Mound
forming termites in rare fruit
David Astridg and Harry Fay
Description
Adult
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Nasutitermes sp. mound high up in a tree |
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Note: in the two soldiers (A and B) the large mandibles in A (Mandibulate type) and flask shaped head in B (Nasute type). |
Termites that attack some rare fruit are from two genera (Nasutitermes spp. and Coptotermes spp.) that build earthen mounds. Termites live in colonies and have four castes including workers, soldiers, queens and kings. They are usually identified on the shape of the soldier caste. The adult soldiers of Nasutitermies spp. have bulbous heads drawn out into a long snout at the front. The snout can be used to squirt fluid that is irritating to other animals. Soldiers of Coptotermes spp. possess more normal shaped heads but have enlarged sickle shaped mandibles (jaws). Soldiers usually have darker and harder exoskeletons (external skeletons) than workers. Workers from both groups are similar in shape to soldiers but have smaller inconspicuous mandibles and normal shaped heads. Queens and kings are similar to workers in shape except that they also have harder and darker exoskeletons and initially they have wings.
Immature stages
Eggs are usually laid only by the queen and are seldom seen. Nymphs are similar in appearance to workers except for a lighter colour (cream to white) and are smaller.
Life history
The queens and kings fly away in large numbers from the mound, usually on warm days or evenings during periods of high humidity. They pair off and find a place to excavate a new mound. They chew off their wings and the queen starts to lay eggs. In the process and over a period she becomes enormous eventually dwarfing the king. She can move only slowly by peristaltic movements of her body and relies on the king and her progeny for food and protection. She produces eggs continuously throughout the year. The environment inside the mound is kept at a more or less stable humidity and temperature.
Distribution
Termites are ubiquitous in Queensland, however they prefer drier environments.
Host range
Termites are mainly a problem in crops grown in drier environments such as cashews, mangoes and citrus.
Management
Importance
Minor and sporadic.
Damage
This insect causes damage to cashews and other fruit trees in drier areas. Large numbers of termites will result in the destruction of the interior of the branches. Strong winds or the weight of fruit will cause damaged branches to break. The size of the mounds in an area may not be an indication of the potential problem as in some areas the major portion of the mound is below ground level. The termites may tunnel up the inside of the trunk and branches or build covered runways to reach damage parts of the trunk or branches to gain access.
Action level
Not determined. Inspect scaffold branches for mounds and covered runways during pruning.
Control methods
Cultural
Prior to planting, old stumps and roots should be removed from the field and burnt. Neglected trees with dead wood are very susceptible to attack. Dead or injured limbs should be removed and destroyed and the pruning surfaces painted with water based paint or a commercially available coating compounds sold specifically for that purpose. Mounds and covered galleries in trees should be destroyed.
Termites are usually not a problem in well managed crops where reasonable growth is maintained.
Chemical
None available at present.
Recommended chemicals
Chlorpyrifos can be used to treat adjacent wooden fences showing termite activity and mounds. Note: This information was correct at the time of publication. However, it is the user's responsibility to ensure that registered agricultural chemicals are used in accordance with legal requirements. (See Further information). Always read the label.
Further information
-
Contact the DPI&F Business Information Centre on 13 25 23 - local call 8 am to
6 pm Monday to Friday (non-Queensland residents phone 07 3404 6999). E-mail:
callweb@dpi.qld.gov.au
- Contact the DPI&F bookshop on 07 3239 3772 or DPI&F
Shop-Online or at some DPI&F offices throughout Queensland for the DPI&F
publications
- 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
Other contacts:
Growcom on 07 3620 3844
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
DPI&F InfoResearch on 07 3239 6989.
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 19 December 2005
