Mean Repellency Research Articles

In Vitro Evaluation of Essential Oils and Saturated Fatty Acids for Repellency against the Old-World Sand Fly, Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae).

The sand fly, Phlebotomus papatasi (Scopoli, 1786), is a major vector for Leishmania major in the Middle East, which has impacted human health and US military operations in the area, demonstrating the need to develop effective sand fly control and repellent options. Here, we report the results of spatial repellency and avoidance experiments in a static air olfactometer using the female P. papatasi testing essential oils of Lippia graveolens (Mexican oregano), Pimenta dioica (allspice), Amyris balsamifera (amyris), Nepeta cataria (catnip), Mentha piperita (peppermint), and Melaleuca alternifolia (tea tree); the 9-12 carbon saturated fatty acids (nonanoic acid, decanoic acid, undecanoic acid, and dodecanoic acid); and the synthetic repellents DEET and IR3535. The materials applied at 1% exhibited varying activity levels but were not significantly different in mean repellency and avoidance from DEET and IR3535, except in regards to nonanoic acid. Some materials, particularly nonanoic and undecanoic acids, produced sand fly mortality. The observed trends in mean repellency over exposure time included the following: (1) P. dioica oil, M. alternifolia oil, decanoic acid, undecanoic acid, DEET, and IR3535 exhibited increasing mean repellency over time; (2) oils of N. cataria, A. balsamifera, M. piperita, and dodecanoic acid exhibited relatively constant mean repellency over time; and (3) L. graveolens oil and nonanoic acid exhibited a general decrease in mean repellent activity over time. These studies identified the essential oils of N. cataria and A. balsamifera as effective spatial repellents at reduced concentrations compared to those of DEET. Additional research is required to elucidate the modes of action and potential synergism of repellents and essential oil components for enhanced repellency activity.

The effect of three plant extracts in the control of Khapra beetle ( Trogoderma granarium Everts) (Coleoptera Dermistidae)

Trogoderma granarium (Everts) is one of the world’s most destructive pest of stored products (Legumes and cereals), oilseeds, dry fruits, copra and other stored products. In this research paper alternative of chemical control were applied to give a repellent effect and more safety method, however Repellent effect of acetone extracts of three medicinal plants: (Eucaaliptus, Rosemary and Ginger) to the Trogoderma granarium (Evetrs) larvae (Stage 3 and 4) was evaluated under laboratory condition. There were four treatments including control and three replications in this experiment. Rotary Shaker was used for the preparation of extracts 0, 10, 14 and 18% concentrations were used in this experiment. Eucalyptus plant extracts showed good results, maximum mean repellency (6.33%) followed by Ginger (5.33 %) and Rosemary (3.00%). The results show repellency was increased with increase in concentration. The application of these plant extracts can protect stored grains against attack of Trogodema granarium.

Traditionally used Botanicals: The Potential Source of Tribolium castaneum (Herbst) Management

Wheat is widely used as a staple food in the world including India. But storage conditions of wheat grains are infected by several coleopteran pests. Tribolium castaneum Herbst is a ubiquitous and pestiferous pest among all. Adult and larvae both are harmful to wheat storage which often demolishes stored grains. The present study attempted at Entomology laboratory, Assam Agricultural University-Jorhat, to manage Dry powders of A. indica, C. roseus, C. heptaphylla, D. stramonium, E. tereticornis, M. struthiopteris, and V. negundo were used against T. castaneum to get rid of problematic local medicinal plants. During probit analysis the highest LD50 value was found in A. indica (1.49%) followed by D. stramonium (1.52%) and E. tereticornis (2.02%) and the lowest LD50 in Matteuccia struthiopteris (11.72%). In the repellency test, the highest rate of repellency was observed in A. indica (82.21%) followed by D. stramonium (72.59%), E. tereticornis (70.36%), and the lowest in Matteuccia struthiopteris (32.58%). Based on LD50 and mean repellency, the three botanicals (A. indica, D. stramonium, E. tereticornis) were selected for further work e.g., mortality and weight loss. A mortality study recorded 100% mortality after 35 days of treatment in the case of A. indica, D. stramonium, E. tereticornis. During the trial in 2018, A. indica (5.76%) had the lowest grain weight loss, followed by D. stramonium (12.05%) and E. tereticornis (12.05). The highest grain weight loss was observed in control with 62.33 per cent. Give your one line conclusion on these research.

