Phytoseiid mites (Acari: Mesostigmata) from Central West Morocco: new records and key to females of all recorded Moroccan species

Several phytoseiid species are excellent biological control agents for suppressing mite pest populations in many crops and preventing yield losses. This paper aims to improve the knowledge of Phytoseiidae diversity in citrus orchards and argan forest in central western Morocco. The surveys were conducted between April and October during three successive years (2017–2019), in nine conventional citrus orchards covering an area of more than 3,000 hectares and on uncultivated plants in argan forest at an altitude ranging from 150 to 700 meters. Twenty-nine species belonging to 15 genera were found, seven of them being new for the Moroccan fauna: Amblyseius largoensis, A. swirskii, Amblyseiella setosa, Euseius batus, E. dossei, Paragigagnathus molestus, and Cydnoseius negevi. Species of nine genera were found on citrus leaves: Neoseiulus, Amblyseius, Amblyseiella, Transeius, Phytoseiulus, Euseius, Phytoseius, Typhlodromus, and Paraseiulus. Stah AlMadina (24.8%), Ouled Abdellah (15.9%), Nour (14.3%) domains contained a high number (more than 60.2%) of individuals in the collected samples. Malva parviflora, Convolvulus althaeoides, Solanum nigrum, Bryonia dioica, Withania somnifera would be interesting companion plants to be associated in the inter-rows in citrus orchards in this region to ensure sustainability, because they host high densities and diversities of Phytoseiidae. A key of females of all recorded Moroccan species until now is provided.

The Phytoseiidae family accounts for more 2,557 species (Demite et al. 2014(Demite et al. , 2023. However, the fauna of some countries such as Morocco has not been completely surveyed (Tixier et al. 2008). Until now, about 50 species are reported from Morocco (McMurtry and Bounfour 1989; Kreiter et al. 2007; Tixier et al. 2016. Knowledge regarding the mite fauna, especially in citrus orchards of central west Morocco, is of considerable importance to establish effective programs for the biological control of pests. The aim of this study is to evaluate the phytoseiid species associated to plants both in citrus orchards, and on uncultivated plants in the argan forest in central western of Morocco, sampled at different seasons.

Material and methods
A survey of phytoseiid diversity was carried out in different citrus orchards in Taroudant region between April and October for two consecutive years 2016-2017 and 2017-2018. Orchard's names and geographic location are shown Table 1. All are conventionally conducted. Some pesticides were applied to control several pests and diseases (sulphur, abamectin, spirodiclofen, fenpropathrin, propargite, benzoxamate, clofentezine, tetradifon, phosmet, malathion, benomyl, deltamethrin, spirotetramat…). Herbicides (glyphosate, oxyfluorfen) were also applied from spring until autumn, and ground was ploughed several times. Additional sampling was undertaken on uncultivated plants in April 2019 between Agadir and Imouzzar Ida or Tanane, area of the argan Forest (Table 1).
Plants (citrus leaves, weeds, and windbreaks) were collected in all orchards in two seasons (spring and autumn). Each sample contains: 150 leaves of citrus varieties/ plot/ date/ year; the aerial part of 50 plants of weeds/ plot/ date/ year and 50 branches of windbreaks/ plot/ date/ year. Mites were collected using the dipping-checking-washing-filtering of leaves method (Boller 1984; Tixier et al. 2016. The collected individuals were preserved in 70% ethanol.
Mites were also collected from uncultivated plants in the area of the argan forest between Agadir city and Imouzzar Ida ou Tanane. This additional sampling was carried out as follows: branches of each plant (perennial woody plant: tree or shrub), at a level between 1 m and 1.5 m, were subjected to between 10 to 15 light taps with a stick during five to ten minutes/ plant. Among the individuals fallen on a black background, only the specimens considered to be phytoseiids were isolated, collected with a fine brush imbibed with alcohol. The collected individuals were kept in ethanol for identification. All phytoseiid mites were counted and were mounted on slides using Hoyer's medium (Gutierrez 1985; André 1986. Slides were then dried in an oven at 47°C for four days for thinning. Once dried, slides were sealed for conservation. Identifications were carried out with a phase and interference contrast microscope (Leica DM LB 2 phase contrast microscope, 10 x 25 HC Plan, Fluotar 100) (400x magnification). The generic classification of Chant and McMurtry (2007) was used for identification. Other more specific literature was used for species determination (Swirski et al. 1998; Kreiter et al. 2007, 2016a; Papadoulis et al. 2009; Ferragut et al. 2010; Tixier et al. 2013.

