Ashraf M. El-Sayed

Ashraf M. El-Sayed
Plant and Food Research · Bioprotection

36.15
 · 
PhD

About

142
Publications
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Publications

Publications (142)
Article
Full-text available
Plants release volatiles in response to caterpillar feeding that attract natural enemies of the herbivores, a tri-trophic interaction which has been considered an indirect plant defence against herbivores. The caterpillar-induced plant volatiles have been reported to repel or attract conspecific adult herbivores. To date however, no volatile signal...
Research
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Eating insects makes good evolutionary sense for plants living in barren soil with few nutrients. But how do the plants avoid eating the insect pollinators they rely on to reproduce?
Article
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Semiochemical-based pest management programs comprise three major approaches that are being used to provide environmentally friendly control methods of insect pests: mass trapping, "lure and kill," and mating disruption. In this article, we review the potential of mass trapping in long-term pest management as well as in the eradication of invasive...
Article
Full-text available
Insect-pollinated carnivorous plants are expected to have higher fitness if they resolve pollinator-prey conflicts by sparing insects pollinating their flowers while trapping prey insects. We examined whether separation between flowers and traps of the carnivorous sundew species or pollinator preferences for colours of flowers enable these plants t...
Article
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This project investigated how kairomone lures, camera traps, and counting software could together contribute to pest management. Images of cumulative daily catch of New Zealand Flower Thrips (NZFT) attracted to a ripe peach lactone (6-pentyl-2H-pyran-2-one; 6-PAP) were automatically loaded to the internet and compared with scanned bases checked wee...
Article
Social wasps are amongst the most loathed exotic predators in New Zealand, with widespread adverse impacts on native ecosystems and fauna. Sustainable alternatives to pesticides are sorely needed in Fuscospora (beech) forests. We tested a new semiochemical evaluation protocol to assess the extent of high-density trap competition as an indicator of...
Article
The composition of the rectal gland secretion and volatiles emitted by female Queensland fruit fly, Bactrocera tryoni was investigated. Esters were found to be the main compounds in the gland extracts and headspace, while amides were the minor compounds in the gland extracts and headspace. Ethyl dodecanoate, ethyl tetradecanoate, ethyl (Z9)-hexadec...
Article
Full-text available
We recently identified unique caterpillar-induced plant volatile compounds emitted from apple leaves infested with the larvae of various leafroller species. In subsequent field tests, binary blends of phenylacetonitrile+acetic acid and 2-phenylethanol+acetic acid were found to be attractive to a range of tortricid leafroller species (Tortricidae: T...
Cover Page
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Three varieties of honey of different dominant floral origin were found to attract social Hymenoptera, including large earth bumble bee, Bombus terrestris in a New Zealand’s mountain beech forest. This study was undertaken to identify volatile organic compounds that induce the attraction of bumble bees to honeybee (Apis mellifera) honey. We have an...
Article
Full-text available
Three varieties of honey of different dominant floral origin were found to attract social Hymenoptera, including large earth bumble bee, Bombus terrestris in a New Zealand’s mountain beech forest. This study was undertaken to identify volatile organic compounds that induce the attraction of bumble bees to honeybee (Apis mellifera) honey. We have an...
Article
Full-text available
Epiphyas postvittana is a major horticultural pest in many countries, including New Zealand. Recently, two minor components (E)-11-tetradecen-1-ol and (E)-11-hexadecenyl acetate were found to increase the attraction of a previously identified two-component sex pheromone (95:5 blend of (E)-11-tetradecenyl acetate [E11-14:Ac] and (E,E)-9,11-tetradeca...
Patent
Full-text available
The invention relates to a composition for attracting Lepidopterous insects comprising a vapour blend of acetic acid and one or more compounds of formula (I), (I) wherein R is selected from the group comprising —CH2OH, —CN, —NC, and —OH; and to methods of using the composition to attract, detect, survey, monitor and/or control Lepidopterous insects...
Article
Full-text available
The ability of insects to associate olfactory cues with food from their environment has been well documented with various insect orders. However, these studies were based on prior training of insects to associate odors with food sources in the laboratory or in the field with almost no evidence for the development of this phenomenon in natural ecosy...
Article
Full-text available
Stone fruit crops grow in various regions around the world and are highly valued for their nutritional content, delicious taste, and economic importance, with an annual worldwide production of up to 42 million tonnes. In spite of their importance as a food resource, little is known about the chemistry of the floral volatiles of these crops, especia...
