Subscribe Now Subscribe Today
Research Article

The Role of Aculus schlechtendali (Apple Rust Mite) in Orchard Pest Management Strategies in Northern Ireland

Andrew G.S. Cuthbertson and Archie K. Murchie
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail

Not Available

Related Articles in ASCI
Search in Google Scholar
View Citation
Report Citation

  How to cite this article:

Andrew G.S. Cuthbertson and Archie K. Murchie , 2006. The Role of Aculus schlechtendali (Apple Rust Mite) in Orchard Pest Management Strategies in Northern Ireland. Journal of Entomology, 3: 267-270.

DOI: 10.3923/je.2006.267.270


The apple rust mite, Aculus schlechtendali (Nalepa) (Prostigmata: Eriophydiae) has a worldwide distribution (Easterbrook, 1979). It was first recorded in Britain by Massee (1928) on wild crab apple and cultivated apple. Since then, the mite has become more widespread and numerous in commercial orchards, probably due to a gradual change from fungicides such as lime sulphur, which are toxic to the mite, to non-acaricidal compounds (Easterbrook, 1979; Cuthbertson and Murchie, 2003).

Adult rust mite are up to 0.18 mm long (Alford, 1984). Males are smaller than protogynes (Easterbrook, 1979). Their body is orange/brown, darkening with age (Easterbrook, 1979). Deutogynes overwinter in groups under loose bark or bud scales (Herbert, 1974; Alford, 1984). The mites emerge and invade the opening fruit buds to feed. They also feed on the leaf and flowers of the plant (Alford, 1984). Eggs are deposited on the green tissue of both fruit and vegetative buds and a generation of males and protogynes appears in May (Alford, 1984). Mites can also be found on the sepals at petal fall, but they do not feed on developing fruitlets, unlike Epitrimerus piri (Nalepa) on pear (Easterbrook, 1978). Breeding of the mites continues throughout the spring and summer, forming several overlapping generations of primary forms (Fig. 1). New deutogynes appear in increasing numbers from late June or early July onwards. The population growth is rapid; egg to adult can occur in 1-2 weeks with warm summer temperatures (Alford, 1984). Easterbrook (1979), working in England, found a mid-summer decline in population was correlated with prolonged temperatures above 35°C and relative humidity near 20%. The mite numbers begin to decline as the new deutogynes enter hibernation during autumn time and breeding ceases (Easterbrook, 1979).

Mites occur on the underside of the leaves and their feeding produces a patchy felt-like malformation on leaf surface and yellowing of hairs. The upper surface of foliage appears speckled, dull and faded.

Image for - The Role of Aculus schlechtendali (Apple Rust Mite) in Orchard Pest Management Strategies in Northern Ireland
Fig. 1: Life cycle of apple rust mite, Aculus schlechtendali

Heavily infested leaves are silvery before turning brown and shrivelling (Easterbrook, 1979). Control of A. schlechtendali within Northern Irish Bramley apple orchards is normally derived from Panonychus ulmi (Koch) control. Acaricides applied to control P. ulmi also have a detrimental effect on A. schlechtendali. However, within Northern Irish orchards, 76 spray hectares were specifically sprayed with the acaricide pirimiphos-methyl for rust mite control in 1996 (Kidd et al., 1996).

