Effects of vanillin, quillaja saponin, and essential oils on in vitro fermentation and protein-degrading microorganisms of the rumen

This study investigated the effects of vanillin on methanogenesis and rumen fermentation, and the responses of ruminal protein-degrading bacteria to vanillin (at concentrations of 0, 0.76 and 1.52 g/L), essential oils (clove oil, 1 g/L; origanum oil, 0.50 g/L, and peppermint oil, 1 g/L), and quillaja saponin (at concentration of 0 and 6 g/L) in vitro. Methane production, degradabilities of feed substrate, and ammonia concentration decreased linearly with increasing doses of vanillin. Concentration of total volatile fatty acids also decreased, whereas proportion of butyrate tended to increase linearly with increasing doses of vanillin. Protozoa population decreased, but abundances of Ruminococcus flavefaciens, Prevotella bryantii, Butyrivibrio fibrisolvens, Prevotella ruminicola, Clostridium aminophilum, and Ruminobacter amylophilus increased with increasing doses of vanillin. Origanum and clove oils resulted in lower ammonia concentrations compared to control and peppermint oil. All the tested essential oils decreased abundances of protozoa, Selenomonas ruminantium, R. amylophilus, P. ruminicola and P. bryantii, with the largest decrease resulted from origanum oil followed by clove oil and peppermint oil. The abundances of Megasphaera elsdenii, C. aminophilum, and Clostridium sticklandii were deceased by origanum oil while that of B. fibrisolvens was lowered by both origanum and clove oils. Saponin decreased ammonia concentration and protozoal population, but increased the abundances of S. ruminantium, R. amylophilus, P. ruminicola, and P. bryantii, though the magnitude was small (less than one log unit). The results suggest that reduction of ammonia production by vanillin and saponin may not be caused by direct inhibition of major known proteolytic bacteria, and essential oils can have different inhibitory effects on different proteolytic bacteria, resulting in varying reduction in ammonia production.     

Essential oils against multidrug resistant gram-negative bacteria

Multi-drug resistant uropathogens are responsible for urinary tract infections. The antibacterial activity of seven essential oils, oregano, thyme, clove, arborvitae, cassia, lemongrass, tea tree) was investigated by agar diffusion method, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations against five multidrug resistant isolates namely Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloaceae, Morganella morganii, Proteus mirabilis. Oregano, thyme, cassia had antibacterial activity with inhibition zones ranging 25–39 mm; clove, arborvitae, tea tree and lemongrass 12–15 mm. The essential oils showed antibacterial activities with MICs ranged from 0.005% (w/v) to 0.5% (w/v). Thyme had the same MIC and MBC on all strains. The effects of the vapors of the essential oils were also tested by placing the oils on the underside of the Petri dish lid. Thyme, oregano and cassia essential oils strongly inhibited the growth of the clinical strains of bacteria tested in vapor phase. This study demonstrates the potential of investigated essential oils as natural alternatives for further application in hospital therapies in order to retard or inhibit the bacterial growth. For the first time antibacterial effects of essential oils (clove, arborvitae, tea tree, lemongrass, and cassia) were evaluated against Enterobacter cloaceae and Morganella morganii clinical isolates.     

Effect of fungicidal essential oils against Botrytis cinerea and Rhizopus stolonifer rot fungus in vitro conditions

The development of natural crop protection products as alternatives to the use of synthetic fungicides is currently popular. The aim of this study is to evaluate the antifungal effects of several essential oils against the fungal pathogens, Botrytis cinerea and Rhizopus stolonifer, under in vitro condition. Four essential oils (fennel, black caraway, peppermint and thyme) were each tested at five concentrations (0, 200, 400, 600 or 800 μl l^?1). In vitro results showed that the essential oil of black caraway and fennel had the highest fungicidal effect against B. cinerea and R. stolonifer, respectively. The growth of B. cinerea was completely inhibited by the essential oil of black caraway at 400 μl l^?1. Fennel oil perfectly inhibited growth of R. stolonifer fungus colonies at concentration higher than 600 μl L^?1 in potato dextrose agar medium. Percentage of spores germination was the lowest in medium of Fennel and black caraway essential oils, and was the highest in Thyme ones. These results show that plant essential oils can have a strong effect on reducing post-harvest decay. These plant essential oils could provide an alternative to synthetic chemicals to control post-harvest phytopathogenic fungi on fruit.     

