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Papers by Asma laarif

Journal of entomology and zoology studies, 2021

The objective of the present study was to investigate the insecticidal activity of essential oils... more The objective of the present study was to investigate the insecticidal activity of essential oils from cultivated aromatic plants and their combinations against larvae of Spodoptera littoralis. Essential oils from Salvia officinalis, Mentha longifolia and Origanum majorana and their mixtures were tested by fumigation. The ability to kill more than 80% was observed in all tested essential oils at 200µL/Lair. In the case of individual essential oils, the LC50 were ranged from the most toxic to the least as fellow: M. longifolia (31.66 μL/L) followed by S. officinalis (42.70 μL/L) and O. majorana (58.28 μL/L). Moreover, the combination of S. officinalis with M. longifolia and with O. majorana might be the two most effectives in controlling the insect than individuals essential oils and the other combinations. The investigation of the efficiency of each essential oil and combination allow us to create potent combinations for the development of powerful eco-friendly control agents.

B-biotype Bemisia tabaci is a severe insect pest worldwide in many ornamental, agricultural, and ... more B-biotype Bemisia tabaci is a severe insect pest worldwide in many ornamental, agricultural, and horticultural crops. Control of this insect is obstructed by resistance to many AcetylCholinEsterase (AChE)-inhibiting insecticides, such as organophosphates and carbamates. In the present work, we evaluated the acetylcholinesterase inhibitory activity of six monoterpenoids namely α-pinene, terpineol, linalool, ß-myrcene, nerol and geraniol in vitro and in vivo. Inhibition of AChE of B. tabaci was measured by colorimetric method. The results showed that all of the monoterpenoids produced AChE inhibitory activity, with IC 50 values ranging from 0.96 to 26.85 mM. Alpha-pinene showed the most potent inhibitory activity (IC 50 = 0.96 mM). Kinetic analysis showed reversible noncompetitive type inhibition, revealing that these components might bind both the enzyme alone and the enzyme-substrate. Results demonstrate the AChE inhibitory activity as mode of action of these monoterpenoids at relatively high concentrations. Thus, this could be useful for investigation of new ecofriendly natural insecticidal compounds.

Journal of entomology and zoology studies, 2015

The insecticidal activity of methanolic extracts from leaves and seeds of Solanum elaeagnifolium ... more The insecticidal activity of methanolic extracts from leaves and seeds of Solanum elaeagnifolium against three pest species (Myzus persicae, Phthorimaea operculella and Tribolium castaneum) was investigated. Seed extract had the greatest effect in causing mortality of 23.6% for peach potato aphids and 34% for the red floor beetle, and inhibiting oviposition (95.9%) and egg hatching (98.6%) for potato tuber moth. Except the effect of leaf extract on P. operculella, no significant toxicity was observed on T. castaneum and M. persicae. The present study suggests that seeds and leaves from S. elaeagnifolium have insecticidal and repellent properties against several crop pests and could be employed as alternatives for chemical pesticides.

DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2014

International Journal of Entomology Research, 2021

Journal of Plant Protection, 2017

Synthetic chemicals used nowadays as insecticides caused many negative effects (pollution, toxici... more Synthetic chemicals used nowadays as insecticides caused many negative effects (pollution, toxicity…) which led to an increasing interest in botanical insecticides because of their minimal costs and less ecological side effects. In this respect, the activity of Melia azedarach leaf extract against the third stage larvae of armyworm (Spodoptera littoralis) has been assessed in this study. The aqueous and ethanolic extracts exhibited an antifeedant activity against S. littoralis larvae according to the applied doses. Ethanolic extract reduced the food consumption and digestibility inducing growth rate decrease of the armyworm larvae. An increase in the larval stage duration was also observed as well as anomalies. Pupation stage was affected and occurred only for the lowest doses with a significant decrease in pupa weight. Consequently, ethanolic M. azedarach leaf extract may be used in the alternative control strategies against S. littoralis pest.

