Australian Journal of Experimental Agriculture (1998) 38, 889-896

M.M. Stevens, D.G. James, K.J. O'Malley and N.E. Coombes (1998)
Seasonal variations in foraging by ants (Hymenoptera : Formicidae) in two New South Wales citrus orchards
Australian Journal of Experimental Agriculture 38 (8), 889-896
Abstract: Pitfall traps were used to monitor the seasonal activity of ants in 2 citrus orchards in the Murrumbidgee Irrigation Area of south-western New South Wales for 22–24 months (November 1992–August/October 1994). Twenty-four species were recorded (22 species at Yanco and 18 species at Cudgel), with Iridomyrmex rufoniger group species being numerically dominant at both sites (63 and 59% of total captures at Yanco and Cudgel respectively). Meat ants, Iridomyrmex purpureus (F.Smith), were a significant (9%) component of trap captures at Yanco where regular soil cultivation was practised, but were less common (<1% of captures) at Cudgel. Sample species richness was generally greater at the Yanco site (mean 9.3 species per trapping interval compared with 6.6 at Cudgel). Total ant captures and sample species richness showed a positive correlation with mean daily temperatures over trapping intervals. Variations in seasonal activity were shown by the numerically dominant species, with 2 distinct patterns being evident. Whilst all taxa were less active during winter, some species [I. rufoniger group sp. 2, Pheidole sp., Rhytidoponera metallica (F.Smith)] continued to forage, albeit at reduced levels. Other species of Iridomyrmex including I. rufoniger group sp. 1 and I. purpureus ceased foraging almost entirely during June–September. Iridomyrmex species are known to interfere with the biological control of honeydew-producing insects in citrus orchards, and our results indicate that ant control programs in southern New South Wales should be initiated in late August–early September to achieve optimal results.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Mark M. Stevens, David G. James

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Iridomyrmex rufoniger	Citrus (genus)	Australia (South+SE)
	Iridomyrmex purpureus	Citrus (genus)	Australia (South+SE)