The Swallow Bug

A while ago I was doing some morning household chores when I noticed a strange bug in the wash basin on our bathroom counter. Upon closer inspection, I was a little freaked out to see that it looked very much like a tick. It has that rounded, triangularly-oval shape and was very flat; it looked like a blood sucker for sure. As I have very little knowledge in concern to bugs, I contacted our local expert Entomologist, Syd Cannings, and sent him my photos of it. After snapping the photos, I unfortunately washed the bug down the sink drain, my only thought being to rid the house of the evil presence… I later regretted that action.

My Swallow Bug

My Swallow Bug

Syd replied a few days later, sending me a link about True Bugs with his opinion that my little exoskeleton of horrors was actually a Swallow Bug (member of the True Bug family). Swallow Bugs had been documented in only one location here in the Yukon, and that is the area around Haines Junction. Seeing as we had just come back from our trip down to Telegraph, we figured that maybe it caught a ride back with us. Its localized status here in the Yukon was why it was unfortunate that I flushed the bug down the drain – a specimen would have been a valuable key to documentation and for 100% positive identification.


I don’t think the bug can be positively identified through my photos as they lack clarity, but it is most likely that it is a Swallow Bug. After our encounter, I decided to do more research about them and share my findings here.

Swallow Bugs (Oeciacus vicarious) are a species of True Bug, and are very closely related to Bed Bugs (family Cimicidae). They are about 3-4mm in length, and can be identified apart from Bed Bugs by the longer length of pronotal hairs (these head/neck [I think] hairs on a Swallow Bug are longer than the width of its eye), the body hairs are longer, and the third and fourth antennal segments are of an equal length. Also, apparently the middle and hind coxae (hip, or leg joints) are distinctly separated from each other and the beak does not reach the second coxae. Swallow Bugs range across North America, and make their homes in swallow nests as parasites.

Cliff Swallow in its Mud-Pellet Nest

Cliff Swallow in its Mud-Pellet Nest

They attack mainly Cliff and Barn Swallows, infesting nests and sucking the blood of adults and nestlings. Sometimes such serious parasitism occurs in nests that nestlings are forced to jump from the nest early to escape the numerous bugs. Some adults are forced to abandon their nestlings before they fledge, due to Swallow Bug infestation. These bugs are one of the main sources of mortality for swallow nestlings, and spread from nest to nest by clinging to the feathers of the flying adult swallows. The interesting thing is that though they will prey on other hosts when swallows are unavailable ( such as mice, bats, and other birds), they cannot reproduce without swallow blood. During the period in between when swallow chicks fledge in summer and when swallows return to their breeding grounds in the spring, Swallow Bugs go dormant in the nests – they can survive a year without any food. Swallow Bugs are long-lived, which means their reproduction is slower than that of most bugs. Eggs typically hatch in around 35 days, and then it take another ten weeks for the nymphs to fully mature.

Down south, Swallow Bugs are carriers of Buggy Creek Virus and Venezuelan Equine Encephalitis Virus (VEEV)

Parasites are such nasty little pests, but I do find them interesting! They are part of the whole cycle that makes the world go round.

Below are some of the resources I used to find the above information. The Bug Guide website is a great guide for the identification of any bug. – Swallows – Bug Guide – Bedbugger Forums – What’s That Bug – Buggy Creek Virus link – VEE Virus link

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