Luc Tirry

Ghent University | UGhent · Department of Crop Protection

Outdoor vegetable cultivation is an important economic activity, both for fresh consumption and for the frozen vegetable industry within Flanders, Belgium. In recent years, due to the intensive nature of vegetable cultivation in the open air, nematode problems increased. The quarantine root-knot nematode Meloidogyne chitwoodi causes economic damage...

Management strategies applied to reduce Meloidogyne chitwoodi populations below economic damage threshold depend strongly on measures taken during the intercrop period. Therefore, this study evaluated the reproductive potentials of M. chitwoodi on different cultivars of cover crops. Twenty-two different cultivars were evaluated against M. chitwoodi...

Problems with plant-parasitic nematodes remain a major challenge in most field vegetable crops worldwide. In agricultural fields in Belgium, these problems have increased in recent years. A major problem is the quarantine root-knot nematode Meloidogyne chitwoodi . The host plant status of the most commonly grown cultivars of spinach ( Spinacia oler...

BACKGROUND The temperature–size rule is a well‐known example of phenotypic plasticity in ectothermic organisms. When exposed to colder temperatures, ectotherms develop more slowly, but mature at larger body sizes and vice versa at higher temperatures. We investigated whether a phytoseiid predatory mite can obtain a larger body size by rearing it at...

Synergists can counteract metabolic insecticide resistance by inhibiting detoxification enzymes or transporters. They are used in commercial formulations of insecticides, but are also frequently used in the elucidation of resistance mechanisms. However, the effect of synergists on genome-wide transcription in arthropods is poorly understood. In thi...

The salivary protein repertoire released by the herbivorous pest Tetranychus urticae is assumed to hold keys to its success on diverse crops. We report on a spider mite-specific protein family that is expanded in T. urticae. The encoding genes have an expression pattern restricted to the anterior podocephalic glands, while peptide fragments were fo...

Significance In animals, carotenoid pigments fulfill a number of essential roles in vision, protection from stresses, and signaling. Although carotenoids are synthesized primarily by plants and some bacteria and fungi, carotenoid biosynthetic genes have been acquired by horizontal gene transfer in some insects and mites. In the two-spotted spider m...

Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a key biological control agent in greenhouse tomato crops. In the present study, we describe the population dynamics of M. pygmaeus after release during two generations in semi-commercial greenhouses in order to optimize biocontrol programs. We tested the effect of the number of weekly supplementa...

Insecticide resistance is a major threat for the control of arthropod pest species as it reduces the effectiveness of insecticides and, consequently, increases the economic and environmental burdens of agriculture. Insecticide synergists can counteract metabolic insecticide resistance by acting as a surrogate substrate or inhibiting enzymes involve...

Background: Previous studies have indicated the control potential of entomopathogenic nematodes (EPN) against Tuta absoluta. Here, the potential of Steinernema feltiae, S. carpocapsae and Heterorhabditis bacteriophora is studied when applied against larvae of T. absoluta inside leaf mines in tomato leaf discs by means of an automated spray boom....

The acaricidal compounds pyridaben, tebufenpyrad and fenpyroximate are frequently used in the control of phytophagous mites such as Tetranychus urticae, and are referred to as Mitochondrial Electron Transport Inhibitors, acting at the quinone binding pocket of complex I (METI-I acaricides). Because of their very frequent use, resistance evolved fas...

The two-spotted spider mite Tetranychus urticae is an extremely polyphagous crop pest. Alongside an unparalleled detoxification potential for plant secondary metabolites, it has recently been shown that spider mites can attenuate or even suppress plant defenses. Salivary constituents, notably effectors, have been proposed to play an important role...

Food supplementation is an emerging strategy to improve the establishment and resilience of generalist predators in greenhouse crops. This study was conducted to assess the pre-establishment of the generalist predatory mite Amblyseius swirskii Athias-Henriot (Phytoseiidae) on two ornamental greenhouse crops, chrysanthemum and ivy. In the first gree...

Background: The European red mite, Panonychus ulmi, is among the most important mite pests in fruit orchards, where it is controlled primarily by acaricide application. However, the species rapidly develops pesticide resistance, and the elucidation of resistance mechanisms for P. ulmi has not kept pace with insects or with the closely related spid...

Background: The zoophytophagous predator Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a successful biocontrol agent against several pest species in protected tomato crops. This predator is considered harmless for the crop. However, during recent years Heteroptera feeding punctures on tomato fruit in Belgian and Dutch greenhouses were misint...

Since its first record in 1993 in Europe, Echinothrips americanus Morgan (Thysanoptera: Thripidae) has been an pesky problem in horticulture. Biological control of this thrips pest is a serious challenge, mainly due to the lack of suitable natural enemies which necessitates the use of chemical treatments. In this study, we investigated whether the...

In the present study, we tested whether the body size of phytoseiid predators can be increased by exploiting the temperature-size rule for ectothermic organisms. This rule states that ectotherms will develop slower at lower temperatures, but will mature at larger body size. Therefore, we reared 4 phytoseiids, namely Phytoseiulus persimilis, Neoseiu...

