Critter Catalog

What do they look like?

Pelidnota punctata is about 20 to 25 mm long and 13 to 15 mm wide. The elytra, which cover its wings, are yellowish orange and slightly metallic. There are three black spots on the outside edges of each elytra, and a single black spot on both outside edges of the thorax (the middle body section between the head and the abdomen). The underside of P. punctata is brownish black, with a green tint. Like all Scarabaeidae beetles, the antennae, which are orange in this species, have a clubbed end that is actually made up of several plates called "lamellae". The lamellae can be either unrolled or held together in a ball.

Eggs of P. punctata are white and oval-shaped. The eggs are 2 mm long and 1.5 mm wide when they are first laid; they get bigger before hatching. A larva is white when it first hatches from an egg, and its head later turns brown. Pupae also are white at first and later turn brown. The pupae are about 22 mm long.

This species likely is "polymorphic", which means that it has many physical variations that look different. In 1915, 10 different species names were given to insects that people thought were separate species, but actually were just individuals of the same species, Pelidnota punctata, that looked different. Some forms have less visible spots, while some have smaller spots. The leg color also is different among populations, with some grapevine beetles having legs that are the same color as the elytra, while others have legs that are the same color as the underside of the body. (Bogue, 1897; Hardy, 1975; Hayes, 1925; Hoffmann, 1936)

• Other Physical Features
• heterothermic
• polymorphic

• Range length

  20 to 25 mm

  0.79 to 0.98 in

Where do they live?

Pelidnota punctata, the grapevine beetle, is native to the Nearctic region. It is widespread throughout the eastern United States and Canada. It ranges as far west as Texas in the United States. In Canada, it is found mainly in Ontario. (Hayes, 1925; Hicks, 1965)

• Biogeographic Regions
• nearctic
  • native

What kind of habitat do they need?

Pelidnota punctata adults can live where cultivated and wild grapes grow--in temperate regions, agricultural vineyards, forests, meadows, and suburban gardens.

Larvae live in decaying wood, like tree stumps. Pelidnota punctata larvae can live in the center of the stump, but usually they dig tunnels in the stump's roots. (Hoffmann, 1936)

• These animals are found in the following types of habitat
• temperate

• Terrestrial Biomes
• savanna or grassland
• forest

• Other Habitat Features
• suburban
• agricultural

How do they grow?

Pelidnota punctata goes through complete metamorphosis, with life stages of egg, larva, pupa, and adult. Eggs are laid in June, July and August. An egg hatches after about 15 days, though it can take much longer or much shorter, depending on the individual. Larvae emerge and grow through 2 to 3 larval stages, which are called instars. This species goes into hiding during the winter (which is called overwintering) as a larva, in decaying stumps and logs. The larvae grow into the second and third instars either before or after overwintering. Larvae can overwinter for up to 2 years. Larval development time varies, but can take over 600 days to complete. Larvae go through a prepupal stage during development, where the larva makes a cocoon out of small pieces of wood and becomes mostly inactive. After 3 to 10 days in the prepupal stage, the larva pupates in the cocoon. After 16 to 24 days of pupating, the adult emerges. Adults live for about 30 more days, during which time they mate and lay eggs. (Hayes, 1925; Hoffmann, 1936)

• Development - Life Cycle
• metamorphosis
• diapause

How do they reproduce?

Little information is available about reproduction in Pelidnota punctata. Mating usually takes place on grape plants at night, though some mating during the day has been seen. (Hayes, 1925)

Little information is available about reproduction in Pelidnota punctata. It is known that eggs are laid in June, July, and August. Eggs are laid one at a time in moist soil, usually under logs and other decaying wood. This ensures that the larvae will have food to eat when they hatch. (Hayes, 1925)

• Key Reproductive Features
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• oviparous

• Breeding season

  Breeding takes place in early summer.

Pelidnota punctata females provide nutrients in the eggs for offspring to use in their growth and development. Females also lay eggs in the soil under decaying logs and stumps, so that larvae will have food to eat when they hatch. Aside from that, P. punctata probably does not provide any parental care. (Hayes, 1925)

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female

How long do they live?

