Patent Description:
The use of arthropods (insects and mites) as Biological Control Agents (BCA) is an expanding field with many advantages over chemical pest control. Arthropod BCA's are able to naturally control other arthropod species that act as pests on the crop. Phytoseiulus is a genus of mites in the Phytoseiidae family. This predatory mite is the most frequently used to control two-spotted spider mites in greenhouses and outdoor crops grown in mild environments. A Phytoseiulus mite can consume up to seven adult spider mites or several dozens of their eggs in a day. A well-fed female lays about <NUM> eggs in her lifetime. The genus Phytoseiulus contains four known species, namely: P. persimilis, P. longipes, P. macropilis and P. fragariae (Chant and McMurtry <NUM>). All species of the genus Phytoseiulus are considered type <NUM> predators, i.e. highly specific to a diet consisting of spider mites, preferably of the genus Tetranychus (McMurtry and Croft <NUM>). The most frequently used species of this genus for biological control of spider mites is Phytoseiulus persimilis. Phytoseiulus persimilis (P. persimilis) adults are bright reddish-orange in color, with long legs and pear-shaped bodies (about <NUM> long).

persimilis is considered as a specialist for spider mites (mites of the family Tetranychidae) which are phytophagous mites (Helle and Sabelis <NUM>, Gerson et al. Gerson et al. <NUM> specifically indicate that "members of the genus Phytoseiulus live and place their eggs almost exclusively within the webbed colonies of Tetranychus spp". It is further noted in Gerson et al. <NUM> that "the specificity of P. persimilis for spider mite prey can be a disadvantage if other predators are present on the same plants".

It was found that P. persimilis might develop and possibly reproduce on another phytophagous (plant feeding) mite, Steneotarsonemus pallidus of the family Tarsonemidae (Simmonds, S.

From a commercial point of view, a significant disadvantage of producing a predatory mite that exclusively feeds on phytophagous mites, such as spider mites, is that it requires rearing prey mites on plants, which has a high cost.

Walzer and Schausberger, <NUM>, examined intra- and interspecific predation of adult females and immature stages of the more generalist Neoseiulus californicus and the specialist Phytoseiuluspersimilis. It was reported that adult females and immatures of both predators exhibited higher predation rates on larvae than on eggs and protonymphs. It was found that predation on P. persimilis by N. californicus was more severe than vice versa. persimilis was reported to have higher predation rates on conspecifics than heterospecifics and was more prone to cannibalism than N. californicus. In addition, it was reported that when provided with phytoseiid prey, P. persimilis suffered higher mortality than N. californicus.

Walzer and Schausberger, <NUM> further teach that females of P. persimilis were not able to sustain oviposition, irrespective of con- or heterospecific prey. Furthermore, mortality of P. persimilis immatures was less when feeding on conspecific vs. heterospecific larvae. These authors concluded that for P. persimilis, neither hetero-nor conspecific prey provides sufficient nourishment for sustained reproduction. This is supported by Yao and Chant (<NUM>), reporting that P. persimilis did not produce eggs when either cannibalizing or preying upon immatures of Iphyseius degenerans. There were only two females in this study that laid a single egg when cannibalizing conspecific.

In summary, it was found that P. persimilis was able to develop on juvenile predatory mites Neoseiulus californicus and Iphyseius degenerans of the family Phytoseiidae. However, it did not lay eggs when feeding on these prey mites. On the other hand, when the predatory mite N. californicus and I. degenerans fed on P. persimilis, they did lay eggs (Yao and Chant, <NUM>). This demonstrates the narrow dietary range of P. persimilis in contrast to other mites of the same family.

persimilis might also develop in a cannibalistic manner, feeding on younger stages of its own. When feeding this way, there were rare cases of oviposition (Walzer and Schausberger, <NUM>; Yao and Chant, <NUM>). In all cases where the Phytoseiidae mites were used as prey, the latter was fed with spider mites, which are grown on plants and therefore involves high costs.

persimilis was further found to develop on thrips (a phytophagous insect) larvae, but it did not lay eggs on this diet (Walzer <NUM>). This is in contrast to the predatory mite N. califonicus that was able to reproduce on this prey (Walzer <NUM>). It should be emphasized that in this study, a high rate of mortality was reported during juvenile development.

<CIT> and <CIT>, as well as <CIT>, disclose a mite composition comprising predatory mite species selected from Mesostigmatid mite species or Prostigmatid mite species and a food source for the predatory mite species comprising Astigmatid mite species. It is further disclosed in these publications that at least a fraction of the Astigmatid individuals is immobilized and that the immobilized Astigmatid individuals are contacted with a fungus reducing agent comprising a fungus reducing mite population selected from a mycophagous mite species or an antifungal exudates producing mite species. These publications mention the Phytoseiulus genus in a list of optional Phytoseiidae members as part of mite species belonging to Mesostigmata order. However, these publications do not show, disclose or even suggest rearing predatory mite species belonging to the Phytoseiulus genus, known as specialist for spider mites (e.g. McMurtry and Croft <NUM>), with Astigmatid mite species as a factitious host for the predatory mites. In addition, these publications teach that when immobilized Astigmatid individuals are used as a prey, they should necessarily be contacted with a fungus reducing agent selected from a mycophagous mite species or an antifungal exudates producing mite species. It is noted in these publications that both optional fungus reducing mite populations should be in a viable form to provide the fungus reducing activity, a factor which might negatively affect mass rearing efficiency.

<CIT> teaches a mite composition comprising a rearing population of a phytoseiid predatory mite species and a factitious host population comprising at least one species selected from the family of the Carpoglyphidae.

