Descriptions of Families and Subfamilies
of Flower-Visiting Beetles
Buprestidae (Metallic Wood-Boring Beetles)
These beetles are small- to medium-sized with a hard carapace. They are rather flat, long, and oval-shaped. The wing-covers are often bumpy or conspicuously ridged, brown or black, with an iridescent sheen. The eyes are rather large for a beetle. Adults occasionally visit flowers for pollen, while the larvae bore through the wood of various trees and shrubs, creating flattened tunnels.
Cantharidae (Soldier Beetles)
Soldier Beetles are medium-sized, rather long, with rectangular wing-cases. They are usually black with yellow or red markings behind the head, but sometimes they are tan or yellow with black markings. Soldier Beetles resemble Lightning Bugs in overall appearance, but there is no light-emitting organ. The larvae are often carnivorous and feed on small, soft-bodied insects, while the adults are often found on flowers feeding on pollen or nectar. One of the more common members of this family, Chauliognathus pennsylvanicus (Goldenrod Soldier Beetle), is found on goldenrod and other flowers during the late summer and early fall.
Cerambycidae (Long-Horned Beetles)
This is a large family of beetles consisting of several subfamilies. Long-Horned Beetles are medium to large-sized. The adults are rather flat, long, and oval or slightly angular. They are often black or brown, but also exhibit other colors, depending on the species. The antennae are quite long, sometimes even longer than the length of the body. The larvae bore round tunnels through the wood of various species of trees and shrubs, and can cause considerable damage. Some species of Long-Horned Beetles visit flowers to feed on pollen or nectar, particularly in the subfamily to be described next. Lepturinae (Flower Longhorns): These are medium-sized beetles with wing-covers that are broad near the head, but taper gradually toward the posterior. The pronotum and head are narrow and flexible, while the antennae are long. Flower Longhorns are often colorful, sometimes iridescent green, black and yellow, black and red, etc. The adults are common visitors to flowers, feeding on pollen or nectar. The larvae feed on the moist dead wood of various trees and various human artifacts, the latter including wooden poles, cross-ties, and fences that are not treated with insect-resistant chemicals.
Chrysomelidae (Leaf Beetles)
This is a large family of small- to medium-sized beetles. Some species are small and round, while others are longer and more angular. The antennae are fairly short. Leaf Beetles exhibit highly variable colors and patterns, including shiny black or brown, greenish-yellow with black dots, pale yellow with black stripes, etc. The adults usually feed on leaves and flowers, while the larvae feed on leaves or roots. The adults of some species feed on pollen, as well as other parts of a plant, often causing more damage than good. Of the various subfamilies, only one will be described next because of the atypical habits of the species. Bruchinae (Seed Beetles): These are small stout beetles with broad oval bodies. They have down-turned heads with a small snout. Seed Beetles are usually dull brown or black, but they may be dull red or yellow with mottled patterns. The adult beetles are occasionally found on flowers, where they lay their eggs. The larvae bore into seeds, where they feed and pupate.
Coccinellidae (Lady Beetles, Ladybirds, Lady Bugs)
Lady Beetles are small, round, with convex wing-covers. The head and pronotum are often shiny black with white markings, while the wing-covers are often shiny orange-red with black dots. Some species, however, are predominantly black, or gray with black dots, and may have fine hairs on their bodies. The adults usually feed on aphids, scale insects, and other small insects, while the larvae tend to feed on the same kinds of insects. Adults occasionally appear on flowers with exposed nectaries to feed on nectar. Lady Beetles are considered beneficial insects, although a few species feed on the foliage of crop plants.
Curculionidae (Weevils, Snout Beetles)
This is a very large family of beetles. The adults range in size from small to large; they have stout bodies and a hard carapace. Weevils have a long narrow snout projecting from the head, with a pair of short, jointed antennae toward the middle of this snout. This provides them with a distinctive appearance. Weevils are generally dull tannish brown or grey, but sometimes have carapace that is red, green, or shiny black. Both adults and larvae feed on various parts of many kinds of plants, and can be very destructive. However, adults sometimes visit flowers to feed on pollen or nectar.