Repellency and Toxicity of Selected Fractions, Identified Compounds and Blends of Commiphora africana Resin Against Bedbugs

Bedbugs are blood-feeding arthropods that cause anemia in humans upon heavy feeding. Control measures are unsuccessful due to resistance to development, environmental pollution, and cost. There is a need to explore natural herbal-based phytochemicals to combat bedbugs. In this study, compounds from Comiphora africana resin were sequentially extracted, fractionated, identified, and evaluated against bedbugs as individual compounds and in combinations. The chemical constituents of the most active fraction were identified using Gas Chromatography-Mass Spectrometry. Results showed that the dichloromethane crude extract had the highest mean repellency (98.5% with an LC50 of 4.96 mg/L after 24 and 72 h of exposure time, respectively), similar to the positive control (neocidol). Column chromatographic separation of the dichloromethane extract yielded 9 fractions where “FR7” (eluted with 60% n-hexane in ethyl acetate) demonstrated the highest mean repellency of 79.0% with an LC50 of 10.12 mg/L after 2 and 24 h exposure times, respectively. From the identified compounds of FR7, cedrol had significantly ( P < .05) higher mean repellency (80.5%) after 6 h of exposure and toxicity (27.43 mg/L) after 24 h exposure. A six-constituent blend of compounds from FR7 [9-octadecenoic acid-ethyl-ester, octadecadien-1-ol, citronellyl formate, cedrol, n-hexadecanoic acid, (1,2)-dihydro-6-methoxy-naphthalene] had the highest mean repellency (93.4% after 12 h exposure) and toxicity (8.83 mg/L after 72 h exposure) than the other blends and individual compounds. This study reports fractions/compounds that can be used in bedbug control measures.

Insecticidal property of methanolic leaf extract of Sweet Basil, Ocimum basilicum (L.) against cigarette beetle, Lasioderma serricorne (Fab.) (Coleoptera: Anobiidae)

The present study was conducted to evaluate the insecticidal property of Ocimum basilicum (L.) against cigarette beetle, Lasioderma serricorne (Fab.). The bioactive compounds from the leaves were extracted using Soxhlet apparatus with methanol. Five different concentrations viz., 1%, 2%, 3%, 4%, 5% were used against adult beetles of L. serricorne. In contact toxicity, highest mean mortality was effected by 5% methanol extract (66.67%), followed by 4% methanol extract (58.33%), 3% methanol extract (52.22%), 2% methanol extract (47.22%) and 1% methanol extract (43.33%). In repellency test, 5% methanol extract produced highest mean repellency (86.88%) (Class V) followed by 4% methanol extract (80.00%) (Class V), 3% methanol extract (73.75%) (Class IV), 2% methanol extract (68.13%) (Class IV) and 1% methanol extract (64.38%) (Class IV).

The antagonistic/synergistic effects of some medicinal plant essential oils, extracts and powders combined with Diatomaceous earth on red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae)

Red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) is a prominent pest of stored products particularly cereal flour. Since resistance of this pest to common chemical insecticides is well documented, we were examined the synergistic/antagonistic interaction between Satureja hortensis L., Trachyspermum ammi L., Ziziphora tenuior L., Cuminum cyminum L. and Foeniculum vulgare Miller essential oils, ethanolic extracts and powders with Diatomaceous earth (DE) against T. castaneum adults under laboratory conditions at 27 ± 1 °C, 65 ± 5% RH and continuous darkness. We assayed repellency of ethanolic extracts and essential oils of mentioned plants on the pest. Results showed that DE had high toxicity to the pest. Plant essential oils and ethanolic extracts (except ziziphora) synergized the performance of DE. Nevertheless, plant powders elicited antagonistic effects (except ziziphora that exhibited synergistic effect). The most repellent EO and extract was cumin which exhibited mean repellency value on adult insect equivalent to 92.58 and 51.47%, respectively.