<CIT> discloses a mite composition comprising a rearing population of the phytoseiid predatory mite species Amblyseius swirskii, a factitious host population comprising at least one Astigmatid mite species selected from the group consisting of: i) Carpoglyphidae, ii) Pyroglyphidae, and iii) Glyciophagidae.

<CIT> discloses a method for rearing predatory mites by providing a food source for prey mites that comprises dextrose; rearing Thyreophagus entomophagus prey mites on said food source; providing predatory mites that feed on Thyreophagus entomophagus in a starting ratio of predatory mites to prey mites from <NUM>:<NUM> to <NUM>:<NUM>, and rearing the predatory mites on said prey mites, to create a breeding population.

<CIT> and <CIT> patents teach that Phytoseiulus persimilis can be only raised on spider mite diet. They report that P. persimilis is an obligate spider mite predator and cannot survive on alternate food sources such as pollen. It is emphasized in these publications that survival tends to be poor if prey is in short supply.

<CIT>, published as <CIT>, discloses a mite composition comprising a rearing population of a phytoseiid predatory mite species and a population of at least one species from the order Astigmata characterized in that the population of the species from the order Astigmata is not alive.

<CIT> discloses mite composition comprising a rearing population of a phytoseiid predatory mite species and a factitious host population characterised in that the factitious host population comprises at least one species selected from the family of the Glyciphagidae. When referring to the phytoseiid mite Phytoseiulus persimilis, it is indicated that spider mites (Tetranychus urticae) is the best prey.

None of the above patent documents discloses or teaches successfully rearing the important predatory mite Phytoseiulus persimilis on mites of the order Astigmata, in any form or developmental stage. On the contrary, all the above patent documents and scientific publications report that P. persimilis is an obligate spider mite predator and it cannot survive on alternate food sources. Therefore, an entomologist/acarologist would not consider P. persimilis as a typical generalist species of the Phytoseiidae family or the Amblyseiinae subfamily but rather a highly specific species.

In view of the above, there is a long felt need for effective and efficient mass rearing of Phytoseiulus persimilis for biological control of crop pests.

The present invention relates to the field of insect control and more specifically to a system and method for rearing biological control agents against plant pests.

It is one object of the present invention to disclose a rearing composition according to claim <NUM>.

It is a further object of the present invention to disclose the rearing composition as defined in any of the above, wherein said predatory mite species is selected from the group consisting of Phytoseiulus fragariae, Phytoseiulus longipes, Phytoseiulus macropilis, Phytoseiulus persimilis and Phytoseiulus robertsi.

It is a further object of the present invention to disclose the rearing composition as defined in any of the above, wherein the species from the order Astigmata comprises members from the family Carpoglyphidae, such as the genus Carpoglyphus, e.g. Carpoglyphus lactis, Carpoglyphus munroi; from the family Glycyphagidae such as the genus Glycyphagus, e.g. Glycyphagus domesticus, from the genus Lepidoglyphus, e.g. Lepidoglyphus destructor; from the family Pyroglyphidae such as the genus Dermatophagoides, e.g. Dermatophagoides farinae, Dermatophagoides pteronisinus, form the family Acaridae, such as the genus Tyrophagus, e.g. Tyrophagus putrescentiae.

It is a further object of the present invention to disclose the rearing composition as defined in any of the above, wherein said Astigmata prey population comprises a mixture comprising non-viable frozen developmental stages of juvenile mites.

It is a further object of the present invention to disclose the rearing composition as defined in any of the above, wherein said composition further comprises a carrier such as sawdust, bran or another carrier material.

It is a further object of the present invention to disclose a method for controlling a crop pest, the method comprising applying a composition as defined in any of the above to a field crop.

It is a further object of the present invention to disclose the use of the composition as defined in any of the above for controlling a crop pest.

It is a further object of the present invention to disclose a biological control agent (BCA) for controlling crop pests comprising a mixture of (a) at least one predatory mite species of the genus Phytoseiulus raised by the composition according to any one of claims <NUM> to <NUM>, (b) optionally, prey mite individuals comprising at least one species from the order Astigmata, said Astigmata individuals are selected from the group consisting of non-viable mites, non-living eggs and a combination thereof; and (c) a carrier material.

It is a further object of the present invention to disclose a container containing the composition according to any one of the above, said container configured to be hung on a crop plant, said container comprises an exit hole from which said predatory mites are slowly and continuously released to said crop during a period of about three weeks.

In order to understand the invention and to see how it may be implemented in practice, a plurality of embodiments is adapted to now be described, by way of non-limiting example only, with reference to the accompanying drawings; wherein:.

The twospotted spider mite, Tetranychus urticae Koch, is the major spider mite pest of ornamental plants and vegetable crops grown in greenhouses. Furthermore, this ubiquitous spider mite is a serious pest of numerous ornamental plants in home landscapes and is of considerable importance as a pest of food and fiber crops throughout the world (van de Vrie et al,. The predacious phytoseiid mite Phytoseiulus persimilis is the major species used to control twospotted spider mites in greenhouse as well as open field crops.

Phytoseiulus persimilis is a predatory mite which specializes on a diet of spider mites. Spider mites are vegetarian mites (phytophagous mites) and therefore require rearing on plants, which is undesirable since it involves complex operations and high rearing costs.

The present invention provides for the first time alternative method for rearing P. persimilis and other mite species of the genus Phytoseiulus. The current invention shows, against the conventional thinking, that mite species of the genus Phytoseiulus, e.g. P. persimilis, could broaden its dietary range, and could be reared on other preys, which are cheaper to produce and therefore much more desirable. The alternative prey mites are mostly Astigmatic mites that feed on stored products and are therefore significantly cheaper to produce.