Plant Biosystems, May 17, 2018

Abstract The main objective of this work is to evaluate the impact of the diurnal variation on th... more Abstract The main objective of this work is to evaluate the impact of the diurnal variation on the essential oil (EO) of Salvia officinalis and on their antioxidant, antifungal and insecticidal potentials. Obtained results showed that the chemical composition of EOs of sage varied significantly during the day. For the EO, the 7 am extract was characterized by the most significant antiradical activity. The EOs of 12 and 5 pm used at a dose of 10 μL were found to have the most effective potential to inhibit the growth of Botrytis cinerea whereas, the EO of 5 pm used at the same dose (10 μL) was the most effective against Fusarium sambucinum. For the fumigant test, the EO from 7 am had the highest activity against Spodoptera littoralis. The EO of 12 pm had the largest repellency activity against Trogoderma granarium. In addition, the EO from 7 am belongs to the repulsive class III, those of 12 and 5 pm belong to the repulsive class IV. The results of this study indicate how to optimize the best harvesting hour to obtain extracts characterized by the best yield of active compounds and by the more effective biological activity.

Journal of Plant Protection Research, Oct 1, 2013

Medicinal plant species were tested for their fumigant activity against Spodoptera littoralis thi... more Medicinal plant species were tested for their fumigant activity against Spodoptera littoralis third instar larvae. Responses varied according to plant species and parts used. For the present investigation, volatile oils were obtained from: Foeniculum vulgare (flowers and seeds), Coriandrum sativum (seeds), Daucus carota (flowers), Pelargonium graveolens (leaves and flowers), Origanum majorana (leaves and flowers), and Salvia officinalis (leaves). Fumigant activity was observed after 24 hours of exposure. All essential oils were proved to be toxic to the third instar larvae. However, the highest mortality was observed in the essential oil of S. officinalis leaves, C. sativum seeds, F. vulgare seeds, D. carota flowers, and O. majorana leaves with LC 50 = 23.050 µl/l air, 68.925 µl/l air, 95.075 µl/l air, 99.300 µl/l air, and 100.925 µl/l air, respectively. Other oils showed an LC 50 between 101 and 183 µl/l air.

New Medit, Dec 15, 2018

The excessive use of pesticides has multiple adverse effects on the environment and human health.... more The excessive use of pesticides has multiple adverse effects on the environment and human health. For a long time this problem was focused on the technical, agronomic, medicinal and pest management's aspects, while the problem is a behavioral problem and the socioeconomic aspect plays an important role. In order to study the Farmers' risk perceptions of pesticides used in agriculture greenhouses in central-eastern Tunisia (Monastir Governorate), an ordered probit model was tested for 110 farms for greenhouse agriculture. The results showed the significance and positivity of the relationship between independent variables such as extension, use of protective equipment, experience, membership of the public irrigation perimeter, agricultural income, and the variable depending on Farmers' risk perceptions of pesticides used. On the other hand, absence of the relationship between the level of education and the perception that it seems contradictory, but it can be justified by the age of the farmers who is high. The overall significance of the ordered probit model with a perceived acceptable level of perception can be improved by taking into account the heterogeneity of the farmers in this region in terms of age, education level, membership in a public or private irrigation perimeter and the possibility of access to extension. Developing awareness-raising methods are based on demonstrative and simple techniques accompanied by optimal monitoring and control can reduce the rate of excessive use of pesticides and guarantee greenhouse agriculture sustainable in the central eastern region of Tunisia.

Entomologia Generalis, Nov 1, 2017

European Journal of Experimental Biology, 2015

Different fruit peel extracts of Punica granatum were tested in vitro for their insecticidal and ... more Different fruit peel extracts of Punica granatum were tested in vitro for their insecticidal and antifungal activities against two pests (Myzus persicae and Phthorimaea operculella) and four fungi (Botrytis cinerea, Fusarium sambucinum, Penicillium digitatum and Aspergillus niger). In fact, significant mortalities were recorded on adults treated with aqueous, ethanol and methanol extracts with mortalities of 29%, 53% and 55%, respectively. For potato tuber moth, similar effects were observed on the first larval penetration of Phthorimaea operculella into potato tubers and the number of eggs. Additionally, all extracts tested were found to be effective in checking the mycelial growth only for Penicillium digitatum and Fusarium sambucinum as compared to the control. But no significant difference between control and treated fungi was found in the case of Botrytis cinerea and Aspergillus niger. The treatment with these botanical extracts may be promising in protecting plants from pests and diseases infections.