Results
A total of 248 individuals of phytoseiid mites were identified from citrus leaves, weeds, and associated windbreaks (Cupressus, other conifers, Acacia) in nine orchards in Taroudant region and in the argan forest in central west of Morocco (Table 1). Twenty-two species found were Table 1 Phytoseiidae species presently observed and their geographical distribution in the sampled citrus orchards and uncultivated plants in the argan forest (the species underlined are new for the Moroccan fauna). already reported and seven species are new for the Moroccan fauna. The list of these species is presented below, with some biological information and uses in biological control when available. Geographical distributions information is issued from Demite et al. (2023).
A key of all recorded Moroccan species is given after.

Taxonomy
Subfamily Amblyseiinae Remarks -Measurements and description of the adult females collected agree with those provided by Beard (1999) and Schicha (1976) for specimens from Australia. This species is commercialised and used in greenhouses to control phytophagous mites and thrips (Messelink et al. 2006). It seems able to control Tetranychus urticae Kock and Phytonemus pallidus (Banks) in field-grown strawberry (Fitzgerald et al. 2008). It was also known to feed on tarsonemid mites (Tuovinen and Lindquist 2010), eggs of Bemisia tabaci (Gennadius) on vegetables (cucumber, sweet pepper, tomato) in laboratory conditions as reported by Kim et al. (2008).  Moraes et al. 1986: 85, 2004a: 128; Chant & McMurtry 2003: 23, 2007 World distribution -Algeria, Israel, Morocco, and Tunisia. Previous records from Morocco -This species has been reported for the first time in Morocco on Echium vulgare (L.) (Boraginaceae) at Larache Beach (Tixier et al. 2016).
Remarks -Measurements and description of the adult females collected agree with those provided by Evans (1987). Tsolakis et al. (2013) showed the ability of this species to feed on T. urticae, Panonychus citri (McGregor), P. ulmi (Koch). This species is only known from the Mediterranean basin and has been observed on Convolvulus spp. (Convolvulaceae) and on Cynodon dactylon (L.) (Poaceae) (Sahraoui et al. 2012). In addition, as reported by Tsolakis et al. (2019), N. longilaterus have similar traits with some phytoseiid species belonging to type II selective predators, but also with some others included within type III generalist predators. As a matter of fact, it can be considered an interesting biocontrol agent towards T. urticae, able also to develop on alternative foods as the pollen of Oxalis spp. L. (Oxalidaceae).
Remarks -Measurements and description of adult females collected in this survey agree with those provided by Ferragut et al. (2010) for specimens from Spain and by Tixier et al. (2016) for specimens from Morocco. Few studies exist on its biology; it has the ability to develop feeding on T. urticae (Kazak et al. 2002) and on Thrips tabaci Lindeman on leek (Allium porrum L.) (Alliaceae) in laboratory conditions (Sengonca and Dresher 2001).
Remarks -The morphological features of the specimens here in collected sample agree with those provided by Tixier et al. (2016) for specimens from Morocco.
Specimens examined -2 ♀♀ and 1 ♀ respectively on Convolvulus althaeoides L. and C. arvensis M. (Bieb) (Convolvulaceae) in May 2017 at Errahim domain in 2017. This is the first record of this species for the Moroccan fauna.
Remarks -The description and measurements of the adult females collected agree with those provided by Swirski et al. (1998) for specimens from Israel and Muma (1955) for specimens from Florida (USA).
Previous records from Morocco -This species was reported from Morocco on citrus . It has been observed in many regions on many other plants such as Remarks -The description and measurements of adult females collected agree with those provided by Denmark and Muma (1989). This species is cosmopolitan and considered a polyphagous predatory mite. It has been reported on a wide range of plants, particularly in vineyards  and on fruit trees like in apple orchards as reported by Tixier et al. (2013). In addition, it feeds on many species of mites, such as Aculops lycopersici (Tryon) (Eriophyidae) responsible for tomato russet, key pests of ornamental coniferous plants, i.e., Oligonychus ununguis (Jacobi) and Pentamerismus taxi (Haller), and pollen of Pinus sylvestris L. (Pinaceae) (Lara et al. 2012; Puchalska et al. 2021. Amblyseius italicus (Chant) Moraes et al. 1986: 16, 2004a: 31; Chant & McMurtry, 2004: 193, 2007 World distribution -Italy, Kenya, and Morocco. Previous records from Morocco -This species was reported by McMurtry and Bounfour (1989) in El Jadida, 2 ♀♀ on cucumber (Cucurbitaceae) leaves in greenhouse.