According to one embodiment, the present invention provides a system and method for using mites (especially dead mites) of the species Carpoglyphus lactis (Cl) or other Astigmatic mite as an alternative food for mite species of the Phytoseiulus genus, such as Phytoseiulus persimilis.

It is shown by the present invention that mite species of the genus Phytoseiulus, especially Phytoseiulus persimilis, can complete its life cycle and reproduce when feeding on dead mites belonging to the order Astigmata (within the Arachnida class).

The present invention is aimed at developing a system for the production of mite species of the genus Phytoseiulus, e.g. Phytoseiulus persimilis, on a diet comprising Astigmatic mites. The system is based on the following components:.

The following rearing methods are within the scope of the present invention:.

It is noted that in all of the above optional rearing methods, the prey mite could be either the above mentioned Astigmatic mites, or other species.

With respect to the final biological control product, the following is within the scope of the present invention:.

According to one embodiment, the present invention provides a rearing composition comprising: a predatory mite population comprising at least one mite species of the genus Phytoseiulus, and a prey mite population comprising individuals of at least one mite species from the order Astigmata, wherein said predatory mite population is capable of oviposition for at least <NUM> generations, further wherein said Astigmata prey is selected from the group consisting of non-viable mites, non-viable eggs and a combination thereof.

It is within the scope of the present invention that the predatory mite is capable of oviposition for at least <NUM> generations and preferably more, having the Astigmata individuals as a prey.

It is further within the scope that the predatory mite population exhibits an increased reproduction rate trait as compared to a control predatory mite population, of the same species, lacking the aforementioned trait.

It is further within the scope that the predatory mite population of the present invention exhibits a daily reproduction rate in the range of about <NUM> -<NUM>.

It is further within the scope of the present invention that the predatory mite population is characterized by a beige-white color, when said Phytoseiulus predatory mite is reared upon said Astigmata prey as a food source.

It is within the scope of the present invention that the predators would have a different appearance than that of the common product containing P. persimilis mites reared on spider mites (white mites in the case of the present invention instead of the usual orange).

According to a further embodiment, the present invention shows for the first time that a population of P. persimilis successfully developed and reproduced on dead Carpoglyphus lactis for at least six months (about <NUM> generations).

It is emphasized that P. persimilis is herein surprisingly reported to complete its life cycle and reproduce on either non-phytophagous prey (prey that doesn't require to feed on living plants), or prey that doesn't consume phytophagous mites.

The present invention provides a mite composition which contains a Phytoseiulus persimilis rearing mite population, and a factitious host mite population comprising at least one species from the order Astigmata or from the family Phytoseiidae. Up until now, mite species of the genus Phytoseiulus, such as the important predator mite Phytoseiulus persimilis, were reared on their natural phytophagous mite diet which involves high costs and resources (such as providing appropriate plants in sufficient abundance, under greenhouse conditions).

The present invention solves the serious problem of rearing the main spider-mite controlling predator, Phytoseiulus persimilis, by rearing it in a cost effective and efficient way on a non-phytophagous alternative diet.

Accordingly, the invention provides a mite composition comprising: a rearing population of mite species of the genus Phytoseiulus, for example Phytoseiulus persimilis predatory mite species, a population of at least one species from the order Astigmata or from the family Phytoseiidae, and optionally a carrier.

According to one embodiment, the present invention provides a rearing composition comprising: predatory mite population comprising at least one mite species of the genus Phytoseiulus, and a prey mite population comprising at least one species from the order Astigmata.

According to a further embodiment, the present invention provides a method for rearing predatory mite population comprising at least one mite species of the genus Phytoseiulus, the method comprising: (a) providing a composition comprising a predatory mite population comprising at least one mite species of the genus Phytoseiulus, and a prey mite population comprising at least one species from the order Astigmata; and (b) allowing individuals of the predatory mite population to prey on individuals of the Astigmatid population.

According to a further embodiment, the present invention provides a rearing composition comprising: predatory mite population comprising at least one mite species of the genus Phytoseiulus, and a prey mite population comprising at least one species from the Phytoseiidae family.

According to a further embodiment, the present invention provides a method for rearing predatory mite population comprising at least one mite species of the genus Phytoseiulus, the method comprising: (a) providing a composition comprising: predatory mite population comprising at least one mite species of the genus Phytoseiulus, and a prey mite population comprising at least one species from the Phytoseiidae family; and (b) allowing individuals of the predatory mite population to prey on individuals of the Phytoseiidae family population.

In some embodiments, the prey population i.e. species from the order Astigmata or species from the Phytoseiidae family, is immobilized and/or not alive.

It is further within the scope that the Phytoseiulus persimilis predatory mite is capable of reproducing for at least <NUM> generations, preferably at least <NUM> generations, more preferably for at least <NUM> generations or more generations, feeding on the aforementioned Astigmata population.

The composition of the present invention provides a considerable number of advantages over previous combinations. In one aspect, the food material used to feed the prey during predator production will no longer be plants or phytophagous mites, but mites that live upon stored products, therefore providing a substantial cost saving.

In another aspect, the present invention provides a rearing composition comprising: predatory mite population comprising at least one mite species of the genus Phytoseiulus, and a prey mite population comprising at least one species from the Phytoseiidae family.

According to some further embodiments of the present invention, the predatory mite species is selected from the group consisting of Phytoseiulus fragariae, Phytoseiulus longipes, Phytoseiulus macropilis, Phytoseiulus persimilis and Phytoseiulus robertsi.

According to further embodiments of the present invention, the predatory mite species is Phytoseiulus persimilis.

According to yet further embodiments of the present invention, the prey mite species is of the genus Amblyseius, e.g. Amblyseius swirskii.

According to further embodiments of the present invention, the rearing composition comprises immobilized prey mites.

According to further aspects of the present invention, the prey mites are immobilized or dead mites.