Article
Many orchids achieve pollination by deceptive means. Sexually deceptive orchids are pollinated by male insects, which are lured to flowers that mimic the sex pheromones and/or appearance of their female conspecifics. This specialised pollination strategy was recently confirmed for the first time in a Pterostylis species in Australia. We investigate...
Article
Background: Habituation to sex pheromones is one of the key mechanisms in mating disruption, an insect control tactic. Male moths often show reduced sexual response after pre-exposure to female sex pheromone. Mating disruption is relatively rare in insect orders other than Lepidoptera. Results: As a positive control we confirmed habituation in a...
Article
Recent studies have demonstrated that key herbivore-induced foliage volatiles from apple, Malus domestica Borkhausen (Rosaceae), can be attractive to conspecific adult male and female tortricid leafrollers when used together with acetic acid lures. Our study reported here was conducted in Washington State during 2013-2014 and assessed the attractiv...
Article
Spilonota ocellana (Denis and Schiffermüller) (Lepidoptera: Tortricidae) can be a serious pest of organic apples ( Malus domestica Borkhausen (Rosaceae)) in British Columbia, Canada. Recent discovery that S. ocellana moths are attracted by a lure combining acetic acid (AA) and benzyl nitrile (BN), identified as a caterpillar-induced apple leaf vola...
Article
Full-text available
Pandemis limitata (Robinson) (Lepidoptera: Tortricidae) is one of several leaf-feeding caterpillar pests of commercial tree-fruit crops in British Columbia, Canada. Recent discovery that European Pandemis Hübner species are attracted by lures combining acetic acid and the caterpillar-induced apple-leaf volatiles, 2-phenylethanol, and phenylacetonit...
Article
Full-text available
Binary and ternary combinations of volatile organic compounds identified earlier from caterpillar-infested apple foliage caught more than one thousand individuals of both sexes of several adult tortricid leafroller species in several days of trials conducted in apple orchards in southern British Columbia. A series of combinations with phenylacetoni...
Article
We evaluated the effectiveness of 2-phenylethanol (PET) in combination with acetic acid (AA) as a binary lure for monitoring male and female obliquebanded leafroller, Choristoneura rosaceana (Harris). Studies were conducted in apple, Malus domestica Borkhausen, orchards treated with or without sex pheromone dispensers for mating disruption (MD). Op...
Preprint
A recent discovery have demonstrated that herbivore induced plant volatile compounds from apple tree infested with leafrollers were highly attractive to con-specific adult male and female leafrollers. However, this work has been conducted in New Zealand and Canada testing only low doses of kairomone. This study has been conducted in US to assess th...
Preprint
Plants release volatiles in response to caterpillar feeding that attract natural enemies of the herbivores, a tri-trophic interaction which has been considered an indirect plant defence against herbivores. The caterpillar-induced plant volatiles have been reported to repel or attract conspecific adult herbivores. Apple seedlings infested with Pande...
Preprint
We evaluated the effectiveness of 2-phenylethanol (PET) in combination with acetic acid (AA) as a binary lure for monitoring male and female obliquebanded leafroller, Choristoneura rosaceana (Harris). Studies were conducted in apple, Malus domestica Borkhausen, orchards treated with or without sex pheromone dispensers for mating disruption (MD). Op...
Article
Full-text available
The currant clearwing Synanthedon tipuliformis (Clerck) (Sesiidae) is a worldwide pest of black currants, Ribes nigrum. This moth has been observed to feed on nectar of inflorescences of Canada thistles, Cirsium arvense (L.) Scop. This work was undertaken to identify floral compound(s) produced by Canada thistles inflorescences that mediate the res...
Article
Full-text available
Straight-chained lepidopteran pheromones are now regulated under a group standard in New Zealand, which is generic for moth pheromone products of similar low risk, under the Hazardous Substances and New Organisms Act (1996). This means that compliant new pheromone products can be developed and commercialized with low regulatory requirements. This e...
Article
Full-text available
Irradiation is used to provide sterile insects from mass-rearing facilities, but irradiation can degrade insect quality. A system is described that uses repeatable pheromone stimuli to activate male moths housed with clean airflow in a commercially available insect activity meter, for potential use in quality assessment of mass-reared moths in ster...
Article
Full-text available
Vespula wasps are widely distributed invasive alien species that are able to reach high population densities in the 1.2 M ha of beech forests (Fuscospora spp.) of New Zealand's South Island. These endemic temperate forests have an abundance of carbohydrate-rich honeydew produced by native scale insects (Ultracoelostoma spp.). A characteristic aroma...