Inhibition of oxidation of unsaturated fatty acid methyl esters by essential oils

The essential oils from 16 various spice plants were studied as natural antioxidants for the inhibition of autooxidation of polyunsaturated fatty acids methyl esters isolated from linseed oil. The content of methyl oleate, methyl linoleate, and methyl linolenoate after 1, 2, and 4 months of autooxidation were used as criteria to estimate the antioxidant efficiencies of essential oils. In 4 months, 92% of the methyl linolenoate and 79% of the methyl linoleate were oxidized in a control sample of a model system. It was found that the most effective antioxidants were essential oils from clove bud, cinnamon leaves, and oregano. They inhibited autooxidation of methyl linolenoate by 76–85%. The antioxidant properties of these essential oils were due to phenols— eugenol, carvacrol, and thymol. Essential oil from coriander did not contain phenols, but it inhibited methyl linolenoate oxidation by 38%. Essential oils from thyme, savory, mace, lemon, and tea tree inhibited methyl linolenoate oxidation by 17–24%. The other essential oils had no antioxidant properties.     

Toxicity of plant essential oils to Trialeurodes vaporariorum (Homoptera: Aleyrodidae)

A total of 53 plant essential oils were tested for their insecticidal activities against eggs, nymphs, and adults of Trialeurodes vaporariorum Westwood, using an impregnated filter paper bioassays without allowing direct contact. Responses varied according to oil type and dose, and developmental stage of the insect. Bay, caraway seed, clove leaf, lemon eucalyptus, lime dis 5 F, pennyroyal, peppermint, rosewood, spearmint, and tea tree oils were highly effective against T. vaporariorum adults, nymphs, and eggs at 0.0023, 0.0093, and 0.0047 microl/ml air, respectively. These results indicate that the mode of delivery of these essential oils was largely a result of action in the vapor phase. Significant correlations among adulticidal, nymphicidal, and ovicidal activities of the test oils were observed. The essential oils described herein merit further study as potential fumigants for T. vaporariorum control.     

Acaricidal Activity of Pla.nt Essential Oils against Tyrophagus putrescentiae (Acari: Acaridae)

The acaricidal activity of 54 commercially available plant essential oils against Tyrophagus putrescentiae adults was compared with those of benzyl benzoate and N, N-diethyl-m-toluamide (deet). Responses varied with test oils. In a test with an impregnated fabric disc bioassay at 12.7 μg/cm², over 80% mortality was observed with bay, citronella java, clove bud, clove leaf, lemongrass, nutmeg, oregano, pimento berry, thyme red, and thyme white oils. These oils were more toxic to T. putrescentiae adults than benzyl benzoate and deet. At 6.4 μg/cm², lemongrass and thyme white oils exhibited 76 and 84% mortality, respectively, whereas the acaricidal activity of the other essential oils was significantly decreased. In a fumigation test with adult mites, lemongrass and pimento berry oils were much more effective in closed containers than in open ones, indicating that the effects of these oils were largely due to action in the vapor phase. Plant essential oils described merit further study as potential T. putrescentiae control agents.     

Repellency of lavender oil and linalool against spot clothing wax cicada,Lycorma delicatula (Hemiptera: Fulgoridae) and their electrophysiological responses

This study was performed to investigate the repellent effect of 5 μl doses of ten essential oils (bergamot, chamomile, clary sage, fennel, lavender, lemongrass, majoram, peanut, pennyroyal, and peppermint) against Lycorma delicatula 4th nymphs using an olfactometer. Only lavender oil exhibited significant repellency. We then tested 10, 5, 2.5, and 1 μl doses of lavender oil against the nymphs and females of L. delicatula. The oil showed significant repellency at 10 and 5 μl, although the latter is less potent to 1st instar nymphs. At the lavender oil dose of 2.5 μl, only 3rd and 4th instar nymphs and females were significantly affected. None of the stages tested were affected by 1 μl. Chromatographic and mass spectrometric analyses of lavender oil detected linalool (42.2%), linalyl acetate (49.4%), terpinen-4-ol (5.0%), and caryophyllene oxide (3.4%). Among the four main components, only linalool showed repellency to all instar nymphs and females. No synergism was detected. Antennae of all instar nymphs and females showed electrophysiological responses only to linalool. In field studies using linalool, 4th nymphs and adults were highly repelled at a dose of 30 μl of lavender oil. The effect differed according to test plot and treatment dose.     

