Can be solo'd by a 65 Beastlord, but it is a little rough. You'll have to tank, since they summon. Temerity is a must and KEI or better helps out since you'll be healing a lot. Keep Ferocity up on yourself and your pet, buff yourself any way you know how. Basically just slow, Incapacitate if you want (I do), and click Protective Disc when it pops. DoT if you like, doesn't seem to make much difference. Even Incapacitated they hit in the 500s fairly often, and doubles of that can really knock down your HP. Basically just tank it out, fights last about 2 minutes.
Soloing these guys isn't as good as grouping, of course, but if you're having trouble finding a group then killing some time with these is doable.
As a side note these guys do stun, maybe 1.5-2 second duration, pretty often.