I volunteer about once per month to look after Lunada Canyon. This weekend I was inspired to spend about an hour cutting back on some Acacia cyclops (aka red-eyed wattle or coastal wattle) which is a native of Australia that is invasive in California due to prolific seed production and bird-dispersal of seeds.
In South Africa, they have used biological pest control to decrease the spread of this plant. They report 90-100% seed damage when a seed-feeding weevil, Melanterius servulus, was unleashed on the Acacia population.(Biological control of an alien tree, Acacia cyclops, in South Africa: impact and dispersal of a seed-feeding weevil, Melanterius servulus, F.A.C. Impsona, V.C. Morana, J.H. Hoffmanna). (The bad news is that the weevil spreads about 2 km per year.)
vulgare). Unless this has seeds, I like to mulch it in place.
There's a ton more of this plant around the peninsula. Fortunately, there may be a biological pest control available. From the abstract of the article mentioned earlier,
Several Australian Acacia species have become highly invasive
in a number of ecologically sensitive areas of South Africa. Many have
useful attributes that, to an extent, have hampered biocontrol efforts
by restricting potential agents to those reducing seed production whilst
not affecting vegetative growth. The outcome of the introduction of a
seed-feeding weevil, Melanterius servulus, against Acacia cyclops
in 1994, was assessed by investigating the plant’s reproductive
phenology, as well as levels of damage caused by the beetles. The study
provided essential information on host/agent interactions and, on the
build up and spread of populations of the agent. Seed damage is commonly
as high as 90% (exceptionally it reaches 100%), and dispersal rates of
the beetles on average is almost 2 km per year. The consistently high
levels of seed damage achieved hold promise for the future of the
program, however, its ultimate success will be further enhanced through
the integration of biological control with other manual clearing
operations that are currently employed on a large scale in South Africa.
So, in other words, you can have your mature plants but slow their spread into new regions while you plot their demise on your own schedule. Sounds good to me.