Efficacy of Essential Oils on Fungi Isolated from Archaeological Objects in Saqqara Excavation,Egypt

The archeological objects constitute an important part of the worldwide cultural heritage. The impact of the fungal activity on the deterioration of cultural heritage is a global problem and their preservation over time is a challenging task. Antifungal activities of 12 essential oils (EOs) (black cumin, castor, cinnamon, clove, cumin, garlic, geranium, lavender, lemongrass, menthe, olive, and thyme) were examined against 16 fungal species isolated from three tested archaeological objects (wall painting stone, wooden statue, and pottery coffin) from Saqqara stores in Egypt. Molecular identification was carried out for the highly frequent species (Aspergillus niger, A. flavus and Rhizopus oryzae) in the three tested archaeological samples. Antifungal activity and minimal inhibitory concentration (MIC) of the tested EOs with different concentrations (0.125, 0.25, 0.5, 0.75, 1?μl/ml) were measured.

The most efficient EOs were thyme (MIC ranged from 0.25–0.75μl/ml) followed by clove (MIC ranged from 0.25–1?μl/ml) and geranium, (MIC ranged from 0.5–1?μl/ml). Thymol (37.1%) and p-Cymene (26.32%) were the active constituents of thyme, while Triacetin (69.36%) and eugenol (28.67) were the most efficient components of clove oil followed by geranium active components (à-Citronellol 20.62% and Geraniol 14.43%). Aspergillus niger was the most resistance species, while Fusarium oxysporum and Penicilium citrinium were the most susceptible ones.     

Sensitivity of heat-stressed yeasts to essential oils of plants.

Eight strains of yeasts (Candida lipolytica, Debaryomyces hansenii, Hansenula anomala, Kloeckera apiculata, Lodderomyces elongisporus, Rhodotorula rubra, Saccharomyces cerevisiae, and Torulopsis glabrata) were examined for changes in sensitivity to eight essential oils of plants (allspice, cinnamon, clove, garlic, onion, oregano, savory, and thyme) after being sublethally heat stressed. With the exception of garlic oil for all test yeasts, onion oil for S. cerevisiae, and oregano oil for R. rubra, the essential oils at concentrations of up to 200 ppm in recovery media did not interfere with colony formation by unheated cells. However, some oils, at concentrations as low as 25 ppm in recovery media, reduced populations of sublethally heat-stressed cells compared to populations recovered in media containing no test oils. This demonstrates that the yeasts were either metabolically or structurally damaged as a result of being exposed to elevated temperatures and that essential oils prohibited repair of injury. The size (diameter) of colonies produced on oil-supplemented recovery agar by heat-stressed cells was reduced compared to that observed on unsupplemented agar. Pigment production by heated R. rubra was inhibited by oils of oregano, savory, and thyme, but enhanced by garlic and onion oils. The influence of essential oils on survival of yeasts in thermally processed foods and in the enumeration of stressed cells in these foods should not be minimized.     

Novel strategies of essential oils,chitosan, and nano- chitosan for inhibition of multi-drug resistant: E. coli O157:H7 and Listeria monocytogenes

Despite the wide range of available antibiotics, food borne bacteria demonstrate a huge spectrum of resistance. The current study aims to use natural components such as essential oils (EOs), chitosan, and nano-chitosan that have very influential antibacterial properties with novel technologies like chitosan solution/film loaded with EOs against multi-drug resistant bacteria. Two strains of Escherichia coli O157:H7 and three strains of Listeria monocytogenes were used to estimate antibiotics resistance. Ten EOs and their mixture, chitosan, nano-chitosan, chitosan plus EO solutions, and biodegradable chitosan film enriched with EOs were tested as antibacterial agents against pathogenic bacterial strains. Results showed that E. coli O157:H7 51,659 and L. monocytogenes 19,116 relatively exhibited considerable resistance to more than one single antibiotic. Turmeric, cumin, pepper black, and marjoram did not show any inhibition zone against L. monocytogenes; Whereas, clove, thyme, cinnamon, and garlic EOs exhibited high antibacterial activity against L. monocytogenes with minimum inhibitory concentration (MIC) of 250–400 μl 100^?1 ml and against E. coli O157:H7 with an MIC of 350–500 μl 100^?1 ml, respectively. Among combinations, clove, and thyme EOs showed the highest antibacterial activity against E. coli O157:H7 with MIC of 170 μl 100^?1 ml, and the combination of cinnamon and clove EOs showed the strongest antibacterial activity against L. monocytogenes with an MIC of 120 μl 100^?1 ml. Both chitosan and nano-chitosan showed a promising potential as an antibacterial agent against pathogenic bacteria as their MICs were relatively lower against L. monocytogenes than for E. coli O157:H7. Chitosan combined with each of cinnamon, clove, and thyme oil have a more effective antibacterial activity against L. monocytogenes and E. coli O157:H7 than the mixture of oils alone. Furthermore, the use of either chitosan solution or biodegradable chitosan film loaded with a combination of clove and thyme EOs had the strongest antibacterial activity against L. monocytogenes and E. coli O157:H7. However, chitosan film without EOs did not exhibit an inhibition zone against the tested bacterial strains.     

