I was shifting some turf I had stacked upside down last year to decompose when I spotted some shiny black eggs I’d never seen before. Rooting around some more I found a New Zealand flatworm. I’ve never seen one before so I was somewhat mystified as to what it was until I remembered reading about the NZ flatworm.
“The egg capsules are shiny, flexible and cherry red in colour at first and later darken to black after several days. After an unknown incubation period, several pale, tiny flatworms hatch out of the brittle capsule.”
These invading species (Arthurdendyus triangulatus) were first noted in Northern Ireland and the western parts of Scotland in the early 1960s and have steadily spread ever since.
Apparently, when an earthworm is located, the flatworm covers it with digestive juices. This dissolves the earthworm which is then sucked up by the predator. Estimates suggest that flatworms consume one or two earthworms per week. When its food supply has been virtually exhausted, a flatworm will shrink and wait until there are sufficient earthworms for feeding to restart. This waiting time can be as long as 12-24 months. It is not yet clear whether flatworms will move long distances to alternative feeding sites.
Great gardening information site with lots of pics and info on loads of pests, diseases and garden friends – Down Garden Services