The nematicidal efficiency of two types of extracts (aqueous and methanolic) of 5 plants
Peganum harmala
L.,
Raphanus raphanistrum
L
.
,
Taxus baccata
L.,
Sinapis arvensis
L
.
, and
Ricinus communis
...L. on second stage juveniles (J2s) of
Meloidogyne incognita
was evaluated at 4 doses in vitro (40, 50, 60 and 80%) at 4 exposure times (12, 16, 24, and 32 h). In a greenhouse, methanol extracts obtained from 0.75, 1.5, or 3 g of the dry matter of
T. baccata
,
S. arvensis
, and
P. harmala
were added in pots of tomato plants (Moneymaker cultivar) to test the effect of the extracts on the nematode, its reproduction, and the plant’s growth. After 32 h of exposure, the in vitro results on J2s showed that all the aqueous and methanolic extracts of the 5 plants had positive effects on J2 mortality compared to controls; water and DMSO (2%) (dimethyl sulfoxyde). In general, methanolic extracts were significantly more effective than the aqueous ones. Methanolic extracts of
T. baccata
,
P. harmala
, and
S. arvensis
had the highest mortality rates (100, 89.2, 86.6%), respectively, followed by the aqueous extract of
T. baccata
(73.8%). After 12 days, the hatching inhibition varies between (61.4%) for the aqueous extract of
R. communis
and (84.2%) for the methanolic extract of
T. baccata
. The average was significantly different from controls (DMSO 23.8 and water 21.8%) for all extracts. Methanolic extracts were not always significantly different than the aqueous ones. In vivo methanolic extracts of
S. arvensis, P. harmala
, and
T. baccata
reduced infestation than the controls. The gall index varied between 3.5 and 5.5 for the extracts than the positive control 6.5. The present study revealed the effectiveness of all tested plant extracts to root-knot nematodes without any chemical inputs.
Within the framework of the development of the Algerian flora, the seriousness of the damage caused by aphids of which the species Chaitophorus populialbae Boyer de Fonscolombe, infested the white ...poplar and the search for alternative solutions more respectful for the environment relying on the role of biopesticides of plant origin, we chose a plant Pteridium aquilinum Linne, belonging to the family Dennstaedtiaceae which presents various biological activities, in particular insecticide. This study is intended to improve our knowledge of these chemical compounds. and evaluate the insecticide activity in vitro, in laboratory conditions, of this plant's methanolic and chloroformic extracts on viviparous apterous females of Chaitophorus populialbae Boyer de Fonscolombe. The best extraction yield of the plant was recorded with the polar solvent methanolic with a rate of 50.5% compared to chloroform, whose extraction rate was 43.5%. The chemical compounds identified by GC/MS are 29 from the ultrasound extraction. Among the 29 chemical compounds, 21 are terpenes, including 6 monoterpenes and 8 oxygenated monoterpenes, 7 fatty acids, and 1 amino acid. Toxicity tests of methanolic and chloroformic extracts, at a concentration of 50 microL/mL reveal corrected mortality of 100% after 24 h of exposure for all the viviparous apterous females of Chaitophorus populialbae Boyer de Fonscolombe.
The essential oils (EOs) of Cymbopogon schoenanthus (L.) collected from six regions of the vast Algerian Sahara were analyzed for their chemical compositions by GC and GC-MS and tested for their ...antioxidant, antimicrobial and insecticidal activities. The EOs compounds-based cluster analysis permitted to distinguish three groups of similar chemical composition. Among the EOs, those of the group 3 were the most different, while those of group 1 and 2 were much more comparable. Overall, all the strains were sensitive to tested oils except E. coli which was generally the less sensitive bacteria. All the EOs showed weak antioxidant activity in the DPPH test while only those of the group 3 displayed low ferric reductive potential. Contrariwise, the piperitone-rich EOs (group 3) showed the highest effectiveness against the cowpea weevil (Callosobrochus maculatus) with the potent reduction of the female's fecundity and the hatchability of laid eggs, especially EO from Tamanrasset province.
