scholarly journals Evaluation of Five Medicinal Plant Extracts on Aphis craccivora (Hemiptera: Aphididae) and Its Predator, Chrysoperla carnea (Neuroptera: Chrysopidae) under Laboratory Conditions

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 398 ◽  
Author(s):  
Samy M. Sayed ◽  
Saqer S. Alotaibi ◽  
Nevien Gaber ◽  
Sayed-Ashraf Elarrnaouty

Botanical insecticides that degrade rapidly are safer than persistent synthetic chemical insecticides, less harmful to the environment, decrease production costs and are not likely to cause insecticide resistance among pests. This study aimed to evaluate the effect of five different botanical extracts on the bean aphid, Aphis craccivora and the 2nd larval instar of the green lacewing, Chrysoperla carnea under laboratory conditions. Also, the flavonoids in the methanolic extracts of these tested plants were detected using HPLC analysis. The data from the HPLC analysis indicated that the tested plants differed in their flavonoid components. The total flavonoids were 869.4, 1125.6, 721.4, 1667.8 and 2025.9 mg/kg in Psiadia penninervia, Salvia officinalis, Ochradenus baccatus, Pulicaria crispa and Euryops arabicus, respectively. Moreover, there were many variations among these plants in the amount of each compound. The lethal concentration (LC50) value of P. penninervia extract on aphids was the lowest among all of the plants (128.546 µg/mL) followed by O. baccatus (626.461 µg/mL). Also, the LC50 value of P. penninervia extract on the 2nd larval instar of C. carnea (232.095 µg/mL) was significantly lower than those of all other four plant species extracts, while the other four plants did not show significant differences among them according to relative median potency analyses. Accordingly, O. baccatus extract had a strong effect on aphids and was safest for the predator. This finding suggests that O. baccatus could be exploited and further developed as an effective plant extract-based insecticide to be utilized in integrated pest management (IPM) programs against A. craccivora.

2009 ◽  
Vol 49 (3) ◽  
pp. 290-296 ◽  
Author(s):  
Gnanadhas Preetha ◽  
Johnson Stanley ◽  
Thiagarajan Chandrasekaran ◽  
Sasthakutty Kuttalam

Toxicity of Imidacloprid and Diafenthiuron toChrysoperla Carnea(Stephens) (Neuroptera: Chrysopidae) in the Laboratory ConditionsInsecticides are unavoidable in pest management programs especially when the pest crosses Econimic Threshold Level (ETL). Nevertheless, often the plant protection products kill the natural enemy population making the pest to resurge and thus demanding more sprays. Therefore, insecticides used in IPM programs should be selective enough to spare the beneficials. Laboratory studies were conducted to find out the toxicity of imidacloprid and diafenthiuron to the eggs, larvae and adults ofChrysoperla carnea.Imidacloprid at the recommended dose of 0.28 ml/l caused 15.38% egg mortality, 26.67 and 33.33% larval mortality by ingestion and contact, respectively and 50.00% adult mortality. The egg mortality was about 15.38% and larval mortality of 23.33% and adult mortality of 26.67% was caused by diafenthiuron. Based on the classification given by IOBC/WPRS working group on Pesticides and non-target invertebrates, both the insecticides were classified as harmless toC. carnea, since the recommended dose caused less than 50% mortality in the laboratory conditions.


2021 ◽  
Vol 19 (1) ◽  
pp. 139-154
Author(s):  
MA Hossain ◽  
MS Yasmin ◽  
MAA Bachchu ◽  
MA Alim

Botanicals are promising and attractive alternatives for pest management. In the present study, three botanical oils namely neem (Azadirachta indica), karanja (Pongamia pinnata) and mehogony (Swietenia mahagoni) were tested against the nymphs of Aphis craccivora Koch to evaluate the toxic and repellent effects under laboratory conditions (25 ± 5oC, 65-75% RH). Four concentrations (0.5, 1.0, 1.5, and 2.0%) along with control were maintained with distilled water and tween-20 was used as emulsifier. Leaf dipped method were used for insect bioassay. Insect mortality was recorded at 24, 48 and 72 hours after intervals while repellency was carried out at 2 hours after intervals upto 10th hours and the collected data were analyzed through MSTAT-C program. Results indicated that all the tested oils had toxic and repellent effects against the A. craccivora nymphs. Among the tested botanical oils, no significant difference was observed in terms of mortality over treatment time. But significant difference was noticed over level of concentrations exerted by the botanical oils. The average highest mortality (28.62%) was recorded by the application of mehogony oil whereas neem oil showed the lowest mortality (27.21%) against the A. craccivora and the mortality was directly proportional to the level of concentrations and hour after treatment (HAT). Probit analysis showed the lowest LD50 values of mehogony oil which revealed the highest toxic effect against the nymph of bean aphid. The highest repellent effect (77.33%) was found in mehogony oil (repellent class IV) among all the botanical oils applied. On the contrary, neem (57.33%) and karanja (55.00%) oils belonged to the same repellent class that is repellent class II. Although all the tested botanical oils evaluated showed toxic and repellent effects but mehogony oil performed as the best potent oil against the nymphs. We therefore suggested using the mehogony oil for the management of bean aphid. SAARC J. Agric., 19(1): 139-154 (2021)


