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Publication #EENY377

Phalaenopsis Mite, Tenuipalpus pacificus Baker (Arachnida: Acari: Tenuipalpidae)1

H. A. Denmark2

Introduction

Pritchard (1949) refers to Tenuipalpus pacificus Baker as the phalaenopsis mite. This flat red mite is one of the most destructive to be found on orchids under Florida greenhouse conditions. It feeds on the leaves of orchids but does not spin a web. Apparently it is an introduced species on orchids from the tropics. It can also be a pest of ferns.

Figure 1. 

Adult female.


[Click thumbnail to enlarge.]

Distribution

Tenuipalpus pacificus was described from specimens intercepted at Hoboken, New Jersey, from the Canal Zone on Phalaenopsis stuartiana in 1943 (Baker).

The known distribution is Australia (New South Wales) (CSIRO 2004), Brazil (De Moraes and Freire 2001), England, Germany, Holland, Java, Panama, Philippines, Siam, South Africa, and the United States.

In the United States it is recorded as being in California, Hawaii (Anonymous 2002), and Florida. It is probably found wherever orchids have been imported directly from South and Central America.

Description

The length of the adult female, including the rostrum, is 312 microns and 190 microns wide. The third, terminal, palpal segment is small with one short straight seta and one longer slightly curved seta. These characters cannot be seen on unmounted specimens. The hysterosoma has four pairs of nonflagellate setae and one pair of flagellate setae caudally. The length of the adult male, including the rostrum, is 269 microns and 150 microns wide, and has the same general appearance as the female, except smaller and narrower.

Figure 2. 

Adult female phalaenopsis mite, Tenuipalpus pacificus Baker.


Credit: Division of Plant Industry
[Click thumbnail to enlarge.]

Figure 3. 

Gnathosoma with palpi.


[Click thumbnail to enlarge.]

Figure 4. 

Adult male phalaenopsis mite, Tenuipalpus pacificus Baker.


Credit: Division of Plant Industry
[Click thumbnail to enlarge.]

Biology

Elongate reddish eggs are laid on the surface of the leaf, usually along the midrib. The eggs hatch in about three weeks into the larval stage which has three pairs of legs. All other stages have four pairs of legs. The larva molts into the protonymph in about two weeks. The protonymph molts into the deutonymph in about two weeks and to the adult stage in about two weeks, according to Dosse (1954). The life cycle is approximately two months depending upon the temperature and humidity. There are several generations per year.

Hosts

This mite is host specific to the Orchidaceae and Polypodiaceae plant families.

Known hosts of Orchidaceae: Aerides, Cattleya, Cypripedium, Dendrobium, Grammatophyllum, Oncidium, Phalaenopsis and Saccolabium.

Known hosts of Polypodiaceae: Davallia fejeensis and Platycerium sp.

Economic Importance

Many of the false spider mites are polyphagous, but T. pacificus is restricted to Orchidaceae and Polypodiaceae. This mite has needle-like cheliceral stylets that pierce the epidermis and remove the chlorophyll, causing the plant tissue to become silvery in appearance and later to turn rusty brown. The white molt skins remain on the leaf and are conspicuous against the rusty brown leaf. The mite feeds and breeds on both sides of the leaf, but prefers the lower surface.

Management

Insect Management Guide for Commercial Orchid Production (http://edis.ifas.ufl.edu/IG007)

Insect Management Guide on Landscape Plants (http://edis.ifas.ufl.edu/IG013)

Insect Management Guide for Natural Products for Insect Pest Management (http://edis.ifas.ufl.edu/ IN197)

Selected References

Anonymous. (2002). Tenuipalpus pacificus. Bishop Museum-Hawaiian Arthropod Checklist (http://www2.bishopmuseum.org/HBS/ checklist/query.asp?grp=Arthropod) (9 May 2011).

Cating RA, Hoy MA, Palmateer, AJ. 2010. Silwet L-77 improves the efficacy of horticultural oils for control of biosduval scale Diaspis boisduvalii (Hemiptera: Diaspididae) and the flat mite Tenuipalpus pacificus (Arachnida: Acari: Tenuipalpidae) on orchids. Florida Entomologist 93: 100-106.

CSIRO. (September 2004). Tenuipalpus pacificus Baker. CSIRO Entomology. http://www.ento.csiro.au/aicn/name_s/b_3952.htm (29 April 2010).

De Moraes GJ, Freire RAP. (2001). A new species of Tenuipalpidae (Acari: Prostigmata) on orchid from Brazil. Zootaxa. (http://www.mapress. com/zootaxa/2001f/z00001f.pdf) (2 June 2006).

Dosse G. 1954. Tenuipalpus orchidarum Parfitt nun auch in deutschen Gewachshäusern. Zeitschrift fuer Angewandte Entomologie 36: 304-315.

Pritchard AE. 1949. California greenhouse pests and their control. California Agricultural Experiment Station Bulletin 713: 1-71.

Pritchard AE, Baker EW. 1952. The false spider mites of California (Acarina: Phytoptipalpidae). University of California Publications Entomology. 9: 1-93.

Footnotes

1.

This document is EENY-377 (IN683), originally published as DPI Entomology Circular 74, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: October 2006. Revised April 2010. Reviewed October 2012. This document is also available on Featured Creatures website at http://entomology.ifas.ufl.edu/creatures. Please visit the EDIS website at http://edis.ifas.ufl.edu.

2.

H. A. Denmark, Florida Department of Agriculture and Consumer Services, Division of Plant Industry, Gainesville, FL.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.