According to further aspects, the present invention provides a method for controlling a crop pest, the method comprising applying a composition as defined in any of the above to a field crop.

According to further aspects, the present invention provides use of the composition as defined in any of the above for controlling a crop pest.

According to further aspects, the present invention provides a biological control product for controlling crop pests comprising a mixture of (a) Phytoseiulus persimilis predatory mite individuals raised by the composition as defined in any of the above, (b) prey mite individuals comprising at least one species from the order Astigmata, and (c) optionally a carrier material.

According to further aspects, the present invention provides a biological control product for controlling crop pests comprising a mixture of (a) Phytoseiulus persimilis predatory mite individuals raised by the composition according to any one of claims <NUM> to <NUM>, and (b) prey mite individuals comprising at least one species from the Phytoseiidae family, and (c) optionally a carrier material.

The present invention further provides a slow release system (e.g. sachet) for mites, especially for mite species of the genus Phytoseiulus, particularly Phytoseiulus persimilis (P. persimilis) configured to be applied on a crop.

A core aspect of the innovative solution is that the predatory mites can reproduce within the system for several generations, while a certain proportion of the predatory mites continuously leaves the system and reaches the crop to control pests. This provides a continuous supply of mites to the crop without the need to apply them repeatedly by the farmer.

Embodiments of the slow release system provided by the present invention are based upon the following features:.

It is noted that such slow release systems for predatory mites are highly desirable for P. persimilis since up until now, P. persimilis was known as a specialist (natural enemy) of spider mites and therefore reared upon spider mites diet. However, spider mites are not suitable to be used in this kind of mite release systems for crop protection for the following reasons:.

The present invention provides an unexpected technological solution for the above problem, which was not shown to be successful up until now. The solution is based upon using frozen eggs of C. lactis or other astigmatid mite species as a factitious host for P. persimilis. Contrary to spider mites, frozen eggs of C. lactis maintain their nutritional value for about three weeks. This innovative solution enables the prolonged release of P. persimilis predatory mites from a container or a mixture combining the predatory mite with its factitious host, applied directly on the crop plant for controlling pests.

As used herein the term "about" denotes ± <NUM>% of the defined amount or measure or value.

The term "controlled release" refers hereinafter to slow release, sustained-release, rapid release, designed to release in a prolonged controlled mode or fashion. In the context of the present invention, it refers to predatory mite release to the crop plant gradually over a specified period of time, e.g. throughout the day or over a week.

The term "slow release system" or a "container" refers herein after to a sachet- type release system, e.g. a sachet, packet, pouch, pocket, sack, a bottle or a bag which contains the composition or formulation of the present invention of Phytoseiulus predatory mites, a factitious host (dead astigmatid mites) and optionally a carrier. It is further included within the scope of the present invention that such a system or container refers to an apparatus, a unit, a device, a compartment, a member, strip or housing for slow release of beneficial insects or predatory mites available or known in the art.

It is also within the scope of the present invention that the Phytoseiulus predatory mite releasing system may be of any suitable type. In general the mite releasing system may comprise a container suitable for holding the individuals of the Phytoseiulus predatory mite (e.g. P. persimilis) and individuals of the factitious host mite (e.g. dead C. lactis eggs). The container comprises an opening and/or means for generating an exit opening for mobile stages of the Phytoseiulus predatory mite. Releasing systems of this type are known to the skilled person and various products are commercially available on the market, e.g. sachet-type releasing systems and other suitable types of releasing systems which are included within the scope of the present invention.

The term "rearing composition" as used herein generally refers to a composition suitable for breeding, bringing up, raising, upbringing or propagating a mite species. More specifically, it refers to a composition suitable for the commercial rearing of mites. It is herein acknowledged that mass rearing systems for predatory mites heavily depend on the availability of suitable prey for the predators. Therefore, there is a continuing need to improve rearing systems of both predatory mites and mites suitable as rearing prey. To solve this problem, the present invention provides a composition or system specifically adapted for effectively and efficiently rearing mite species of the genus Phytoseiulus, especially Phytoseiulus persimilis, a highly important predatory mite used for crop pest (spider mites) biological control. For the first time, Phytoseiulus persimilis is shown to complete its life cycle and reproduce, i.e. for at least <NUM> generations, by being reared on Astigmatid mite species or on Phytoseiidae prey mite species, e.g. Amblyseius swirskii.

The term "carrier" refers hereinafter to an inactive or inert substance or particles or vehicle. In a preferred embodiment the rearing composition of the present invention comprises a carrier for the individuals of the mite species. The carrier can be any solid material which is suitable to provide a carrier surface to the mite individuals. Examples of suitable carriers are plant materials such as bran (e.g. wheat), sawdust (e.g. fine sawdust), corn cob grits, vermiculite, etc..

The term "Phytoseiulus" as used hereinafter refers to a genus of mites in the Phytoseiidae family. This genus of predatory mites is most frequently used to control two-spotted spider mites in greenhouses and outdoor crops. It is within the scope of the present invention that the genus Phytoseiulus contains the following species: Phytoseiulus fragariae, Phytoseiulus longipes, Phytoseiulus macropilis, Phytoseiulus persimilis and Phytoseiulus robertsi. The Phytoseiulus predetoy mites are known as specialists for spider mites (mites of the family Tetranychidae) which are phytophagous mites.