Lampyridae (Lightning Bugs, Fireflies)
These insects are beetles, not plant bugs or flies, as the common names suggest. They are medium-sized, black, with red or yellow markings, especially behind the head. The wing-covers are rectangular, while the posterior of the abdomen usually has a light-emitting organ. Lightning Bugs are often observed shortly after dusk, when they emit a yellow or greenish-yellow blinking light to attract members of the opposite sex. Both adults and larvae prey upon small, soft-bodied insects, but the former sometimes appear on flowers, where they seek nectar or feed on pollen.
Meloidae (Blister Beetles)
These beetles are medium to medium-large in size. They are fairly long, with rectangular wing-cases, and heads that are wider than the pronotum. They are black, brown, tan, or red, with variable patterns. When disturbed, Blister Beetles exude blood with an irritating chemical that can cause blisters. Adults are often serious pests that feed on foliage and flowers, as well as pollen and nectar. The larvae are usually beneficial, feeding underground on grasshopper egg cases and the immature specimens of other insects. A typical example is Epicauta pensylvanica (Black Blister Beetle), which sometimes appears in large numbers on goldenrod and other flowers.
Melyridae (Soft-Winged Flower Beetles)
These are small beetles with soft wing-covers, which are broader towards the posterior than the anterior. Both the head and pronotum are rather wide. Soft-Winged Flower Beetles are variously colored, and their bodies are often covered with fine hairs. The adults prey on other flower-visiting insects, or they may feed on pollen. The larvae are carnivorous, or scavenge for dead animal material on the ground.
Mordellidae (Tumbling Flower Beetles)
Tumbling Flower Beetles are often found on flowers. With even slight disturbance, they are likely to jump or tumble to the ground, thereby making their escape. They range in size from small to medium. The wing-covers are oval-shaped, broader in front than behind, with a pointed abdomen protruding from the posterior. These beetles are usually black. The hind legs are rather long, which probably facilitates the capacity to jump and escape. Adults feed on pollen, if not the flowers themselves, while the larvae feed on rotting wood, fungi, or the pith of stems.
Rhipiphoridae (Wedge-Shaped Beetles)
This family consists of two major groups. The first group, consisting primarily of Macrosiagon spp., have wing-covers that are black, long, and narrow, extending beyond the abdomen. The head and pronotum are often yellow or tan. The larvae of these beetles are parasitoid on the larvae of wasps. The second group, consisting primarily of Rhipiphorus spp., are small black insects with atrophied wing-covers and a short, blunt abdomen, appearing quite unbeetle-like. The larvae of these beetles are parasitoid on the larvae of Halictid bees. The females of both groups are often found on flowers, where they lay their eggs and suck nectar. The Rhipiphorid larvae, after hatching, attach themselves to a flower-visiting host insect, and hitch a ride back to the nest. There, they search for an egg, and bore into the emerging bee or wasp larvae, eventually killing the host.
Scarabaeidae (Scarab Beetles)
This a large family of beetles, ranging in size from small to very large. They are usually black with a heavy carapace, and powerfully built. Many of these beetles display little interest in flowers, preferring to roam across the ground and hunt for other insect prey. Some of them are attracted to dung, which is shaped into a ball and rolled along the ground. This is deposited in a suitable hole, where the eggs are laid. Only one subfamily will be described, because the Scarab beetles in this group are more likely to visit flowers. Cetonniae (Flower Scarab Beetles): These are medium-sized beetles, somewhat round and flattened in shape. They are variably colored, sometimes iridescent green, black, or with brown and yellow patterns. The antennae are short and stout, like other Scarab beetles. The adults often appear on flowers, feeding on pollen, if not the flowers themselves. The larvae feed on plant roots, rotting wood, and decaying organic material in the ground.