How do you make sticky non-drying glue from sugar (for flypaper)?

Now I live in African country where is many flies and no flypaper.
I have idea to produce it myself for selling. While design question is other topic, here I came to ask advice about flypaper glue. I want to make it natural and without importing materials (like raisins). So instead I want to use local sugar. I need to cover fly paper that it is sticky and do not become dry.

As far as I understood, I should take brown sugar, melt it with minimum water, then add may be citric acid (and maybe lye?). Then boil on low temperature. So I have get syrup which is not crystallizing. With it I cover paper and I have sticky fly paper. Does it need to add something else?
So I am trying to find information about it in internet.

recipy:-

Fly trap
1/4 cup of. Vinegar
1/4 cup of. sugar
Water

Put first 2 ingredients in and put enough water in a jar to make it about 1/2 full and punch a couple holes in the lid. Works great! Good for Patio's or barns

Fly paper recipe 1
The following will make a six 18inch strips of fly paper that will be irresistible to flies.
4 fl oz Golden Syrup
1 tablespoon dark brown sugar
1 tablespoon granulated sugar

Combine the ingredients in a small bowl and then place six 18 inch strips of brown paper in a flat container and cover them with the sticky mixture. Leave them to soak overnight. Next day scrape off all the excess mixture make a little hole in one end and insert a string. Hang near open doorways and windows.

Flypaper recipe 2
To make your own flypaper, take a brown paper bag and cut it into small manageable strips. Using a quart of corn syrup and a quart of water, boil this mixture and then dunk your strip of paper into the mixture. Hang your strip using a thumb tac and you are on your way to collecting those little bugs in your home!

for performing these kind of experiments you should be clear with BASIC-CONCEPTS-OF-CHEMISTRY which will help you while performing experiments.