Red firebug (Pyrrhocoris apterus) is native to Europe and western Asia.  It was first discovered in North America in Utah in 2008 and has quickly expanded its range since.  It has quickly established itself as an urban pest in Toronto in the last couple of years and is considered to be a common household pest.  Combined with its appearance and behaviour, this insect is readily confused with Eastern box elder bug.

Life Cycle and Description
Red firebugs go through simple life cycle (egg, nymph, adult) and typically have one generation per year.  Some adult firebugs have been known to live up to two years. Their life cycles can be influenced by climactic factors (IE. Weather and temperature) but typically can take 2 to 3 months.
Overwintering females can lay 40-80 eggs in a lifetime, usually starting in June. The eggs are fairly inconspicuous but are initially white in colour gradually turn yellow-red before hatching. Red fire bug nymphs go through physiological changes over a 17 to 24 day period before finally reaching their adult form.

Red Firebug

Young nymphs (Fig.2) look similar to box elder bug nymphs while older nymphs look similar to the adults except are smaller and have reduced wing pads. Adult firebugs (Fig. 1) begin mating within a week of emerging; however, females do not lay eggs until the next year. Adults will begin to hibernate as winter months begin to set in.  This hibernation usually begins when the day length is less than 12 hours per day. The adults are 6.5-12 mm long, and in general the females are slightly longer and wider. The fore wings are variable in size, ranging from shortened to absent. The fore wing colour pattern is also highly variable when present, but is generally red body with black spots. The wings cross over the back and are held flat against the body at rest.

Fire Redbug nymphs

Hosts and Behaviour
Red fire bugs feed on the fallen seeds from a wide range of plants. The most common host plant that the insects are found on in the G.T.A. are linden trees (Tilia sp.).
Nymphs and adults seek shade during the day to ensure only one generation a year. Similar to Eastern box elder bugs, Red firebugs are gregarious and can be found massing on homes, structures, plants and under leaf litter.
As the season progresses into the fall months and day light begins to shorten, the adults will begin to seek places to overwinter, generally finding their way into homes and other structures, becoming a nuisance to home owners.
In spite of their warning coloration and the threatening name, red firebugs are harmless to humans as well as their hosts.  They have numerous natural enemies which include mites, birds, mammals, amphibians and ants.  If threatened however, they have been known respond to potential threats in two different ways. Red fire bugs have a scent gland on each side of the abdomen that can emit a foul odor, and they can also regurgitate an offensive fluid from the stomach.

Specific Management Practices for Control of red firebug
Because this insect does not harm the health of trees, it is not considered a Forest Health Concern; Therefore the City of Toronto does not provide treatments for red firebug.  Urban Forestry recommends the following to individuals that are experiencing issues with this insect:

  • It is not recommended to squish these insects as they can omit a foul odor when crushed. This odor has potential to draw further insects to the area, in turn exacerbating the situation. There is also potential to stain carpets and fabrics when they are crushed.
  • Focus should be on preventing the insects from accessing homes and buildings.The best way to keep box elder bugs out of building is to make sure that there are no entry points. Filling gaps around windows and doors with weather stripping, repairing or filling holes in foundations and using window and door screens will help to prevent their entry.  In some cases, completely sealing up the home may be next to impossible. If the insects do manage to find their way into the home, simply vacuum them up and dispose of them.
  • The use of an insecticide labeled for red firebug control could be applied, by treating the exterior of the building at the time of the swarming in the fall. Treat sidings, windows, doors and the foundation the building with an insecticide. Many pest control companies provide services that help control the insect around homes.
  • True bugs, such as red firebugs or Eastern box elder bugs, especially the nymphs, are easily drowned. Regular use of a high-pressure water from a garden hose sprayed directly on the insect congregations can be effective.
  • An alternative to synthetic insecticides is a mixture of soapy water that can be used to spray the insects directly has shown to have some knock-down effect:
    • Recipe:
      • 2 tbsp. of liquid dish soap
      • 1 litre of water
      • 2 tbsp. of cooking oil (IE. canola, olive)
    • Instructions
      • Mix ingredients together and put into empty spray bottle or hand pump sprayer. Spray insects directly ensuring to cover them as best as possible with the solution to achieve best results. Spray as often as necessary.  Soap only kills the bugs that are being sprayed and has no residual effects once it is dry.

      The Ontario's Cosmetic Pesticides Ban Act prohibits pesticides to be used for cosmetic purposes on lawns, vegetable and ornamental gardens, patios, driveways, cemeteries, and in parks and school yards. There are no exceptions for pest infestations (insects, fungi or weeds) in these areas, as lower risk pesticides, biopesticides and alternatives to pesticides exist. Over 95 pesticide ingredients are banned for cosmetic uses.