Black beetles with yellow spots

Updated February 21, 2017

Beetles are insects of the Coleoptera order, which has the most species of any order in the world and constitutes 25 per cent of all known life forms. Characteristics of beetles include hard elytra (forewings) and a particularly hard exoskeleton made up of plates that are separated by thin sutures. A beetle's life consists of four stages: egg, larva, pupa and adult. This lifespan can last anywhere from three weeks to 12 years, depending on the variety. Beetles can be plain or very colourful; several genera of beetle feature yellow spots on their black elytra.

Ornate Checkered Beetle

Beetles of the Trichodes genus, commonly called ornate checkered beetles, are usually less than 0.4 inches in length. Most species of this beetle are black with markings of bright colour, including yellow. The adults feed frequently on flower pollen and nectar. In the immature larva stage this beetle lives as a cleptoparasite, or scavenger, of other insects living in wooden galleries. In the immature grub stage, it feeds inside leaf cutter bee nests, which can destroy chambers of bee grubs. Since leaf cutter bees are considered valuable pollinators, the ornate checkered beetle is sometimes considered a pest. This beetle is widespread and common across western North America, from Canada to Mexico.

Flower Buprestid

The very large and colourful Acmaeodera genus beetles are commonly called flower buprestids or yellow-marked buprestids. Species of this beetle are generally black with patterns of bright yellows, reds, greens or blues and are favourites of collectors. Their size ranges from 0.2 inches to 3 inches and are seen on leaves and flowers, particularly in the late summer and fall. As larvae, they live in the twigs or stems of various plants; associations between the host plants and adults are not well established, however. These beetles are widely distributed in North America, but are the most diverse in the Southwest.

Metallic Wood Boring Beetle

Beetles from the Chrysobothris genus, commonly known as metallic wood boring beetles, are also known as a jewel beetles because of the bright spots on their black backs. Their large eyes provide acute vision and a wary nature; they also can fly with great agility. This beetle lays its eggs beneath tree bark where they hatch into grub that tunnel under the outer bark, feeding on the nutritious plant tissue. There are at least 134 different species of the Chrysobothris genus that are generally distributed throughout North America; they range in size from 0.12 inches to 4 inches in length.

Sap Beetle

The Carpophilus genus is commonly known as the sap beetle. It has a small, broad flattened body -- usually only 0.08 inches to 0.24 inches -- and a large head and eyes. Most Carpophilus species are black with bright yellow or red spots or bands. Sap beetles lay eggs and pupate in the soil, spending their winter as adults. The adult beetles are found abundantly in flowers, particularly cactus flowers, and sometimes under tree bark. They are also attracted by decaying vegetable matter, sap and fermenting fruit. Sap beetles are common across North America and worldwide.

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About the Author

Based in Royal Oak, Mich., Christine Wheatley has been writing professionally since 2009. She contributes to several websites, specializing in articles about fitness, diet and parenting. Wheatley has a Bachelor of Arts in art from Calvin College.