This study was designed to determine the chemical composition, antioxidant, antimicrobial and insecticidal activities of essential oils of Thymus guyonii and Thymus algeriensis. The essential oils ...(EOs) were isolated by hydrodistillation and analyzed by GC and GC-MS. The leading components of the oils were p-cymene (15.8%), γ-terpinene (15.3%), thymol methyl ether (15.7%) and thymol (19.1%) for T. guyonii and α-pinene (4.4%), camphor (4.6%), bornyl acetate (5.4%) and terpinenyl actate (28.1%) for T. algeriensis. The antioxidant activity was evaluated in terms of scavenging of free radicals DPPH
●
and ABTS
●+
. The essential oil of T. guyonii was the most efficient in inhibiting free radicals but less active compared to synthetic antioxidants (Trolox and BHT). Also, T. guyonii essential oil showed the highest effectiveness against the rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae) as well as against five microorganisms, two gram-positive (Staphylococcus aureus and Bacillus subtilis), one gram-negative (Escherichia coli), one yeast (Candida albicans) and one fungus (Aspergillus brasiliensis). The results suggest that the EO of T. guyonii could be considered in pharmaceutical and food fields as well as for preservation of stored products from S. oryzae damage.
A nematode survey conducted in 2013 in Algeria, revealed that potato cyst nematodes
(
PCN) and cereal cyst nematodes (CCN) are widely distributed in several potato and cereal growing regions of the ...country. Sixteen PCN populations from five localities and five CCN populations from four of these localities were collected and characterized at the morphological and molecular levels. The PCN populations were identified as
Globodera rostochiensis
and
G. pallida
occurring separately or in mixed populations. Two species of CCN were detected.
Heterodera avenae
was found in four localities, whereas
H. hordecalis
only in one locality in association with
H. avenae.
The morphological and morphometric identification of PCN and CCN was confirmed by diagnostic ITS-RFLP profiles and sequencing. Phylogenetic analysis of the ITS, D2-D3 expansion domains of the 28S rRNA gene and 18S rRNA gene was made for PCN and CCN populations.
Globodera pallida
and
G. rostochiensis
from Algeria show great similarity with European and South American populations. Because of the high divergence among Algerian populations of
G. pallida
and
G. rostochiensis
it can be assumed that they were multi-introduced in Algeria. The most divergent population of
G. pallida
, that formed a well-separated group with some populations from Chile and Peru, suggests a later or independent introduction of this population into Algeria.
Heterodera avenae
and
H. hordecalis
formed a well-supported cluster with the corresponding populations.
Within the framework of the development of the Algerian flora, the seriousness of the damage caused by aphids of which the species Chaitophorus populialbae Boyer de Fonscolombe, infested the white ...poplar and the search for alternative solutions more respectful for the environment relying on the role of biopesticides of plant origin, we chose a plant Pteridium aquilinum Linne, belonging to the family Dennstaedtiaceae which presents various biological activities, in particular insecticide. This study is intended to improve our knowledge of these chemical compounds. and evaluate the insecticide activity in vitro, in laboratory conditions, of this plant's methanolic and chloroformic extracts on viviparous apterous females of Chaitophorus populialbae Boyer de Fonscolombe. The best extraction yield of the plant was recorded with the polar solvent methanolic with a rate of 50.5% compared to chloroform, whose extraction rate was 43.5%. The chemical compounds identified by GC/MS are 29 from the ultrasound extraction. Among the 29 chemical compounds, 21 are terpenes, including 6 monoterpenes and 8 oxygenated monoterpenes, 7 fatty acids, and 1 amino acid. Toxicity tests of methanolic and chloroformic extracts, at a concentration of 50 microL/mL reveal corrected mortality of 100% after 24 h of exposure for all the viviparous apterous females of Chaitophorus populialbae Boyer de Fonscolombe. Keywords: Pteridium aquilinum Linne, Poplar leaf aphids, GC/MS, chemical compounds, plant extract
In recent decades, phytochemicals in plant extracts have been recognized as having insecticidal activity against insect pests. They have also been described as an alternative method to synthetic ...chemicals. The present study is a contribution on the insecticidal activity, under semi-natural conditions, of extracts of Nerium oleander L. on viviparous females of Chaitophorus leucomelas. Two extraction methods were performed with polar solvent to obtain two extracts used to carry out the insecticide tests. To identify the highest number of metabolites present in the plant three approaches were performed using supercritical fluid, ultrasound and enzymatic methods. Thirty-eight bioactive molecules were identified by GC/MS, some of which could be responsible for the insecticidal activity on viviparous females of C. leucomelas. The enzymatic extraction showed a very high monoterpene content of 34.62%, while the supercritical fluid extraction gave a content of 71.91% of oxygenated terpenic compounds. The results relating to the temporal estimation of insecticidal activity of the three studied concentrations of pure methanol and methanol-water extracts were found to be effective in terms of toxicity to viviparous females of C. leucomelas. A 100% mortality rate was observed 4 days after treatment at a concentration of 5.15 g/m2.
