Mononychellus tanajoa (cassava green mite)
Index
- Pictures
- Identity
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Description
- Distribution
- Distribution Table
- History of Introduction and Spread
- Introductions
- Risk of Introduction
- Habitat List
- Hosts/Species Affected
- Host Plants and Other Plants Affected
- Growth Stages
- Symptoms
- List of Symptoms/Signs
- Biology and Ecology
- Climate
- Air Temperature
- Rainfall
- Natural enemies
- Notes on Natural Enemies
- Means of Movement and Dispersal
- Pathway Causes
- Pathway Vectors
- Plant Trade
- Impact Summary
- Impact
- Economic Impact
- Environmental Impact
- Social Impact
- Risk and Impact Factors
- Uses List
- Detection and Inspection
- Similarities to Other Species/Conditions
- Prevention and Control
- Gaps in Knowledge/Research Needs
- References
- Organizations
- Contributors
- Distribution Maps
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Top of pageIdentity
Top of pagePreferred Scientific Name
- Mononychellus tanajoa Bondar
Preferred Common Name
- cassava green mite
Other Scientific Names
- Mononychus tanajoa Fletchman & Baker, 1970
- Tetranychus tanajoa Bondar
International Common Names
- English: cassava green mite
- Spanish: acaro amarillo de la yucca; acaro verde de la yucca
- French: acarien vert
Local Common Names
- Brazil: acaro verde da mandioca
- East Africa: utitiri wa muhogo
EPPO code
- MONNTA (Mononychellus tanajoa)
Summary of Invasiveness
Top of pageThe cassava green mite, M. tanajoa, is of Neotropical origin but was accidentally introduced to Africa in 1971 (Nyiira, 1972). By 1985, the pest had spread throughout the cassava belt of Africa (Yaninek and Heren, 1988). M. tanajoa affects the important annual crop cassava (Manihot esculenta) and can cause a reduction of about 50% in leaf weight, and up to 80% tuber yield loss (Shukla, 1976; Gutierrez et al., 1988; Pallangyo et al., 2004). M. tanajoa is mainly dispersed by human activity, whereby infested plant materials and contaminated media are transported over long distances. Natural dispersion by wind and water may also spread the cassava green mite. In areas where both the pest and host plant are exotic, there is no evidence that indigenous natural enemies are significant factors in limiting the mite population growth rates. M. tanajoa can feed and reproduce on other plant species (Moraes et al., 1995) and is reported as a quarantine pest (Delalibera et al., 1992; EPPO, 2009).
Taxonomic Tree
Top of page- Domain: Eukaryota
- Kingdom: Metazoa
- Phylum: Arthropoda
- Subphylum: Chelicerata
- Class: Arachnida
- Subclass: Acari
- Superorder: Acariformes
- Suborder: Prostigmata
- Family: Tetranychidae
- Genus: Mononychellus
- Species: Mononychellus tanajoa
Notes on Taxonomy and Nomenclature
Top of pageMononychellus tanajoa was first described in Brazil as Tetranychus tanajoa by Bondar (1938). Tanajoa is a Brazilian Indian word meaning disease of cassava. Wainstein (1960) first proposed the genus Monochychus for species closely related to tanajoa. The species was later transferred to the genus Mononychus by Flechtmann and Baker (1970). Because of the prior usage of the name Mononychus for another group of animals, this group was newly named Mononychellus by Wainstein (1971).
In previous versions of the Compendium, M. caribbeanae was incorrectly listed as a synonym of M. tanajoa. This synonymy was proposed by Tuttle et al. (1977), but recent mite catalogues (Bolland et al., 1998; Vacante, 2016; Vásquez-Ordonez, 2014) list M. tanajoa and M. caribbeanae as distinct species.
Taxonomic keys for the separation of tetranychid mites feeding on cassava can be found in Flechtmann (1978, 1986), Macfarlane (1984) and Yaninek et al. (1989b).
The history of the nomenclature of M. tanajoa up to 1978 is given by Salas (1978). See also the catalogue by Bolland et al. (1998).
Description
Top of pageM. tanajoa, like other members of the Acari, are recognized by their inconspicuous or absent body segmentation giving the appearance of a single body unit. This mite also lacks wings, compound eyes and antennae. Adult females are bigger than the males and attain a size of 0.8 mm.
For more details refer to Jeppson et al. (1975) and Smith Meyer (1987).
Distribution
Top of pageLike cassava, its primary host, M. tanajoa originated from the neotropics, where it occurs sporadically.
Due to the misidentification of the exotic mite M. progresivus as M. tanajoa in Africa, the distribution of M. tanajoa in this region requires careful scrutiny. Distribution data for M. tanajoa published from the 1970s to the mid 1990s during a time of taxonomic ambiguity may not be as accurate as more current references (Hicks, 2017).
For further references to Central American records, see Bolland et al. (1998).
Records of M. tanajoa in Antigua and Barbuda, Argentina, Chile, French Guiana, Peru, Suriname, Uruguay, Northern Mariana Islands and Micronesia (EPPO, 2014) published in previous versions of the Compendium are now considered unreliable (EPPO, 2016).
A record of M. tanajoa in Australia (EPPO, 2014) published in previous version of the Compendium was based on an old record which is now considered to be erroneous. In 2016, Australian mite specialists confirmed the absence of M. tanajoa in Australia to the NPPO (EPPO, 2016).
Records of M. tanajoa in Florida (Pena et al., 1984) and Puerto Rico (Cruz, 1981) published in previous versions of the Compendium are considered invalid as they refer to M. caribbeanae, which was previously considered a synonym of M. tanajoa (Tuttle et al., 1977) but is now recognized as a separate species (Doreste, 1981).
