This is the last in the series on a collection of beetles (fireflies, Asian lady beetles, and carrion beetles) I found on an apple tree of mine. It was a butterfly that first piqued my interest about what was going on with the apple tree. The butterfly was a mourning cloak (Nymphalis antiopa) a species common around here. The mourning cloak was feeding on fermenting sap coming from a wound in the bark. Unfortunately the photo of this dark-colored butterfly was too dark in the wrong places and a bit blurry, too. The butterfly didn’t like my prying and so kept moving about. I looked closely at where the butterfly was feeding and saw the carrion beetles. I wondered why they were there.
A few days later I went back to the tree to see what the carrion beetles were up to and if more had come. On the tree with the carrion beetles was another beetle. I recognized it as a species of scarab beetle called the bumble flower beetle (Euphoria inda). Flower beetles eat sweet substances like nectar and tree sap so it was in heaven on the tree.
The bumble beetle’s light cinnamon colored wing covers (elytra) marked with broken rows of rectangular and linear black spots. The head, sides of the thorax and abdomen, and the legs are densely hairy. The body measures 12 to 16 mm long and 8 to 10 mm wide.
The larvae of the bumble beetle are white grubs. Eggs are laid in the early summer in rich soil and decaying organic matter such as rotting hay piles, compost heaps, and manure piles. Time to hatching is eleven days. The grubs crawl on their backs as they tunnel through the soil and organic debris on which they feed. When the larvae are ready to pupate they burrow into the soil a few inches and build a cocoon of mud. Development time beginning with hatching and ending with emergence as adults takes about twelve weeks. From late August to September the adult bumble beetles are active feeding on sap, rotting fruit, and flower nectar. As the season winds down the adult bumble hibernate. In the spring they emerge to seek out mates and begin the process anew.
Class: Insecta (Insects)
Order: Coleoptera (Beetles)
Suborder: Polyphaga (Water, Rove, Scarab, Long-horned, Leaf and Snout Beetles)
Superfamily: Scarabaeoidea (Scarab, Stag and Bess Beetles)
Family: Scarabaeidae (Scarab Beetles)
Subfamily: Cetoniinae (Fruit and Flower Chafers)
Genus/species: Euphoria inda
Bumble beetles can be found over much of the US from Maine to Florida and westward to Oregon and Arizona. In Canada they range from British Columbia to Quebec. Bumble beetles also occur in Mexico. The tribe Cetoniini which includes the genus Euphoria with its 59 species is very diverse in Mexico and Central America.
Beddes, T. and Davis, R. S. (2011). Utah Pests Fact Sheet, Bumble Flower Beetle. Utah State University Extension and Utah Plant Pest Diagnostic Laboratory.
Cranshaw, W. (2009) Colorado Insect of Interest, Bumble Flower Beetle. College of Agricultural Sciences, Colorado State University May 27, 2009 version.
Hayes, W. P. (1925). A Comparative Study of the History of Certain Phytophagous Scarabæid Beetles. Kansas Technical Bulletin 15. Kansas State Agricultural College, Manhattan, Kansas. 146 pages.
Hayes, W. P. (1930). Morphology, Taxonomy, and Biology of Larval Scarabaeoidea. Illinois Biological Monographs 12(2): 5-119.
Orozco, J. and Philips, T. K. (2010. Phylogenetic analysis of the American genus Euphoria and related groups based on morphological characters of adults (Coleoptera: Scarabaeidae: Cetoniinae: Cetoniini). Insect Systematics & Evolution 41: 39–54.
Richter, P. O. (1966). White grubs and Their Allies, A Study of North American Scarabaeoid Larvae. Oregon State Monographs Number 4. Oregon State University Press. 219 pages.