Hi John,
Rosemary is only moderately effective. The Pyrethrum Daisy is better.
Check for water stagnating in the guttering on your house roof.
Report the problem to your local council. There has to be a breeding area of water somewhere.
I have noticed that people who have a small infestation of mud nests on the eaves of the house, (Fairy Martens or Swallows) have absolutely no mossies.
Years ago I was called to get rid of the nests at a private house. I talked them into keeping the little birds and myself out of a small job.
It was a time when any where you went outdoors the mossies attacked.
A local service station had a similar problem. I told them, "Do you want birds or mossies?" They chose birds. Another lost job.
Along with Geckos, frogs, toads, spiders, the birds are very effective insecticides. Not to forget micro-bats.
You can't just plant some of these creatures in your viewing area. However you should be able to acquire the P Daisy from the local nursery. The plant is quite hardy and if you forget your spray. Rubbing the leaves on your bare skin is very effective. It does break down quickly. That is why it is used in food preparation areas. It becomes harmless in a few hours before it can do any human damage, also its mammalian toxicity is very low. The occasional skin contact is nothing.
Bushmans and Tiger Balm are effective but long exposure is not good. Like 4 or 5 times a week for months on end. Best to change the brand or type of repellent occasionally.
Cheers
they are 20mm long and attack in squadrans , Horrible things . And you cant feel them land until you look and they are all over you having a feast ! Bad ! 