In 2010, M. tanajoa was reported in Hainan, China (Lu et al., 2012), but the mite was incorrectly identified. Subsequent publications by Lu identify the species as M. mcgregor (Lu et al., 2014). Cassava green mite is not present in China (Parsa et al., 2015). M. tanajoa has not been reported in any of the Asian cassava-producing countries (Bellotti et al., 2012).
Korang-Amoakoh et al. (1987) described the species found in Ghana as “M. tanajoa sensu latu”, therefore the mite’s specific epithet was not verified. This record is unreliable as no current sources include Ghana in the distribution of M. tanajoa.
Distribution Table
Top of pageThe distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
Last updated: 12 May 2022Continent/Country/Region | Distribution | Last Reported | Origin | First Reported | Invasive | Reference | Notes |
---|---|---|---|---|---|---|---|
Africa |
|||||||
Angola | Present | ||||||
Benin | Present, Widespread | ||||||
Burkina Faso | Present, Widespread | ||||||
Burundi | Present, Widespread | ||||||
Cameroon | Present, Widespread | ||||||
Central African Republic | Present | ||||||
Chad | Present | ||||||
Congo, Democratic Republic of the | Present, Widespread | Original citation: Leuschner (1978) | |||||
Congo, Republic of the | Present, Widespread | ||||||
Côte d'Ivoire | Present, Widespread | ||||||
Equatorial Guinea | Present, Widespread | ||||||
Gabon | Present, Widespread | ||||||
Ghana | Absent, Unconfirmed presence record(s) | ||||||
Guinea | Present, Widespread | ||||||
Kenya | Present, Widespread | Invasive | |||||
Liberia | Present, Widespread | ||||||
Malawi | Present, Widespread | Invasive | |||||
Mali | Present, Widespread | ||||||
Mozambique | Present, Widespread | ||||||
Niger | Present | ||||||
Nigeria | Present, Widespread | ||||||
Rwanda | Present, Widespread | ||||||
Sierra Leone | Present, Widespread | ||||||
Sudan | Present, Widespread | ||||||
Tanzania | Present, Widespread | ||||||
-Zanzibar Island | Present, Widespread | ||||||
Togo | Present, Widespread | ||||||
Uganda | Present, Localized | Invasive | |||||
Zambia | Present | Original citation: Chakupurakal et al., 1994 | |||||
Zimbabwe | Present | ||||||
Asia |
|||||||
China | Absent, Invalid presence record(s) | ||||||
-Hainan | Absent, Invalid presence record(s) | ||||||
North America |
|||||||
Antigua and Barbuda | Absent, Unconfirmed presence record(s) | ||||||
Costa Rica | Present | ||||||
Dominican Republic | Present | ||||||
El Salvador | Present | ||||||
Guadeloupe | Present | ||||||
Mexico | Present | ||||||
Nicaragua | Present | ||||||
Panama | Present | ||||||
Puerto Rico | Absent, Invalid presence record(s) | ||||||
Trinidad and Tobago | Present, Widespread | ||||||
United States | Absent, Invalid presence record(s) | ||||||
-Florida | Absent, Invalid presence record(s) | ||||||
Oceania |
|||||||
Australia | Absent, Invalid presence record(s) | ||||||
Federated States of Micronesia | Absent, Unconfirmed presence record(s) | ||||||
Northern Mariana Islands | Absent, Unconfirmed presence record(s) | ||||||
South America |
|||||||
Argentina | Absent, Unconfirmed presence record(s) | ||||||
Bolivia | Present | ||||||
Brazil | Present | ||||||
-Alagoas | Present | ||||||
-Amazonas | Present, Widespread | Original citation: De Silva et al., 1981 | |||||
-Bahia | Present, Widespread | ||||||
-Ceara | Present, Widespread | ||||||
-Fernando de Noronha | Present | Original citation: Fletchmann, 1987 | |||||
-Maranhao | Present | ||||||
-Mato Grosso do Sul | Present | ||||||
-Minas Gerais | Present | ||||||
-Paraiba | Present | ||||||
-Pernambuco | Present, Widespread | ||||||
-Piaui | Present, Widespread | ||||||
-Rio Grande do Norte | Present | ||||||
-Roraima | Present | ||||||
-Sergipe | Present | ||||||
Chile | Absent, Unconfirmed presence record(s) | ||||||
Colombia | Present, Localized | ||||||
Ecuador | Present | ||||||
French Guiana | Absent, Unconfirmed presence record(s) | ||||||
Guyana | Present | ||||||
Paraguay | Present | ||||||
Peru | Absent, Invalid presence record(s) | ||||||
Suriname | Absent, Invalid presence record(s) | ||||||
Uruguay | Absent, Invalid presence record(s) | ||||||
Venezuela | Present, Localized |
History of Introduction and Spread
Top of pageM. tanajoa is native to South America but has spread widely across Africa. It was introduced to Uganda, East Africa, in 1971 with infested cassava cuttings imported from Colombia (Nyiira, 1972). In 1972, the pest had already spread to Ukerewe Island in Tanzania, which is about 970 km from Kampala. By 1988, the pest had spread to cover much of sub-Saharan Africa (Yaninek and Herren, 1988). Severe damage symptoms were found on the attacked cassava, especially during the dry season. For further references to Central American records, see Bolland et al. (1998).