Temperature-dependent fumigant activity of essential oils against twospotted spider mite (Acari: Tetranychidae)

Fumigant activity of 34 commercial essential oils was assessed on female adults and eggs of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) at three temperatures (5, 15, and 25 degrees C). Common thyme, cinnamon, and lemongrass oils were equally effective on twospotted spider mite adults showing 85.8-100% mortality at 5 and 10 microl/liter air at 25 degrees C. At a lower temperature of 15 degrees C, lemongrass and peppermint resulted in > or =90% mortality of adults at 10 microl/liter air. Only lemongrass was relatively active at 5 microl/liter air, at 15 degrees C. At 5 degrees C, lemongrass and peppermint caused significantly higher adult mortality than controls but only at 10 microl/liter air. Common thyme oil showed the highest ovicidal activity at 5 microl/liter air at 25 degrees C. Among the main components of common thyme and lemongrass oils, citral was lethal to twospotted spider mite adults at all tested temperatures. Carvacrol, thymol, and citral caused the same inhibitory effects on the hatch of twospotted spider mite eggs at 25 degrees C. However, citral was more active than other compounds to twospotted spider mite eggs at 15 degrees C. Therefore, we conclude that citral has the best potential for development as a fumigant against twospotted spider mite on agricultural products harvested late in the growing season.     

Repellent Efficacy of Caraway and Grapefruit Oils for Sitophilus oryzae (Coleoptera: Curculionidae)

This study examined the repellent efficacy of six essential oils extracted from caraway, clary sage, grapefruit, strawberry, thyme white, ylangylang, and their related volatile constituents against the adult rice weevil, Sitophilus oryzae using an olfactometer. The caraway and grapefruit oil showed the highest repellent efficacy against the rice weevil at a dose of 10μl. Gas Chromatography-Mass Spectrophotometer analysis revealed caraway oil to be rich in carvone and limonene, and grapefruit oil to be rich in limonene, β-myrcene and α-pinene. When the monoterpene was mixed in equal parts with the caraway and grapefruit essential oils, carvone with limonene in caraway oil demonstrated the highest repellent efficacy (96.7%). Limonene with α-pinene and β-myrcene in grapefruit showed strong repellent efficacy (86.4%) with synergistic effects on the S. oryzae.A mixture of caraway and grapefruit oils, as well as carvone and limonene, can be potent repellents that may be useful for controlling S. oryzae.     

Effect of some essential oils on mycelial growth of <Emphasis Type="Italic">Penicillium digitatum</Emphasis> Sacc.

The antifungal action of four essential oils of Foeniculum vulgare (fennel), Thymus vulgaris (thyme), Eugenia caryophyllata (Clove) and Salvia officinalis (sage) was tested in vitro against Penicillium digitatum Sacc. Direct contact and vapour phase were used to test the antifungal activity of these essential oils against P. digitatum that is responsible for green mould rot of citrus fruits. The vapour phase and direct contact of clove and thyme essential oils exhibited the strongest toxicity and totally inhibited the mycelial growth of the test fungus. Thyme and clove essential oils completely inhibited P. digitatum growth either when added into the medium 600 μl l⁻¹ or by their volatiles with 24 μl per 8 cm diameter Petri dish. In in vitro mycelial growth assay showed fungistatic and fungicidal activity by clove and thyme essential oils. Sage and fennel oils did not show any inhibitory activity on this fungus. Scanning electron microscopy (SEM) was done to study the mode of action of clove oil in P. digitatum and it was observed that treatment with the oil leads to large alterations in hyphal morphology.     