The aim of this study was to further our understanding of the chemical composition of Algerian Melissa officinalis plant and to evaluate the insecticidal action of the extract against heterogeneous ...larval and apterous adult populations of Chaitophorus populialbae and Chaitophorus populeti on populus alba as an eco-friendly alternative control method. M. officinalis was extracted using the supercritical fluid extraction method with a yield of 1.43% ± 0.16. The chemical composition of the extract was determined by gas chromatography-mass spectrometry and enabled identification of 20 chemical compounds including eugenol, geraniol 6.71 mg/L, D-limonene 0.48 mg/L and ortho-cresol with insecticidal activity. Our results showed that a concentration of 0.4 μL/mL had an effect on the heterogeneous larval stages of both species of the Chaitophorus genus during the first 9 h of exposure. The larval population of both Chaitophorus species was shown to be more sensitive than adults of the two species.
Research is increasingly focused on identifying alternatives to the use of chemicals for the management of pests in stored grains. In this context, we tested the insecticidal and antifungal ...activities of methanolic extracts of
Artemisia absinthium
L. (Asteraceae), and two Cupressaceae species, namely
Juniperus phoenicea
L. and
Tetraclinis articulata
(Vahl) Mast., collected in the north of Algeria, against
Sitophilus oryzae
L. (Coleoptera, Curculionidea)—a pest of primary infestation of stored grains—and
Fusarium
sp., mycotoxigenic fungi. The extracts were analyzed by UPLC-PDA-MS. The extraction yield was in the range of 11–21 %. UPLC chromatographic data showed the presence of several phenolic acids, flavonoid glycosides, and flavonoid aglycones. Insecticidal activity was evaluated by means of contact toxicity test, which showed that all three extracts were highly effective. Pest mortality was recorded after 24 h for
A. absinthium
. The LC50 results revealed that the most toxic extract was that of
A. absinthium
(15.53 mg/cm
2
), followed by that of
J. phoenicea
(22.14 mg/cm
2
), and
T. articulata
(24.05 mg/cm
2
). The antifungal activities of these extracts were evaluated using the poisonous medium technique on potato dextrose agar medium. All three extracts reduced the growth of
Fusarium culmorum
and
F. graminearum
under in vitro conditions.
T. articulata
had the greatest inhibitory effect (55.8 %) on mycelial growth of the former. Our results reveal the potential of plant methanolic extracts to control pests common to stored grains.
Thymus pallescens
de Noé essential oils were isolated from the plant’s dried leaves, by hydrodistillation, with different distillation times (30 min, 1, 2 and 3 h). The essential oils compositions ...and their antioxidant, antimicrobial and insecticidal activities were examined. The chemical compositions of the oils were determined by GC and GC-MS. The antioxidant capacity was tested by four complementary methods: thiobarbituric acid reactive substances, ferric reducing power and scavenging of radicals DPPH
•
(2,2-diphenyl-1-picrylhydrazyl) and ABTS
•+
2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid). The antimicrobial activity was tested against three bacteria, two gram-positive (
Staphylococcus aureus
and
Bacillus subtilis
) and one gram-negative (
Escherichia coli
) and one yeast (
Candida albicans
). The insecticidal activity against confused flour beetle
Tribolium confusum
Jacquelin du Val (Coleoptera: Tenebrionidae) was evaluated using direct contact application and fumigant method. The predominant components in the oils were carvacrol (63.3–68.2 %),
γ
-terpinene (6.9–9.1 %),
p
-cymene (6.2–10.3 %) and thymol (6.5–7.5 %). The antioxidant activities were dependent on the time of hydrodistillation and the method used. The essential oils extracted for 30 min and 1 h were the most efficient against all the bacteria used. Toxicity tests against
T. confusum
showed that the oils isolated for 3 h and 30 min caused highest mortality with contact method and fumigant test, respectively. The results suggest that distillation time can determine the value of the oil designed to be applied to any biological material.
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