Introductions
Top of pageIntroduced to | Introduced from | Year | Reason | Introduced by | Established in wild through | References | Notes | |
---|---|---|---|---|---|---|---|---|
Natural reproduction | Continuous restocking | |||||||
Congo | Uganda | 1975 | Crop production (pathway cause) | Yes | No | Yaninek et al. (1989b) | Rate of spread 1600 km/yr | |
Nigeria | Congo | 1979 | Crop production (pathway cause) | Yes | No | Yaninek et al. (1989b) | Rate of spread 825 km/yr | |
Tanzania | Uganda | 1972 | Crop production (pathway cause) | Yes | No | Yaninek et al. (1989b) | Rate of spread 970 km/yr | |
Uganda | South America | 1971 | Crop production (pathway cause) | Yes | No | Nyiira (1972); Yaninek and Herren (1988) | Found near Kampala |
Risk of Introduction
Top of pageM. tanajoa has spread to almost all tropical countries where cassava is grown.
Habitat List
Top of pageCategory | Sub-Category | Habitat | Presence | Status |
---|---|---|---|---|
Terrestrial | Managed | Cultivated / agricultural land | Principal habitat | Harmful (pest or invasive) |
Terrestrial | Managed | Protected agriculture (e.g. glasshouse production) | Secondary/tolerated habitat | Harmful (pest or invasive) |
Terrestrial | Managed | Managed forests, plantations and orchards | Principal habitat | Harmful (pest or invasive) |
Terrestrial | Managed | Industrial / intensive livestock production systems | Secondary/tolerated habitat | Natural |
Terrestrial | Managed | Disturbed areas | Secondary/tolerated habitat | Natural |
Terrestrial | Managed | Rail / roadsides | Secondary/tolerated habitat | Natural |
Terrestrial | Managed | Urban / peri-urban areas | Secondary/tolerated habitat | Harmful (pest or invasive) |
Terrestrial | Natural / Semi-natural | Natural grasslands | Secondary/tolerated habitat | Natural |
Terrestrial | Natural / Semi-natural | Wetlands | Secondary/tolerated habitat | Natural |
Terrestrial | Natural / Semi-natural | Scrub / shrublands | Secondary/tolerated habitat | Natural |
Other | Vector | Principal habitat |
Hosts/Species Affected
Top of pageM. tanajoa is found on cassava (Manihot esculenta) and other plants in the genus Manihot, such as Manihot glaziovii and Manihot dichotoma (Bastos and Flechtmann, 1985; Ezulike and Egwuatu, 1993a). However, Moraes et al. (1995) reported that cassava green mite could feed and develop to the adult stage on Phaseolus vulgaris and also develop to the adult stage and lay eggs on the wild passion fruit Passiflora cincinnata. Several other hosts are listed in the catalogue by Bolland et al. (1998).
Tomato was previously listed as a host of M. tanajoa, but this host record was for M. caribbeanae, which is now recognized as a separate species (Doreste, 1981).
Common bean (Phaseolus vulgaris) is a conditional non-preferred host of M. tanajoa (Hicks, 2017).
Host Plants and Other Plants Affected
Top of pagePlant name | Family | Context | References |
---|---|---|---|
Manihot esculenta (cassava) | Euphorbiaceae | Main |
Symptoms
Top of pageM. tanajoa usually feed on the underside of young leaves, by inserting their piercing and sucking mouthparts (chelicerae) into individual cells and extracting the cell contents. This causes chlorosis as the chlorophyll is sucked from the cells. The leaves may become mottled, die and abscise. Severe attack leads to death and shedding of terminal shoots leading to the characteristic 'candle stick' symptom.
List of Symptoms/Signs
Top of pageSign | Life Stages | Type |
---|---|---|
Leaves / abnormal colours | ||
Leaves / abnormal leaf fall |
Biology and Ecology
Top of pageThe life history of M. tanajoa is typical of all tetranychids. Reproduction is arrhenotokous (Helle and Pijnacker, 1985). There are four active instars: a six-legged larva, two nymphal instars (protonymphs and deutonymphs) and an adult stage.
The biology of M. tanajoa, including the developmental time, fecundity and adult longevity depends on temperature, humidity, host plant and sex (Byrne et al., 1982b; Mesa et al., 1987; Yaninek et al., 1989a, c). Yaninek et al. (1989a) report that at 27°C, with relative humidity of 70% and a photoperiod of 12 hours light and 12 hours dark, the developmental times of egg, larva, protonymph and deutonymph on leaves of cassava (variety TMS 30572) were 5.4, 3.0, 1.1 and 2.8 days, respectively. At this temperature, typical of most areas in sub-Saharan Africa, the adult female mite lives for 11.6 days and lays an average of 62.8 eggs over a period of 9.8 days. The net reproduction rate reached a maximum of 43.2 progeny. Egg to adult developmental periods were estimated to be 21.3, 15.5, 12.3, 7.7 and 6.9 days at 20, 24, 27, 31 and 34°C, respectively. Yaninek and Gnanvossou (1993) reported that eggs, larvae and protonymphs had average fresh weights of 0.637, 0.625 and 1.013 µg respectively. Male and female deutonymphs had average weights of 1.209 and 2.715 µg, whereas male and female adults averaged 1.633 and 7.035 µg, respectively.
The availability of new foliage on cassava plants and the presence of rainfall are the major factors that determine the population dynamics of M. tanajoa in the field (Yaninek et al., 1989a, c). The population increases on new leaf growth during the early dry season (20-200 mites/leaf), but declines when defoliation and reduced leaf production follow drought. Prolonged rainfall also leads to a decrease in population (<1 mite/leaf) because the mites are washed off the plant.