Antimicrobial activity of Pelargonium essential oils added to a quiche filling as a model food system

Eight essential oils obtained by steam distillation from the scented leaves of Pelargonium species and cultivars were added at 250, 500 and 1000 ppm to a quiche filling, inoculated with either Saccharomyces ludwigii or Zygosaccharomyces bailii (at 10⁸ cfu g⁻¹), Salmonella enteriditis or Listeria innocua (at 10⁹ cfu g⁻¹). The quiche fillings were then kept at 25 °C for 24 h and the residual number of micro-organisms determined using the pour plate technique. There was an effective antimicrobial activity by the Pelargonium essential oils at 250 ppm, comparable with that of commercial thyme oil, an excellent antimicrobial agent, against Saccharomyces ludwigii and Zygosaccharomyces bailii , and a lesser inhibition compared with commercial thyme against Salm. enteriditis. There was a greater diversity of activity against L. innocua, which was in some cases more effective than commercial thyme oil. At 500 ppm, there was a greatly increased inhibition of microbial growth using the Pelargonium essential oils, which was comparable with that of commercial thyme, clove, geranium and coriander oils. As there is no evidence for the toxicity of any of these novel Pelargonium oils, and their odour does not make the delicately flavoured quiche filling unpalatable, there is a strong potential for their use in food processing.     

In vitro and in vivo antifungal activates of the essential oils of various plants against strawberry grey mould disease agent Botrytis cinerea

In order to investigate the effects of antifungal essential oils on postharvest decay and some quality factors of strawberry fruit, experiments were conducted under in vitro and in vivo conditions. The antifungal activates of essential oils obtained from fennel, anis, peppermint and cinnamon at concentrations 0, 200, 400, 600 and 800 μL L^?1 were investigated against Botrytis cinerea with four replications. In vitro results showed that the growth of B. cinerea was completely inhibited by fennel, cinnamon and anis essential oils at relatively low concentrations (400–800 μL L^?1). In vivo results showed that all the used essential oils at all applied concentrations caused an increase in the shelf life and inhibited of B. cinerea growth on strawberry fruits completely in comparison to the controls. The results of this study confirmed the antifungal effect of four essential oils in both in vitro and on fruit postharvest.     

Antifungal activity of essential oils evaluated by two different application techniques against rye bread spoilage fungi

AIMS: To study how antifungal activity of natural essential oils depends on the assay method used. METHODS AND RESULTS: Oils of bay, cinnamon leaf, clove, lemongrass, mustard, orange, sage, thyme and two rosemary oils were tested by two methods: (1) a rye bread-based agar medium was supplemented with 100 and 250 microl l-1 essential oil and (2) real rye bread was exposed to 136 and 272 microl l-1 volatile oil in air. Rye bread spoilage fungi were used for testing. Method 1 proved thyme oil to be the overall best growth inhibitor, followed by clove and cinnamon. On the contrary, orange, sage and rosemary oils had very limited effects. Mustard and lemongrass were the most effective oils by the volatile method, and orange, sage and one rosemary showed some effects. Oil compositions were analysed by gas chromatography-mass spectrography. CONCLUSIONS: Antifungal effects of the essential oils depended on the application method. Larger phenolic compounds such as thymol and eugenol (thyme, cinnamon and clove) had best effect applied directly to medium, whereas smaller compounds such as allyl isothiocyanate and citral (mustard and lemongrass) were most efficient when added as volatiles. SIGNIFICANCE AND IMPACT OF THE STUDY: This study proves that the method used for screening essential oils as potential antimicrobials should correspond with the application sought.     

Insecticidal and feeding deterrent activities of essential oils in the cabbage looper,Trichoplusia ni (Lepidoptera: Noctuidae)