Article
Field studies were conducted in the United States, Hungary, and New Zealand to evaluate the effectiveness of septa lures loaded with ethyl (E,Z)-2,4-decadienoate (pear ester) and (E)-4,8- dimethyl-1,3,7-nonatriene (nonatriene) alone and in combination with an acetic acid co-lure for both sexes of codling moth, Cydia pomonella (L.). Additional studi...
Article
Full-text available
Invasive wasps have major impacts on bird populations and other biodiversity in New Zealand beech forests and new solutions are needed for their management. Baits were combined from four phylogenetically diverse sources (protein and carbohydrate) to improve attraction to a level that could be used as the basis for more powerful attract-and-kill sys...
Article
Full-text available
Background New Zealand flower thrips (NZFT), Thrips obscuratus (Crawford), is an economic pest of various horticultural crops in New Zealand and is recognised as a quarantine pest globally. We investigated two chemical attractants (ethyl nicotinate and 6-pentyl-2H-pyran-2-one), three dispensers, three trap designs, and four trap heights to determin...
Article
Full-text available
1. The functional features of carnivorous plants’ traps have been mostly interpreted as adaptations to capture prey. Carnivorous plants that feed on insects, however, run the risk that increasing trapping effectiveness might in turn reduce reproductive success through capture of pollinators. Such a pollinator-prey conflict might play an important r...
Article
Novel technologies for controlling invasive pest insects could benefit New Zealand environmentally and economically Current technologies could be improved by reducing nontarget impacts and running costs and improving delivery to target populations A novel aerosol technology currently in development is presented for control of pest insects The data...
Article
Full-text available
New Zealand's fruit sectors are making excellent progress with insecticide risk reduction, and organophosphate insecticides are now rarely used on apples. Pheromones and similar natural products are playing an increasing role as low impact tools for monitoring and controlling pests, including codling moth and leafrollers. Recent discoveries expecte...
Article
The identification of new attractants can present opportunities for developing mass trapping, but standard screening methods are needed to expedite this. We have developed a simple approach based on quantifying trap interference in 4 × 4 trap arrays with different spacings. We discuss results from sex pheromones in Lepidoptera (lightbrown apple mot...
Patent
Full-text available
The invention relates to a four component pheromone composition that attracts male light brown apple moths and can be used to control moth populations. The pheromone composition comprises (E)-11-tetradecenyl acetate, (E,E)-9,11-tetradecadienyl acetate, (E)-11-tetradecen-1-ol and (E)-11-hexadecenyl acetate.
Article
Full-text available
The first sex attractant for the genus Izatha is reported as (Z)-7-tetradecen-1-yl acetate in I. peroneanella. A trapping trial for tortricid moths in New Zealand forests resulted in the serendipitous capture of 310 male lichen tuft moths, I. peroneanella, to this compound which is presumed to be part of the sex pheromone. The inhibitory response f...
Article
Full-text available
The introduction of invasive social wasp species of the genus Vespula (Hymenoptera: Vespidae) to New Zealand has caused a major ecological problem, particularly in the beech forests (Nothofagus spp.) of the South Island, where they have destabilized the native bird and invertebrate biodiversity. New attractants are under investigation as part of a...
Article
Full-text available
With growing globalisation and trade, insect incursions are increasing worldwide. A proportion of incursions involve pests of major economic crops (e.g. Mediterranean fruit fly), conservation value (e.g. tramp ants) or health significance (e.g. mosquitoes), and may be the targets of eradication programs. Historically, such responses have included t...
Article
Full-text available
New Zealand flower thrips, Thrips obscuratus (Thysanoptera: Thripidae), are attracted to ripening fruits, especially peaches. Volatiles from unripe and ripe peach fruits were collected and analyzed by gas chromatography/mass spectrometry. Six lactones were found only in ripe peach volatiles: γ-heptalactone, γ-octalactone, γ-nonalactone, 6-pentyl-2H...
Article
Full-text available
Two glasshouse trials in a capsicum crop near Warkworth, New Zealand, in January 2011 and two field trials in a nectarine orchard near Lleida, Spain, in July 2013 were undertaken to determine if trap capture of Frankliniella occidentalis (western flower thrips, WFT) and Thrips tabaci (onion thrips, OT) could be increased by alternative volatile com...
