In the past month, bug of the week has visited several insects active in winter. This includes the chilly fall cankerworm, hardy hemlock woolly adelgid, and frosty winter stoneflies. Another strategy for coping with cold temperatures and relative lack of food winter brings is to enter a state of arrested development. In many species of insects development may halt completely for extended periods of time. In some insects growth and development resume as soon as favorable conditions such as warm temperatures return. However, in other species development only resumes
when critical environmental cues such as increasing day length trigger physiological changes within the insect ending the period of arrested development. This type of developmental delay is called diapause. Diapause is a clever strategy employed by many insects that have a single generation each year. Recall that an insect's life cycle is rather more complex than our own. As babes we appear much as we do as adults, smaller, fewer winkles and larger heads, perhaps, but quite similar in
appearance. By contrast, insects usually begin life as an egg that hatches into either a larva or a nymph depending upon whether the insect has complete or incomplete metamorphosis. In the process of becoming a full-fledged adult, a tour of duty as a pupa takes place for insects with complete metamorphosis. With all these life stages as options how does the insect overwinter? The answer is that all stages of development are used to overwinter by some type or insect or an other. But, for many of our most common species, eggs are the overwintering stage. About this time of year, people begin sending me pictures or samples of insect eggs collected in their yard, garden, or nearby meadow. This week's bug of the week is devoted to a few of the insect eggs that have been sent to me with the question, "What is it?" Have a look at these strange overwintering eggs and egg masses. Venture a guess as to who laid the eggs, then click on the image and you will learn who laid the egg and what will hatch out in the spring. I'll give you a hint. All of the insects featured in this egg hunt have been subjects of previous bugs of the week. Happy egg hunting and if you find a really cool egg or egg mass send me an image and, perhaps, we can use it in a future bug of the week.

For more information on insect development and diapause, please visit the following web sites.