Though the development time of Pelidnota punctata varies widely among individuals, the growth from egg to adult takes about 2 years. An adult lives for about 30 days after completing the pupal stage. (Hayes, 1925; Hoffmann, 1936; Ritcher, 1958)

• Average lifespan
  Status: wild

  2 years

• Average lifespan
  Status: captivity

  2 years

How do they behave?

Pelidnota punctata is nocturnal and often gathers at lights at night. During the day, it stays on the leaves of grape plants and does not move around much. These beetles fly quite often at night to find host plants and mates. (Hayes, 1925)

• Key Behaviors
• flies
• nocturnal
• motile

How do they communicate with each other?

Not much specific information exists about communication and perception in Pelidnota punctata, but it is a scarab beetle, so an educated guess is that it uses the ends of its antennae to smell. The clubs at the end of the antennae of Scarabaeidae beetles are made up of plates called lamellae, and these lamellae work as sensory organs by sensing smells. Pelidnota punctata probably finds grape plants using its sense of smell. Other related Scarabaeidae beetles also use their lamellae to smell pheromones that are important for mating, which also may be true for P. punctata.

Grapevine beetles probably also perceive their environment and mates using sight. (Larsson, et al., 2001)

• Communication Channels
• visual
• chemical

• Other Communication Modes
• pheromones

• Perception Channels
• visual
• chemical

What do they eat?

Pelidnota punctata feeds mostly on the leaves, but also the fruit, of grapevines, both those grown as crops and those that grow in the wild. Its feeding habits give the insect its common name of "grapevine beetle". It also has been seen feeding on spinach and Virginia creeper.

Larvae feed on the decaying stumps and wood that they live in. Larvae have been seen eating the decaying wood of elm, walnut, cherry, and birch trees, among many others. (Hayes, 1925; Hoffmann, 1936; Ritcher, 1958)

• Primary Diet
• herbivore
  • folivore

• Plant Foods
• leaves
• fruit

• Other Foods
• detritus

What eats them and how do they avoid being eaten?

Raccoons sometimes eat Pelidnota punctata. Blue jays also feed on grapevine beetles, and many other bird species probably prey on these beetles. In Texas, the remains of P. punctata have been found in nests of the pallid bat, Antrozous pallidus, suggesting that A. pallidus is another predator.

In defending itself against predators, the grapevine beetle may take advantage of the bright color and slight metallic tint of its elytra (the part of its body covering its wings). Other brightly colored, shiny beetles in the family Rutelinae reflect polarized light, which helps them blend in with the greens and browns of their environment. Other theories suggest that the metallic tint can cause a glare of light to temporarily blind predators, or that the metallic tint reflects the colors of the environment, which can camouflage the beetle. Pelidnota punctata is not as metallic as these other species, though, so these defensive strategies may or may not be true for the grapevine beetle. (Beal, 1896; Giles, 1939; Herreid II, 1961; Thomas, et al., 2007)

• These animal colors help protect them
• cryptic

• Known Predators

  • Raccoon (Procyon lotor)
  • Blue jay (Cyanocitta cristata)
  • Pallid bat (Antrozous pallidus)

What roles do they have in the ecosystem?

Pelidnota punctata feeds almost entirely on grape plants of the genus Vitis. When the beetle occurs in very high numbers, P. punctata can damage grape crops by eating the leaves, but the beetle does not cause much damage in most years.

Larvae can benefit the environment by speeding up the decaying process of the old wood that they live in.

These beetles are prey to many species of animals, including raccoons, blue jays, and pallid bats. The parasitic mite Caloglyphus phyllophagianus is known to use Pelidnota punctata as a host. This mite lives under the wings of the beetle and is thought to use P. punctata as a way to move from place to place, rather than as food. Parasitic Rickettsia bacteria have been found in the intestine of some grapevine beetles. The yeast Candida maltosa also has been found in the intestine of P. punctata, probably helping the beetle to digest plant material that the beetle could not otherwise digest. This is a mutualistic relationship, meaning that both the beetle and the yeast benefit from the interaction. The yeast gets nutrients by living in the beetle, and the beetle gets plant nutrients through the yeast, which is able to digest leaves. (Cowdry, 1923; Crocker, et al., 1992; Hayes, 1925; Suh, et al., 2008)

• Ecosystem Impact
• biodegradation

Do they cause problems?

