WAYNESBURG, Pa. (AP) – Swarms of dragonflies are taking over several western Pennsylvania communities and have even showed up on weather radar. WTAE-TV reports that meteorologists with the National Weather Service in Cleveland spotted an unusually large blob on their radar earlier this week. It turned out to be dragonflies. Entomologists say the swarms of dragonflies are quite common, and usually happen when they are migrating south to find warmer weather as winter approaches. The swarms have also been reported in Indiana, Ohio and Virginia. A similar phenomenon occurred earlier this year when a massive bloom of ladybugs was detected by radar in the area of San Diego.