Remarks -The description and measurements of the adult females collected agree with those provided by McMurtry and Bounfour (1989) for specimens from Morocco.  Moraes et al. 1986: 17, 2000: 239, 2004a: 143, 2004b: 33; Chant & McMurtry 2004: 208, 2007 Amblyseius sakalava Blommers, 1976: 96 (Synonymy according to Ueckermann & Loots 1988). Gupta, 1977: 53 (Synonymy according to Gupta 1986 Remarks -The description and measurements of the adult females collected agree with those provided by McMurtry and Moraes (1984) for specimens from South Pacific, by Karmakar et al. 2017 for specimens from West Bengal (India) and by Fang et al. (2020) for specimens from Vietnam. This species is an important natural enemy of mite pests in China (Wu et al. 2009). It prefers high humidity environment, and was found the dominant native species in surveyed citrus orchards in Vietnam (Fang et al. 2020). Amblyseius largoensis is a generalist predator that feeds on a diversity of phytophagous mites, mainly those of the families Eriophyidae, Tenuipalpidae, and Tetranychidae, small insects and other food types, including pollen Ramos 2004; Navia et al. 2007).
Remarks -The description and measurements of the adult females collected agree with those provided by Ferragut et al. (2010) for specimens from Spain, by Zannou and Hanna (2011) for specimens from sub-Saharan Africa and by Kreiter et al. (2016a, b) for specimens from Reunion Island and from various countries in the world. Amblyseius swirskii is one of the most efficient phytoseiid species; it is currently released in more than 50 countries of the world (Calvo et al. 2015). It originates from the East Mediterranean coast and has been described in 1962 from almond [Prunus dulcis (Mill.) D.A. Webb.] (Rosaceae) in Bet Dagan, Israel by Athias-Henriot. This species is able to develop not only in the Mediterranean basin, but also in subtropical and tropical areas in Africa (Zannou and Hanna 2011). It is commonly used to control whiteflies and thrips in greenhouse vegetables (especially cucumber and pepper) and some ornamental crops in Europe and North America (Buitenhuis et al. 2014; Calvo et al. 2015.  (Chant, 1959): 87 (Synonymy according to Athias-Henriot 1966). Graminaseius exiguus (Hirschmann, 1962): 26 (Synonymy according to Athias-Henriot 1966). Remarks -The description and measurements of the adult females collected agree with those provided by Döker et al. (2019) for specimens from Turkey. This species is distributed worldwide and has been collected on a great variety of plants including citrus (Kreiter et al. 2010; Sahraoui et al. 2012) and horticultural crops (Tixier et al. 2016  Remarks -The description and measurements of the adult females collected agree with those provided by Moraes et al. (2001) for specimens from Sub-Saharan Africa by Basahih et al. (2015) for specimens from Saudi Arabia.
Specimens examined -8 ♀♀ on Malva parviflora L. (Malvaceae) in September 2018 at Ouled Abdellah. This is the first record of this species in Morocco.
Remarks -The description and measurements of the adult females collected agree with those provided by Moraes et al. (2001) for specimens from Sub-Saharan Africa. This species is mainly reported from the South of the West Palaearctic region and is found in dry climates. It is very common in Maghreb and South of Spain (Kreiter et al. 2004) and recorded in Tunisia on many plants including citrus (Kreiter et al. 2010; Sahraoui et al. 2012. This species is able to feed on T. urticae and P. citri (Abbassy et al. 2012). It can be reared on pollen and is considered as a biological control agent against phytophagous mites, scale insects, and whiteflies on greenhouse cucumber (Nomikou et al. 2002).
Previous records from Morocco -This species was recorded in many regions in Morocco and collected on several plants as reported by Tixier et al. (2016).
Remarks -The description and measurements of the adult females collected agree with those provided by Döker et al. (2018) for specimens from Turkey. This species has a wide distribution in Africa and South Europe and around the Mediterranean Sea (Swirski and Amitai, 1997b; Moraes et al, 2004a; Sahraoui et al, 2012. It is described by McMurtry and Croft (1997) as a generalist (type III predator), able to feed on a wide range of food such as thrips larvae, spider mites, and pollen (Nwilene and Nachman 1996; Van Rijn and Tanigoshi 1999; Vantornhout et al. 2004; Messelink et al. 2006). This species is commercialised for biological control of the western flower thrips Frankliniella occidentalis (Pergande) in greenhouses (Vantornhout et al. 2005).  (Beglyarov 1958): 116 (Synonymy according to Pritchard & Baker 1962). Specimens examined -6 ♀♀ on citrus leaves in July 2017at Taoufiqui 1 domain.