The term "Phytoseiulus persimilis" or "P. persimilis" as used hereinafter refers to a predatory mite population comprising the Phytoseiulus persimilis (P. persimilis). Phytoseiulus is a genus of mites in the Phytoseiidae family. This predatory mite is the mite predator most frequently used to control two-spotted spider mites in greenhouses and outdoor crops grown in mild environments.

persimilis is generally used for spider mite control and management. They are voracious predators of most of the spider mite pests (Tetranychus spp). Some of the species they impact include: the two-spotted mite Tetranychus urticae, the carmine red mite T. cinnabarinus, and the Pacific mite T. Unlike Neoseiulus californicus (Order: Mesostigmata, Family: Phytoseiidae, Subfamily: Amblyseiinae) which may not eat for relatively long periods, Phytoseiulus persimilis must have fresh feed. Furthermore, Phytoseiulus persimilis are not flexible by their diet as other available predatory mite species for spider mite control, since they are known to only feed upon specific Tetranychus species, but not all of them.

The present invention solves these problems by providing for the first time a composition for mass rearing P. persimilis which contains mite species of the order Astigmata. The rearing system of the present invention is much more cost effective than rearing P. persimilis on its conventional diet which consists of phytophagous mites.

The term "factitious host" generally refers hereinafter to an unnatural host or host other than the target host for the predatory mite, one that biocontrol practitioners may more readily rear than the target host in a laboratory. In the context of the present invention, factitious host or prey refers to organisms unlikely to be attacked by a natural enemy or predatory mite in its natural habitat, but that is artificially used to support its development and/or reproduction. Usually it is a species that is easier and less expensive to rear. Examples within the scope of the present invention include storage mites (such as astigmatid mites) for predatory mites (such as Phytoseiulus mite species), mite eggs for predatory insects and mites. According to further aspects, the term factitious host is used when a biological control agent is forced to feed on an insect or mite that it would not feed on it in nature. This can allow higher production levels. The present invention shows for the first time that species of commercially available Phytoseiulus mites can be mass reared using astigmatid mites (Acari: Astigmata) as factitious prey.

The term "juvenile mite" or "juvenile mites" refers hereinafter to mite developmental life stages or mite developmental phases or instar including egg, larva, protonymph and deutonymph (third instar) individuals.

The term "individual" or "individuals" or "mite individuals" refers in the context of the present invention to mite developmental stages including, but not limited to eggs, juvenile mite stages such as larva, protonymph and deutonymph (third instar) individuals.

The term "mobile stages" refers hereinafter to mite developmental stages including larva, protonymph, deutonymph (third instar) and adult stages.

The term "non-viable" used hereinafter generally means not capable of living, growing, developing, or functioning. According to main aspects of the present invention it refers to dead or not alive or non-living or immobilized mites (i.e. any mite developmental stage or phase) or mite eggs. In a specific embodiment of the present invention, non-viable Astigmata mites and/or eggs are used as a prey for predatory mites of the Phytoseiulus genus.

According to some embodiments of the present invention the non viable mites or eggs are produced by or exposed to a treatment including, but not limited to, thermal treatment, such as freezing, freeze-drying, heating, cold-shock or heat-shock treatment; chemical treatment, such as gas or fume treatment; radiation treatment, such as UV, microwave, gamma irradiation or X-ray treatment; mechanical treatment, such as vigorous shaking, or stirring, subjecting to shear forces, collision; gas pressure treatment, such as ultrasound treatment, pressure changes, pressure drops; electrical treatment, such as electrocution; immobilizing with an adhesive; immobilization by starvation, such as induced by water or food deprivation; immobilization by suffocation or anoxia treatment, such as by temporarily eliminating oxygen from the atmosphere or replacing oxygen by another gas and any combination thereof.

According to a specific embodiment, the composition of the present invention comprises dead frozen C. lactis eggs used as a prey for predatory mites of the Phytoseiulus genus. The term "Astigmatid" or "Astigmata" or "Astigmatic mites" or "Astigmatina" as used herein refers to mites order within the Subclass: Acari. The Astigmatina are a "cohort" of mites. Astigmatina belongs to the Sarcoptiformes, which contains the "biting" Acariformes. The Astigmata order contains superfamilies with over thousands of genera. Non limiting examples of such superfamilies and families, within the scope of the present invention may include:.

A preferable Astigmatid mite species used by the biological control system of the present invention as a factitious host population for the Phytoseiulus predatory mite, e.g. P. persimilis, is a mite species of the Carpoglyphidae family, more preferably Carpoglyphus lactis (C.

Carpoglyphidae is a mite family in the order Astigmatina, containing four genera: Carpoglyphus, Coproglyphus, Dichotomiopus and Pullea.

Carpoglyphus lactis (Acarus lactis), preferably used by the present invention as a diet for rearing P. persimilis, belongs to the Carpoglyphus genera. Carpoglyphus lactis is acknowledged herein as a stored product mite, infesting saccharide-rich stored commodities including dried fruits, wine, beer, milk products, jams and honey. lactis is capable of feeding on stored products, it is highly desirable and cost effective to raise P. persimilis on this mite species, as shown for the first time by the present invention.

In a further embodiment of the present invention, the Phytoseiulus predatory mite, e.g. P. persimilis, can complete its life cycle and reproduce when feeding on dead mites of the species Carpoglyphus lactis and/or Dermatophagoides farinae both belonging to the Astigmata order.

The term "trait" refers hereinafter to characteristic or phenotype. A phenotypic trait may refer to the appearance or other detectable characteristic of an individual, resulting from the interaction of its genome, proteome and/or metabolome with the environment. For example, in the context of the present invention an increased reproduction rate as described herein is a phonotypical trait characterizing the predatory mites of the composition of the present invention. According tp a further embodiment of the present invention, a trait may also arise from interaction between the mite and its associated microorganisms. A trait may be inherited in a dominant or recessive manner, or in a partial or incomplete-dominant manner. A trait may be monogenic (i.e. determined by a single locus) or polygenic (i.e. determined by more than one locus) or may also result from the interaction of one or more genes with the environment. A dominant trait results in a complete phenotypic manifestation at heterozygous or homozygous state; conventionally, a recessive trait manifests itself only when present at homozygous state.

