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6 Nature Foolers: Can You Tell the Difference?

  • 7/10/2015 8:54:00 AM
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Mimicry is about more than flattery for these Iowa organisms. Looking similar to a dangerous model helps the mimics of these pairs avoid confrontation, predation and disturbance, particularly from animals that learn to pick a meal based on what its prey looks like. Can you tell the difference?

Viceroy (Limenitis archippus)vs. Monarch (Danaus plexippus) Butterflies Monarch butterflies are easily identifiable by the stark orange and black pattern on their wings. Birds recognize this coloration as a sign of danger, as monarchs eat poisonous milkweeds and subsequently taste terrible as prey. Viceroy butterflies (on the right in the photo below) have evolved to mimic this orange and black color scheme, and careful birds will avoid eating them.

Monarchs and viceroys - can you tell the difference? | Iowa DNR 

Wild Parsnip (Pastinaca sativa) vs. Golden Alexander (Zizia aurea) The primary difference between these plants is a matter of scale. Both are lacy-looking plants with thick green stems topped with disk-like clusters of yellow flowers, but golden alexander is significantly smaller when mature. Wild parsnip also has significantly broader leaves, and bigger, flatter flower clusters. Wild parsnip is the dangerous model organism of this pair, as the plant secretes an oily sap containing psoralen. When this compound comes into contact with skin and is exposed to sunlight, it induces a rash similar to severe burns. Golden Alexander does not secrete any such compound, and the greatest threat it poses may be as an allergen.

 Wild parsnip | Iowa DNR Golden alexander | Iowa DNR 

Eastern Poison Ivy (Toxicodendron radicans) vs. Virginia Creeper (Parthenocissus quinquefolia) While many people learned rhymes like “leaflets of three, leave it be” to help remember how to identify poison ivy, these tricks don’t always work. Virginia creeper looks very similar to the most common poison ivy in Iowa, commonly called eastern poison ivy. Both plants have small clusters of leaflets, take on a red tinge during parts of their growing season, and exhibit viney, climbing growth. However, Virginia creeper only has clusters of three leaflets when immature, and when mature the leaflets grow in clusters of five. Parthenocissus vitacea, commonly called woodbine, is also mistaken for poison ivy due to climbing and small leaflet clusters, but its uniform leaflets grow in clusters of five with serrated edges. Part of the reason real poison ivy is inherently difficult to identify is that its leaflet shape varies widely, and can appear lobed, serrated, lopsided, or just about any other shape. Use this to your advantage when trying to identify a species, as you can likely rule out poison ivy if all the leaflets match.

 Poison ivy | Iowa DNR Virginia creeper | Iowa DNR 

Black (Papilio polyxenes) vs. Pipevine (Battus philenor) Swallowtail Black swallowtails are well known in Iowa, but few people realize how different the males and females appear. The males have a few lines of large yellow dots along the edges of their wings, with a bright blue shock and a red bullseye in the middle of their hind wings. The undersides of the wings have a series of orange dots surrounded by a powdery blue color. Females have similar underwings, but much less pronounced yellow and red sections on top, with an expanded blue shock on their hind wings. This sexual dimorphism leads to only the female black swallowtail being a mimic of the Pipevine swallowtail, which has black forewings, blue hindwings, and a familiar orange dot pattern underneath. Pipevine swallowtail larvae feed on poisonous plants like pipevine, Dutchman’s pipe, Virginia snakeroot and others, and confer a nasty taste on the adult, making them a poor meal for birds and other predators. By being a copycat, female black swallowtails also appear to be nasty-tasting and avoid being eaten. Occasionally, an alternate morph of a male black swallowtail will look like a female. These males enjoy the double benefits of reduced predation and reduced competition with other black swallowtail males, who are territorial.

Black swallowtail butterfly | Iowa DNR  Pipevine swallowtail butterfly | Iowa DNR

Craneflies (Tipulidae family) vs. Mosquitos (Culicidae family) Craneflies are often mistaken for giant mosquitos, but this resemblance is more detrimental to them than helpful. Craneflies and mosquitos have very proportionally long legs and an elongated body, with clear veined wings that they hold flat and close to their body when not in flight. However, craneflies are approximately twice the size of the largest mosquitos. While there are a few cranefly species regarded as invasive and agricultural pests in coastal states like Washington, California and New York, those species do not live in Iowa and many species here pose no foreseeable harm. You don’t need to worry about becoming a meal yourself either. Craneflies do not have the special piercing mouthparts to be an ectoparasite, and cannot drink blood. Their greatest common offense towards humans is their mosquito-like appearance.

 Cranefly | Iowa DNR  Mosquito | Iowa DNR

Cicada Killer (Sphecius speciosus) vs. Wasps (suborder Apocrita) To the unaccustomed eye, and even by name, cicada killers seem quite alarming. Their defined yellow and black stripes combined with their size seem to signal the one of the most dangerous wasps imaginable, but in reality they’re a very docile species. While technically wasps, Cicada killers show little to no aggression towards humans – although males display territorial behavior towards one another (and sometimes their own reflections in windows). These male cicada killers don’t even have stingers, and females will very seldom use theirs on anything but a cicada unless under extreme duress (like being stepped on). Unfortunately, this is a primary concern for these gentle wasps because they dig burrows in the ground in which to feed and nest. So as long as you watch your step, these giants won’t bother you in the least.

Cicada killer | Iowa DNR Baldfaced hornet | Iowa DNR

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