Markus Knapp- Dr
- Scientist at Koppert B.V.
Markus Knapp
- Dr
- Scientist at Koppert B.V.
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Independent Researcher
April 2008 - present
Koppert Biological Systems
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- Researcher
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Publications (84)
Biological control is widely successful at controlling pests, but effective biocontrol agents are now more difficult to import from countries of origin due to more restrictive international trade laws (the Nagoya Protocol). Coupled with increasing demand, the efficacy of existing and new biocontrol agents needs to be improved with genetic and genom...
Insect and mite pests are a major constraint to greenhouse production of vegetables, fruits and ornamentals. As the abiotic conditions in greenhouses are relatively stable and uniform in most parts of the world, the insect and mite pest fauna is dominated by a relative small number of usually polyphagous species. Many of these pests have a worldwid...
The ability of an organism to adapt to short-term environmental changes within its lifetime is of fundamental importance. This adaptation may occur through phenotypic plasticity. Insects and mites, in particular, are sensitive to changes in temperature and humidity, especially during the juvenile stages. We studied the role of phenotypic plasticity...
Under drought stress, Phytoseiulus persimilis females are able to lay drought-resistant eggs through an adaptive maternal effect. The mechanisms making these eggs drought resistant still remain to be investigated. For this purpose, we studied the physiological differences between drought-resistant and drought-sensitive eggs. We compared the volume...
Biological control is widely successful for controlling pests, but effective biocontrol agents are now more difficult to obtain due to more restrictive international trade laws. Coupled with increasing demand, the efficacy of existing and new biocontrol agents needs to be improved with genetic and genomic approaches. Although they have been underut...
The predatory mite Phytoseiulus persimilis is widely used for augmentative biological control, as an effective predator of the spider mite Tetranychus urticae. However, the biocontrol efficacy of P. persimilis decreases under dry conditions. One of the reasons for this decline concerns P. persimilis’ eggs, which are sensitive to low humidity. In th...
Predatory mites play the leading role in commercial augmentative biological control. They are mainly used in protected vegetable and ornamental cultivation systems to control phytophagous mites, thrips and whiteflies. Use in open-field systems and in animal husbandry is still limited. Phytoseiidae species are by far the most important group of comm...
Euseius gallicus is a new phytoseiid species recently described from southern France that has shown potential as a biocontrol agent for thrips and whitefly in rose, if pollen is supplied as an additional food source. To investigate if the use of E. gallicus provides improved thrips and whitefly control, we conducted laboratory experiments examining...
The predatory mite Amblyseius swirskii quickly became one of the most successful biocontrol agents in protected cultivation after its introduction into the market in 2005 and is now released in more than 50 countries. There are several key factors contributing to this success: (1) it can control several major pests including the western flower thri...
The fauna of phytoseiid mites in the state of Mato Grosso do Sul, in midwestern Brazil, is poorly known. The tomato red spider mite, Tetranychus evansi Baker and Pritchard, is an important pest of Solanaceae in several countries, but it is usually found in low densities in Brazil. It has been hypothesized that this is due to the effect of natural e...
In the present study, the susceptibility of different developmental stages (eggs, larvae, protonymphs, deutonymphs and adults) of Tetranychus urticae Koch to the entomopathogenic fungi Beauveria bassiana (Balsamo-Crivelli) Vuillemin and Metarhizium anisopliae (Metchnikoff) Sorokin was evaluated in the laboratory. At each developmental stage, four c...
Farmers in Kenya continue to raise concerns of difficulty in managing Tetranychus evansi, the most widespread pest species of tomato applying the most commonly used acaricides. This invasive pest species is not only found in Kenya, but in Eastern and Southern Africa, as well as parts of Europe and Asia. In the current study, populations of T. evans...
The efficacy of aqueous and emulsifiable formulations of the fungus Metarhizium anisopliae isolate ICIPE78 was evaluated on the population density of Tetranychus urticae infesting common bean plants under screenhouse and field conditions. Synthetic acaricide abamectin was included as a check. Bean plants were artificially infested with T. urticae a...