The term "genetic linkage" is understood within the scope of the invention to refer to an association of characters in inheritance due to location of genes in proximity on the same chromosome, measured by percent recombination between loci (centi-Morgan, cM).

As used herein, the term "population" means a genetically heterogeneous collection of mites sharing a common genetic derivation.

As used herein, the phrase "genetic marker" or "molecular marker" or "biomarker" refers to a feature in an individual's genome e.g., a nucleotide or a polynucleotide sequence that is associated with one or more loci or trait of interest In some embodiments, a genetic marker is polymorphic in a population of interest, or the locus occupied by the polymorphism, depending on context. Genetic markers or molecular markers include, for example, single nucleotide polymorphisms (SNPs), indels (i.e. insertions deletions), simple sequence repeats (SSRs), restriction fragment length polymorphisms (RFLPs), random amplified polymorphic DNAs (RAFDs), cleaved amplified polymorphic sequence (CAPS) markers, Diversity Arrays Technology (DArT) markers, and amplified fragment length polymorphisms (AFLPs) or combinations thereof, among many other examples such as the DNA sequence per se. Genetic markers can, for example, be used to locate genetic loci containing alleles on a chromosome that contribute to variability of phenotypic traits. The phrase "genetic marker" or "molecular marker" or "biomarker" can also refer to a polynucleotide sequence complementary or corresponding to a genomic sequence, such as a sequence of a nucleic acid used as a probe or primer.

A genetic marker can be physically located in a position on a chromosome that is within or outside of the genetic locus with which it is associated (i.e., is intragenic or extragenic, respectively).

As used herein, the term "germplasm" refers to the totality of the genotypes of a population or other group of individuals (e.g., a species).

The terms "hybrid" and "hybrid progeny" used herein refers to an individual produced from genetically different parents (e.g., a genetically heterozygous or mostly heterozygous individual).

The term "allele(s)" used herein means any of one or more alternative or variant forms of a gene or a genetic unit at a particular locus, all of which alleles relate to one trait or characteristic at a specific locus. In a diploid cell of an organism, alleles of a given gene are located at a specific location, or locus (loci in plural) on a chromosome. One allele is present on each chromosome of the pair of homologous chromosomes. A diploid plant species may comprise a large number of different alleles at a particular locus. Such alternative or variant forms of alleles may be the result of single nucleotide polymorphisms, insertions, indels, inversions, translocations or deletions, or the consequence of gene regulation caused by, for example, by chemical or structural modification, transcription regulation or post-translational modification/regulation. An allele associated with a qualitative trait may comprise alternative or variant forms of various genetic units including those that are identical or associated with a single gene or multiple genes or their products or even a gene disrupting or controlled by a genetic factor contributing to the phenotype represented by the locus. As used herein, the term "locus" (loci in plural) means a specific place or places or region or a site on a chromosome where for example a gene or genetic marker element or factor is found. In specific embodiments, such a genetic element is contributing to a trait.

As used herein, the term "breeding" and grammatical variants thereof, refer to any process that generates a progeny individual. Breeding can be sexual or asexual, or any combination thereof. Exemplary non-limiting types of breeding include crossing, introgressing, selfing, backcrossing, doubled haploid derivative generation, and combinations thereof.

The term "genetic determinant" as used herein refers to genetic determinants such as genes, alleles, QTLs or traits.

Introgression of a genetic determinant means the incorporation of genes, alleles, QTLs or traits into a line wherein essentially all of the desired morphological and physiological characteristics of the line are recovered, in addition to the genetically introgressed determinant. Such a process is often used in cultivar development, in which one or a few genetic determinants are transferred to a desired genetic background, preferably by using backcrossing.

The term "genotype" refers to the genetic constitution of a cell or organism. An individual's genotype includes the specific alleles, for one or more genetic marker loci, present in the individual's haplotype. As is known in the art, a genotype can relate to a single locus or to multiple loci, whether the loci are related or unrelated and/or are linked or unlinked. In some embodiments, an individual's genotype relates to one or more genes that are related in that the one or more of the genes are involved in the expression of a phenotype of interest. Thus, in some embodiments a genotype comprises a summary of one or more alleles present within an individual at one or more genetic loci. In some embodiments, a genotype is expressed in terms of a haplotype.

According to a further embodiment of the present invention, the Phytoseiulus predatory mite, e.g. P. persimilis, can complete its life cycle and reproduce (i.e. including development and oviposition) for at least <NUM> generations, when feeding on living juvenile mites of the species Amblyseius swirskii that belongs to the Phytoseiidae family.

It is further within the scope of the present invention to disclose a population of Phytoseiulus predatory mites, e.g. the mite species P. persimilis, reared by feeding on dead or immobilized mite species selected from the group comprising Carpoglyphus lactis, Dermatophagoides farinae, Lepidogyphus destructor, Glyciphagus domesticus, Dermatophagoidespteronisinus, Amblyseius swirskii, and any combination thereof.

According to a further embodiment, the predatory mite fed on the above prey mites, developed and reproduced for at least two generations.

According to a further embodiment of the present invention, P. persimilis or other Phytoseiulus predatory mite, can develop on dead individuals of the following species belonging to the Astigmata order: Carpoglyphus lactis, Lepidoglyphus destructor, Glycifagus domesticus and Dermatophagoides pteronisinus.

