Repellent and insecticidal activities of Melia azedarach L. against cotton leafworm, Spodoptera littoralis (Boisd.)

A crude acetone extract and oil of ripe fruits from Melia azedarach L. were evaluated against the 2nd and 4th instar larvae of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae). Both oil and extract exhibited highly significant growth inhibition at all concentrations tested, while the oil of M. azedarach recorded higher insecticidal activity against both instars than the crude extract. GC-MS analysis of the oil revealed the presence of linoleic acid methyl ester, oleic acid methyl ester, and free oleic acid as the main components in addition to hexadecanol, palmitic acid, methyl esters of stearic acid and myristic acid. Fatty acids and their esters were not only the main constituents of essential oil from the ripe fruits of M. azedarach, but also mainly responsible for the insecticidal and growth inhibition activity against S. littoralis.     

Laboratory evaluation of Melia azedarach L. and Eucalyptus globulus Labill. Extracts in order to control Ocneridia volxemi Bolivar (Orthoptera, Pamphaginae) hoppers

This study was carried out to evaluate the effect of Melia azedarach L. (Meliaceae) dry fruit extracts (oil and water) and Eucalyptus globulus Labill. (Myrtaceae) dry leaves extracts (water) on Oneridia volxemi hoppers (fifth-instar) feeding on cereals leaves (Triticum durum) under laboratory conditions. Larva feeding reduced and mortality was significatly (p < 0.05) on cereals leaves sprayed with three concentrations 0, 5, 1 and 2% of oil extracted from Melia azederach. In addition, O. volxemi feeding and mortality was significantly (p < 0.05) on cereals leaves sprayed with two concentrations 50 g/l and 80 g/l of water extracts from Melia azedarach dry fruits soaked for 24 hours. the water extract solution of 80 g/l significantly reduced feeding than the other concentrations 50 and 25 g/l. This study showed also the water extract solution from Eucalyptus globulus dry leaves reduced also feeding and induced the mortality of O. volxemi but not better than Melia azedarach dry fruit extracts water at the same concentration (80 g/l). The aim of this study is in an integrated management program for control of O.     

Efficacy of extracts of Melia azedarach L. callus, leaves and fruits against adults of the sweetpotato whitefly Bemisia tabaci (Hom., Aleyrodidae)

Bioassays with extracts of callus, fruit and leaves of the Chinaberry tree, Melia azedarach L., were performed against adults of Bemisia tabaci (Gennadius). Tissue culture of M. azedarach was carried out in Murashige and Skoog (MS) medium supplemented with indole butyric acid and benzyl adenine. Fresh and frozen leaves or fruits and the callus product were extracted in water or methanol at a ratio of 1 : 5 (w/v) for 48 h. The aqueous and methanol extracts were applied on tomato plants to determine their effect on B. tabaci adults and their corresponding oviposition and consequent adult emergence in comparison with the control, distilled water. Results have shown that extracts of callus and different age classes of M. azedarach leaves and fruits have shown significant repellent activity of 58.9–67.7% and have significantly decreased the oviposition rate of the insect without affecting the adult whitefly emergence in comparison with the control. Aqueous and methanol extracts have shown comparable effects against adult whiteflies indicating a similar efficacy of the two solvents in extracting the bioactive components of Melia . Extracts of frozen samples were found to be as effective against the pest as fresh samples, thus allowing storage of Melia parts to be used in case of shortage. This is the first report of the use of M. azedarach callus against B. tabaci; the M. azedarach callus, leaf and fruit extracts seem to present a potential source for management of B. tabaci .     