2013 ◽  
Vol 10 (4) ◽  
pp. 1096-1101
Author(s):  
Baghdad Science Journal

The present study was conducted to determine the pathogenicity of Paecilomyces farinosus as biocontrol agents against Tragoderma granarium (khapra) under laboratory conditions with three concentrations ( 2.8 x 108 , 2.8 x 106 ,2.8 x104 spores/ ml). The laboratory results revealed that fungi showed it's higher pathogencity to larve stage on 2nd instar and 6th instar , although their capability differs according to the fungi concentrations this fungi caused higher mortality of 2nd larval instar 70% and 60% ,55% when it was used at concentrations 2 .8 x 106 ,2.8 x104 spores/ ml respectively. On the other hand on 6th larval instars 55% , 35% , 30% at concentrations ( 2.8 x 108 , 2.8 x 106 ,2.8 x104 spores/ ml) respectively, and the highest rate of distortions in the adult insects from the 2nd instar treatment than the adult insects from the 6th instar treatment concentration of this fungi.


Author(s):  
Amaka, John I. ◽  
Attah, D. Daniel ◽  
Obisike, Victor U. ◽  
Benedict, Aboje G.

This study evaluated the larvicidal potential of the ethanolic and aqueous leaf extracts of Hyptis suaveolens Poit on the 4th larval instar of laboratory-reared Anopheles spp at varying concentrations of 0.1ml, 0.2ml, 0.3ml, 0.4ml and 0.5ml for specified periods of 24hrs, 48hrs and 72hrs. Qualitative phytochemical screening of the leaf extracts identified bioactive components like alkaloid, saponin, phenol, anthraquinone and flavonoid. The LC50 and LC90 values obtained indicate that the ethanolic leaf extracts of Hyptis suaveolens Poit had the greatest toxicity on the test organisms within 24hrs of exposure at median LC50 value of 0.485ml compared to the LC50 value of 0.625ml by its aqueous extract. The relative median potency estimates indicate that within 24 hrs, the ethanolic Hyptis suaveolens Poit was 0.161 times more potent on the test organism than aqueous Hyptis suaveolens Poit. The result of this research, therefore, underscores the efficacy of Hyptis suaveolens Poit as an eco-friendly alternative in Anopheles mosquito control. It is, therefore, recommended that quantitative phytochemical screening, application of column chromatography as well as thin layer chromatography be carried out on the extracts to isolate and purify toxic phytochemicals with larvicidal potentiality.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1511
Author(s):  
Abdelkader Meni Mahzoum ◽  
María Villa ◽  
Jacinto Benhadi-Marín ◽  
José Alberto Pereira

Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) is a voracious predator of soft-bodied insects such as juveniles of scale insects and the black scale Saissetia oleae (Olivier) (Hemiptera: Coccidae) is an important pest of several crops, such as the olive tree. However, the predatory efficiency of C. carnea on S. oleae has been unstudied yet. The present work aimed to study the functional response of larvae of C. carnea fed on S. oleae nymphs. In a controlled laboratory environment, increasing densities of S. oleae second and third nymph stages were offered to newly emerged specimens of the three larvae instars of C. carnea. After 24 h, the number of killed S. oleae was recorded and the functional response of C. carnea was assessed. The three larval stages of C. carnea displayed a type-II functional response, i.e., killed prey increased with higher S. oleae densities up to a maximum limited by the handling time. The attack rate did not significantly differ among the three instars while the maximum attack rate was significantly higher for the third instar. The handling time of the first larval instar of C. carnea was higher than that of the third instar. Our results demonstrated that S. oleae could act as a food resource for all larval stages of C. carnea. Furthermore, the third larval stage of the predator was the most efficient in reducing S. oleae densities. These results suggest that C. carnea larvae could contribute to S. oleae control in sustainable agriculture.


Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1867 ◽  
Author(s):  
Mohammad Reza Youssefi ◽  
Mohaddeseh Abouhosseini Tabari ◽  
Aryan Esfandiari ◽  
Sohrab Kazemi ◽  
Ali Akbar Moghadamnia ◽  
...  

Background: Insect vector control is facing the challenges of resistance development and environmental hazards caused by synthetic pesticides. This has led to a considerable market opportunity for botanical insecticides. In this scenario, our study investigated the potential of selected bioactive monoterpenoids, carvacrol and thymol, as safe and effective tools to control the West Nile vector Culex pipiens. Furthermore, the combined effect of thymol-carvacrol mixtures and their possible interactions were assessed. Methods: For determining larvicidal and ovicidal 50% lethal concentration (LC50), each monoterpenoid was tested at different concentrations (5–500 mg/L). Then, the fixed ratio method was used for evaluating their combinational efficacy. Results: Carvacrol was more toxic against larvae of Cx. pipiens, with a LC50 value of 14 mg/L, whereas thymol exhibited a LC50 value of 49 mg/L. Comparable trends of efficacy were observed when toxicity on Cx. pipiens eggs was investigated, with LC50 values of 7 and 13 mg/L for carvacrol and thymol, respectively. In combinational toxicity assays, the mixture thymol-carvacrol at 1:4 ratio achieved a synergistic effect against larvae of Cx. pipiens, whereas an additive effect was observed on eggs. Other ratios showed antagonistic effects. Conclusions: Overall, our findings pointed out that the 1:4 ratio of thymol-carvacrol blend can enhance the insecticidal efficacy on Cx. pipiens young instars and can be considered further as active ingredient for developing botanical insecticides to be used in mosquito control operations.


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