It is further within the scope that the mites used as prey are immobilized by immobilization treatment selected from the group consisting of: thermal treatment, such as freezing, heating, cold-shock or heat-shock treatment; chemical treatment, such as gas or fume treatment; radiation treatment, such as Gamma irradiation, UV, microwave or X-ray treatment; mechanical treatment, such as vigorous shaking, or stirring, subjecting to shear forces, collision; gas pressure treatment, such as ultrasound treatment, pressure changes, pressure drops; electrical treatment, such as electrocution; immobilizing with an adhesive; immobilization by starvation, such as induced by water or food deprivation; immobilization by suffocation or anoxia treatment, such as by temporarily eliminating oxygen from the atmosphere or replacing oxygen by another gas.

The skilled person will understand how these treatments may result in the immobilization of the Astigmatid individuals or other mites of the Phytoseiidae family and that the immobilization treatment should be such that the mite individuals remain a suitable prey (food source) for the predatory mite individuals.

It is further within the scope that the term "immobilized mites" may also mean dead or non-living mites.

Reference is now made to <FIG> photographically presenting different developmental stages of P. persimilis reared on dead or immobilized C. The figure presents an adult female (<FIG>) and a juvenile that had just hatched from the egg (<FIG>). As can be seen in this figure, all stages are characterized by a pale whitish color, typical to this diet, in contrast to the normal orange color obtained when feeding P. persimilis by spider mites, their conventional diet. In other words, the predators of the present invention, fed on C. lactis, turn to beige-white instead of the typical orange color. In addition, the dorsal shield of the predator is darker than the cuticle around it. This figure demonstrates that P. persimilis can develop and reproduce on dead or immobilized C. lactis mites. As explained above, C. lactis (Acari: Astigmata) are significantly more cost effective to produce than the conventional P. persimilis diet, which is the phytophagous spider mite.

Reference is now made to <FIG> photographically presenting P. persimilis reared on dead or immobilized C. As can be seen, the predator has a unique appearance, where it turns to beige-white instead of the typical orange (when fed on conventional spider mite diet) and the dorsal shield of the predator is darker than the cuticle around it.

It is herein acknowledged that twospotted spider mites feed on many species of plants and are a major pest of vegetables, ornamentals, fruit trees, hops, cotton, and strawberries (van de Vrie et al. At present, it can be assumed that most of the major spider mite problems in greenhouses will involve twospotted spider mite. The larva, protonymph, deutonymph, and adult feed mainly on the undersides of the leaves.

It is within the scope of the present invention to provide a composition for controlling mite pests, particularly members of the Acari class, family Tetranychidae such as twospotted spider mite, more particularly spider mite species, especially the genera Tetranychus, Panonychus and various other mite species.

According to some embodiments of the present invention, the crop is selected from the group consisting of greenhouse grown crops and open field crops. Non limiting examples of crop types within the scope of the present invention include vegetables, ornamentals, fruit trees, hops, cotton and strawberries.

Specific examples of mite pests- host plant species within the scope of the present invention include the following:.

The term "fungus reducing agent" or "fungal reducing agent" refers hereinafter to chemical fungus reducing agents such as a natural or synthetic fungicide, or to a biological fungus reducing agent such as a population of a mite species producing antifungal exudates, or a population of mycophagous mites.

It is within the scope of the current invention that the rearing composition as defined in any of the above is absent of or is lacking a fungus reducing agent. The claimed Phytoseiulus mites of the present invention are capable of completing their life cycle and reproducing for at least <NUM> generations when reared upon Astigmata non-living individuals including mites at any developmental stage and/or eggs. It is noted that the non-viable Astigmata mite developmental stages are incapable of producing or secreting a fungus reducing agent.

In order to understand the invention and to see how it may be implemented in practice, a plurality of preferred embodiments will now be described, by way of non-limiting example only, with reference to the following examples.

In this example, rearing is done by feeding P. persimilis with a mixture comprising dead frozen developmental stages of C. lactis and sawdust or another carrier material (e.g. bran). The prey mites were immobilized by an immobilization treatment, e.g. by freezing them or by a gamma irradiation treatment, prior to using them as food.

By using the aforementioned feeding regime, P. persimilis population was increased by an average of about <NUM>%, per day.

<FIG> graphically describes the daily multiplication rate of P. persimilis, feeding on a mixture of dead C. lactis eggs and mobile stages (killed by freezing) during a <NUM> weeks period. As can be seen, an average increase of between about <NUM>% and about <NUM>% in multiplication rate of P. persimilis was recorded per day.

persimilis population was reared using dead C. lactis as prey at <NUM> degrees Celsius and <NUM>% relative humidity in a mixture with sawdust. Every week the mixture was weighed, and four samples containing about <NUM> were taken, placed on a black adhesive tape and counted. Total population size was calculated according to these counts and <NUM> individuals were left in the rearing each week. The multiplication rate was calculated by dividing the total number of the individuals found by <NUM>, giving the factor by which the population multiplied during this week. To switch to a daily multiplication rate, the 7th root of this number was taken according to the following formula: <MAT>.

Where λ is the daily multiplication rate, N(<NUM>) is the number of mites left in the rearing in the former count (<NUM> in this case), N(t) is the number of mites found at the current count, and t=<NUM>.

In this experiment, different mite species were tested as food for P. persimilis using the following protocol:
<NUM> P. persimilis mites were isolated in modified Munger cells, and served with frozen astigmatic mites of the species that are listed below. Food was replaced daily, and the mites were checked for feeding signs. The signs used as indicators were a full roundish body (contrary to a flat body of non-feeding mites), and whitish coloration in contrast to the usual orange color when feeding on spider mites.

Reference is now made to <FIG> graphically presenting the percentage of P. persimilis showing feeding signs, as appeared by their body's shape and color, after given food for <NUM> consecutive days from each of the following prey species:.

It can be seen that P. persimilis can feed on all of the above Astigmatic prey species, with varying efficiency.