Cyenopyrafen is a recently developed acaricide with a new mode of action as complex II inhibitor. However, it was recently shown that cross-resistance to cyenopyrafen can occur in resistant field strains of Tetranychus urticae, which might be linked to the previous use of classical METI acaricides. Here, we selected for cyenopyrafen resistance and...

The consumption rate of an ectothermic predator is highly temperature-dependent and is a key driver of pest-predator population interactions. Not only average daily temperature, but also diurnal temperature variations may affect prey consumption and life history traits of ectotherms. In the present study, we evaluated the impact of temperature alte...

The impact of daily temperature variations on arthropod life history remains woefully understudied compared to the large body of research that has been carried out on the effects of constant temperatures. However, diurnal varying temperature regimes more commonly represent the environment in which most organisms thrive. Such varying temperature reg...

In IPM systems in greenhouse crops, the predatory mite Amblyseius swirskii is becoming increasingly important as a biological control agent of various pests, especially thrips and whiteflies. An emerging strategy to promote the predator's establishment and retention in the crop consists of providing food supplements. However, when faced with omnivo...

Acaricides are one of the cornerstones of an efficient control program for phytophagous mites. An analysis of the global acaricide market reveals that spider mites such as Tetranychus urticae, Panonychus citri and Panonychus ulmi are by far the most economically important species, representing more than 80% of the market. Other relevant mite groups...

The South American tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a devastating pest in tomato crops. After having spread rapidly in the Mediterranean area since its first detection in 2006, it has recently become established in greenhouses in Western Europe. It was assumed that the low temperatures commonly associated with...

In order to better adapt the use of predatory mites with the modern greenhouse climate regulation strategies, functional response models were constructed to demonstrate the impact of realistic climate variations on the predation efficiency on Tetranychus urticae eggs by Neoseiulus fallacis, Phytoseiulus persimilis and N. californicus predatory mite...

In order to reduce the cost of repeated introductions of natural enemies in protected crops, food supplements can be provided when target prey levels are low. However, selecting such foods should be done with extreme care, as some omnivorous pests may also benefit from those resources. Western flower thrips, Frankliniella occidentalis Pergande (Thy...

Amblydromalus limonicus (Garman & McGregor) (Acari: Phytoseiidae) is a commercially available predator of key pests in protected crops, particularly of thrips and whiteflies. Basic information on the developmental and reproductive performance of the predator as a function of food is largely lacking. In the present study, development, reproduction a...

In greenhouses with ornamental crops, predatory mites like Amblyseius swirskii Athias-Henriot and Amblydromalus limonicuss Garman & McGregor (Acari: Phytoseiidae) are increasingly implemented in crop protection strategies due to resistance problems and legal restrictions on pesticides. As predatory mites can only control pests adequately when repea...

Predatory mites like Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus McGregor (Acari: Phytoseiidae) are essential in sustainable control strategies of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) in warm greenhouse cultures to complement limited available pesticides and to tackle emerging resistance...

Genome portals of arthropods consulted in order to retrieve potential homologues of Tu-CAS in addition to NCBI nr/nt databases. DOI: http://dx.doi.org/10.7554/eLife.02365.014

List of primers used in PCR in T. urticae and T. evansi. DOI: http://dx.doi.org/10.7554/eLife.02365.016

Differentially expressed genes in the London-CYANO strain compared to the London strain. DOI: http://dx.doi.org/10.7554/eLife.02365.013

List of the pyridoxal-5′-phosphate-dependent protein sequences used in phylogenetic tree construction. DOI: http://dx.doi.org/10.7554/eLife.02365.015

Coding sequences of Tu-CAS. DOI: http://dx.doi.org/10.7554/eLife.02365.017

Cyflumetofen and cyenopyrafen are novel acaricides acting as complex II inhibitors. This new mode of action is extremely useful for devising efficient resistance management strategies for mite control. We determined the cross-resistance risk of both compounds using a collection of well-characterized resistant strains of Tetranychus urticae, and als...

Predatory mites like Phytoseiulus persimilis Athias-Henriot, Neoseiulus californicus McGregor and N. fallacis (Garman) (Acari: Phytoseiidae) are essential in sustainable control strategies of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) in warm greenhouse cultures to complement imited available pesticides and to tackl...

Cyanogenic glucosides are among the most widespread defense chemicals of plants. Upon plant tissue disruption, these glucosides are hydrolyzed to a reactive hydroxynitrile that releases toxic hydrogen cyanide (HCN). Yet many mite and lepidopteran species can thrive on plants defended by cyanogenic glucosides. The nature of the enzyme known to detox...

Diapause or developmental arrest, is one of the major adaptations that allows mites and insects to survive unfavorable conditions. Diapause evokes a number of physiological, morphological and molecular modifications. In general, diapause is characterized by a suppression of the metabolism, change in behavior, increased stress tolerance and often by...

