Aphid repellents

Eremophilanolides are commonly found in Senecio species.56 Two new eremophilanolides were isolated from the methanolic extract of the aerial parts of Senecio miser (Asteraceae). The more nonpolar fraction of this methanolic extract (Fr-1 and Fr-2) contained two sesquiterpene lactones of the eremophilanolide type and was identified as la-acetoxy-8/3-methoxy-10/3H-eremophil-7( 1 l)-en-8tt,l 2-olide (91) and lct-angeloyloxy-6/3-hydroxy-8/3-methoxy-10/3H-eremophil-7(1 1 )-en-8ci,12-olide (92).57 Eremophilanolide (91) proved to be a strong aphid repellent, while 92 was the most active deterrent to the CPB. None of these sesquiterpene lactones was active in no-choice tests, while fractions Fr-1 and Fr-2 were, suggesting a possible synergistic effect of these compounds, either with themselves or with 1 rt-angeloyloxy-8/3H,10/3H-crcmophil-7(l 1 )-en-8tt,l 2-olide (93), which is not active alone.57... 

Se8qulterpenold semlochemlcals. The aphid-repellent effect of Type B trichomes of S. berthaultii (25) appears to be due to the presence of sesquiterpenes (22). Three major components, identified by GC-MS, were B-caryophyllene, B -cubebene and A-cadinene. E-B-farnesene was also identified, but was a minor component. GC-MS of the other major components in Type B trichome exudate indicated sesquiterpenold structures, but these have not been identified. 

Soule S, Giintner C, Vazquez A, Argandona V, Moyna P, Ferreira F (2000) An Aphid Repellent Glycoside from Solarium laxum. Phytochemistry 55 217... 

Ave DA, Gregory P, Tingey WM (1987) Aphid repellent sesquiterpenes in glandular trichomes of Solatium berthaultii and Solarium tuberosum. Entomol Exp Appl 44(2) 131-138... 

Sodium selenate has been used on a small scale in commercial greenhouses, primarily for growing carnations and chrysanthemums. It is transformed by the plants into volatile selenides, which repel red spiders, mites, thrips, and aphids (see Insect control technology). Sodium selenite is not intended for crops which could ultimately be used as food for humans or domestic animals. 

One recent study addressed the response of a parasitoid to the host s spacing pheromone. Aphidius rhopalosiphi did not respond to the spacing pheromone of one host, the cherry-oat aphid Rhopalosiphum padi, which consists of 6-methylhept-5-en-2-one 16,6-methylhept-5-en-2-ol, tridecan-2-one and methyl salicylate. These compounds did not attract or repel the parasitoid. Because the aphid spacing pheromone can potentially be used to cause aphids to disperse, the failure of the parasitoid to respond to the spacing pheromone makes simultaneous use of the spacing pheromone and the parasitoid possible in aphid management [87]. 

Reflective plastic mulch in various colors and aluminum foil mulch can be used to repel thrips and aphids on some vegetables. Reducing aphid and thrips infestations may also reduce the spread of virases carried by these insects. These mulches apparently confuse thrips and aphids, making it more difficult for them to locate vegetable plants. 

Many types of soaps have been used to kill, dislodge or repel certain garden pests. They vary greatly in effectiveness and in toxicity to plants. They are frequently effective against thrips and other small, soft-bodied insects such as aphids, mealybugs and whiteflies. Their disadvantages are that they are expensive and they need to be reapplied frequently, possibly every three or four days. 

Bernasconi, M. L., Turlings, T. C. J., Ambrosetti, L., Bassetti, P. and Dorn, S. (1998). Herbivore-induced emissions of maize volatiles repel the corn leaf aphid, Rhopalosiphum maidis. Entomologia Experimentalis etApplicata 87 133-142. 

Hardie J., Isaacs R., Pickett J. A., Wadhams L. J. and Woodcock C. M. (1994) Methyl salicylate and (-)-(lR,5S)-myrtenal are plant-derived repellents for the black bean aphid. Aphis fabae Scop. (Homoptera Aphididae). J. Chem. Ecol. 20, 2847-2855. 

Insect repellant (damson-hop cereal aphids), insect attractant (seven-spot ladybird aphid parasitoid)... 

Areas of application Mode of action Advantages Remarks Apple and plum sawfly, also effective against aphids, tortricid larvae and cherry fruit fly Repellent, contact and ingestion insecticide against sawfly Not harmful to beneficials Use against sawfly at end of flowering... 

Protection Offered Use capsaicin dusts to repel onion maggots and other root maggots in vegetable seedlings. Pepper dusts will help repel ants, thus controlling the aphids they protect. 

The effects of sesquiterpene mixtures from leaf extracts of wild and cultivated potatoes on the settling behavior of green peach aphid were studied in dual-choice assays (22). The sesquiterpene fraction of JS. berthaultii had a strong repellent effect on aphid behavior. Due to use of the slow release medium Carboset, this effect was still apparent beyond six hours. The sesquiterpenoid fraction from cv. Chippewa leaves also strongly repelled aphids. The major foliar sesquiterpene in all extracts, B-caryophyllene, had no adverse effect on settling behavior. 

The sesquiterpenes of j>. tuberosum foliage are not present in sufficient quantities at the leaf surface interface to discourage aphid settling. By contrast, the exudate of the Type B glandular trichomes on S. berthaultii foliage contains sesquiterpenes, thus enhancing the external level of these insect-repellent compounds. 

Its strong smell may help to repel aphids such as greenfly and blackfly. 

Attracts beneficial insects and may repel aphids from plants. 

In aphids, pymetrozine (1) inhibits feeding immediately after application, resulting in death by starvation without producing visible neurotoxic effects. No repellent or antifeedant effects were observed that could explain the inhibition of feeding. 

Gibson, R.W. Pickett, J.A. 1983. Wild potato repels aphids by release of aphid alarm pheromone. Miri/rg, 302, 608-609. 

P-Ocimene (47) is a repellent to die leaf cutter ant Atta cephalotes in both field and laboratory experiments (Har-bome, 1987). Experiments with the aphid Cavariella aego-podii, which feeds on umbellifer species in summer, indicate that the aphid can be captured in traps baited with carvone (48), but are repelled by linalool (6) (Chapman et al., 1981 Harbome, 1987). Carvone occurs in the essential oils of several plants of the Apiaceae. 

Loebe, L., 2001. Olfactory remedies for the evaluation of repellent and attractive properties of essential oils against the pea aphid Acyrthosiphon pisum. Master thesis. University of Vienna, Vienna, Austria. 

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