In this experiment, <NUM> predatory mites were given frozen mites of A. swirskii as food at <NUM> degrees Celsius, <NUM>% RH, and checked daily. Mites were showing feeding signs by their large body shape and whitish coloration. When oviposition started, eggs were removed from the population, isolated, and hatchability was monitored. Hatching was noticed followed by maturation of the resulting larvae. When these mites matured, two were isolated to check for egg laying. These females did lay eggs, and hatching of the resulting eggs was observed. This demonstrates that P. persimilis can develop and reproduce on frozen A. swirskii as food for at least two generations, and that eggs laid at the third generation are viable.

Reference is now made to a description of a controlled release system for P. persimilis according to some embodiments of the present invention. Mixture containing about <NUM> P. persimilis mites reared on dead C. lactis prey and sawdust as a carrier was inserted into a container (e.g. sachet or a small plastic bottle of about <NUM>) with an exit hole in its lid. The container was placed on an adhesive tape or surface under controlled conditions (<NUM> degrees Celsius and <NUM>% humidity). The adhesive tape was replaced twice a week, and P. persimilis mites which appeared on it were counted to assess the release rate from the container.

Reference is now made to <FIG> graphically illustrating mites release rate from the container as a function of the number of days since the setup of the experiment.

As can be seen in <FIG>, mites are continuously released from the container for a period of <NUM> days, with a release peak occurring around day <NUM> (between days <NUM> and <NUM>). The predatory mite release rate is between about <NUM> to <NUM> mites per day. This example demonstrates that a slow or controlled release system for P. persimilis (for at least about <NUM> days) is constructed, based on the rearing composition and method of the present invention.

Reference is now made to an example in which rearing is done by feeding Phytoseiulus longipes (P. longipes), as a further representative example of the Phytoseiulus genus, with a mixture comprising dead C. lactis as a prey.

Exemplified rearing protocol: A P. longipes population was reared using dead C. lactis as prey at <NUM> degrees Celsius and <NUM>% relative humidity in a mixture with sawdust. Mites showed feeding signs by changing their color from typical redish to white, as shown above for P, perdimilis fed on C. lactis (see <FIG> and <FIG>). In addition, all of the different life stages of the P. longipes mites have been observed, indicating that this species completed its development cycle on this alternative diet. The rearing was maintained for three weeks, showing that the P. longipes population can be reared upon dead C. lactis diet for at least this period of time.

This experiment shows successful breeding and selection for a P. persimilis population adapted for rearing on C. lactis as prey. As shown in this example, the selected P. persimilis population is characterized by advantageous and desirable properties of significantly increased reproduction rate when reared on Astigmatid mite individuals.

persimilis were reared using dead C. lactis as prey at <NUM> degrees Celsius and <NUM>% relative humidity in a mixture with sawdust. Every week the mixture was weighed, and four samples containing about <NUM> each were taken, placed on a black adhesive tape and counted. Total population size was calculated according to these counts and <NUM> individuals were left for rearing each week. The multiplication rate was calculated by dividing the total number of the individuals found, by <NUM>, giving the factor by which the population multiplied during this week. To calculate the daily multiplication rate, the <NUM>th root of this calculated number was taken according to the following formula: <MAT> where λ is the daily multiplication rate, N(<NUM>) is the initial number of mites left for rearing (i.e. <NUM> mites), N(t) is the total number of mites found after rearing for a week period of time, and t=<NUM>.

It is noted that each population was maintained and measured for <NUM>-<NUM> weeks. The entire procedure was replicated for <NUM> times.

Reference is now made to <FIG> demonstrating the observed differences in the daily reproduction rate (represented by λ, the finite rate of increase) between the P. persimilis population bred and selected for adaptation for C. lactis as a factitious host prey (marked as P+ in <FIG>), as compared to the conventional or commercially available P. persimilis population (reared upon its natural host, i.e. spider mites) used as a control (marked as P- in <FIG>). The figure represents the means and the standard error found in the λ values during the trial.

As can be seen in <FIG>, the P. persimilis population subjected to selection for improved adaptation to rearing upon C. lactis individuals (P+) demonstrated a significant increased daily reproduction rate of about <NUM> fold (P+/P-: <NUM>/<NUM>) on C. lactis as a prey, as compared to the control P. persimilis population, not subjected to the breeding and selection process as inter alia described (P-).

To conclude, the present invention provides for the first time a P. persimilis population characterized by increased reproduction rate trait when reared upon Astigmatid mites such as C. lactis individuals as a prey. This enables the highly desirable, revolutionary, indoor production of improved P. persimilis predatory mites exhibiting increased yield when reared upon Astigmata species, as compred to non-selected currently available P. persimilis mites, which demonstrate significantly reduced reproduction rate and yield when reared upon the same Astigmata species prey.

This example shows the performance of a slow release system of the current invention (e.g. as described in Example <NUM> above) in greenhouse conditions.

Sweet pepper plants were planted in the greenhouse, and exposed to three different treatments in <NUM> replicates:.

The sachet was located on the lower parts of <NUM> meter tall plants. Infestation was carried out by stapling an infested leaf with spider mites to one of the top leaves of the plant. The mite population on each plant was sampled <NUM> days after the plants were infested. The spider mites and P. persimilis mites found on the infested leaf or above it were counted.

Claim 1:
A rearing composition comprising:
a predatory mite population of at least one mite species of the genus Phytoseiulus, and individuals of a prey mite population of at least one mite species from the order Astigmata as a food source for Phytoseiulus predatory mites, wherein said predatory mite population is capable of oviposition for at least two generations,
wherein said Astigmata prey is selected from the group consisting of nonviable mites, non-viable eggs and a combination thereof.