Susceptibility of different populations of ticks to entomopathogenic fungi

This study aimed to evaluate the in vitro effect of the entomopathogenic fungi Metarhizium anisopliae sensu lato (s.l.) and Beauveria bassiana sensu lato (s.l.) on two distinct populations of Rhipicephalus microplus, from two different experimental farms. Bioassays were performed with engorged females, eggs and larvae. Fungal infection was evaluated based on biological parameters of treated engorged females, percentage of hatch from treated eggs, and percentage of mortality and mean lethal time (LT90) of treated larvae. When the treatments were compared between the two populations, there were significant differences in the following parameters: pre-oviposition period, hatching period and egg production index. Moreover, the results showed that B. bassiana s.l., isolate Bb 986, was more virulent than M. anisopliae s.l., isolate 959, for engorged females, showing a control percentage of 49%. In the bioassay with eggs, the hatching percentage ranged from 3.1% to 49.5% in one population and from 3.4% to 42.7% in the other, with no significant difference between the two populations. In the bioassay with unfed larvae, the mortality percentage ranged from 91.8% to 98.7% in one population and from 71.0% to 94.0% in the other. The LT(90) varied from 19.52 to 27.51 days in one of the populations and 22.89 to 37.31 days in the other. These results suggest that populations of R. microplus show distinct variation in their susceptibility to B. bassiana s.l. and M. anisopliae s.l.     

Larvicide and oviposition deterrent effects of fruit and leaf extracts from Melia azedarach L. on Aedes aegypti (L.) (Diptera: Culicidae)

Aedes aegypti (L.) (Diptera: Culicidae), the main urban vector of dengue, has developed resistance to various insecticides, making its control increasingly difficult. We explored the effects of Argentine Melia azedarach L. (Meliaceae) fruit and senescent leaf extracts on Ae. aegypti larval development and survival, by rearing cohorts of first instar mosquitoes in water with different extract concentrations. We also analysed oviposition deterrent activity in choice tests with extract-treated ovitraps. The leaf extract showed a strong larvicide activity, with all larvae dying before pupation, and significantly delayed development time. It strongly inhibited oviposition by Ae. aegypti females. The fruit extract showed much weaker effects. This first report of highly effective larvicidal, growth regulating and oviposition deterrent activity of a senescent leaf extract of M. azedarach against Ae. aegypti, suggests that such extract could represent a promising tool in the management of this mosquito pest.     

Efficacy of Melia azedarach L. extract on the malarial vector Anopheles stephensi Liston (Diptera: Culicidae)

Methanolic extracts of leaves and seeds from the chinaberry tree, Melia azedarach L. (Meliaceae) was tested against mature and immature mosquito vector Anopheles stephensi Liston (Diptera) under laboratory condition. The extract showed strong larvicidal, pupicidal, adulticidal, antiovipositional activity, repellency and biting deterency. The M. azedarach seed and leaf extracts were used to determine their effect on A. stephensi adults and their corresponding oviposition and consequent adult emergence in comparison with the control. The seed extracts showed high bioactivity at all doses, while the leaf extracts proved to be active, only in the higher dose. Results obtained from the laboratory experiment showed that the seed extracts suppressed the pupal and adult activity of A. stephensi even at low dose. In general, first and second instar larvae were more susceptible to both leaves and seed extracts. Clear dose-response relationships were established with the highest dose of 2% plant extract evoking 96% mortality. Entire development of A. stephensi was inhibited by M. azedarach treatment. Less expensive (less than 0.50 US dollars per 1 kg seed), naturally accruing bio-pesticide could be an alternative for chemical pesticides.     

三种植物提取物对菟丝子及大豆生长发育和宿主保护酶活性的影响

利用不同浓度的苦楝树皮和叶、隆缘桉叶和乌桕叶的乙醇提取物对菟丝子及其宿主大豆幼苗进行处理,15d后评价三种提取物对菟丝子和大豆幼苗的影响。结果表明:三种提取物在低浓度时对菟丝子及其宿主大豆幼苗生长发育均无显著影响,在高浓度(0.25g/mL)下,桉树叶提取物对大豆和菟丝子的损伤程度分别达到了64%和70%,苦楝树皮提取物对菟丝子损伤程度为78%,但对大豆幼苗仅为7%。桉树叶和苦楝树皮提取物处理均导致大豆叶片超氧化物歧化酶(SOD)活性升高,最高值分别为相应对照组的2.37倍和2.0倍;但对过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响不同,桉树叶提取物使大豆幼苗POD活性最大值为对照组的2.28倍,而苦楝树皮提取物处理则是CAT活性升高,最大值为对照组的1.58倍,提示桉树叶提取物对大豆较强的伤害作用与其较低的CAT活性有关。     

In vitro anthelmintic effect of Melia azedarach L. and Trichilia claussenii C. against sheep gastrointestinal nematodes