Climate
Top of pageClimate | Status | Description | Remark |
---|---|---|---|
Af - Tropical rainforest climate | Preferred | > 60mm precipitation per month | |
Am - Tropical monsoon climate | Preferred | Tropical monsoon climate ( < 60mm precipitation driest month but > (100 - [total annual precipitation(mm}/25])) | |
As - Tropical savanna climate with dry summer | Preferred | < 60mm precipitation driest month (in summer) and < (100 - [total annual precipitation{mm}/25]) | |
Aw - Tropical wet and dry savanna climate | Preferred | < 60mm precipitation driest month (in winter) and < (100 - [total annual precipitation{mm}/25]) | |
Cs - Warm temperate climate with dry summer | Tolerated | Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers | |
Ds - Continental climate with dry summer | Tolerated | Continental climate with dry summer (Warm average temp. > 10°C, coldest month < 0°C, dry summers) |
Air Temperature
Top of pageParameter | Lower limit | Upper limit |
---|---|---|
Absolute minimum temperature (ºC) | 14.4 | |
Mean annual temperature (ºC) | 18 | 34 |
Rainfall
Top of pageParameter | Lower limit | Upper limit | Description |
---|---|---|---|
Mean annual rainfall | 40 | 60 | mm; lower/upper limits |
Natural enemies
Top of pageNatural enemy | Type | Life stages | Specificity | References | Biological control in | Biological control on |
---|---|---|---|---|---|---|
Amblyseius aripo | Predator | Adults; Eggs; Arthropods|Nymphs | not specific | Benin; Cameroon; Congo; Kenya; Malawi; Mozambique; Nigeria; Tanzania; Uganda; Zambia | cassava | |
Amblyseius degenerans | Predator | Adults; Eggs; Arthropods|Nymphs | ||||
Amblyseius idaeus | Predator | Adults; Arthropods|Nymphs | Africa; Benin; Ghana | |||
Amblyseius limonicus | Predator | Adults; Eggs; Arthropods|Nymphs | ||||
Amblyseius papayana | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Brumoides nigrifrons | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Cheilomenes sulphurea | Predator | Adults; Arthropods|Nymphs | Burundi | cassava | ||
Chilocorus distigma | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Coniopteryx crassicornis | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Conwentzia africana | Predator | Adults; Arthropods|Nymphs | Rwanda | cassava | ||
Euseius concordis | Predator | Adults; Arthropods|Nymphs | Africa | |||
Euseius fustis | Predator | Adults; Eggs; Arthropods|Nymphs | not specific | Burundi; Kenya; Malawi; Rwanda | cassava | |
Euseius lokele | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Euseius talinga | Predator | Adults; Arthropods|Nymphs | Kenya; Rwanda | cassava | ||
Exochomus ventralis | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Galendromus annectens | Predator | Adults; Eggs; Arthropods|Nymphs | Africa | |||
Galendromus helveolus | Predator | Adults; Eggs; Arthropods|Nymphs | ||||
Hirsutella thompsonii | Pathogen | Adults; Arthropods|Nymphs | ||||
Holobus fageli | Predator | Adults; Arthropods|Nymphs | Burundi; Kenya; Malawi; Rwanda | cassava | ||
Holobus minutus | Predator | Adults; Eggs; Arthropods|Nymphs | ||||
Holobus pallidicornis | Predator | Adults; Arthropods|Nymphs | Burundi; Kenya; Malawi; Rwanda | cassava | ||
Hyperaspis pumila | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Micraspis striata | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Neoseiulus anonymus | Predator | Adults; Eggs; Arthropods|Nymphs | ||||
Neoseiulus californicus | Predator | Adults; Arthropods|Nymphs | Africa | |||
Neoseiulus teke | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Neozygites floridana | Pathogen | |||||
Phorocera assimilis | Predator | Adults; Eggs; Arthropods|Nymphs | Kenya | cassava | ||
Phytoseiulus macropilis | Predator | Adults; Arthropods|Nymphs | Africa | |||
Phytoseius guianensis | Predator | Adults; Arthropods|Nymphs | ||||
Scymnus scapuliferus | Predator | Adults; Arthropods|Nymphs | Burundi | cassava | ||
Stethorus aethiops | Predator | Adults; Arthropods|Nymphs | Kenya; Malawi | cassava | ||
Stethorus jejunus | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Typhlodromalus manihoti | Predator | Adults; Eggs; Arthropods|Nymphs | not specific | Benin; Burundi; Ghana; Nigeria | cassava | |
Typhlodromalus saltus | Predator | Adults; Arthropods|Nymphs | Kenya | cassava | ||
Wollastoniella gatti | Predator | Adults; Arthropods|Nymphs | Kenya | cassava |
Notes on Natural Enemies
Top of page
Predatory insects and mites are the most abundant and important natural enemies of M. tanajoa. Most of the known insect predators are either opportunists or effective only at high mite populations. The most commonly encountered insect predators in the neotropics are in the families Coccinellidae, Staphylinidae, Lygaeidae, Chrysopidae, Syrphidae, Anthocoridae and Cecidomyiidae (Farias et al., 1981; Byrne et al., 1983) and the order Thysanoptera. Stethorus spp. and Holobus (=Oligota) spp. have been reared and released in a number of countries.
Mites of the family Phytoseiidae are the most important predators of M. tanajoa because they have a high capacity for predation, even at low prey densities and are also easy to rear. Bellotti et al. (1987) listed 46 phytoseiid species found in association with M. tanajoa on cassava in Colombia.
Means of Movement and Dispersal
Top of pageNatural Dispersal
M. tanajoa is able to disperse actively by walking from one plant to another, or passively by aerial drifting, though species of Mononychellus are not known to produce silk for ballooning (Bellotti, 1985). Wind and water are important pathways for M. tanajoa dispersal. It is reported that M. tanajoa can disperse 200 meters with prevailing wind in 13 weeks (Yaninek, 1989). However, this distance is small in comparison to the hundreds of kilometres per day that infested plant materials can be transported by human beings across regions.
