Lady Bugs

Use: Ladybugs prefer to eat aphids and will devour up to 50 a day, but they will also attack scale, mealy bugs, boil worms, leafhopper, and corn ear worm. They dine only on insects and do not harm vegetation in any way.
Release: Ladybugs should always be released after sundown since they only fly in the daytime. During the night, they will search the area for food and stay as long as there is food for them to eat. The more they eat the more eggs they lay and the more insect eating larvae you will have. It is best if the area has been recently watered. Ladybugs tend to crawl up and toward light. So release them in small groups at the base of plants and shrubs that have aphids or other insects, and in the lower part of trees.
Recommendations: Ladybugs may be kept in the refrigerator after they are received (35-50 degrees F.) and released as needed. Ladybugs received March through May should not be stored more than 2 to 3 days since their body fat has been depleted. From June on, they may be stored 2 to 3 months.
 
For more information:
https://www.marshallgrain.com/post/copy-of-ladybugs-dine-on-soft-bodied-insects