Amblydromalus limonicus (Acari: Phytoseiidae) was described in 1956 from citrus in California; its distribution range covers North and South America, Australia and New Zealand. It first caught the attention of biocontrol workers in the 1960s as natural enemy of the spider mites Oligonychus punicae and Tetranychus cinnabarinus in avocados and other...
The tomato red spider mite, Tetranychus evansi, is the most important dry season pest in tomato and indigenous Solanaceae vegetable (nightshades) production in various African countries. The pest probably originates from southern America and spread to Africa, Europe and Asia. It however represents a serious problem mainly in Africa. Several predato...
This is an updated checklist of phytophagous and fungivorous mites from Peru (Prostigmata: Tetranychidae, Tarsonemidae, Tenuipalpidae, Tydeidae, Eriophyidae, Diptilomiopidae; Astigmata: Acaridae, Winterschmidtiidae). The data are mainly based on an extensive survey carried out in the Peruvian territory in 2006, as well as on the new records of mite...
A new spider mite species Brevinychus meshacki Toroitich and Ueckermann n. sp., collected on Philonoptera eriocalyx Harms (Schrire) from Sangasanga in Mvomero district of Tanzania, is described and illustrated. This species is distinct from the other species of this genus by having only one pair of dorsocentral setae d1 being of similar length to t...
The tomato red spider mite Tetranychus evansi Baker & Pritchard is a serious pest of solanaceous plants worldwide. Management of this oligophagous pest in African nightshades has been a challenge to smallholder African farmers due to its high reproductive rate and rapid development of resistance to synthetic pesticides. The aim of the present study...
We surveyed the phytoseiid mites in four different geographical zones of Kenya: Zone I, upper highland and tropical al-pine (2400-4400m); Zone II, lower highland (1800-2400 m); Zone III, midland (800-1800 m); Zone IV, tropical, hot and humid (0-800 m). A total of 107 species was found. In the subfamily Amblyseiinae there were 14 species in the genu...
The spider mite Tetranychus evansi has a broad range of host plants. Control of T. evansi has been a big challenge to tomato farmers due to its fast rate of reproduction, development of resistance to chemical pesticides and its ability to use weeds as alternative hosts when the tomato plants are not available. The aim of the current study was to de...
The spider mite Tetranychus evansi Baker & Pritchard can cause severe damage to tomato crops. The predatory mite Phytoseiulus longipes Evans was recently reported in association with T. evansi in Uruguaiana, Rio Grande do Sul State, Brazil. The objective of the present study was to evaluate the effects of P. longipes on the population of T. evansi...
The tomato red spider mite Tetranychus evansi Baker et Pritchard occurs on solanaceous plants, and causes serious damage to a variety of crops in Africa and Europe. In 2001 this species was also found in Japan, on nightshade (Solanum nigrum L.), and its invasion to solanaceous of agricultural importance is feasible. To evaluate its potential severi...
The tomato red spider mite, Tetranychus evansi Baker and Pritchard, has been considered as a threat to tomato production in some countries. Limited efforts have been dedicated to search for this mite and its natural enemies in Argentina. The objective of this study was to further study the distribution of T. evansi and the occurrence of associated...
Three elite tomato (Solarium lycopersicum L., syn. Lycopersicon esculentum Mill.) breeding lines (TOM-687, TOM-688, TOM-689) with high foliar acylsugar (AS) contents were obtained, and used along with two low-AS lines (TOM-690, TOM-684) in hybrid combinations, to obtain six hybrids between one low-AS line x one high-AS line (= hybrids with intermed...
The effect of five African nightshade (Solanum sp.) species on the biological and demographic parameters of the tomato spider mite, Tetranychus evansi Baker and Pritchard, was examined in the laboratory at 25 ± 1°C, 70–80% RH and 12L:12D photoperiod. Duration of each development stage, reproduction rate, longevity, intrinsic rate of natural increas...