Article
The Pherobase is a freely accessible database of pheromones and semiochemicals. It comprises several databases to provide comprehensive information about pheromones and semiochemicals. Currently, the Pherobase contains pheromones and semiochemicals of more than 7500 species and 6500 semiochemical compounds. The Pherobase lists the occurrence of the...
Article
Full-text available
Vespid wasps (Vespula vulgaris L. and V. germanica Fab. Hymenoptera; Vespidae) are highly abundant in 1 million ha of New Zealand's indigenous beech forests (Nothofagus spp.) and have had detrimental effects on the New Zealand native fauna. This hyperabundance is due in part to the vast supply of carbohydrate-rich honeydew produced by scale insects...
Article
Sex attraction studies were carried out to investigate the mate-finding behaviour of invasive Vespula vulgaris (Linnaeus) (Hymenoptera: Vespidae) wasps. Delta traps were baited with live, caged males, and gynes (virgin queens) of V. vulgaris to determine whether either sex produced a long-range sex attractant. Traps baited with gynes caught 71 male...
Article
Full-text available
Codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), is a major cosmopolitan pest of apple and other pome fruits. Ethyl (E,Z)-2,4-decadienoate (pear ester) has been identified as a host-derived kairomone for female and male codling moths. However, pear ester has not performed similarly in different fruit production areas in terms of the rel...
Article
Full-text available
Mating disruption for leafrollers has been conducted on a commercial scale using a single multi-species pheromone dispenser on contiguous blocks of cherries in Central Otago for 4 years. Pheromone trap and packhouse results were collected from isolated untreated (65.4 ha) and pheromone-treated cherry orchard areas (76.4 ha) in the Cromwell district...
Article
New Zealand flower thrips (NZFT) are a pest in New Zealand stone fruit orchards In this study NZFT density was manipulated in the field using a known kairomone It was discovered that the addition of the kairomone to any given tree within an orchard increased NZFT density in direct proportion to the amount of kairomone used It was also found that de...
Article
Full-text available
Background: The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world. The trail pheromone Z,E-α-farnesene (91% purity) was prepared, and disruption of worker trail orientation was tested using an ethanol-based aerosol formulation presenting a single puff of this compound by airbrush and compressed air. Trai...
Article
A new four-component sex pheromone blend for light brown apple moth (Epiphyas postvittana) was examined for efficacy of communication disruption in laboratory and field trials. Vineyard trials using SPLAT LBAM™ examined disruption of traps in the presence of: a) the current two-component ((E)-11-tetradecenyl acetate and (E,E)-9,11-tetradecadienyl a...
Patent
Full-text available
The invention relates to a compound of formula (I) or a salt thereof: wherein the substituents R1, R2, R3, R4, R5, R6, R7 and X are defined herein, its synthesis and methods of controlling and monitoring populations of mealybugs.
Article
The volatile compounds emitted from uninfested apple seedlings, cv. Royal Gala, and apple seedlings infested with generalist herbivore Epiphyas postvittana larvae were sampled using headspace collection and analyzed by gas chromatography-mass spectrometry. Nine additional compounds were only detected in infested apple seedlings [including benzyl al...
Article
Full-text available
Pheromones of two native leafrollers of economic importance to the New Zealand horticulture industry, Planotortrix octo [(Z)-8-tetradecenyl acetate and tetradecyl acetate] and Ctenopseustis obliquana [(Z)-5-tetradecenyl acetate and (Z)-8-tetradecenyl acetate], were reinvestigated and combined with pheromone of Epiphyas postvittana [light-brown appl...
Article
Full-text available
In recent years, Conogethes pluto (Lepidoptera: Crambidae) has become a major pest of Alpinia and other ornamental gingers in the Northern Territory and Queensland, Australia. This pest damages the flowers and bores into the stems, causing substantial losses to production. Currently, no synthetic sex pheromone is available to monitor or control thi...
Article
Full-text available
The sale of pheromone traps, lures and mating disruption products for horticultural insect pest species has grown steadily since the late 1980s, with expanding sales to New Zealand growers from Plant & Food Research (PFR) and its predecessors. New biosecurity incursions led to pheromone identifications for delimitation and pest management of other...
Article
Most carnivorous plants utilize insects in two ways: the flowers attract insects as pollen vectors for sexual reproduction, and the leaves trap insects for nutrients. Feeding on insects has been explained as an adaptation to nutrient-poor soil, and carnivorous plants have been shown to benefit from insect capture through increased growth, earlier f...