Bioassay of Plant Extracts AgainstAleurodicus dispersus(Hemiptera: Aleyrodidae)

The spiraling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae), is a destructive invasive pest in many parts of the world. Topical spray and dry film contact assays were conducted to measure the toxicity of 8 plant extracts and their mixtures traditionally used as insecticides in South Asian countries such as Bangladesh, India, and Nepal. The highest mortality (100%) of adults was recorded for neem (Azadirachta indica A. Juss.; Meliaceae) (ethanol) extract (500 mg/L) at 6 h after topical spray. This was followed by 5-leaved chaste tree (Vitex negundo L.; Lamiaceae) (ethanol), sweet sop (Annona squamosa L.; Annonaceae) (acetone), water pepper (Polygonum hydropiper L.; Polygonaceae) (acetone), banyan (Ficus benghalensis L.; Moraceae) (ethanol), banyan (acetone), and crown flower (Calotropis gigantea [L.] W. T. Aiton; Apocynaceae) (ethanol) extracts at 500 mg/L at 12 h after the spray. For the dry film method, the highest mortality (100%) of adults was also recorded for neem (ethanol) extract (500 mg/L) at 18 h after the treatment. Bioassay results indicate that neem (ethanol) extract mixed with crown flower (acetone), oleander (Nerium indicum Mill.; Apocynaceae) (acetone), or sweet sop (ethanol) (in the ratio of 1:1, 1:2, and 1:3 for each plant extract) showed synergism. Neem (ethanol) extract also showed the highest mean repellency rate (93%). In conclusion, neem, 5-leaved chaste tree, sweet sop, water pepper, banyan, and crown flower extracts showed good potential to control A. dispersus, and the mixtures of these plant extracts showed synergistic activity against A. dispersus.

Efficacy of plant extracts against rice weevil Sitophilus oryzae (L.) in stored maize

The acetone extracts of Adathoda vasica, Lantana camera, Vitex negundo and Catharanthus roseus at 1% and 2% w/v were evaluated for their contact toxicity and repellent activity against rice weevil. Adults were exposed to 1 and 2% plant extracts treated maize and mortality assessed after 14 days. The plant extracts of A. vasica, L.camera, V. negundo and C. roseus at two doses showed significantly higher mortality and less seed damage. Mortality increased in dose dependent manner and from 63.30 to 83.33% with A. vasica, 76.60 to 80% with L. camera and 60 to 73.30% with V. negundo while it was 53.33 to 56.60% with C. roseus for 1% and 2%. The plant extracts of A. vasica, L. camera and V.negundo at 2% (w/v) showed strong repellency from 71.66 to 77.11% while the acetone extract of C. roseus showed the moderate mean repellency of 58.88%. Moreover the germination of grains treated with plant extracts was not significantly affected. These results revealed that the plant extracts have toxicidal and repellent properties, and seed protective effect to a promising level and can reduce the dependency on chemical pesticides against rice weevil in stored maize.

Repellent efficacy of Crotalaria burhia and Anacardium occidentale against Odontotermes obesus (Isoptera: Termitidae) under laboratory conditions

Laboratory studies were carried out at bioassay lab, Institute of Pesticide Formulation Technology, Gurgaon to incur the repellent efficacy of Crotalaria burhia Buch.-Ham and Anacardium occidentale L. against Odontotermes obesus (Rambur). Aqueous root extracts of C.burhia at different concentrations, viz. 0.5%, 1%, 2.5%, 5%, 10% and 20% and powdered leaf dusts of A. occidentale at 0.5%, 1%, 2.5%, 5%, 7.5% and 10% concentrations were prepared and tested for their repellent action against O. obesus, Chlorpyrifos 20% EC was maintained as standard check. An area of preference test described by Landani et al. (1955) and Mc Donald et al. (1970) was followed and the results unveiled that root extracts of C. burhia at concentration of 10% and 20% gave a mean repellency of 66.66% and 70%, whereas 5% and 7.5% powdered leaf dust of A. occidentale gave a mean repellent efficacy of 56.66% and 60%. The lower doses of C. burhia and A. occidentale were not much effective in repelling away O. obesus. The standard check chlorpyrifos 20% EC resulted in 96.66 % and 100% repellency in both the studies. Thus higher doses of root extracts of C. burhia and powdered leaf dust of A. occidentale can be further tested for their repellent efficacy in field against O. obesus and can be included in IPM for termites, as botanicals in IPM are gaining accent as they are environmentally safe.