The control of parasitic diseases in small ruminants is mainly done with the use of synthetic anthelmintics. However, incorrect and indiscriminate use of these products has caused the emergence of parasite resistance. Plants with anthelmintic activity are used in folk veterinary medicine, but it is necessary to investigate and scientifically validate low-cost phytotherapeutic alternatives for future use to control gastrointestinal nematodes in small ruminants by family farmers. Thus, the aim of this study was to evaluate the in vitro anthelmintic effect of plant extracts from Melia azedarach and Trichilia claussenii by the egg hatch test (EHT) and larval development test (LDT) against sheep gastrointestinal nematodes. The hexane extract of M. azedarach fruits was extracted through cold percolation and the methanol extract of T. claussenii leaves was obtained by extraction at room temperature in solvents in order of increasing polarity. The efficacy results were analyzed using the Probit program of SAS. The M. azedarach extract showed a LC(50) of 572.2 μg/mL and LC(99) of 1137.8 μg/mL in the EHT, and LC(50) of 0.7 μg/mL and LC(99) of 60.8 μg/mL in the LDT. In turn, the T. claussenii extract presented a LC(50) of 263.8 μg/mL and LC(99) of 522.5 μg/mL in the EHT and LC(50) of 1.1 μg/mL and LC(99) of 26.4 μg/mL in the LDT. Comparing the extracts of the species from the Meliaceae family, T. claussenii showed greater anti-parasite potential in vitro than M. azedarach. However, studies on the isolated compounds, toxicity and administration forms to animals are also needed to validate low-cost alternative herbal remedies for use to control gastrointestinal nematodes by family farmers.     

Gene silencing of the tick protective antigens, Bm86, Bm91 and subolesin, in the one-host tick Boophilus microplus by RNA interference

The use of RNA interference (RNAi) to assess gene function has been demonstrated in several three-host tick species but adaptation of RNAi to the one-host tick, Boophilus microplus, has not been reported. We evaluated the application of RNAi in B. microplus and the effect of gene silencing on three tick-protective antigens: Bm86, Bm91 and subolesin. Gene-specific double-stranded (dsRNA) was injected into two tick stages, freshly molted unfed and engorged females, and specific gene silencing was confirmed by real time PCR. Gene silencing occurred in injected unfed females after they were allowed to feed. Injection of dsRNA into engorged females caused gene silencing in the subsequently oviposited eggs and larvae that hatched from these eggs, but not in adults that developed from these larvae. dsRNA injected into engorged females could be detected by quantitative real-time RT-PCR in eggs 14 days from the beginning of oviposition, demonstrating that unprocessed dsRNA was incorporated in the eggs. Eggs produced by engorged females injected with subolesin dsRNA were abnormal, suggesting that subolesin may play a role in embryonic development. The injection of dsRNA into engorged females to obtain gene-specific silencing in eggs and larvae is a novel method which can be used to study gene function in tick embryogenesis.     

Mosquito larvicidal activity of aqueous extracts of long pepper (Piper retrofractum vahl) from Thailand.

Aqueous extracts of nine medicinal plants were bioassayed against larvae of Culex quinquefasciatus Say and Aedes aegypt (L.). Among these plants, the long pepper, Piper retrofractum Vahl (Piperaceae), showed the highest level of activity against mosquito larvae. To gain more information on larvicidal activity of P. retrofractum, fresh fruits of this plant were extracted in water and the extracts made into powder and bioassayed against 3rd and 4th instar larvae of Cx. quinquefasciatus and Ae. aegypti in the laboratory. Extracts of unripe (001/3) and ripe (002/3 and 001/4) fruits showed different levels of activity against Cx. quinquefasciatus larvae. Extracts 001/3 and 002/3 were equi-toxic to a Bacillus sphaericus resistant and susceptible strains, both from Thailand. The ripe fruit extract 002/3 was somewhat more active against Ae. aegypti than Cx. quinquefasciatus. Another ripe fruit extract (001/4) was much more toxic to both mosquito species. Diluted solutions of the solid extract (002/3) in distilled water lost their larvicidal activity upon aging. Loss of activity at 25 degrees C was greater than that stored at 4 degrees C, and greater in water than in acetone solution.     

