Bed bugs are more of a serious nuisance pest than a health threat. Some people do not react to bed bug bites or notice bites at all. However, some people find the bite painful, while others can react to the saliva the bed bugs inject while feeding, resulting in a localised allergic reaction.
Life cycle of bed bugs
Egg
Bed bug eggs are shaped and coloured like a tiny grain of opaque white rice but are hard to see. They are about 0.8–1.3 mm long and 0.4–0.6 mm wide. Adult female bed bugs can lay from three to 12 eggs a day and from 150 to 500 eggs in her lifetime. Eggs usually hatch within a week to 10 days depending on ambient conditions (sometimes up to three weeks in cooler conditions) and the new bed bug nymphs will immediately begin to feed.
Nymph
They grow from 1 mm to 4 mm in length during the nymph phase of their life cycle. Newly hatched nymphs feed as soon as food is available – each nymph requires one full blood meal before moulting to the next stage.
Adult
Adult bed bugs can live for about six months at room temperatures of about 20–23ºC and much longer–up to a year or more – in cooler climates. They can live for several months without feeding. With frequent feeding at average room temperatures (about 20 ºC) adult bed bugs can live for nine to 18 months.
The complete cycle from egg to adult can take about nine to 18 weeks. With these average-to-warm conditions, nymphs feed at about 10-day intervals and adults weekly. Nymphs and adults can survive long periods without a blood meal. Under cool conditions starved adults could survive for several months and as long as a year.