Antifeedant, malformations, and growth inhibition induced by leaves and seeds methanolic extracts... more Antifeedant, malformations, and growth inhibition induced by leaves and seeds methanolic extracts of Solanum elaeagnifolium against Spodoptera littoralis were investigated. Seeds and leaves extracts were added to an artificial diet which was found to have an inhibitory effect on the growth of the larvae. The highest growth inhibition was recorded on larvae treated with seeds extract (59.68%) compared to leaves extract (45.17%). The toxicity was demonstrated by a reduction of the weight do to the anti-feeding activity, an elongation of the larval stadiums until development stopping and larval mortality. The seeds extract shows strong antifeedant activity (28.50%) as compared to leaves extract tested (6.64%). The larval mortality was caused by seeds extract (100%) in response to exuviation difficulties. While, the leaves extract caused various degrees of morphogenesis abnormalities in pupae, with mortality rate around 80%. Our results suggest that seeds methanolic extract of S. elaeagnifolium shows an effective insect growth inhibiting and exhibits great promise in suppressing the population of S. littoralis.

Journal of entomology and zoology studies, 2016

Present study was analyzed to determine the toxicological effects of Urginea maritime at differen... more Present study was analyzed to determine the toxicological effects of Urginea maritime at different concentrations (0.1, 1 and 10%) against larvae and adults of Tribolium castaneum. In the present study it was observed that by tropical application, leaf extract shows highest toxicity to larvae as compared to adults. LC50 value and LC90 value was found to be 27.8g/L and 55.1g/L respectively in probit analysis of leaf extract for the larvae. However the bulb extract was found to be more toxic, LC50 and LC90 values were much lesser with 16.6 and 34.4g/L respectively. The present study also determined the in vivo toxicity of leaf as well as bulb extracts on larvae and the LC50 value was found to be 92 and 19.3g/L respectively. Similarly in residual film toxicity, LC50 and LC90 were found to be 87.9 and 495.4g/L, respectively. However no mortality was observed in the present study in the control experiment.

Effect of olive leaf extracts on the feeding, growth and metabolism of Spodoptera littoralis. Ben Hamouda, A., Boussadia, O., Bedis, K., Chaieb, I., Laarif, A., and Braham, M. (Tunisia)

DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2016

In the present study, methanol and acetone crude extracts of olive leaf were investigated for the... more In the present study, methanol and acetone crude extracts of olive leaf were investigated for their antifeedant activity, growth and metabolism inhibitory against the cotton leaf worm, Spodoptera littoralis under laboratory conditions. Two feeding tests: leaf discs and artificial diet at three concentrations (0.1, 1 and 10%) of each extract, were implemented in the experiment. Results revealed that the leaf discs bioassay was more effective than the artificial diet bioassay for the antifeedant activity and the weight loss of S. littoralis larvae. Acetone and methanol extracts caused strong antifeedant activity at 10% with 68.33 and 61.44%, respectively. Tests performed on growth generated a very pronounced inhibition of growth gain using leaf disc test for the two extracts and at all tested concentrations. Data indicated that the lowest relative consumption rate (RCR) and the relative growth rate (RGR) were recorded using acetone extract at 10% for leaf discs bioassay (5.88 ± 0.75 and 0.07 ± 0.05 mg/mg/day, respectively). The efficiency of the conversion of ingested food (ECI) and the efficiency of conversion of digested food (ECD) were significantly lowered using methanol extract at 10% in artificial diet bioassay (2.5 ± 0.58 and 2.55 ± 0.6%, respectively). The highest approximate digestibility (AD) of S. littoralis larvae was found in both extracts for the artificial diet bioassay. Moreover, larvae exposed to 10% methanol extract in artificial diet test exhibited a delayed growth rate by 17.7 days, relative to control at the same concentration, compared to 5.7 days noted using acetone extract in leaf disc test. The antifeedant activity, growth and metabolism parameters are appropriate tools in feeding tests and extracts' activity evaluation. They could provide profound understanding of the choice of the best plant extracts that could be proposed as bioinsecticides in a more environmentfriendly approach.