The number of phytoseiid mite species varied greatly according to the geographical zones in Keyna. In the upper highlands (2400–4400m) 22 species were recorded, 44 in the lower highlands (1800–2400m), 57 in the midlands (800–1800m) and 25 in the lowlands (0–800m). The predacious mites Euseius kenyae (Swirski & Ragusa) and E. albizzae (Swirski & Rag...
Seven tomato (Lycopersicon sp.) accessions were evaluated for their resistance to the tomato red spider mite, Tetranychus evansi Baker and Pritchard, in the laboratory. Data recorded was: (i) trichome density and (ii) fecundity and longevity. Whole potted intact tomato plants were used for the olfactometer bioassays, while leaf disk sections were u...
This paper reports 18 tetranychid mite species (Acari: Tetranychidae) from various plant hosts in Kenya. Four species of these belong to the subfamily Bryobiinae and the other 14 belong to the subfamily Tetranychinae. Eight of the mite species identified belong to the genera Bryobia, Petrobia, Peltanobia, Paraplonobia, Duplanychus, Eutetranychus an...
Predicting the potential geographical distribution of a species is particularly important for pests with strong invasive abilities. Tetranychus evansi Baker & Pritchard, possibly native to South America, is a spider mite pest of solanaceous crops. This mite is considered an invasive species in Africa and Europe. A CLIMEX model was developed to pred...
Predatory behaviour and reproductive output of the ladybird beetle Stethorus tridens Gordon as function of the tomato red spider mite (TRSM), Tetranychus evansi Baker & Pritchard, densities was investigated in the laboratory. Adult female of S.tridens were isolated in cylindrical plastic arenas, containing a leaf disc of Solanum americanum Mill. wi...
Cultivated tomato (Lycopersicon esculentum Mill. cv. Money Maker) was crossed with the spider mite-resistant wild tomato, Lycopersicon hirsutum var. glabratum Mull, accession 'LA 2204', and assessed for trichome density and resistance to the spider mite Tetranychus evansi Baker and Pritchard. Trichome types I, III, IV, V, VI, and VII were identifie...
FIGURE 1. Peltanobia erasmusi Meyer female (from Meyer 1974, with permission). A—Peritreme, B— Dorsum, C—Palp-tarsus, D—Empodium, E—Tarsus and tibia I, F—Tarsus and tibia II.
FIGURE 2. Peltanobia erasmusi Meyer, male: (A) dorsum, (B) peritreme (C) distal segment of the palp tarsus, (D) male aedeagus.
FIGURE 4. Eutetranychus sp. aedegi (from Meyer, 1974 with modifications): (A) E. africanus aedeagus, (B) E. carinae aedeagus, (C) E. orientalis aedeagus.
FIGURE 3. (D) tarsus and tibia leg I, (E) tarsus and tibia leg II, (F) tarsus and tibia leg III, (G) tarsus and tibia leg IV.
FIGURE 5. Tetranychus sp. aedegi modified after Meyer, 1974 (with permission).: (A) T. evansi aedeagus; (B) T. lombardiini aedeagus; (C) T. ludeni aedeagus; (D) T. neocaledonicus aedeagus; (E) T. urticae aedeagus.
Twenty-three isolates of Metarhizium anisopliae (Metschnikoff) Sokorin and three isolates of Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales: Clavicipitaceae) were assessed for their virulence against the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). Based on the screening results, nine isolates of M. ani...
The virulence of three isolates of Beauveria bassiana (Bals.) Vuill. and 23 isolates of Metarhizium anisopliae (Metschnik.) Sorok. (Ascomycota: Hypocreales) against the tomato spider mite, Tetranychus evansi Baker and Pritchard (Acari: Tetranychidae), was assessed in the laboratory. The effect of temperature on germination, radial growth and virule...
