Boisea trivittata, Boxelder bug,
Order: Hemiptera. (meaning half-wing)
Length 1.5mm to average 12.5mm (sizes of nymphs to adult)
Season May to September
Boxelder bugs are “true bugs,” belonging to the same family as, cicadas and stink bugs.
Widespread throughout, south and central Europe and in most warm climates in the world. Often seen clustered in “family groups,” especially the nymphs. Commonly found on a variety of herbaceous plants in gardens and park areas. Feeding mainly on fallen leaves and Boxelder seeds. Can become a pest for fruit growers and also certain trees (main ones being Maple and Ash) but is NOT a serious threat.
(Boxelder trees are found growing in South America, Australia, New Zealand, South Africa, much of Europe, and parts of Asia).
Boisea trivittata can be a serious pest to homeowners, when the colder weather approaches; they will sometimes seek to enter houses in colonies of hundreds, even thousands of insects; (Mainly a problem in American countries), as the cold weather approaches.
Nymphs are bright red in colour, being a warning to would be predators they are poisonous.
The nymphs go through five stages, continuing to turn red as they reach maturity.
Nymphs are seen through most of the year here in Spain, in countries further north, nymphs have less chance of surviving throughout the winter months; just the adults will have a chance survive in colder countries by taking shelter under loose bark, plant debris, or in houses and out-houses.
The adults can be mistaken as stink bugs, because they are very similar in appearance.
Males are slightly smaller than the female, but similar in appearance.
The female will lay between 200 to 300 eggs in clusters of approximately 10 eggs, on seedpods, the crevasses of plant stems, underside of leaves and branches. Eggs take 10 to 14 days to hatch, they are red, elongated and about 1.6mm in length; hatching between 10 to 20 days, depending on climate.
Images below are of the nymphs.