Tunisian journal of plant protection, Jun 30, 2022

Repellency and insecticidal activities of Thapsia garganica leaf methanolic extract were investig... more Repellency and insecticidal activities of Thapsia garganica leaf methanolic extract were investigated against Tribolium castaneum, Myzus persicae, Phthorimaea operculella, and Spodoptera littoralis. Repellency and toxic activities (by ingestion and topical application) were evaluated on T. castaneum nymphs and adults. Topical application treatment caused total larval growth inhibition at 10%, until mortality after 7 days. The highest mortality was recorded with 94% at the same concentration. Methanolic extracts incorporation into T. castaneum larvae artificial diet at 10% caused 100% mortality after 3 days. The extract at 1% cause high repellent effect on T. castaneum after 60 min of exposure, while M. persicae was less sensitive. P. operculella female's showed sensitivity by a repellent effect at oviposition. Egg's number laid on treated tubers at 1% and 2% decreased significantly to 32% and 72%, respectively. In addition, methanolic extracts had a preventive effect on P. operculella larval penetration. In fact, the number of larvae was reduced by 30.46% and 76.12% in the treated tubers at 1% and 2%, respectively. For S. littoralis, a low antifeeding effect was recorded. However, the relative growth rate (RGR), conversion of ingested and digested food to biomass, were decreased. The approximate digestibility increased. Moreover, a delay in larval development was observed. This study suggests that the leaf extract of T. garganica could be applied as bio-insecticide.

Entomology and applied science letters, Apr 12, 2018

A recently described species of Pteromalidae, Anisopteromalus quinarius (Hymenoptera: Pteromalida... more A recently described species of Pteromalidae, Anisopteromalus quinarius (Hymenoptera: Pteromalidae) parasitizing Lasioderma serricorne (Coleoptera: Anobiidae), a pest of stored products, has been found for the first time in Tunisia. The affinities of the new species along with the related species are discussed in this paper.

International Journal of Tropical Insect Science, Sep 28, 2020

The efficiency of essential oil depends upon the chemical nature, composition, and the relative p... more The efficiency of essential oil depends upon the chemical nature, composition, and the relative proportion of its functional groups. In some case, individual compounds can exhibit a pertinent effect than do the essential oils. To underline their efficiency according to their chemical structure, five cyclic and acyclic alcohols were tested in vitro for their potential insecticidal and repellent activities against Tribolium castaneum (Herbst). The ability to repel more than 95% was observed in all tested compounds from 15 min to 10 h, except for eugenol that exhibited the weakest effect. Fumigant bioassay showed that the five alcohols applied separately caused significant insect mortality that exceeds 60% at 400 μL/L air. The lowest median lethal dose, LC 50 = 18.24 μL/L was observed with citronellol. PCA analysis revealed that the acyclic alcohols showed stronger toxicity compared to the cyclic ones. Moreover, the combined effect of these alcohols was lower than individual ones in all tested combinations. According to the outcome of this study, acyclic alcohols might be more effective in reducing stored grain Tribolium infestation than cyclic ones as a single compound. The knowledge of the degree of efficiency of each chemical group gives the possibility to create artificial combinations of different constituents for the development of more effective eco-friendly control agents.

Tunisian Journal of Plant Protection

Egyptian Journal of Biological Pest Control

Background The baculovirus Spodoptera littoralis nucleopolyhedrovirus (SpliNPV) is an entomopatho... more Background The baculovirus Spodoptera littoralis nucleopolyhedrovirus (SpliNPV) is an entomopathogenic virus utilized as a biological control agent of the Egyptian cotton leaf worm, Spodoptera littoralis. Several studies have focused on the identification of different SpliNPV isolates from a biological and molecular point of view, but few of them conducted in-depth analyses of the genomic composition of these isolates. Results Identification of a novel isolate of SpliNPV, termed Tun2, which was purified from infected S. littoralis larvae from Tunisia was reported. This isolate was propagated in vivo and its median lethal concentration (LC50) was determined to be 1.5 × 104 occlusion bodies (OBs)/ml for third instar S. littoralis larvae at 7 days of post-infection. OB production in late fourth instar larvae was estimated to be at least 2.7 × 109 OBs/g larval weight. The completely sequenced genome of SpliNPV-Tun2 was 137,099 bp in length and contained 132 open reading frames (ORF). It...