Stem maggots in Bermuda

When does everybody that get stem maggots start seeing them do they show up early in the year or late like army worms do. Around here central Arkansas the Amy worms will show up late August early september like clock work but as of now the extension service says the stem maggots really are not in our area but I got to wonder and figure they will show up here eventually as they seam to be growing in population. I am only asking because my last cutting last year and first cutting this year have been less the a 1/8 of the yeld I have been getting in years past and my soil test show that my ground it the best it has every been and the grass looks really good it’s just thinner. Just trying to make sure I am not missing anything or if it is something I can do to change.

Stem maggots in Bermuda