how to encode this data to parent / children structure in JSON

I am working with d3.js to visualise families of animals (organisms) (up to 4000 at a time) as a tree graph, though the data source could just as well be a directory listing, or list of namespaced objects. my data looks like:

json = {
    organisms:[
        {name: 'Hemiptera.Miridae.Kanakamiris'},
        {name: 'Hemiptera.Miridae.Neophloeobia.incisa'},
        {name: 'Lepidoptera.Nymphalidae.Ephinephile.rawnsleyi'},
        ... etc ...
    ]
}

my question is: I am trying to find the best way to convert the above data to the hierarchical parent / children data structure as is used by a number of the d3 visualisations such as treemap (for data example see flare.json in the d3/examples/data/ directory). Here is an example of the desired data structure:

{"name": "ROOT",
 "children": [
        {"name": "Hemiptera",
         "children": [
             {"name": "Miridae",
              "children": [
                  {"name": "Kanakamiris", "children":[]},
                  {"name": "Neophloeobia",
                   "children": [
                       {"name": "incisa", "children":[] }
                   ]}
              ]}
         ]},
        {"name": "Lepidoptera",
         "children": [
             {"name": "Nymphalidae",
              "children": [
                  {"name": "Ephinephile",
                   "children": [
                       {"name": "rawnsleyi", "children":[] }
                   ]}
              ]}
         ]}
    ]}
}

EDIT: enclosed all the original desired data structure inside a ROOT node, so as to conform with the structure of the d3 examples, which have only one master parent node.

I am looking to understand a general design pattern, and as a bonus I would love to see some solutions