Life history and habits

All these insects develop and reproduce on different hosts. Only bed bugs can reproduce on human blood and are found near beds or other areas where humans sleep. Bat bugs, swallow bugs, and H. coloradensis can only reproduce on the blood of their wild animal host and tend to occur around roosting areas or nests. These species have similar life history, with eggs laid in cracks or crevices near resting areas of the host animal. Upon hatching, nymphs immediately seek out a host animal and begin feeding on blood until fully engorged, which takes only a few minutes. The nymph then moves to a nearby hiding place to digest the blood meal, and gradually molts through several instars until reaching adulthood. After mating, females begin laying eggs over months and continue feeding on blood meals periodically. The exact behavior depends on the pest species.

Bat bugs: Both eastern and western bat bugs are only found in buildings that harbor roosting bats. They tend to be found in the upper areas of buildings where bats are likely to roost such as attics, between walls, in chimneys, and under shingles. Bat bugs often move off the bat after feeding but can also hide in the folded wings of a resting bat and be transported to new roosting areas when the bat migrates. Bat bugs can live seven or eight months without feeding, and when bats are excluded from the building or die, bat bugs will migrate into living areas where they are more likely to encounter humans. Bat bugs are most likely to be found on the building’s upper floor near the roosting site, unlike bed bugs who tend to reside near human resting areas such as beds, chairs, and sofas. Furthermore, bat bugs are typically spotted individually rather than in aggregations like bed bugs.

Swallow bugs: Swallow bugs feed on the blood of swallows, with cliff swallows (Petrochelidon pyrrhonata) serving as the main host. Cliff swallows build jug-shaped mud nests on cliffs or overhangs of man-made structures. A single nest can be used for multiple years, and when a nest is abandoned for the winter, swallow bugs move to nearby sheltered areas such as cracks and crevices where they can survive without feeding for months. Swallow bugs are more likely to bite humans in spring before swallows return to the nests or in autumn after swallows have abandoned the nest. In the spring, swallow bugs are highly starved and may aggressively seek out alternate hosts for a blood meal.

Hesperocimex coloradensis: This species is rarely reported in Colorado homes, and there are no conclusive reports that this species bites humans. This insect can be found in homes where a woodpecker or flicker has constructed a nest, and the nest is occupied by a suitable bird host. After the nest is abandoned, H. coloradensis may wander into living areas of the home.

Management

Excluding animal hosts from returning to roosting or nesting sites within buildings will cause infestations of bat bugs, swallow bugs, or H. coloradensis to die out. When host animals are absent in October through early April, entry points into the building can be sealed with screening or other barriers. When bats hibernate in the building, installing a one-way door can help evict bats in early spring before they produce young. It is worth noting that bats are protected under Federal law and their removal involves important health considerations such as the transmission of rabies. For these reasons, seeking out professional help is highly recommended.

After the animal host has been excluded from the building, the remaining bat bugs or bird-feeding bugs can continue wandering through the structure for several months in search of a blood meal. Their movement can be restricted by sealing cracks around windows, gaps around electrical sockets, or other holes and cracks in walls. They will starve to death eventually, but in certain conditions can survive over a year without a blood meal. Applying insecticide dusts or sprays into cracks and crevices can speed up the elimination of bat bugs and bird-feeding bugs. To be effective, insecticides must have residual activity, and it is recommended to seek professional assistance when applying insecticides for these pests.

References

Cranshaw, W., M. Camper, and F. Peairs. 2013. Bat Bugs, Bed Bugs and Relatives. Colorado State University – Extension. Available https://extension.colostate.edu/topic-areas/insects/bat-bugs-bed-bugs-and-relatives-5-574/