Broad Mite in rare fruit
David Astridge, Harry Fay & Rod Elder, Department of Primary Industries and Fisheries.
Broad Mite in rare fruit
Adults, nymphs and eggs of broad mite (Polyphagotarsonemus latus)
Description
Adult
The adults are white-yellow, about 0.2 mm long, and the male is extremely active.
Immature stages
Eggs laid on the underside of leaves are oval, translucent and covered with five or six rows of white tubercles.
Life history
The life cycle through egg, two nymphal stages, to adult takes between 6 to 9 days.
Distribution
Occurs in all districts in Queensland.
Host range
Broad mite is a serious pest of lemons, Hickson and Ellendale mandarins and occasionally grapefruit. There are a wide range of other hosts including papaya, babaco, capsicum, cocoa, and most nursery plants.
Management
Importance
Major and frequent pest, more often in autumn in southern Queensland. Minor and infrequent in northern Queensland.
Damage
This mite causes damage to babaco and cocoa.
Broad mite attacks the growing point and the underside of young leaves causing hardening and distortion. Broad mite damage is often confused with injury caused by hormone herbicides because in both cases the leaves become claw-like with prominent veins. Grey or bronze scar tissue between the veins on the underside of the leaves distinguishes mite from hormone damage. Broad mite infestation can sometimes be confirmed with a by 10 hand lens although they have often disappeared before the damage is noticed. The characteristic egg can be seen near the veins beneath the leaf as a translucent, flat oval with a stippling of white dots. The mite itself is flat but is less easily identified than its egg.
Action level
Examine 5 consecutive plants in the row at 6 widely spaced locations throughout the crop. Spray if 2 plants out of 30 plants shows damage symptoms and mites are present. Close inspection of the growing point of the tree at fortnightly intervals during September to October and March to April should enable early detection of damage, which is necessary if control action is to be taken before serious distortion of terminal growth occurs.
Control methods
Biological
Broad mites are usually suppressed by natural enemies.
Chemical
Apply 2 miticide sprays 10 to 14 days apart. Good coverage is essential. Affected trees usually recover and specific control measures are not normally required in northern districts.
Recommended chemicals
Check the Australian Pesticides & Veterinary Medicines Authority website www.apvma.gov.au for products that are currently registered for control of broad mites on the host plant..Further information
- For further information on the production of minor tropical fruit contact the DPI&F Business Information Centre on 132523 (local call) 8am to 6pm Monday to Friday or visit DPI&F Information Centres in Mareeba, South Johnstone, Applethorpe, Gatton, Maroochy or Redlands.
- Growers interested in the production of minor tropical fruits can join their local branch of the Rare Fruits Council and subscribe to their newsletter. Contact the Rare Fruits Council at PO Box 1375 Aitkenvale 4814
- The DPI&F library provides a personalised information search service that may be useful for producers seeking information on minor and exotic crops. Contact DPI&F InfoSearch on 07 3239 6989.
- Visit the DPI&F website on www.dpi.qld.gov.au for other DPI&F notes on rare fruits.
- Hely, P.C., Pasfield, G. & Gellatley, J.G. Insect Pests of fruit and vegetables in NSW. Inkata Press, Melbourne.
- Infopest CD-ROM contains current national information on registered agricultural chemicals and is available from Infopest, DPI&F, GPO Box 46, Brisbane, Qld. 4001 or by email from infopest@dpi.qld.gov.au
- Swaine, G., Ironside, D.A. and Corcoran, R.J. 1991, Insect pests of fruit and vegetables, 2nd Edition, Queensland Department Primary Industries, Information Series QI91018.
Information contained in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought. The Department of Primary Industries and Fisheries, Queensland has taken all reasonable steps to ensure the information in this publication is accurate at the time of publication. Readers should ensure that they make appropriate inquiries to determine whether new information is available on the particular subject matter.
Last updated 31 January 2007
