Surface water temperatures in most lakes in the Bemidji area have reached the mid-60s, which is the point when major insect hatches begin in the lakes.
There have already been minor hatches of midges and other insects this spring, and there should be some major insect hatches beginning soon, if it has not already started.
There will be minor hatches of insects such as dragonflies and midges all summer long, but the biggest hatches of mayflies or fish flies happen in June.
Midges are the adult phase of blood worms, which are usually the first major hatch of the spring. Midges are a clear skinned worm that lives in the mud basin of the lakes by the tens of millions or maybe hundreds of millions in some larger lakes.
Midges are an important forage species for perch and other fish during the winter. This gives the fish a dependable and plentiful food source during the lean months and helps them survive the winter.
When anglers talk about bug hatches in the spring, they are usually thinking about midges that look like mosquitoes without stingers, and mayflies which are large insects that end up sitting all over everything in the mornings after they hatch, drying their wings.
According to Wikipedia, there are about 630 species of mayflies living in North America and more than 3,000 species worldwide.
Mayflies spend virtually all of their lives in the water, only to emerge and spawn for a few days at the end of their life cycle. Mayflies have such a short life span in their adult phase, they don't even have mouths to feed.
The two kinds of mayflies most anglers recognize in the Bemidji area are the smaller grey colored mayflies that hatch first and the larger cream colored mayflies that have a touch of green, which are usually one of the last major insect hatches of the spring.
Insects form the base of the food pyramid in most lakes, with insects an important food source for minnows and smaller fish species of all types.
There are also adult species of fish that feed heavily on insects including tullibees, whitefish, sunfish, perch and rockbass.
Walleyes and other predators are more indirectly affected by the insect hatches, with predators often preying on minnows, baitfish and perch that are feeding on the insects.
Now that spottail shiners are finishing spawning and will be moving away from shoreline structure, this removes a major food source in shallow water for walleyes.
This will force walleyes to switch forage species and begin looking for different food options in other parts of the lakes.
The next best thing for most walleyes are the insect hatches that begin in deeper water about the same time shiner minnows are done spawning and moving away from shore.
Walleyes often head for mid-lake structures that are surrounded by the mud basin, which is where most of the insects hatch.
The jig and shiner minnow bite is already beginning to die down in the shallows for walleyes and soon the supply of spottail shiners will also begin to run out in the bait stores.
Anglers can catch walleyes in the weeds all summer long in some lakes, but in other lakes, anglers have to look for rock structures, chara covered sand flats or deeper mid-lake structures to find walleyes.
Walleyes in Leech Lake continue to move out of the shallow bays and move towards main lake structures and deeper bays.
Upper Red Lake is still producing good numbers of walleyes along the shoreline break, with many anglers using spinner rigs to cover more water and locate the schools of active walleyes.
Lake Bemidji has the best cabbage weeds in the area, with walleyes and other fish relating to the inside or outside edge of the cabbage weeds.
Walleyes in Cass Lake are using chara covered sand flats or areas with rocks that are holding crayfish.
Walleyes in Lake Winnibigoshish are beginning to move off the shoreline weeds and showing up on the numerous mid-lake structures.