This paper reports the mites of the family Phytoseiidae known from Argentina. It is based mostly on a survey conducted in the northern region of that country as well as on published information. Twenty-two species were found in that survey, ten of which are new records from that country, including a new species here described as Neoseiulus argentin...
This paper reports the mites of the family Phytoseiidae known from Argentina. It is based mostly on a survey conducted in the northern region of that country as well as on published information. Twenty-two species were found in that survey, ten of which are new records from that country, including a new species here described as Neoseiulus argentin...
This paper reports the mites of the subfamily Amblyseiinae (Phytoseiidae) known from Peru, based on an extensive survey conducted in different regions of the country as well as on published information. Forty-eight species are reported, four of which are new to science, namely Aristadromips escarsidentatus Guanilo & Moraes n. sp., Proprioseiopsis p...
This paper reports the mites of the subfamily Amblyseiinae (Phytoseiidae) known from Peru, based on an extensive survey conducted in different regions of the country as well as on published information. Forty-eight species are reported, four of which are new to science, namely Aristadromips escarsidentatus Guanilo & Moraes n. sp., Proprioseiopsis p...
The spider mites Tetranychus urticae Koch and Tetranychus evansi Baker and Pritchard are important pests of horticultural crops. They are infected by entomopathogenic fungi naturally or experimentally. Fungal pathogens known to cause high infection in spider mite populations belong to the order Entomophthorales and include Neozygites spp. Studies a...
Tetranychus
evansi is an important pest of tomato in several countries. The predatory mite Phytoseiulus
longipes has been found in association with it in Uruguaiana, State of Rio Grande do Sul, Brazil. The objective of this study was to evaluate the distribution of those two species in Uruguaiana region. Bi-weekly samples of plant parts were taken...
The tomato red spider mite, Tetranychus evansi Baker and Pritchard, is an invasive species in Africa causing considerable damage to Solanaceous crops. The fungal pathogen Neozygites floridana Weiser and Muma from Brazil has been considered a potential candidate for introduction into Africa for the control of T. evansi. To be incorporated in the tom...
This paper reports the mites of the subfamilies Phytoseiinae and Typhlodrominae (Phytoseiidae) from Peru, providing descriptions of 2 new species, Phytoseius ortegae Guanilo and Moraes, n. sp. and Phytoseius poripherus Guanilo and Moraes, n. sp., and a taxonomic key to separate the species reported.
This paper reports the mites of the subfamilies Phytoseiinae and Typhlodrominae (Phytoseiidae) from Peru, providing descriptions of 2 new species, Phytoseius ortegae Guanilo and Moraes, n. sp. and Phytoseius poripherus Guanilo and Moraes, n. sp., and a taxonomic key to separate the species reported.
Tetranychus evansi Baker and Pritchard and Tetranychus urticae Koch (Acari: Tetranychidae) are important pests of Solanaceae in many countries. Several studies have demonstrated that T. urticae is an acceptable prey to many predatory mites, although the suitability of this prey depends on the host plant. T. evansi, has been shown to be an unfavorab...
FIGURE 1. Female of Phytoseius ortegae Guanilo and Moraes n. sp.. A. Dorsal shield; B. ventral shields; C. Genu, tibia and basitarsus of leg IV; D. Chelicera; E. Variations of spermatheca.
FIGURE 2. Phytoseius poripherus Guanilo and Moraes n. sp.. Female: A. Dorsal shield; B. ventral shields; C. Chelicera; D. Variations of spermatheca; E. Genu, tibia and basitarsus of leg IV; Male: F. Spermatodactyl; G. Ventrianal shield.
FIGURE 7. Typhlodromips amazonensis Guanilo & Moraes n. sp. A. Dorsal shield; B. Ventral shields; C. Genu, tibia and basitarsus of leg IV; D. Chelicera; E. Spermatheca.
FIGURE 3. Female of Proprioseiopsis parabelizensis Guanilo & Moraes n. sp .. A. Dorsal shield; B. Ventral shields; C. Genu, tibia and basitarsus of leg IV; D. Chelicera; E. Spermatheca.
