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 established itself as an urban pest in Toronto over the last couple of years and can now be considered a common household pest. Combined with its appearance and behaviour, this insect is readily confused with the Eastern box elder bug.
Red firebugs go through a 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 climatic factors (i.e., 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 inconspicuous but are initially white in colour and gradually turn yellow and red before hatching. Red fire bug nymphs go through physiological changes over a 17-to-24-day period before finally reaching their adult form. Young nymphs look like box elder bug nymphs, while older nymphs look like the adults, except that they are smaller and have reduced wing pads. Adult firebugs begin mating within a week of emerging; however, females do not lay eggs until the next year. Adults will begin to hibernate as the 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 forewings are variable in size, ranging from shortened to absent. The forewing colour pattern is also highly variable when present, but is generally red with black spots. The wings cross over the back and are held flat against the body at rest.
Red fire bugs feed on the fallen seeds from a wide range of plants. Generally, the most common host plant that the insects can be found upon in Toronto is linden trees (Tilia sp.).
Nymphs and adults seek shade during the day, like the Eastern box elder bugs, and are just as gregarious as they can be found amassing on homes, structures, plants and under leaf litter.
As the season progresses into the fall months and daylight 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 homeowners.
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 are known to respond to potential threats in two different ways: a scent gland on each side of the abdomen can emit a foul odour, and they can also regurgitate an offensive fluid from the stomach.
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 homeowners follow the management practices listed below.
Recipe:
Instructions:
Mix ingredients and put into an empty spray bottle or hand pump sprayer. Spray insects directly, ensuring to cover them as best as possible with the solution to achieve the 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 Cosmetic Pesticides Ban Act prohibits pesticides from being 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 use.