Ten essential oils were tested against the cabbage looper, Trichoplusia ni larvae for contact, residual and fumigant toxicities and feeding deterrent effects. Against third instar T. ni, Syzygium aromaticum (LD₅₀ = 47.8 μg/larva), Thymus vulgaris (LD₅₀ = 52.0 μg/larva) (the two positive controls) and Cinnamomum glanduliferum (LD₅₀ = 76.0 μg/larva) were the most toxic via topical application. Litsea pungens (LD₅₀ = 87.1 μg/larva), Ilex purpurea (LD₅₀ = 94.0 μg/larva), Cinnamomum cassia (LD₅₀ = 101.5 μg/larva) and Litsea cubeba (LD₅₀ = 112.4 μg/larva) oils were equitoxic. Thymus vulgaris (LC₅₀ = 4.8 mg/ml) and S. aromaticum (LC₅₀ = 6.0 mg/ml) oils were the most toxic in residual bioassays. Cymbopogon citratus (LC₅₀ = 7.7 mg/ml) and C. cassia (LC₅₀ = 8.5 mg/ml) oils were equitoxic followed by Cymbopogon nardus (LC₅₀ = 10.1 mg/ml) in this bioassay. The remaining five oils showed little or no residual effects. In a fumigation bioassay, L. cubeba (LC₅₀ = 16.5 μl/l) and I. purpurea (LC₅₀ = 22.2 μl/l) oils were the most toxic. Cinnamomum glanduliferum (LC₅₀ = 29.7 μl/l) and Sabina vulgaris (LC₅₀ = 31.2 μl/l) oils were equitoxic. Interestingly, S. aromaticum did not exhibit any fumigant toxicity. Cymbopogon citratus, C. nardus and C. cassia strongly deterred feeding by third instar T. ni (DC₅₀s = 26.9, 33.8 and 39.6 μg/cm², respectively) in a leaf disc choice bioassay. The different responses of T. ni larvae to the oils in different bioassays suggest that these essential oils exhibit different modes of action. Based on their comparable efficacy with essential oils already used as active ingredients in many commercial insecticides (i.e. clove oil and thyme oil), some of these essential oils may have potential as botanical insecticides against T. ni.     

Antifungal activity of essential oils and their combinations in in vitro and in vivo conditions

Natural additives are in demand for the control of microbial growth in foods. Several natural compounds including essential oils (EOs) are being explored for food uses. In the present investigation, the antifungal activity of cinnamaldehyde, eugenol, peppermint and clove EOs and their combinations was evaluated against 12 species of Aspergillus, Fusarium, Penicillium and Rhizopus in in vitro and tomato fruit system (in-vivo). The EOs were able to inhibit complete growth of tested fungi at or below 0.6% level and 80?μL of EOs (except peppermint oil) in in vitro condition and tomato system, respectively. The fractional inhibitory studies showed either additive or indifferent effect by combining eugenol and peppermint, and indifferent or antagonist effect by combining the cinnamaldehyde and clove in both in vitro and in vivo studies. The findings may be useful for application of these EOs in foods, but their effects on organoleptic quality of foods need to be investigated.     

Screening for inhibitory activities of essential oils on the growth of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc., the causal agent of leaf spot disease of Murraya koenigii L.

Seven essential oils namely clove, cedar wood, lemongrass, peppermint, eucalyptus, citronella and neem oils were tested for their inhibitory effect on spore germination, growth of germ tube and mycelial growth of Colletotrichum gloeosporioides isolated from diseased Murraya koenigii. All essential oils inhibited the germination and growth of germ tube at different concentrations. However, significant reduction in colony growth was observed with citrus, lemongrass and peppermint oils at 1000, 1500 and 2000 ppm concentrations, respectively. Citrus oil at 1360 ppm inhibited the maximum growth of the fungus followed by lemongrass oil at 1720 ppm and peppermint at 2260 ppm, respectively. The effect of essential oils on mycelial dry weight also showed antifungal activity on the growth of Colletotrichum gloeosporioides. The study revealed the possible utilisation of these essential oils for foliar spray for the management of leaf spot disease of Murraya koenigii.     

Contact and fumigant activities of Citrullus colocynthis formulations against Callosobruchus chinensis (Coleoptera: Bruchidae)

The efficacy of two different formulations of Citrullus colocynthis extracts (emulsifiable and powder) were tested as contact and fumigant toxicants against cowpea weevil adults, Callosobruchus chinensis. The emulsifiable concentrate showed repellent activity against the adults. No eggs were laid by females in the choice test at 1.0% concentration compared with 150.0 eggs in control. Using the same concentration, the females deposited 1.4 eggs in the non-choice test compared with 78.2 eggs in control. The concentration of 2.5 μl/38.5 ml air of citrullus emulsifiable caused 100% mortality to adults during one day in the fumigation test. Also, the vapor of citrullus emulsifiable was highly effective against eggs of cowpea weevil, where, at 2.5 μl/38.5 ml air, no eggs hatched. Both formulations affect the different biological aspects of cowpea weevil, however, citrullus emulsifiable concentrate was more potent than the citrullus powder.