FIGURE 5. Aristadromips escarsidentatus Guanilo & Moraes n. sp. A. Dorsal shield; B. Ventral shields; C. Genu, tibia and basitarsus of leg IV; D. Chelicera; E. Variations of the spermatheca.
FIGURE 1. Variations of the spermatheca of Amblyseius chungas Denmark & Muma (based on specimens collected in this study in Callanca, Chiclayo, Lambayeque).
FIGURE 2. Proprioseiopsis neotropicus (Ehara). Female: Variations of the spermatheca. Figures based on specimens collected in this study in Soritor, San Martín (A) and in San Ignacio, Cajamarca (B and C).
FIGURE 6. Typhlodromips angustus Guanilo & Moraes n. sp. Female: A. Dorsal shield; B. Ventral shields; C. Genu, tibia and basitarsus of leg IV; D. Variations of the spermatheca; E. Chelicera. Male: F. Spermatodactyl; G. Ventrianal shield.
FIGURE 4. Euseius emanus (El-Banhawy). Female: A. Dorsal shield; B. Ventral shields; C. Genu, tibia and basitarsus of leg IV; D. Variations of the spermatheca; E. Chelicera; Male: F. Spermatodactyl; G. Ventrianal shield. Figures based on specimens collected in this study in Ingenio, Nazca, Ica.
FIGURE 8. Typhlodromips digitulus Denmark. Female. A. Variations of the spermatheca; B. Chelicera (based on a paratype female collected in Polk City, Florida, USA). Typhlodromips hellougreus Denmark & Muma. Female: C. Spermatheca; D. Chelicera (based on the holotype).
FIGURE 1. Neoseiulus argentinus n. sp.: A. Female dorsal shield; B. Female, ventral idiosoma; C. Female, genu, tibia and basitarsus of leg IV; D. Female, variations of spermatheca; E. Female, chelicera. F. Male, spermatodactyl; G. Male, ventri-anal shield.
Plants may defend themselves against herbivores via morphological traits, chemical traits, or a combination of both. Herbivores that overcome the defensive mechanisms of a plant tend to specialize on this plant due to enhanced protection from natural enemies. Well-known examples of plants possessing a suite of defensive mechanisms are found in nigh...
The mite Tetranychus evansi Baker & Pritchard (Tetranychidae) probably originated in South America. Because of its importance as a tomato pest in Africa, an extensive project has been conducted to detect potentially effective natural enemies in South America for the classical biological control of the pest in Africa. A search for the natural enemie...
Tetranychus evansi Baker and Pritchard, is a key pest of tomato in Africa. Surveys have been conducted in the last few years to search for predators associated with this pest in Brazil for introduction into Africa. Biological parameters of Phytoseiulus longipes Evans, one of the predators found in those surveys, were evaluated when it was exposed t...
The bionomics of Stethorus tridens Gordon fed Tetranychus evansi Baker & Pritchard were studied in the laboratory. The number of prey consumed by S. tridens increased with increasing instar levels and the total mean number consumed during immature development was 184.1 ± 18.02 T. evansi nymphs per individual. For adult male and adult female, the da...
Tetranychus evansi is an exotic pest of Solanaceous crops in Africa discovered in Zimbabwe in 1979. Two natural enemies, the pred-atory mite Phytoseiulus longipes and the fungal pathogen Neozygites floridana are important causes of mortality in T. evansi populations in Brazil. The first part of this study assessed the effects of N. floridana on pre...
The tomato red spider mite, Tetranychus evansi, is reported as a severe pest of tomato and other solanaceous crops from Africa, from Atlantic and Mediterranean Islands, and more recently from the south of Europe (Portugal, Spain and France). A population of the predaceous mite Phytoseiulus longipes has been recently found in Brazil in association w...
