Bed Bug Life Cycle

It is important to understand the life cycle of bed bugs as this information can give you an idea of when the infestation started.

A bed bug life cycle (egg to egg) takes about 4 – 5 weeks–longer depending on the temperature/climate. High temperature and humidity are ideal conditions for bed bugs to reproduce and go through their life cycle faster. Bed bugs will go through five molting cycles before reaching adulthood. Each cycle requires a single blood meal before molting (shedding its skin) to the next developmental stage. Once bed bugs reach maturity, the females will begin to lay eggs after mating and feeding.

This image is from MidMos Solutions Ltd. Photography: Stephen Doggett

Bed bug eggs are oval shaped (rounded at one end and flat at the other). The flat end opens like a hatch top when the first instar emerges and the nymph actively seeks a blood meal. Typically eggs hatch in 3-12 days. First instar bed bugs or nymphals are approximately 1/32 of an inch long. Prior to taking a blood meal, first instar bed bugs, are translucent and may appear tan in color. Once engorged, the lower part of their bodies take on a bright red color and will remain that color as long as they have remnants of a blood meal in the abdomen. Fully-engorged nymphs can grow up to six times their body weight. After a few days, they will molt (shed their skin) to the second stage of development. This will occur five times before reaching the adult stage. Bed bugs must feed to molt or grow to the next instar or stage of development. Each time they shed their skin to advance to new stage of development, their color gets darker. Unfed, adult bed bugs are flat (as thin as a business card); reddish-brown in color and are approximately 1/4″ in size. Fully engorged adult bed bugs takes on a oval shape and could grow twice its original size. An adult female bed bug lay could 3-10 eggs a days and could lay up to 500 eggs in its lifetime. Eggs are often deposited in cracks, crevices and/or on rough surfaces–usually in clusters–scattered if not producing many eggs in one day. Bed bugs could go from being a small egg to a full grown adult in as little as 28 days. Again the rapidity of the cycle depends greatly on interior temperature and humidity.

Bed bugs have the unique ability to survive without feeds. First instar nymphs (first hatchlings) can survive up to six weeks without any blood meal. Nymph bed bugs can survive up to 3-4 months without a meal and adults can survive over year. The length of survival depends on the temperature and stage.