Gumtree Scale sacs

Description:

A row of felty oval-shaped sacs on a eucalyptus tree branchlet. Each sac would have been about 2mm long with a dark patch at the upper part. These sacs were tended to by sugar ants (Camponotus nigriceps). Each sac is said to contain an adult female scale insect. She lays hundreds of eggs within the sac. The whole cycle of this scale insect is said to take upto 50 days.

Habitat:

These scale insects are found only on several species of Eucalytpus trees. They are native to Australia but have spread to New Zealand.

Notes:

Crawlers (nymphs of the scale insect) hatch out of these eggs and spread over the tree - some get blown away and so, spread over a wide area. The insects suck a large amount of sap from the tree and excess sap is secreted as a sticky "honeydew" which attracts sugar ants. These sugar ants are interesting in their own right - they are known to protect some hemipterans because of the honeydew. Pic #2 shows a little black ladybird on a neighbouring leaf. This ladybird is said to feed on the gumtree scale-http://www.projectnoah.org/spottings/13910435 There are three species of insects in the spotting, their lives all interconnected making this spotting pretty complex but a perfect albeit small example of life on this planet ! Info on ant: Camponotus nigriceps http://www.brisbaneinsects.com/brisbane_... Info on gumtree scale:Eriococcus coriaceus http://www.nzffa.org.nz/farm-forestry-mo...