Accidental Introduction
Mites can survive on cassava leaves removed from the cassava plant for up to five days. They can also persist on cassava cuttings and isolated from external nutrients for up to 60 days. Collection and movement of planting material is considered as the most important mode of dispersal for M. tanajoa. Cassava stems and leaves are exported from rural to urban areas where they are sold as planting materials or vegetables. Farmers have a tendency of sharing planting materials, which may sometimes be infested. Researchers may also distribute planting materials to farmers and sometimes to fellow researchers in distant regions; by doing so they may spread the disease accidentally. Vehicles/ships containers, farm implements and clothing can also get contaminated and spread the pest from one area to another.
Intentional Introduction
Taxonomy, biology and ecological studies require live insects. Such studies may involve movement of M. tanajoa from infested fields to laboratories where the studies are conducted. Mass rearing of natural enemies also involves collection and movement of M. tanajoa.
Pathway Causes
Top of pageCause | Notes | Long Distance | Local | References |
---|---|---|---|---|
Biological control | Deliberate introduction, rare pathway | Yes | ||
Botanical gardens and zoos | Accidental introduction, rare pathway | Yes | ||
Breeding and propagation | Accidental introduction, rare pathway | Yes | Yes | |
Crop production | Accidental, common pathway | Yes | Yaninek et al. (1989b) | |
Flooding and other natural disasters | Accidental introduction, rare pathway | Yes | ||
Forage | Accidental introduction, rare pathway | Yes | ||
Garden waste disposal | Accidental introduction, common pathway | Yes | ||
Hitchhiker | Accidental introduction, common pathway | Yes | Yes | |
Horticulture | Accidental introduction, rare pathway | Yes | Yes | |
Interconnected waterways | Accidental introduction, rare pathway | Yes | ||
Landscape improvement | Accidental introduction, rare pathway | Yes | ||
Nursery trade | Accidental introduction, rare pathway | Yes | ||
People sharing resources | Accidental introduction, common pathway | Yes | Yes | |
Research | Accidental introduction, rare pathway | Yes | Yes | Yaninek et al. (1989b) |
Seed trade | Accidental introduction, common pathway | Yes | Yes | |
Self-propelled | Actively by crawlers and adults | Yes |
Pathway Vectors
Top of pageVector | Notes | Long Distance | Local | References |
---|---|---|---|---|
Aircraft | Egg, crawlers/adults, rare pathway | Yes | ||
Bulk freight or cargo | Eggs, crawlers/adults. Rare pathway | Yes | ||
Clothing, footwear and possessions | Eggs, crawlers/adults. Common pathway | Yes | ||
Containers and packaging - non-wood | Eggs, crawlers/adults. Rare pathway | Yes | ||
Containers and packaging - wood | Eggs, crawlers/adults. Rare pathway | Yes | ||
Debris and waste associated with human activities | Eggs, crawlers/adults. Common pathway | Yes | ||
Floating vegetation and debris | Eggs, crawlers/adults. Rare pathway | Yes | ||
Germplasm | Eggs, crawlers/adults. Rare pathway | Yes | Yes | |
Host and vector organisms | Eggs, crawlers/adults. Common pathway | Yes | Yes | |
Land vehicles | Eggs, crawlers/adults. Common pathway | Yes | Yes | |
Livestock | Eggs, crawlers/adults. Rare pathway | Yes | ||
Luggage | Eggs, crawlers/adults. Rare pathway | Yes | ||
Machinery and equipment | Eggs, crawlers/adults. Rare pathway | Yes | ||
Eggs, crawlers/adults. Common pathway | Yes | Yes | ||
Mulch, straw, baskets and sod | Eggs, crawlers/adults. Common pathway | Yes | ||
Plants or parts of plants | Eggs, crawlers/adults. Common pathway | Yes | Yes | |
Ship structures above the water line | Eggs, crawlers/adults. Rare pathway | Yes | ||
Water | Eggs, crawlers/adults. Rare pathway | Yes | ||
Wind | Eggs, crawlers/adults. Common pathway | Yes |
Plant Trade
Top of pagePlant parts liable to carry the pest in trade/transport | Pest stages | Borne internally | Borne externally | Visibility of pest or symptoms |
---|---|---|---|---|
Bark | arthropods/adults | Yes | Pest or symptoms not visible to the naked eye but usually visible under light microscope | |
Flowers/Inflorescences/Cones/Calyx | arthropods/adults; arthropods/eggs | Yes | Pest or symptoms not visible to the naked eye but usually visible under light microscope | |
Growing medium accompanying plants | arthropods/adults | Yes | Pest or symptoms not visible to the naked eye but usually visible under light microscope | |
Leaves | arthropods/adults; arthropods/eggs | Yes | Pest or symptoms not visible to the naked eye but usually visible under light microscope | |
Seedlings/Micropropagated plants | arthropods/adults; arthropods/eggs | Yes | Pest or symptoms not visible to the naked eye but usually visible under light microscope | |
Stems (above ground)/Shoots/Trunks/Branches | arthropods/adults; arthropods/eggs | Yes | Pest or symptoms not visible to the naked eye but usually visible under light microscope | |
Wood | arthropods/adults | Yes | Pest or symptoms not visible to the naked eye but usually visible under light microscope |
Plant parts not known to carry the pest in trade/transport |
---|
Bulbs/Tubers/Corms/Rhizomes |
Roots |
Impact Summary
Top of pageCategory | Impact |
---|---|
Cultural/amenity | Negative |
Economic/livelihood | Negative |
Environment (generally) | Negative |
Human health | Negative |
Impact
Top of pageDamage caused by M. tanajoa varies according to the cassava cultivar and the length of the dry season. Prolonged drought encourages the build up of mites and increases yield losses. Chlorosis and stunted growth reduce the harvest of leaves as a vegetable. In some east and central African countries, tuber yield losses of 10-80% have been recorded (Shukla, 1976; Markham and Robertson, 1987). Skovgard et al. (1993) studied the effect of M. tanajoa on the growth and yield of cassava in Kenya and found that after 10 months, the dry matter of the infested plants was reduced by 29% in the storage roots and by 21% in the stems, compared with uninfested plants.