When the grapevine beetle occurs in very large numbers, Pelidnota punctata can destroy the leaves of many grapevines. In 1965, Pelidnota punctata was considered a pest of the grape industry in southern Ontario, Canada. But in general, the grapevine beetle usually does not cause much damage to grape crops, though it does have the potential. The suggested method of removal is to pick the beetles off the plants by hand, which is possible due to their relatively large size. (Bogue, 1897; Hayes, 1925; Hicks, 1965)

• Ways that these animals might be a problem for humans
• crop pest

How do they interact with us?

There are no known positive effects of Pelidnota punctata on humans.

Are they endangered?

Pelidnota punctata is not an endangered species.

• IUCN Red List

  Not Evaluated

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Some more information...

The beetle in the short story "The Gold Bug" by Edgar Allen Poe probably was based on the grapevine beetle, Pelidnota punctata. (Thomas, et al., 2007)

Contributors

Angela Miner (author), University of Michigan-Ann Arbor, Elizabeth Wason (editor), Animal Diversity Web Staff.

References

Beal, F. 1896. The Blue Jay and its Food. Washington, D.C.: U.S. Department of Agriculture.

Bogue, E. 1897. Some Injurious Orchard Insects. Stillwater, Oklahoma: Oklahoma Agricultural and Mechanical College.

Cowdry, E. 1923. The distribution of Rickettsia in the tissues of insects and arachnids. The Journal of Experimental Medicine, 37/4: 431-456. Accessed June 07, 2013 at http://jem.rupress.org/content/37/4/431.full.pdf.

Crocker, R., H. Cromroy, R. Woodruff, W. Nailon, M. Longnecker. 1992. Incidence of Caloglyphus phyllophagianus (Acari, Acaridae) on adult Phyllophaga spp and other Scarabaeidae (Coleoptera) in North Central Texas. Annals of the Entomological Society of America, 85/4: 462-468.

Giles, L. 1939. Fall food habits of the raccoon in central Iowa. Journal of Mammology, 20/1: 69-70.

Hardy, A. 1975. A revision of the genus Pelidnota of America north of Panama (Coleoptera: Scarabaeidae: Rutelinae). University of California Publications in Entomology, 78/1: 1-43.

Hayes, W. 1925. A comparative study of the history of certain phytophagous Scarabaeid beetles. Kansas State Agricultural College Experiment Station Technical Bulletin, 16: 1-146. Accessed June 07, 2013 at http://www.ksre.ksu.edu/historicpublications/pubs/stb016.pdf.

Herreid II, C. 1961. Notes on the pallid bat in Texas. The Southwestern Naturalist, 6/1: 13-20.

Hicks, S. 1965. The Northern Limits of Several Species of Coleoptera with Special Reference to Their Occurrence in the Ottawa District, Ontario. The Coleopterists' Bulletin, 19/2: 37-42.

Hoffmann, C. 1936. Additions to Our Knowledge of the Biology of Pelidnota punctata Linn. (Scarabaeidae- Coleoptera). Journal of the Kansas Entomological Society, 9/3: 103-105.

Larsson, M., W. Leal, B. Hansson. 2001. Olfactory receptor neurons detecting plant odours and male volatiles in Anomala cuprea beetles (Coleoptera: Scarabaeidae). Journal of Insect Physiology, 47/9: 1065-1076.

Ritcher, P. 1958. Biology of Scarabaeidae. Annual Review of Entomology, 3: 311-334.

Suh, S., N. Nguyen, M. Blackwell. 2008. Yeasts isolated from plant-associated beetles and other insects: seven novel Candida species near Candida albicans. FEMS Yeast Research, 8/1: 88-102. Accessed June 07, 2013 at http://onlinelibrary.wiley.com/doi/10.1111/j.1567-1364.2007.00320.x/full.

Thomas, D., A. Seago, D. Robacker. 2007. Reflections on golden scarabs. American Entomologist, 53/4: 224-230. Accessed June 07, 2013 at http://www.entsoc.org/PDF/Pubs/Periodicals/AE/AE-2007/Winter/Thomas.pdf.