect on the development of the bugs. The more concentrated treatment (250 ppm) was the most effective, showing a 97% mortality, fewer exuvias and and fewer adults in the end of the experiment.


1997 ◽  
Vol 14 (1) ◽  
pp. 40-43 ◽  
Author(s):  
Barry C. Kostyk ◽  
Kevin W. Wanner

Abstract A neem seed extract was applied to black spruce trees at two stages of reproductive development to control insect damage to the seed cones. Applied after pollination, neem had no effect on damage by the spruce cone maggot but did provide some protection against defoliation by the spruce budworm. Neem had no effect on the numbers of spruce budworm larvae for the first 9 days of the experiment, but after 23 days, populations declined on trees with two of three neem treatments compared to control trees. Neem reduced cone grazing damage by lepidopteran larvae when applied during the flowering stage. However, increased female flower abortion also resulted. The application of neem seed extract for controlling spruce budworm damage appears promising, but more information is needed on earlier applications in the field to determine if this product could be used operationally without causing substantial flower abortion. North. J. Appl. For. 14(1):40-43.


PLoS ONE ◽  
2017 ◽  
Vol 12 (9) ◽  
pp. e0184639 ◽  
Author(s):  
Farhan Mahmood Shah ◽  
Muhammad Razaq ◽  
Abid Ali ◽  
Peng Han ◽  
Julian Chen

2011 ◽  
Vol 110 (2) ◽  
pp. 769-773 ◽  
Author(s):  
Heinz Mehlhorn ◽  
Volker Walldorf ◽  
Fathy Abdel-Ghaffar ◽  
Saleh Al-Quraishy ◽  
Khaled A. S. Al-Rasheid ◽  
...  

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