Aculus schlechtendali, although a pest, is an important part of integrated pest management (IPM) programmes in the USA (Hoyt, 1969; Croft, 1975). This species is available as food for phytoseiids such as Phytoseius macropilis, Amblyseius finlandicus, Typhlodromus rhenanus (Herbert, 1959; Burrell and McCormick, 1964) earlier than P. ulmi, which does not begin hatching until early May (Cranham, 1973). Later in the year, phytoseiids, or other predatory species, which have reduced P. ulmi populations to low levels maintain themselves on A. schlechtendali. Therefore, if A. schlechtendali is allowed to remain in orchards to provide food for predators that then also feed on P. ulmi it is important to know the population levels that can be tolerated without damage to the tree (Easterbrook, 1979). Populations of up to 300 per leaf have been stated to cause little crop damage (Hoyt, 1969). In Michigan, there was a tolerance level of 200 per leaf for 10-14 days before fruit production or tree vigour were adversely affected (Croft, 1975). In Northern Irish orchards Cuthbertson and Murchie (2006) recorded numbers of A. schlechtendali up to 160 per eight leaf sample with no visible damage being recorded. However, population development of these mites can be very rapid and so even on trees of low nutrient status and in the presence of predacious mites, they are capable of attaining levels that can cause damage. This means that selective sprays may sometimes be necessary to reduce A. schlechtendali populations in an IPM programme (Easterbrook, 1979).

The presence of alternative prey species in the orchard does not necessarily reduce a predators’ effectiveness against the main pest species (Collyer, 1964; Putman and Herne, 1964). Anystis baccarum (L.) (Prostigmata: Anystidae), the most commonly occurring predatory species in Northern Irish orchards (Cuthbertson and Murchie, 2005a), is known to be a predator of various invertebrate species (Baker, 1967) and when juvenile or during times of low alternative prey numbers, will feed on A. schlechtendali (Cuthbertson et al., 2003a). The potential of A. baccarum to control pest species such as A. schlechtendali in the Bramley orchards may be underestimated. Northern Ireland’s apple growers are unaware that this mite occurs in their orchards (Cuthbertson, 2004, 2005; Cuthbertson and Murchie, 2005b). Within the United Kingdom and indeed the world, most research on biocontrol within the apple sector has concentrated on Typhlodromus pyri Scheuten (Acari: Phytoseiidae) as the major predator of apple pests and its potential within IPM programmes. Typhlodromous pyri does occur in Northern Irish orchards, but in smaller numbers compared to English orchards (Cuthbertson and Murchie, 2005a). With A. baccarum commonly occurring in local orchards (Cuthbertson and Murchie, 2005a), this mite needs to be considered in any IPM programmes developed within the Bramley orchards. Anystis baccarum has shown much potential in aiding the control of economically important pests (Cuthbertson et al., 2003a, b; Cuthbertson and Murchie, 2004). This generalist predator may well survive by feeding upon A. schlechtendali when other prey items are scarce. Therefore, the presence of A. schlechtendali within the Bramley orchards, though classed as a pest (Cuthbertson and Murchie, 2006), may well have a more important role in sustaining the populations of predatory species and in particular A. baccarum.


Dr. Andrew G.S. Cuthbertson was funded by a Department of Agriculture and Rural Development (Northern Ireland) Studentship.


  1. Alford, D.V., 1984. A Colour Atlas of Fruit Pests, their Recognition, Biology and Control. Wolfe Publishing Ltd., London, pp: 320

  2. Baker, W.V., 1967. Some observations on predation in an anystid mite. Entomol. Mon. Mag., 103: 58-59.

  3. Burrell, R.W. and W.J. McCormick, 1964. Typhlodromus and Amblyseius (Acarina: Phytoseiidae) as predators on orchard mites. Ann. Entomol. Soc. Am., 57: 483-487.

  4. Collyer, E., 1964. The effect of an alternative food supply on the relationship between two Typhlodromus species and Panonychus ulmi (Koch) (Acarina). Entomol. Exp. Applied, 7: 120-124.

  5. Cranham, J.E., 1973. Variation in the intensity of diapause in winter eggs of fruit tree red spider mite, Panonychus ulmi. Ann. Applied Biol., 75: 173-182.