The Repellent Effect of Some Indigenous Plant Extracts Against Pulse Beetle (Callosobruchus chinensis)

An Experiment was conducted in the laboratory of the Division of Entomology, Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh to evaluate the efficacy of four indigenous plants parts such as leaves of raintree (Albizia saman), riot lata (Mikania micrantha), pithraj (Aphanamixis polystachya) and seeds of mahogani (Swietenia macrophylla) with methanol extracts at the rates of 10.0, 7.5, 5.0 and 2.5% for their direct toxicity against the pulse beetle, Callosobruchus chinensis (L.). Among the four plants extracts tested, pithraj leaf showed the highest (52.28%) mean repellency effect followed by riot lata (Mikania) leaf extract (46.07%), mahogani seed extract (38.79%) and raintree leaf extract (25.13%). On the basis of mean repellency rate, it was found that mahogany seed, pithraj leaf and riot lata (Mikania) leaf extracts were in the same repellency class i.e. Class Ill and except raintree leaf (Class II).DOI: http://dx.doi.org/10.3329/jesnr.v7i2.22224 J. Environ. Sci. & Natural Resources, 7(2): 151-154 2014

English

The essential oils from four medicinal plants viz., Azadirachta indica, Curcuma longa, Nigella sativa and Piper nigrum were assessed at a rate of 5, 10, 15 and 20% concentrations against khapra beetle, Trogoderma granarium (Everts) for their potential to protect stored wheat grains in term of their repellency and toxicity. Essential oils of A. indica gave the highest mean repellency (90.00%) at 20% concentration. The minimum value of repellency (23.56%) was observed in case of P. nigrum at 5% concentration. Highest value of mortality (30.68%) was recorded in case of A. indica, while minimum value of mortality (14.82%) was observed after 30-days of treatment application at 20% concentration. Similarly, after 5days of treatment application at 5% concentration, highest mortality was 3.45% in case of A. indica and minimum value was 2.24% where application of P. nigrum was carried out. Essential oils from these plants caused significant T. granarium mortality and deterred the larvae from feeding on wheat grains. Essential oils of these plants could serve as the foundation for development of new botanical insecticides.

Effectiveness of Neem, Garlic and Red Chili Against Adult Dermestid Beetle in Sun Dried Fish

The suitability of neem (Azadirachta indica), garlic (Allium sativum) and red chili (Capsicum frutescens) in repelling insects in dried fish during processing and storage was determined. Their acetone extracts were used to evaluate toxic effects against adult dermestid beetle, Dermestes sp. The concentration of plant extracts were 60%, 80% and 100% for adult Dermestes sp. The LC50 values of neem, garlic and red chili were 1.81%, 4.85% and 1.11%, respectively at 24 hours after treatment (HAT), indicating that red chili was the most toxic plant. Red chili possessed the highest toxic effect at 48 HAT (0.87%) and 72 HAT (0.03%). It was observed that all of the three plant extracts had repellent action on adult Dermestes sp. The highest mean repellency was observed in neem extract (62.67%) followed by red chili (38.44%) and garlic (31.11%). Repellent effects increased with the concentration of plant extracts.DOI: http://dx.doi.org/10.3329/pa.v20i1-2.16865 Progress. Agric. 20(1 & 2): 133 – 142, 2009

Repellency of Dettol, a Commercial Cleaning Product, Against Adult American Cockroaches <i>Periplaneta americana</i> (L.)