Insect growth regulator and insecticidal activity of beta-dihydroagarofurans from Maytenus spp. (Celastraceae)

From the aerial parts of Maytenus disticha, we have isolated 9beta-benzoyloxy-1alpha,2alpha,6beta,8alpha,15penta-acetoxy-dihydro-beta-agarofuran (1) and from seeds of Maytenus boaria 9beta-furoyloxy-1alpha,6beta,8alpha-triacetoxy-dihydro-beta-agarofuran (2). These compounds and their MeOH and hexane/ethyl acetate (1:1 v/v) extracts were evaluated for their effects on the fall armyworm (Spodoptera frugiperda). Toosendanin, a commercial insecticide derived from Melia azedarach was used as a positive control. When tested for activity using neonate larvae in a nochoice artificial diet bioassays, the agarofurans 1, 2 and toosendanin as well as the MeOH and hexane/EtOAc extracts caused significant growth inhibitory effects with GC50 of 7.55; 3.84; 1.75; 14.0 and 7.3 ppm at 7 days, respectively. Compounds 1 and 2 caused 100% larval mortality at 25 and 15 ppm, respectively. MeOH and hexane/EtOAc extracts caused 100% larval mortality at 25.0 ppm, respectively, they also increased the development time of surviving larvae and a significant delay for the time of pupation and adult emergence. These compounds showed comparable potency of activity with toosendanin. Acute toxicity against adults of S. frugiperda was also found, for hexane/EtOAc extract and 2 had the most potent activity with LD50 value of 4.7 and 1.9 ppm, respectively. MeOH extract, hexane/EtOAc extract, 1 and 2 caused acetylcholinesterase inhibition with 78.0, 89.2, 79.3 and 100% inhibition at 15.0 ppm, respectively. Therefore, the furoyloxy agarofuran may be responsible for the insecticidal activity of these plants.     

Effect of methanolic extracts of neem (Azadirachta indica A. Juss) and bakain (Melia azedarach L) seeds on oviposition and egg hatching of Earias vittella (Fab.) (Lep., Noctuidae)

Abstract: The effects of methanolic extracts of neem ( Azadirachta indica ) and bakain ( Melia azedarach ) seeds on the oviposition behaviour and hatchability of eggs of Earias vittella were investigated under laboratory conditions. Treatments included 2, 4, 6, 8 and 10% concentrations of both extracts to compare with nimbecidine and untreated control. When able to choose, the adults preferred to lay a greater number of eggs on the untreated portion of the oviposition substrate (muslin) compared with the extract-treated portion. However, under no-choice conditions, higher concentrations of extracts caused proportionate reductions in the number of eggs laid. The extracts also manifested repellent activity by reducing the number of eggs laid even when the ovipositing females were not in direct contact with the extracts. Eggs laid on extract-treated oviposition substrate exhibited reduced hatching and marked adverse effects on hatching were noticed when the eggs were dipped in different concentrations of extracts. Adults fed on an extract-containing sucrose diet laid significantly fewer eggs with poor hatching. There was no egg laying when the moths were fed on a sucrose diet containing 6, 8 and 10% neem and 10% bakain extracts.     

Effects of tomato genotypes and aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds on Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

Insecticide plants are an important tool among the new alternatives for pest control in IPM systems because they reduce the use of synthetic insecticides, preserving human health and the environment. We investigated the effects of aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds and three tomato genotypes, 'Santa Clara', 'IPA-5'--Solanum lycopersicum (=Lycopersicon esculentum Mill), and LA444-1--S. peruvianum (=L. peruvianum), on the development, reproduction and longevity of the tomato pinworm Tuta absoluta (Meyrick), under laboratory conditions. The trials were set up in a completely randomized design, with nine treatments [three genotypes x two extracts (M. azedarach and A. indica) and control]. The replication consisted on five tubes, each with three newly hatched larvae, totalizing 90 individuals per treatment. The larvae were fed with tomato leaves treated with aqueous extracts at 0.1% concentration or distilled water (control) and daily observed until adults' emergence. Larval and pupal development and mortality, pupal weight, longevity and fecundity were evaluated. The accession LA444-1 negatively affected the development and reproduction of T. absoluta; the tomato pinworm had similar development and reproduction on 'IPA-5' and 'Santa Clara' (the susceptible control). The association of resistant tomato genotypes and extracts of M. azedarach leaves and neem seeds did not result in synergistic or antagonistic effects on T. absoluta.     