Subfamily Phytoseiinae Berlese
Remarks -The measurements of adult females collected agree with those provided by Tixier et al. (2016) for specimens from Morocco. Phytoseius finitimus is often recorded on plants with highly pubescent leaves (Walter 1992; McMurtry andCroft, 1997). It is found in higher densities on such host plants (Tixier et al. 1998; Duso andVettorazzo 1999), suggesting that it may be promising candidates for biological control of pests. Hairy structures may offer shelters and domatia with favourable microclimatic conditions (increased relative humidity, reduced temperature) for the development and reproduction of this mite (Walter 1996; McMurtry and Croft 1997; Tixier et al. 1998; Kreiter et al. 2003. Phytoseius finitimus is a generalist phytoseiid mite mainly recorded in the Mediterranean region on a variety of both cultivated and non-cultivated plants, such as grapevine, hazelnut, citrus, walnut, mulberry, peach, plum, pomegranate, and cotton (Swirski and Ragusa 1977; Duso and Vettorazzo 1999; Papaioannou Souliotis et al. 1999; Tsolakis et al. 2000; Nomikou et al. 2001. It is a natural enemy of tetranychid and eriophyid mites, but it also feeds on small insect and pollen (Nomikou et al. 2001; Momen andEl-Borolossy 2010 (Yousef 1980): 122 (Synonymy according to Chant & Yoshida-Shaul 1986). Cydnoseius schusteri (Yousef & El-Borolossy in Zaher 1986): 129 (Synonymy according to Kanouh et al. 2012).
Remarks -The measurements of adult females fit well with those provided by Alatawi et al. (2017) for specimens from Saudi Arabia. Previous records from Morocco -This species has been reported for the first time by Tixier et al. (2016). It has been collected on Convolvulus althaeoides L. (Convolvulaceae) and Vinca major L. (Apocynaceae).
Remarks -The measurements of adult females collected agree with those provided by Chant and McMurtry (1994). Previous records from Morocco -This species has been reported for the first time by Tixier et al. (2003). It has been collected on Ulmus spp. L. (Ulmaceae) at Ifrane city.

Tribe Typhlodromini Wainstein
Remarks -The measurements of adult females collected agree with those provided by Ferragut (2018)  World distribution -Cape Verde, Greece, Israel, Morocco, and Spain. Previous records from Morocco -This species was reported in Morocco and was mainly found near the Atlantic Ocean coast. Tixier et al. (2016)  Remarks -The measurements of adult females collected agree with those provided by Kanouh et al. (2010) for specimens from France.  Remarks -The measurements of adult females agree with redescription provided by Tixier et al. (2016) for specimens from Morocco. This species has been reported on many uncultivated plants and sometimes on some orchards such as peach, plum, olive, citrus, and vineyards (Ragusa 2006). Nothing is known of its ability to control pests (Tixier el al. 2016).
Specimens examined -4 ♀♀ on citrus leaves were collected in July 2017 at Taoufiqui 2 domain; 5 ♀♀ on citrus leaves in September 2018 at the same domain.
Remarks -The measurements of adult females fit well with those provided by Tixier et al. (2016) for specimens from Morocco. The measurements of adult females agree with those provided by Tixier et al. (2010) for specimens from Croatia on Cornus sanguinea L. (Cornaceae) and by Tixier et al. (2016) for specimens from Morocco.