Dettol, a commercial cleaning product was tested for its repellent action against adults of Periplaneta americana (L.). Experimental cage was constructed with pieces of polypropylene plastic material to have a finished form measuring 30×30×60cm. Two cardboard shelters (for each trial) were assembled each 10cm square by size with an opening of 1.5×1.5cm to allow for free passage. One of the shelters was treated with undiluted Dettol, the other with water (control) prior to placement in the cage. Twenty five adult roaches were released in the cage also provided with water and 50g dog biscuit at each trial. The cage was placed close to the sunlight by midday over seven days observation period and the number of roaches in and close to the shelters were recorded three times by 30 minutes interval. Similar procedure was used when applying 1:37 and 1:74 dilutions of the product. A highest mean repellency (0.00±0.00) was observed in the treated shelter (TS) with undiluted concentration while the least (13.33±1.15) was in the control shelter (CS). Similarly, repellency was extended close to the treated shelter (CTS) than close to the control shelter (CCS). However, repellency was observed to be indirectly proportional to both concentration and exposure time. The active ingredient responsible for repelling the roaches in Dettol is discussed. Keywords: Repellency, Periplaneta americana, Dettol

Hydraulic properties of soil aggregates as influenced by compaction

Hydraulic properties of aggregates affect soil processes like gas, water, and nutrient fluxes, the accessibility and storage of nutrients, and define the living conditions for microbes including their decomposing or precipitation capacities. However, these properties depend on the soil and aggregate strength and are therefore affected by soil compaction. In this study the effects of soil compaction on water and ethanol sorptivity and water repellency index of variously sized aggregates of loamy Orthic Luvisol was assessed. The various compaction levels were obtained by three tractor traffic treatments using a 3.4 Mg tractor with a contact area stress of 135 kPa and a rear axle load of 22.6 kN: (NC) zero traffic, (MC) three passes, (SC) five passes. Water and ethanol sorptivity data of the initially air-dry soil aggregate fractions: 8–10 mm, 14–16 mm, 20–22 mm were determined by a steady state flow using an infiltration device. Water repellency was identified by the ethanol/water sorptivity method. All the measurements were done for aggregates from topsoil (0.05–0.15 m) and subsoil (0.25–0.35 m) layers. Effect of soil compaction on the aggregate hydraulic properties was related to the soil layer and aggregate size fraction. Aggregate water and ethanol sorptivities of all aggregate fractions were highest under NC. In subsoil layer (B horizon) the sorptivities were lowest under SC. The response of repellency index to compaction was greater for aggregates from subsoil than topsoil layer. All subsoil aggregate fractions displayed maximum mean repellency index in SC. The 20–22 mm aggregates from the subsoil layer in the moderately and most compacted soil exhibited the highest repellency index (2.32–2.60). Among all 540 individual repellency index values, about one fourth exceeded the value 1.95 which defines soil as subcritical water repellent. The results show that the responses of the aggregate hydraulic properties to compaction markedly depend on interactions between compaction level, aggregate size and depth.

Novel Arthropod Repellent, BioUD, Is an Efficacious Alternative to Deet

For >50 yr, N,N-diethyl-3-methylbenzamide (deet) has been the standard for arthropod repellents and has been an important tool to protect people from disease agents carried by ticks, mosquitoes, and other arthropods. However, some people avoid using deet because of concerns about adverse health effects. In 2007, a new repellent, BioUD, with the active ingredient 7.75% 2-undecanone, originally derived from wild tomato (Lycopersicon hirsutum Dunal f. glabratum C. H. Müll) plants, was registered by the U.S. Environmental Protection Agency. In the current study, repellent efficacy of BioUD was compared using arm-in-cage studies with 7 and 15% deet against the mosquitoes Aedes aegypti (L.) and Aedes albopictus Skuse. No differences were found in mean repellency over 6 h after application between BioUD versus 7 and 15% deet for Ae albopictus. For Ae. aegypti, no differences were found over the same time period for 7% deet. Compared with 15% deet, BioUD mean repellency was lower over the 6-h test period. Human subject field trials were conducted in North Carolina, United States, and Ontario, Canada, comparing the repellency of BioUD to products containing 25 and 30% deet. BioUD provided the same repellency or was more efficacious than 25 and 30% deet, respectively, in these studies. Laboratory trials were conducted to determine the repellent activity of BioUD against the American dog tick, Dermacentor variabilis (Say), on human skin and cloth. BioUD repelled ticks at least 2.5 h after application to human skin. On cloth, no differences in mean repellency were found through 8 d after application between BioUD and 7% deet. In a two-choice test for BioUD versus 15% deet on filter paper, ticks spent significantly more time on the deet-treated surface than the BioUD-treated surface. Based on these studies in toto, BioUD is an efficacious alternative to deet in its repellent activity.