Acaricidal activity of Cassia alata against Rhipicephalus (Boophilus) annulatus

Using adult immersion test, the acaricidal activity of ethanolic extracts of leaves of Cassia alata L. was studied against Rhipicephalus (Boophilus) annulatus. The efficacy was assessed by measuring per cent adult mortality, inhibition of fecundity and hatching rate. The ethanolic extract of C. alata produced a concentration dependant increase in the adult tick mortality. The highest mortality (45.8%) and inhibition of fecundity (10.9%) were observed at the highest concentration tested (100 mg/ml). The plant extract did not affect egg hatchability.     

Susceptibility of the cattle tick Boophilus microplus (Acari: Ixodidae) to isolates of the fungus Beauveria bassiana

The susceptibility of the tick Boophilus microplus to Beauveria bassiana was evaluated by inoculating eggs, larvae and engorged females of the tick with five fungal isolates at concentrations of 10⁶, 10⁷ and 10⁸ conidia/ml. Tick eggs (0.25 g) were immersed in 1 ml of a suspension of the different conidial concentrations for 1 min. Similar exposure was performed by immersion of 2000 larvae and homogeneous groups of nine engorged females in 2 and 20 ml of conidial suspension, respectively. Treated eggs, larvae and adults were placed in an incubator at 27 ± 1 °C and relative humidity above 80% for evaluation of the fungal action. All fungal isolates applied at all conidial concentrations reduced the hatching rate of larvae from treated eggs by 1.36–65.58% and increased the mortality rate of inoculated larvae by 0.8–70.49%. In the bioassay with engorged females, oviposition period was reduced by 9.69–47.80%, egg mass weight by 4.71–53.87%, estimated reproduction by 8.3–60.62%, egg production index by 5.03–54.20%, percent larval hatching by 0.27–13.96%, and the mortality rate of treated females was increased by 96.60–100%. The reduction of the estimated reproduction obtained for the treated groups ranged from 8.37 to 64.52%. The sporulation of the pathogen on dead females ranged from 3.70 to 88.88% depending on the isolate and concentration used. Isolates AM 09, CB 7 and JAB 07 were the most effective and effectiveness increased with increasing concentrations of conidia in the suspensions.     

The Susceptibility of Boophilus annulatus (Ixodidae) Ticks to Entomopathogenic Fungi

The pathogenicity of five species of entomopathogenic fungi (Deuteromycetes, species: Beauveria bassiana, Metarhizium anisopliae, Metarhizium flavoviride, Paecilomyces fumosoroseus and Verticillium lecanii ) to the various developmental stages of Boophilus annulatus ticks was compared under laboratory conditions. M. anisopliae and B. bassiana strains were most virulent to engorged females and caused 85-100% mortality within 7-10 days post-inoculation (PI). The highest mortality of engorged females caused by other fungi reached only 25-60%. All tested fungi prevented or reduced the egg laying capability of the ticks several days before their death. Females surviving after treatment with the most virulent M. anisopliae strain (Ma-7) reached only 7-8% of their egg laying capacity as compared with the control. Other fungi caused a reduction of the weight of laid eggs by 35.4-80.8% as compared with untreated females. Only M. anisopliae and B. bassiana strains caused 70-98% mortality of the treated eggs. Unfed larvae of Boophilus annulatus were sensitive to M. anisopliae and M. flavoviride strains. The Ma-7 strain was most virulent to unfed larvae, with a mortality rate of 80.4% at a concentration of 1 ×107 spores ml -1 and 100% mortality at a concentration of 1 ×108 spores ml -1 .     

Biocontrol evaluation of extracts and a major component,clusianone, from Clusia fluminensis Planch. & Triana against Aedes aegypti

Studies evaluated the effects of hexanic extracts from the fruits and flowers ofClusia fluminensis and the main component of the flower extract, a purified benzophenone (clusianone), against Aedes aegypti. The treatment of larvae with the crude fruit or flower extracts from C. fluminensis did not affect the survival ofAe. aegypti (50 mg/L), however, the flower extracts significantly delayed development of Ae. aegypti. In contrast, the clusianone (50 mg/L) isolate from the flower extract, representing 54.85% of this sample composition, showed a highly significant inhibition of survival, killing 93.3% of the larvae and completely blocking development of Ae. aegypti. The results showed, for the first time, high activity of clusianone against Ae. aegypti that both killed and inhibited mosquito development. Therefore, clusianone has potential for development as a biopesticide for controlling insect vectors of tropical diseases. Future work will elucidate the mode of action of clusianone isolated from C. fluminensis.     