Economic Impact
Top of pageDepending on cassava cultivar and the length of the dry season, M. tanajoa can cause up to 80% tuber yield loss, up to 47.5 stem yield loss and up to 40.7 leaf yield loss (Shukla, 1976; Markham and Robertson, 1987, Pallangyo et. al., 2007). Since cassava leaves and tubers serve as a staple food source as well as a cash crop, decline in cassava yield can lead to household food and income insecurity.
Environmental Impact
Top of pageImpact on Biodiversity
M. tanajoa causes cassava leaves to become stunted and can reduce them to a quarter of their original size. The leaves also become speckled with yellow spots (chlorosis) after infection by the cassava green mite. These spots, which frequently occur along the main veins of the leaves, can result in complete loss of chlorophyll pigment. Other mite species which suck chlorophyll from cassava leaves include two spotted spider mites, Tetranychus urticae and the red spider mite, Oligonychus gossypii. Red spider mites are larger than M. tanajoa and normally attack mature leaves lower down on the plants and cover the attacked leaves with webs. Although possible, there have been no reports of competition between these species and the invading cassava green mite.
Social Impact
Top of pageDecline in cassava yield causes a shortage of food and raw material for the food and feed processing industry. Such shortages may lead to malnutrition and a rise in unemployment. M. tanajoa also causes declines in the yield and quality of the cassava stems which can result in a shortage of planting materials for perpetuation of the crop.
Risk and Impact Factors
Top of page- Proved invasive outside its native range
- Is a habitat generalist
- Capable of securing and ingesting a wide range of food
- Highly mobile locally
- Fast growing
- Has high reproductive potential
- Host damage
- Negatively impacts agriculture
- Negatively impacts human health
- Negatively impacts livelihoods
- Interaction with other invasive species
- Highly likely to be transported internationally accidentally
- Difficult to identify/detect as a commodity contaminant
- Difficult to identify/detect in the field
- Difficult/costly to control
Uses List
Top of pageEnvironmental
- Biological control
General
- Research model
Genetic importance
- Gene source
- Test organisms (for pests and diseases)
Detection and Inspection
Top of pageM. tanajoa typically feeds on the underside of young leaves, starting along the veins and at the base of the leaves. Damage symptoms can be seen with the naked eye but eggs, crawlers or adults are usually only visible under a light microscope. Examination of the underside of young leaves and growing terminals of cassava reveals the presence of this pest. Fresh sprouts from cassava stem cuttings may also harbour these mites and must be examined to prevent spread.
Similarities to Other Species/Conditions
Top of pageM. tanajoa is similar to the red spider mites (Tetranychus spp. and Oligonychus spp.). Although M. tanajoa is greenish/yellowish in appearance and the red spider mites are reddish in colour, all of them cause yellow specks (chlorosis) on leaves, especially along the main veins. However, red spider mites are larger than M. tanajoa and normally attack mature leaves lower down on the plants and cover the attacked leaves with webs.
The damage caused by M. tanajoa also looks similar to that caused by African cassava mosaic disease. Both cause leaf chlorosis, but the greenish-yellowish patches of African cassava mosaic disease are usually larger and severe leaf distortion is common.
Prevention and Control
Top of pageDue to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.
Regulatory Control
Close inspection of cutting materials and the use of clean certified cuttings may reduce the spread of M. tanajoa and delay the time of infestation of the cassava crop.
Cultural Control
Cultural control is limited owing to economic, technical and social constraints. Options include early planting at the onset of the rains to encourage vigorous growth and thereby increase tolerance to mite attack. Cassava plants aged 2-9 months are the most vulnerable to infestation.
The way a mite-infested cutting is planted influences the presence of the mites on the leaves soon after sprouting. Cuttings planted in a slanting position had mites on the leaves soon after sprouting, but those planted horizontally did not (Ezulike and Egwuatu, 1990). Ezulike and Egwuatu (1993b) reported that cassava intercropped with pigeon pea suffered less damage from M. tanajoa than that grown on a pure stand. They also found that cassava intercropped with pigeon pea in triple and double rows gave higher tuber yields than when it was alternated in a single row or in a pure stand.
Host-Plant Resistance
Certain attributes, such as leaf pubescence (Leuschner, 1982), have been claimed to confer tolerance to M. tanajoa. Some attempts have been made to identify mite-resistant cassava cultivars (Shukla, 1976; Santos et al., 1977; Byrne et al., 1982a,b; Markham and Robertson, 1987; Msabaha, 1984) but further studies including damage symptoms, tuber yields and disease resistance of the selected cultivars need to be carried out. Immunity to M. tanajoa is not known.
Biological Control
The importation of phytoseiids from the neotropics (especially from Colombia and Brazil) and their release into Africa began in 1984. In 1991, Amblyseius (=Neoseiulus) idaeus from north-eastern Brazil was reported to have persisted for over 18 months after release in Benin (Yaninek et al., 1991).
Toko et al. (1996) released the predator Amblyseius manihoti into a cassava field infested with M. tanajoa at the beginning of the dry season and recorded a 20% decrease in the numbers of M. tanajoa compared with control areas where there were no predators.
Herrera et al. (1994) studied the population dynamics of M. tanajoa and its predators Amblyseius limonicus and A. idaeus on cassava at three sites in Colombia between 1988 and 1990. The numbers of the phytoseiids increased in response to the population growth of M. tanajoa, but higher predator densities were observed when M. tanajoa densities were low. At one site (Pivijay), A. limonicus appeared at the peak population of M. tanajoa and suppressed the pest population, while itself persisting during the wet season in the absence of M. tanajoa. Compared with plots without predators, cassava plots with predators harboured less than 50% of the M. tanajoa population and produced double the fresh tuber yields.