Novel Arthropod Repellent, BioUD, Is an Efficacious Alternative to Deet

For >50 yr, N,N-diethyl-3-methylbenzamide (deet) has been the standard for arthropod repellents and has been an important tool to protect people from disease agents carried by ticks, mosquitoes, and other arthropods. However, some people avoid using deet because of concerns about adverse health effects. In 2007, a new repellent, BioUD, with the active ingredient 7.75% 2-undecanone, originally derived from wild tomato (Lycopersicon hirsutum Dunal f. glabratum C. H. Müll) plants, was registered by the U.S. Environmental Protection Agency. In the current study, repellent efficacy of BioUD was compared using arm-in-cage studies with 7 and 15% deet against the mosquitoes Aedes aegypti (L.) and Aedes albopictus Skuse. No differences were found in mean repellency over 6 h after application between BioUD versus 7 and 15% deet for Ae albopictus. For Ae. aegypti, no differences were found over the same time period for 7% deet. Compared with 15% deet, BioUD mean repellency was lower over the 6-h test period. Human subject field trials were conducted in North Carolina, United States, and Ontario, Canada, comparing the repellency of BioUD to products containing 25 and 30% deet. BioUD provided the same repellency or was more efficacious than 25 and 30% deet, respectively, in these studies. Laboratory trials were conducted to determine the repellent activity of BioUD against the American dog tick, Dermacentor variabilis (Say), on human skin and cloth. BioUD repelled ticks at least 2.5 h after application to human skin. On cloth, no differences in mean repellency were found through 8 d after application between BioUD and 7% deet. In a two-choice test for BioUD versus 15% deet on filter paper, ticks spent significantly more time on the deet-treated surface than the BioUD-treated surface. Based on these studies in toto, BioUD is an efficacious alternative to deet in its repellent activity.

Repellency and toxicity of mint oil granules to red imported fire ants (Hymenoptera: Formicidae).

Repellency and toxicity of 2% mint oil granules were evaluated against worker red imported fire ants. Solenopsis invicta Buren, in a series of laboratory and field experiments. In continuous exposure experiments, LT50 values ranged from 1.2 h with 164.8 mg/cm2 of 2% mint oil granules to 15.3 h with 1.65 mg/cm2 of granules. LT50 values declined exponentially with increasing rate of mint oil granules. Limited exposure to 164.8 mg/cm2 mint oil granules resulted in > 50% knock down (KD) after 30 min; however, there was no KD at 15 min. Twenty-four hour mortality increased linearly with increasing exposure time. Mean repellency of worker red imported fire ants ranged from 49.2 +/- 5.4% for 0 mg/cm2 (untreated control) of mint oil granules at 30 min to 100% for 147.8 mg/cm2 of mint oil granules at 3 h. Repellency increased with increasing milligrams per square centimeter of mint oil granules and exposure time. In field tests, 100% of mounds opened and treated with mint oil granules were abandoned 5 d after treatment and ants had relocated or formed satellite mounds by 2 d after treatment. Unopened mounds treated topically with mint oil granules were not abandoned, but ants formed satellite mounds 2 d after treatment. Mint oil granules could provide another tool for red imported fire ant integrated pest management, particularly in situations in which conventional insecticides would be inappropriate.