This insect is a Ravenous Leaf Beetle (Orsodacne atra).This identification is based on several key features visible in your photograph, combined with the location and time of year.Key Identifying Features:Serrated Antennae: The most distinct feature is the saw-toothed appearance of its antennae.Color Pattern: While this species is known for being extremely variable in color, the pattern in your photo—a black head and thorax with yellowish-brown "shoulders" on the wing covers (elytra)—is a common form. They can range from all black to mostly yellowish.Habitat: It was found on a flower, which is typical for this beetle. Adults are commonly found on a wide variety of flowers, including wild roses (which the flower in the photo resembles), feeding on pollen in late spring and early summer.Location: Orsodacne atra is widespread across North America, and its range includes Ontario.
This insect is a Ravenous Leaf Beetle (Orsodacne atra).This identification is based on several key features visible in your photograph, combined with the location and time of year.Key Identifying Features:Serrated Antennae: The most distinct feature is the saw-toothed appearance of its antennae.Color Pattern: While this species is known for being extremely variable in color, the pattern in your photo—a black head and thorax with yellowish-brown "shoulders" on the wing covers (elytra)—is a common form. They can range from all black to mostly yellowish.Habitat: It was found on a flower, which is typical for this beetle. Adults are commonly found on a wide variety of flowers, including wild roses (which the flower in the photo resembles), feeding on pollen in late spring and early summer.Location: Orsodacne atra is widespread across North America, and its range includes Ontario.
The insect captured in the photograph taken in June 2025 near Kennisis Lake, Ontario, has been definitively identified as Toxomerus marginatus, commonly known as the Margined Calligrapher. This precise identification was achieved through a meticulous morphological analysis, focusing on key distinguishing features such as the single pair of wings, large contiguous eyes, short antennae, slender body, and, most critically, the intricate and characteristic yellow and black abdominal pattern with oblique spots and a narrow yellow margin. These features collectively differentiate it from bees, wasps, and other similar-looking hoverfly species common to Ontario. The presence of Toxomerus marginatus in the Kennisis Lake region is consistent with its known distribution across North America.The Margined Calligrapher plays a dual and indispensable role in its ecosystem. As an adult, it serves as an essential pollinator, contributing significantly to plant reproduction and biodiversity by feeding on nectar and pollen from a wide array of flowers. In its larval stage, it acts as a highly effective natural predator of common agricultural and garden pests, including aphids, thrips, and small caterpillars, thereby providing valuable biological control services.
