Answer: The presence of moisture favors termite exploration, tunneling and feeding. Therefore, any landscape mulch may improve conditions for termite colonies, whether the termites consume the mulch or not.
This does not mean you should avoid use of mulch, nor does it endorse one type of mulch as preferable over another. The same conclusion was recently reported from research at the Structural IPM Program at the University of Maryland. They studied the impact of landscape mulches on termite foraging activity in the laboratory and in the field. Termites that fed on a steady diet of either eucalyptus, hardwood or pine bark mulch suffered significantly lower survivorship than did termites fed the standard laboratory control diet of white birch. This result suggests that although we routinely discover termites in wood chip mulch, it is unlikely that they feed heavily on organic wood-based mulches.
In the field, termites were detected with equal frequency beneath mulches of eucalyptus, hardwood, pine bark and pea gravel and bare, uncovered soil. Sustained activity over time was significantly higher beneath gravel mulch. The hospitable conditions beneath mulch likely accounted for the termite foraging activity. However, there is no evidence that the moist conditions attract termite foragers from the surrounding landscape. Rather, when the termites wander into a suitable habitat they are more likely to remain and feed in that area.
The bottom line - the jury is still out. Choose whatever mulch material you like and remember to rake through it once or twice a season to make sure it hasn't become home to pesky termites.
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