Surveys for predators of the tomato red spider mite Tetranychus evansi Baker & Pritchard on solanaceous plants were carried out in north-eastern and south-eastern Brazil to determine prospective species for the control of the pest in Africa. Surveys were carried out in areas identified as climatically similar to regions in Africa where T. evansi ha...
Surveys for predators of the tomato red spider mite Tetranychus evansi Baker & Pritchard on solanaceous plants were carried out in north-eastern and south-eastern Brazil to determine prospective species for the control of the pest in Africa. Surveys were carried out in areas identified as climatically similar to regions in Africa where T. evansi ha...
Surveys for predators of the tomato red spider mite Tetranychus evansi Baker & Pritchard on solanaceous plants were carried out in north-eastern and south-eastern Brazil to determine prospective species for the control of the pest in Africa. Surveys were carried out in areas identified as climatically similar to regions in Africa where T. evansi ha...
The red spider mite Tetranychus evansi Baker and Pritchard is a pest of tomato in East and Southern Africa. It is probably native to South America. Three models were established to identify priority areas for the search of natural enemies in South America for classical biological control of this pest in Africa. The models were based on the concept...
The susceptibility of various developmental stages of Tetranychus evansi Baker & Pritchard (eggs, larvae, protonymphs, deutonymphs and adults) to the entomopathogenic fungi Metarhizium anisopliae (Metschnikoff) Sorokin and Beauveria bassiana (Balsamo) Vuillemin was evaluated under laboratory conditions. Three concentrations (3.0 × 106, 1.0 × 107...
Tetranychus evansi Baker & Pritchard is an important pest of Solanaceae in several countries. Introduced accidentally to Africa, it presently occurs in many countries of that continent. In some of them, it is considered a key pest. The suspected area of origin of this mite is South America. The objective of the present study was to identify phytose...
The spatial distribution of motile life stages of the two-spotted spider mite Tetranychus urticae Koch in Kenyan small-scale tomato fields was described by Taylor's power law and an enumerative sampling plan was designed for research purposes. The exponential increase of T. urticae populations during three growing seasons permits the development an...
The occurrence of the tomato red spider mite (Tetranychus evansi Baker & Pritchard) and predatory mites on four of the most abundant native solanaceous plants in coastal Pernambuco, Brazil, was evaluated. Monthly samples were collected from mid September 2002 to late May 2003 in Alianca, Carpina, Camaragibe, Goiana, Igarassu and Recife. A total of...
A survey of natural enemies of the tomato red spider mite (Tetranychus evansi Baker & Pritchard) was conducted in October 2002 in parts of northeastern Brazil on solanaceous plants. Samples on other plant species near the solanaceous plants were also collected. T. evansi has been reported from different parts of the world and has been most recently...
Seventeen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and two isolates of Beauveria bassiana (Balsamo) Vuillemin were evaluated for their pathogenicity against the tobacco spider mite, Tetranychus evansi Baker & Pritchard. In the laboratory all the fungal isolates were pathogenic to the adult female mites, causing mortality between 22...
Red spider mite, Tetranychus evansi Baker & Prichard, is a relatively new pest of tomato ( Lycopersicon esculentum ) in Africa, accidentally introduced into southern Africa around 1980. Since then, the species has spread and was recorded for the first time in Kenya in 2001. The International Centre of Insect Physiology and Ecology (ICIPE), together...
The resistance of 63 tomato (Lycopersicon esculentum Mill.) accessions to the twospotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae), was investigated in screen house experiments and compared to Money Maker, a T. urticae-susceptible variety widely grown in Kenya. The number of motile mite stages 12 days after inoculation with 5 adul...
The effects of four different neem formulations (Neemros®, Neemroc EC®, Neemroc Combi and Saroneem) and a combination of Neemros® with a synthetic acaricide (Mitac®) on the twospotted spider mite (Tetranychus urticae Koch) were compared with Mitac® on tomato (Lycopersicon esculentum Mill.) leaf discs in the laboratory. The following LC50 were deter...
Zugl.: Hohenheim, Universiẗat, Diss., 1997.