有机稻田内不同生态措施对褐稻虱种群的控制作用

应用害虫生态控制理论和方法,以抗性品种、施用有机肥、种植对天敌具有助迁或保护作用的植物为基础,将稻田放鸭、薇甘菊(MikaniamicranthaKunth)乙醇提取物、现代苦楝油(MeliaazedarachL.)等各项生态措施,科学、合理地组配成褐稻虱Nilaparvatalugens(Stl)种群生态控制系统,研究其对褐稻虱种群的控制作用。结果表明稻田放鸭对褐稻虱若虫具有60.92%的控制效果,现代苦楝油200倍对褐稻虱种群的作用优于薇甘菊乙醇提取物1gDW·100mL-1,不同生态措施组合对褐稻虱自然种群的控制作用显著,但其联合作用效果与组合组分不成正比例增长。所组建的生态措施组合可将褐稻虱种群数量降至经济阈值以下,完全可达到持续控制褐稻虱种群的目的。     

SYSTEMIC INSECTICIDAL ACTION OF AZADIRACHTIN, NEEM SEED AND CHINABERRY SEED EXTRACTS APPLIED AS SOIL DRENCHES TO POTTED PLANTS

Abstract  The systemic insecticidal activities of: 1) azadirachtin, a potent insect antifeedant and growth regulator isolated from seeds of the neem tree, Azadirachta indica , 2) a neem seed extract containing 0. 30 quantitative fraction of azadirachtin, and 3) a methanolic extract of seeds from the chinaberry tree, Melia azedarach , a close relative of neem were determined. Soil drenches of azadirachtin or the neem seed extract at 1 and 2. 5 mg to potted potato ( Solanum tuberosum ) and tomato ( Lycopersicon esculentum ), remarkably retarded the growth of Manduca sexta larvae and strongly disrupted the pupation of Leptinotarsa decemlineata larvae, respectively. However, five to ten times as much azadirachtin or neem seed extract was needed to reduce the amount of tomato and potato foliage consumed. On sorghum ( Surghum biocolor ), much higher quantity (≥25 mg) of azadirachtin or the neem seed extract was necessary to slow the population growth of Schizaphis graminum , and prolong the survival of treated plants. But methanolic extracts of chinaberry seeds ( M. azedarach ) from two sources (Guangdong, PRC and Hurricane, Utah, USA) at 150 mg per pot were ineffective in reducing aphid population growth and preventing plant damage.     

Insecticidal activity of cerrado plant extracts on Rhodnius milesi Carcavallo, Rocha, Galvão & Jurberg (Hemiptera: Reduviidae), under laboratory conditions

Chagas' disease is chiefly transmitted by feces of haematophagous bugs (Triatominae) that ingested Trypanosoma cruzi from blood of infected people or animals. Pyrethroids have been the main insecticides used against these insects. However, some populations of insects have shown significant levels of resistance to several pyrethroids, indicating the need of new insecticides for the control of triatomines. Insecticidal activity of 24 Cerrado plant extracts belonging to five species of four families were assayed on fourth instar nymphs of Rhodnius milesi Carcavallo, Rocha, Galv?o & Jurberg (Hemiptera: Reduviidae), under laboratory conditions. For the extract application on triatomines, 50 microg of the extract were topically applied in duplicate on dorsal tergites of ten insects. Insects topically treated with acetone, ethanol, as well as insects with no treatment were used as controls. Triatomines were observed over a 28-day period. Hexanic and ethanolic extracts of Simarouba versicolor, Guarea kunthiana, Guarea guidonia and Talauma ovata caused mortality between 20% and 95% of R. milesi in comparison with the controls, which showed no insect mortality. These preliminary data suggest that the ethanolic extract of the root bark of S. versicolor and the hexanic extract of the root of G. guidonia, responsible for a 95% and 75% insect mortality, respectively, should be chemically investigated and monitored through biological assays in order to determine their insecticidal components, that could be used as a molecular model or as biorational compounds for use in insect control programmes.