Homemade Insect Repellent

Second son is lifeguarding again this summer at some local springs.  The deer flies love to munch on him and the other humans, so I decided to make some homemade insect repellent.  After searching online I found some recipes that, of course, I tweaked a bit and came up with a spray I liked.  Here are the sites:
http://chemistry.about.com/od/healthbeautyprojects/a/naturalinsectrepellent.htm   and
http://wellnessmama.com/2565/homemade-natural-bug-spray-recipes-that-work/#
I used half jojoba oil and half lavender witch hazel (with no alcohol) as my base and added drops of citronella, lemongrass and tea tree oils.  It smells wonderful and my son says it works well.  Made a second bottle for my husband, as mosquitoes seem to seek him out in a crowd.  I found an amber 2 ounce spray bottle for dispensing at my local health food store.