Amblydromalus limonicus Garman & McGregor (Acari: Phytoseiidae) is a generalist predatory mite with economic potential to control thrips and whiteflies in protected cultivation. We tested the development and reproduction of A. limonicus on three food sources with potential for use in laboratory production or to support its populations in a crop: fr...

Predatory mites like Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus McGregor (Acari: Phytoseiidae) are essential in sustainable control strategies of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) in warm greenhouse cultures to complement limited available pesticides and to tackle emerging resistance...

In greenhouses with ornamental crops, predatory mites like Amblyseius swirskii Athias-Henriot and Amblydromalus limonicuss Garman & McGregor (Acari: Phytoseiidae) are increasingly implemented in crop protection strategies due to resistance problems and legal restrictions on pesticides. As predatory mites can only control pests adequately when repea...

Increasing energy costs force glasshouse growers to switch to energy saving strategies. In the temperature integration approach, considerable daily temperature variations are allowed, which not only have an important influence on plant growth but also on the development rate of arthropods in the crop. Therefore, we examined the influence of two con...

Background The ABC (ATP-binding cassette) gene superfamily is widespread across all living species. The majority of ABC genes encode ABC transporters, which are membrane-spanning proteins capable of transferring substrates across biological membranes by hydrolyzing ATP. Although ABC transporters have often been associated with resistance to drugs a...

The complete genome of the two-spotted spider mite, Tetranychus urticae, has been reported. This is the first sequenced genome of a highly polyphagous and resistant agricultural pest. The question as to what the genome offers the community working on spider mite control is addressed. Copyright © 2012 Society of Chemical Industry.

Bifenazate is one the most frequently used acaricides to control spider mites. Although first thought to be a neurotoxin, genetic evidence has pointed towards a mitochondrial target site, in particular the Qo site of mitochondrially encoded cytochrome b. In this study, we present the first biochemical evidence for a physical interaction between [14...

Egg parasitoids of the genus Trichogramma (Hymenoptera: Trichogrammatidae) are important natural enemies of many lepidopterous pests in agricultural and forest areas. Because the use of indigenous Trichogramma populations/species can significantly increase the biological control efficiency, the characterization of endemic populations and precise sp...

The cys-loop ligand-gated ion channel (cysLGIC) super family of Tetranychus urticae, the two-spotted spider mite, represents the largest arthropod cysLGIC super family described to date and the first characterised one within the group of chelicerates. Genome annotation, phylogenetic analysis and comparison of the cysLGIC subunits with their counter...

Because of its importance to the arthropod exoskeleton, chitin biogenesis is an attractive target for pest control. This point is demonstrated by the economically important benzoylurea compounds that are in wide use as highly specific agents to control insect populations. Nevertheless, the target sites of compounds that inhibit chitin biogenesis ha...

The braconid parasitoid Microplitis mediator (Haliday) is a key natural enemy of the cabbage moth, Mamestra brassicae (L.), in Europe. In the context of an Integrated Pest Management approach, the use of selective insecticides is essential for the conservation of naturally occurring beneficial arthropods. The present laboratory study investigated t...

The spider mite Tetranychus urticae is a cosmopolitan agricultural pest with an extensive host plant range and an extreme record of pesticide resistance. Here we present the completely sequenced and annotated spider mite genome, representing the first complete chelicerate genome. At 90 megabases T. urticae has the smallest sequenced arthropod genom...

Spider mites are important crop pests that rapidly develop resistance to acaricides. To investigate whether acaricide resistance is a threat to greenhouse rose culture in the Netherlands, the susceptibility of 15 strains of Tetranychus urticae was tested to several currently used acaricides, and resistance mechanisms were investigated. Although the...

The hoverfly Episyrphus balteatus (Degeer) is one of the most abundant predators of the cabbage aphid (Brevicoryne brassicae (L.)) in brussels sprouts in Belgium. In the current laboratory study, the toxicity of several insecticides applied at maximum recommended field rates was investigated on the larvae of E. balteatus. Two- to 3-day-old larvae w...

Bifenazate is a recently developed acaricide that is mainly used to control spider mites on a variety of crops. Although first thought to be a neurotoxin, genetic evidence obtained from bifenazate resistant Tetranychus urticae strains suggested an alternative mode of action as a Qo pocket inhibitor of the mitochondrial complex III. In this study, w...

The ability of a natural enemy to tolerate a wide temperature range is a critical factor in the evaluation of its suitability as a biological control agent. In the current study, temperature-dependent development of the two-spotted ladybeetle A. bipunctata L. (Coleoptera: Coccinellidae) was evaluated on Myzus persicae (Sulzer) (Hemiptera: Aphididae...

The two-spotted spider mite Tetranychus urticae Koch is one of the economically most important pests in a wide range of outdoor and protected crops worldwide. Its control has been and still is largely based on the use of insecticides and acaricides. However, due to its short life cycle, abundant progeny and arrhenotokous reproduction, it is able to...