The mite Typhlodromalus manihoti has been established in West Africa since its importation in 1989 from north-eastern Brazil (which is ecologically more similar to sub-Saharan Africa than is Colombia).
Typhlodromalus aripo was introduced from Brazil into West Africa to control M. tanajoa in 1993 (IITA, 1996). T. aripo has now spread, at times at a rate of 200 km/year, and established itself in more than 11 countries in Africa. M. tanajoa populations have dropped to less than 20/leaf, from more than 40/leaf before the introduction of T. aripo. Post release surveys conducted under farm field conditions in Tanzania reported a decline of M. tanajoa population densities from > 200 mites per leaf (before T. aripo introduction) to < 20 mites per leaf (Pallangyo et al., 2004). During a predator exclusion experiment, M. tanajoa population densities and damage severity were reduced by 64.3% and 45.3% respectively leading to an increase in cassava yield by up to 70% (Pallangyo et al., 2004). In Benin, this has led to a 30% increase in tuber yields, equivalent to a gain of $3 million per season.
The predatory insects Stethorus spp. and Holobus (=Oligota) spp. have been reared and released in a number of countries.
Among the pathogens, Neozygites spp. have shown the greatest potential for biological control. It has been reported to cause mortalities among M. tanajoa populations in Venezuela (Agudelo-Silva, 1986), Brazil (Delalibera et al., 1992), Colombia (Alvarez et al., 1993), Benin (Yaninek et al., 1996) and Kenya (Bartowski et al., 1988). The effect of abiotic factors on the ability of this fungus to cause epizootics among populations of M. tanajoa has been studied by Oduor et al. (1995a, b; 1996a, b; 1997a, b). Brazilian species are being compared with African strains to identify the ideal isolate for mass release in Africa.
Chemical Control
Most cassava is grown on a small scale by subsistence farmers with few resources. Lack of knowledge and finance makes the use of chemicals a non-sustainable option for controlling M. tanajoa. Pesticide resistance is also a problem in the long term.
Gaps in Knowledge/Research Needs
Top of pageThere is a need to investigate the impact of M. tanajoa on other mite species including Tetranychus urticae and Oligonychus gossypii; also on cassava diseases including CMD and Cassava Brown Streak Disease Viruses. Research needs to be undertaken to establish the impact of M. tanajoa on biodiversity and Pest Surveillance to determine the current status of M. tanajoa.
References
Top of page1981. Nigeria - outbreak of Mononychellus tanajoa. Plant Protection Bulletin, FAO, 29(1/2):29
Bellotti AC, 1985. Cassava. In: Helle W, Sabelis MW, eds. Spider Mites: Their Biology, Natural Enemies and Control. World Crop Pests, Vol. 1B. Amsterdam, Netherlands: Elsevier Science Publishers, 333-338.
Bolland HR, Gutierrez J, Flechtmann CHW, 1998. World Catalogue of the Spider Mite Family (Acari: Tetranychidae). Leiden, Netherlands: K. Brill, 392 pp.
Bondar G, 1938. Notas entomologicas da bahia III. Revista Entomologica do Brasil, 9:441-445.
Byrne DH, Bellotti AC, Guerrero JM, 1983. The cassava mites. Tropical Pest Management, 29(4):378-394
De Silva AB, Magalhaes BP, Costa MS, 1981. Insects and mites injurious to cassava. Boletim de Pesquisa, Centro de Pesquisa Agropecuaria do Tropico Humido, EMPRAPA, Brasil, No. 31.
Doreste E, 1981. Acaros del genero Mononychellus Wainstein (Acari: Tetranychidae) asociados com la yuca (Manihot spp) em Venezuela. Boletin de Entomologia Venezuelana, 1:119-130.
EPPO, 2014. PQR database. Paris, France: European and Mediterranean Plant Protection Organization. http://www.eppo.int/DATABASES/pqr/pqr.htm
EPPO, 2016. EPPO Global database (available online). Paris, France: EPPO. https://gd.eppo.int/
Farias ARN, Fletchmann GJ, McMurtry JA, 1981. Predadores do acaro verde da mandioca do dordeste do Brasil. Emprese Brasileira de Pesquisa Agropecuaria (EMBRAPA), 16:313-317.
Fletchmann CHW, 1986. The cassava green spider mite complex; taxonomy (Acari: Tetranychidae: Mononychellus spp.) In: Herren HR, Hennessey RN, Bitterh R, eds. Biological Control and Host Plant Resistance to Control the Cassava Mealybug and Green Spider Mite in Africa. Proceedings of an International Workshop, Ibadan, Nigeria. Nigeria: IITA, 70-80.
Fletchmann CHW, Baker EW, 1970. A preliminary report on the tetranychidae (Acari) of Brazil. Annals of the Entomological Society of America, 63:156-163.
Grieser J, Gommes R, Cofield S, Bernardi M, 2006. Short Tabular Presentation of Koeppen Classes FAO of the UN, Viale delle Terme di Caracalla, 00100 Rome, Italy. Short Tabular Presentation of Koeppen Classes, FAO of the UN, Viale delle Terme di Caracalla, 00100 Rome, Italy. Rome, Italy: FAO of the UN.
Helle W, Pijnacker LP, 1985. Parthenogenesis, chromosomes and sex. In: Helle W, Sabelis MW, eds. Spider Mites: Their Biology, Natural Enemies and Control. World Crop Pests, Vol. 1A. Amsterdam, Netherlands: Elsevier, 129-139.