Identification key to females of recorded species of Moroccan Phytoseiidae
This key contains the 59 species presently recorded from Morocco.

Discussion and conclusion
Predacious mites of the family Phytoseiidae are small mesostigmatid mites whose habits are very diverse (Chant 1959; McMurtry et al. 1970, 2013; Kreiter et al. 2001; Tixier et al. 2016. Some species of predatory mites rank among the most important biological control agents used in populations control of various pests (whiteflies, thrips, and mites), such as: Phytoseiulus persimilis, Neoseiulus californicus, Amblyseius andersoni and A. swirskii. Fiftytwo species were known from Morocco until 2016(McMurtry and Bounfour 1989; Kreiter et al. 2001; Tixier et al. 2003; 2016. In this study, we report 29 species of Phytoseiidae in surveys carried out in nine citrus orchards covering an area of over 3000 hectares and from uncultivated plants in the argan forest between Agadir city and Imouzzar Ida ou Tanane. Among the 29 species herein reported (belonging to 15 genera), seven are new for the Moroccan fauna: Amblyseius largoensis, A. swirskii, Amblyseiella setosa, Euseius dossei, E. batus, Paragigagnathus molestus, and Cydnoseius negevi. Some genera were found on citrus leaves such as: Amblyseius, Neoseiulus, Transeius, Typhlodromus, Phytoseiulus, Paraseiulus, and Phytoseius. Phytoseiulus persimilis is collected from four domains. Cydnoseius negevi is observed in two domains, while Amblyseius largoensis and Transeius audeae were observed in only one domain. The Taoufiqui 3 orchard does not contain phytoseiid mites. These results could probably be explained by the importance of chemical applications and their detrimental effect on natural enemy fauna (Howarth 1991; Naranjo 2001; Cock et al. 2010; El Wakeil et al. 2013.
Some species have been mainly found on weeds (Malva parviflora and Convolvulus althaeoides) such as Phytoseius finitimus, Neoseiulella litoralis, Typhlodromus (Typhlodromus) setubali, Typhlodromus (T.) octogenipilus and Paraseiulus talbii. Some weeds such as Malva parviflora and Convolvulus althaeoides show quite high numbers of Phytoseiidae. This can be explained by leaf characteristics, food occurrence or to biological preferences of mite species as reported by Tixier el al. (2016). The new-recorded species were found in Stah Al Madina, Saouda, Ouled Abdellah, Errahim and Nour orchards ( Table 1). The global diversity of Phytoseiidae in these four orchards represented more than 70% of species recorded. Results of the present survey will improve phytoseiid fauna knowledge especially in this region of Morocco area with more than 70% of the citrus production intended for export, and will be helpful in biological pest management programs against T. urticae, P. citri and E. orientalis. These species are serious pests, especially species of many fruit trees and grapevines in many countries (Bolland et al. 1998; Hare and Phillips 1992; Meck et al. 2009; Ledesma et al. 2011; González-Domínguez et al. 2015. Among phytoseiid species collected in orchards, some Amblyseiinae such as Neoseiulus californicus, Neoseiulus longilaterus, Neoseiulus cucumeris, Amblyseius andersoni, Amblyseius italicus, Phytoseiulus persimilis, Euseius stipulatus, E. sculatis, Euseius batus, Iphiseius degenerans and some Typhlodrominae can constitute potential biological control agents since some are considered as general predators which feed on a wide variety of food sources including mites, insects, and pollen. Malva parviflora, Convolvulus arvensis, C. althaeoides, Solanum nigrum, Bryonia dioica, Withania somnifera, Tecoma spp. would be among the best plant species to plant in the inter-row in citrus orchards in this region of Morocco to ensure sustainability, high densities and diversity of Phytoseiidae and insect predators species. It would be interesting to complete this survey by studying extent of exchanges of Phytoseiidae between citrus and the ground cover, as well as the influence of the weed management practices currently adopted in orchards on the diversity and density of native fauna, especially to determine how these plants that shelter phytoseiid mites can not also be host plants for mite pests.