Life Stages & Reproduction
Eggs
As spring approaches and temperatures begin to rise, overwintering stink bugs emerge from hiding to begin the reproduction process. The insects typically mate and produce eggs from May to August.
Where do they lay eggs?
Female stink bugs lay batches of 20 to 30 barrel-shaped eggs on the undersides of leaves.
The female is very neat about the whole business. She lays them in orderly rows of 12 to 14 eggs each, laying from 30 to 100 eggs at a time. The eggs look like little barrels, and they come in different colours, depending on the type of stink bug.
They especially like fruit like apples, oranges, and cherries, but vegetables – e.g. tomatoes, squash, turnips, beans, corn, cabbage, cauliflower – will do just as well for them if there is no fruit around. Even the leaves of cotton plants have been known to be egg laying areas of stink bugs. So gardens, orchards, and farms are the areas where you normally find stink bugs laying their eggs.
You will not find the eggs inside your home
Contrary to what many people fear, stink bugs do not lay eggs in people’s houses. The reason this is so is that the bugs go to houses to overwinter or hibernate. They go indoors to sleep off the cold and take it easy. It’s not the right time to reproduce as cold weather is not conducive to the full development of eggs and nymphs. If you find stink bug eggs in your house, they probably came in with the exotic plants you brought in from the grocery or plant store nearby.
How to look for the eggs
A good way for checking if there are stink bug egg clusters in your vicinity is to attach a small mirror on a long stick and check the undersides of plant leaves. Many homeowners choose to check for eggs and eliminate them as they discover them in order to prevent an infestation of the bugs come cold weather.
Nymphs
Eggs hatch into tiny black and red nymphs that measure less than an eighth of an inch. The nymphs moult through five different stages before becoming winged and full-sized adults. Typically, this process is completed in about a month.
photo source: stopbmsb.org
Impact of Climate & Temps
Fully grown stink bugs measure about one inch in length. Stink bugs usually produce one or two generations per year.
However, temperatures influence reproduction rates, and warm spring and summer seasons can result in three to four generations in a year.
Sub-tropical regions can see as many as six generations of stink bugs in one year. Temperate climate usually limits stink bugs to one generation per year.
Summer
Stink bug populations spike as summers progress.
Fall
During the fall, typically between September and October, the insects begin searching for overwintering sites.
Winter
Outdoor stink bugs overwinter in piles of leaf litter and become active again when temperatures increase. Stink bugs may also enter homes to overwinter, often invading in large numbers. Warm temperatures inside the home keep stink bugs active, making them winter-long nuisances.