Hicks, C.B., 2017. Mononychellus tanajoa: Assessment of Taxonomic Synonyms, Distribution Status in the United States, and Host Status of Solanum lycopersicum L. and Phaseolus vulgaris L.:16 pp.
Macfarlane D, 1984. Key to spider mites (Tetranychidae) recorded on cassava in Africa. With a note on slide preparation. Integrated pest management of cassava green mite. Proceedings of a regional training workshop in East Africa, 30 April - 4 May 1984 [edited by Greathead, A.H.; Markham, R.H.; Murphy, R.J.; Murphy, S.T.; Robertson, I.A.D.] Ascot, United Kingdom; Commonwealth Institute of Biological Control, 31-35
Markham RH, Robertson IAD, eds. , 1987. Cassava green mite in Eastern Africa: yield losses and integrated control. In: Proceedings of a Regional Workshop, Nairobi, Kenya. Ascot: CIBC.
Mesa NC, Bellotti A, Duque MC, 1987. Tabelas de vida de Mononychellus progressivus Dorests e Tetranychus urticae (Koch) (Acari: Tetranychidae) en Yuca. Revista Colombiana de Entomologia, 13:11-12.
Nyiira ZM, 1972. Report on investigation of cassava mite, Mononychus tanajoa Bondar. Unpublished report. Kampala, Uganda: Kawanda Research Station.
Oduor GI, Yaninek JS, Moraes GJ de, Geest LPS van der, 1997a. Effect of pathogen dose on the pathogenicity of Neozygite floridana to Mononychellus tanajoa. Journal of Invertebrate Pathology, 70:127-130.
Pallangyo B, Hanna R, Toko M, Gnanvossou D, Mgoo V, Otema M, Onzo A, Hountondji F, Nsami E, Mfugale O, 2004. Biological control of cassava green mite in Tanzania. Proceedings of 9th Triennial Symposium of the International Society for Tropical Root Crops - Africa Branch (ISTRC - AB) Mombasa, Kenya 1 - 5 Nov 2004 IITA [ed. by Mahungu, N. \Manyong, V.]. Mobasa, Kenya, Africa: IITA, 597-604 pp.
Salas LA, 1978. Algunas notas sobre las ara±itas rojas (Tetranychidae: Acari) halladas en Costa Rica. Agronomia Costarricense, 2(1):47-59. [In Spanish].
Smith Meyer MKP, 1987. African Tetranychidae (Acari: Prostigmata), with reference to the world genera. Entomology Memoir, Department of Agriculture and Water Supply, Republic of South Africa, No. 69, 175 pp.
Urias Lopez MA, Carrillo Sanchez JL, 1983. Main pests of cassava, Manihot esculenta Crantz, in the savanna area of Huimanguillo, Tabasco. Agricultura Tecnica en Mexico, 9(1):65-83.
Wainstein BA, 1960. Tetranichovye Kleshchi Kazachstana (s reviziei semeistva) [Tetranychoid mites of Kazakhstan (with revision of the family)]. Kazachskaya Akademiya Sel'skokhozyaistvennich Nauk. Trudy, Nauchno-Issledovatel'skogo Instituta Zashchity Rastenii, Tom 5:1-276.
Wainstein BA, 1971. Mononychellus, a new genus for Mononychus (Acariformes: Tetranychidae) Zool. Zh., 50:589.
Wudil BS, Rwegasira GM, Kudra AB, Jeremiah SK, 2016. Response of Some Cassava Varieties to Mononychellus tanajoa Bondar. (Tetrachynidae: Acarina) Infestation in the Lake Zone, Tanzania. Journal of Agriculture and Ecology Research International, 7(4):1-9.
Distribution References
Anon, 1981. Report, Ministry of Agriculture and Lands, Solomon Islands.,
CABI, Undated. Compendium record. Wallingford, UK: CABI
CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI
Doreste E, 1981. (Acaros del genero Mononychellus Wainstein (Acari: Tetranychidae) asociados com la yuca (Manihot spp) em Venezuela). In: Boletin de Entomologia Venezuelana, 1 119-130.
Hicks CB, 2017. Mononychellus tanajoa: Assessment of Taxonomic Synonyms, Distribution Status in the United States, and Host Status of Solanum lycopersicum L. and Phaseolus vulgaris L., 16 pp.
Organizations
Top of pageBenin: IITA (Institut International d'Agriculture Tropicale), BP 08-0932 Cotonou, http://www.iita.org/
Kenya: International Centre for Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, http://www.icipe.org/
Tanzania: Ministry of Agriculture, Food Security and Cooperatives, PO Box 2462, Dar es Salaam, http://www.agriculture.go.tz/
Tanzania: TanBIF, TanBIF, P.O. Box 4302, Ali Hassan Mwinyi Road, Kijitonyama (Sayansi ) COSTECH Building, Dar-es-Sala, http://www.tanbif.or.tz/
France: EPPO European and Mediterranean Organization, OEPP/EPPO, 1 rue Le Nôtre, 75016 Paris, France, http://www.eppo.org
Brazil: EMBRAPA, Embrapa Sede, Parque Estação Biológica - PqEB s/n°. Brasília, DF - Brasil - CEP 70770-901, http://www.embrapa.br/english
Colombia: CIAT International Centre for tropical Agriculture, Km 17, Recta Cali-Palmira, Apartado Aéreo 6713, Cali, http://ciat.cgiar.org/
Contributors
Top of page26/08/2013 Updated by:
Beatrice Pollangyo, Ministry of Agriculture Food Security and Cooperatives, P.O.BOX 9071, Dar Es Salaam, Tanzania
03/11/1998 Orginal text by:
George Odour, CABI, ICRAF Complex, PO Box 633, Village Market, Nairobi, Kenya
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