Article
Light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), is the target of the sterile insect technique, but reduced moth fitness from irradiation lowers the effective overflooding ratio of sterile to wild moths. New measures of insect quality are being sought to improve field performance of irradiated insects, thus improvin...
Article
Full-text available
The composition of the sex pheromone gland of the lightbrown apple moth, Epiphyas postvittana (Walker) was re-investigated. In addition to the two previously identified compounds, (E)-11-tetradecenyl acetate (E11-14Ac) and (E,E)-9,11-tetradecadienyl acetate (E9E11-14Ac), seven additional candidate pheromone compounds were identified: (E)-11-tetrade...
Article
Full-text available
The absolute configuration of the sex pheromone of the citrophilous mealybug, Pseudococcus calceolariae, was determined to be (1R,3R)-[2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropyl]methyl (R)-2-acetoxy-3-methylbutanoate. NMR, derivatization reactions, chiral gas chromatography-mass spectrometry, and comparison with synthetic chiral reference comp...
Article
Full-text available
Leafrollers are important pests of apples and infested fruit can result in rejection of export consignments. Leafroller mating disruption using a pheromone blend with activity against three species was examined in 12 Hawke's Bay orchards over two seasons (2009-10 and 2010-11). Pheromone dispensers (600/ha) and a single insecticide were applied to t...
Conference Paper
Increasing volumes of tourists and cargo are generating unprecedented levels of alien invasive species establishment across the world, which can threaten productive and natural ecosystems. Invasive species are very diffi cult to eradicate. Government-sanctioned pest eradication programmes are increasingly being commenced worldwide in response, at a...
Article
Full-text available
Leafrollers are important pests of apples and infested fruit can result in rejection of export consignments. Leafroller mating disruption using a pheromone blend with activity against three species was examined in 12 Hawke's Bay orchards over two seasons (2009-10 and 2010-11). Pheromone dispensers (600/ha) and a single insecticide were applied to t...
Article
Full-text available
Leafrollers are important pests of apples and infested fruit can result in rejection of export consignments. Leafroller mating disruption using a pheromone blend with activity against three species was examined in 12 Hawke's Bay orchards over two seasons (2009-10 and 2010-11). Pheromone dispensers (600/ha) and a single insecticide were applied to t...
Article
Full-text available
The fire ant, Solenopsis invicta (Hymenoptera: Formicidae), is considered one of the most aggressive and invasive species in the world. Toxic bait systems are used widely for control, but they also affect non-target ant species and cannot be used in sensitive ecosystems such as organic farms and national parks. The fire ant uses recruitment pheromo...
Article
Full-text available
All of the four stereoisomers of (1′S)-1′-ethyl-2′-methylpropyl 3,13-dimethylpentadecanoate, the major component of the female sex pheromone of Clania variegata, were synthesized by employing olefin cross metathesis as the key reaction and starting from (R)- or (S)-2-methyl-1-butanol, (R)- or (S)-citronellal, and (S)-2-methyl-3-pentanol. Their bioa...
Article
Headspace volatiles collected from virgin females of the citrophilous mealybug, Pseudococcus calceolariae, contain three compounds not present in the headspace of control samples. The main female-specific compound is identified as [2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropyl]methyl 2-acetoxy-3-methylbutanoate (chrysanthemyl 2-acetoxy-3-methylbu...
Conference Paper
Pheromone trapping-based thresholds and mating disruption of codling moth, Oriental fruit moth and several leafrollers including lightbrown apple moth, greenheaded and brownheaded leafrollers, are making an increasingly valuable contribution to fruit exports from New Zealand, a process that has been building for some years. Our recent development o...
Article
Full-text available
Headspace volatiles collected from virgin females of the citrophilous mealybug, Pseudococcus calceolariae, contain three compounds not present in the headspace of control samples. The main female-specific compound is identified as [2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropyl]methyl 2-acetoxy-3-methylbutanoate (chrysanthemyl 2-acetoxy-3-methylbu...
Article
1. Scientists have been fascinated by carnivorous plants for centuries and they have thoroughly investigated how these plants can benefit from insect capture for example through increased growth, earlier flowering, and increased seed production. How prey is actually lured into the traps, however, is less well understood. Trapping prey may be achiev...
Article
Full-text available
The common wasp, Vespula vulgaris (L.), and the German wasp, Vespula germanica (F.), are significant problems in New Zealand beech forests (Nothofagus spp.), adversely affecting native birds and invertebrate biodiversity. This work was undertaken to develop synthetic attractants for these species to enable more efficient monitoring and management....