  6. Croft, B.A., 1975. Integrated Control of Apple Mites. Michigan State University, USA., pp: 12

  7. Cuthbertson, A.G.S. and A.K. Murchie, 2003. The impact of fungicides to control apple scab (Venturia inaequalis) on the predatory mite Anystis baccarum and its prey Aculus schlechtendali (apple rust mite) in Northern Ireland Bramley orchards. Crop Prot., 22: 1125-1130.
    Direct Link  |  

  8. Cuthbertson, A.G.S., A.C. Bell and A.K. Muchie, 2003. Impact of the predatory mite Anystis baccarum (Prostigmata: Anystidae) on apple rust mite Aculus schlechtendali (Prostigmata: Eriophyidae) populations in Northern Ireland Bramley orchards. Ann. Applied Biol., 142: 107-114.
    Direct Link  |  

  9. Cuthbertson, A.G.S., C.C. Fleming and A.K. Murchie, 2003. Detection of Rhopalosiphum insertum (apple-grass aphid) predation by the predatory mite Anystis baccarum using molecular gut analysis. Agric. For. Entomol., 5: 219-225.
    Direct Link  |  

  10. Cuthbertson, A.G.S., 2004. Unnecessary pesticide applications in Northern Ireland apple orchards due to mis-identification of a beneficial mite species. Res. J. Chem. Environ., 8: 77-78.

  11. Cuthbertson, A.G.S. and A.K. Murchie, 2004. The phenology, oviposition and feeding rate of Anystis baccarum, a predatory mite in Bramley apple orchards in Northern Ireland. Exp. Applied Acarol., 34: 367-373.
    PubMed  |  Direct Link  |  

  12. Cuthbertson, A.G.S., 2005. Re-discovery of a predatory mite in Northern Irish apple orchards. Biodiversity News, 30: 29-29.

  13. Cuthbertson, A.G.S. and A.K. Murchie, 2005. Techniques for environmental monitoring of predatory fauna on branches of Bramley apple trees in Northern Ireland. Int. J. Environ. Sci. Technol., 2: 1-6.
    Direct Link  |  

  14. Cuthbertson, A.G.S. and A.K. Murchie, 2005. Anystis baccarum an apple orchard assassin. Biologist, 52: 324-327.

  15. Cuthbertson, A.G.S. and A.K. Murchie, 2006. Environmental monitoring of economically important invertebrate pests in Bramley apple orchards in Northern Ireland. Int. J. Environ. Sci. Tech., 3: 1-7.
    Direct Link  |  

  16. Easterbrook, M.A., 1978. The life-history and bionomics of Epitrimerus piri (Acarina: Eriophyidae) on pear. Ann. Applied Biol., 88: 13-22.

  17. Easterbrook, M.A., 1979. The life-history of the eriophyid mite Aculus schlechtendali on apple in South-East England. Ann. Applied Biol., 91: 287-296.

  18. Herbert, H.J., 1959. Notes on feeding ranges of six species of predaceous mites (Acarina: Phytoseiidae) in the laboratory. Can. Entomol., 91: 812-812.

  19. Herbert, H.J., 1974. Notes on the biology of the apple rust mite, Aculus schlechtendali (Prostigmata: Eriophyoidae) and its density on several cultivars of apple in Nova Scotia. Can. Entomol., 106: 1035-1038.

  20. Hoyt, S.C., 1969. Integrated chemical control of insects and biological control of mites on apple in Washington. J. Eco. Entomol., 62: 74-86.

  21. Kidd, S.L.B., S. Jess and T. McCallion, 1996. Pesticide Usage Survey Report 147: Northern Ireland top fruit crops. Pesticide Usage Survey Group. Department of Agriculture for Northern Ireland, HMSO Belfast, UK., pp: 17

  22. Massee, A.M., 1928. An eriophyid mite on apple. Bull. Ent. Res., 19: 203-204.

  23. Putman, W.L. and D.H.C. Herne, 1964. Relations between Typhlodromus caudiglans Schuster (Acarina: Phytoseiidae) and phytophagous mites in Ontario peach orchards. Can. Entomol., 96: 925-943.

©  2022 Science Alert. All Rights Reserved