When you're near the lake you rarely need to worry about any annoying insects. The cold water and the frequent winds will usually keep them to a minimum. For 2-3 weeks in the middle of summer you will come across horseflies and gadflies, especially if you are traveling in the Tazheransky or other nearby steppe-lands. Of course, if you are alergic or sensitive to insect bites, you should pack away some non-toxic repellent for your visit to the lake.
The one time where you will need to be careful of insects is during the months of May and June, when the forests here will have ticks. These ticks can be carriers of encephalitis, borreliosis, or other unpleasant diseases. So if you come in late spring, and plan to take hikes out into the wild, then you should be very careful, bring special repellent, and try not to brush up against trees—all the while checking yourself for ticks on a regular basis.