Wednesday, March 18, 2020

About Ground Beetles, of the Family Carabidae

About Ground Beetles, of the Family Carabidae Turn over a rock or log, and youll see dark, shiny beetles running for cover- ground beetles. This diverse group of predators are among the top 10 beneficial garden insects. Though hidden by day, at night the Carabids hunt and feed on some of our worst garden pests. Description The best way to get to know the ground beetles is to observe some up close. Since most are nocturnal, you can usually find them hiding under boards or stepping stones during the day. Try using a pitfall trap to collect a few, and check for the telltale Carabid characteristics. Most ground beetles are black and shiny, though some display metallic colors. In many Carabids, the elytra are grooved. Look at a ground beetles hind legs, and youll notice the first leg segments (the hips) extend backward  over the first abdominal segment. Threadlike antennae emerge from between the eyes and the jaws of the ground beetle. The pronotum is always wider than the area of the head where the eyes are present. Classification Kingdom: AnimaliaPhylum: ArthropodaClass:  InsectaOrder:  ColeopteraFamily: Carabidae Diet Nearly all ground beetles prey on other invertebrates. Some Carabids are specialized predators, feeding exclusively on one type of prey. A few ground beetles feed on plants or seeds, and others are omnivores. Life Cycle Like all beetles, Carabids undergo complete metamorphosis with four stages of development: egg, larva, pupa, and adult. The entire cycle, from egg to reaching reproductivity, takes a full year in most species. Ground beetles usually lay their eggs on the surface of the soil or cover their eggs with soil. In general, eggs take up to a week to hatch. Larvae go through 2-4 instars before reaching the pupal stage. Ground beetles which breed in the spring typically overwinter as adults. Carabids that breed during the summer months tend to overwinter as larvae, then finish their development to adults in the spring. Special Adaptations and Defenses Many ground beetles employ chemical defense systems to fend off attackers. When handled or threatened, they use abdominal glands to produce pungent odors. Some, like the bombardier beetles, can even make chemical compounds that burn on contact. Range and Distribution Ground beetles live in almost every terrestrial habitat on earth. Worldwide, about 40,000 species in the family Carabidae have been described and named. In North America, the ground beetles number well over 2,000.

Sunday, March 1, 2020

Countershading Definition and Examples

Countershading Definition and Examples Countershading is a type of coloration commonly found in animals and means that the animals back (dorsal side) is dark while its underside (ventral side) is light. This shading helps an animal blend in with its surroundings. Description In the ocean, countershading camouflages an animal from predators or prey. When viewed from below, an animals lighter belly would blend in with the lighter sky above. When viewed from above, its darker back would blend in with the ocean bottom underneath. Countershading in the Military Countershading has also had military applications. German and U.S. military planes used countershading to hide from their enemies by  painting the bottom of the plane white and the top of the plane to match the color of the surrounding area.   Reverse Countershading Theres also reverse countershading, light on top and dark on the underside, which can be seen in skunks and honey badgers. Reverse countershading is typically seen in animals with strong natural defenses.   Alternate Spellings: Counter Shading, Counter-Shading Several rorqual whales are counter-shaded, including fin whales, humpback whales, and minke whales.