web analytics

Tag Archive | "Insects"

Leg Joints


 

Ranger Steve Mueller

By Ranger Steve Mueller

 

Femur, tibia, fibula, metatarsals, and tarsals comprise the bones in our legs and feet. Their arrangement allows movement. Other mammals have bones in different arrangements that serve their mobility for greatest survival. Other groups of organisms like birds and frogs have their own special configurations to meet their needs.

Diagram of a typical insect leg.

Insects do not have bones but have specialized leg joints. Insect exoskeletons are on the outside of the body instead of inside like ours. Leg section names are similar but are structurally different. Between the body and femur is a rounded knob called the coxa followed by another small section called the trochanter. The femur is often the largest leg section much like our femur. Though the name is the same, the insect femur is made of a hard chiton comparable to our fingernails that are on the outside to protect inner tissues and muscles. Consider an insect’s skeleton to be like a knight’s armor that protects from the outside.

To move, it is necessary to have flexible connective tissue between various sections of the leg like is used in a knight’s armor. Progressing from the body to leg tip, the leg sections have adaptations that serve the insects life style for survival in its nature niche. The tibia connects the femur with the tarsi. The tibia is comparable to the tibia and fibula of our lower leg.

A series of small leg sections called tarsi beyond the tibia allow flexibility. Most insects have three, four or five aligned in a row. Go outside to look at a large grasshopper or katydid’s leg joints. Some of the large Carolina Grasshoppers with black wings are still active. The last pair of legs on the grasshopper are large, adapted for jumping and are easiest for viewing leg construction. When you try to capture a grasshopper, it becomes obvious how well suited their legs are for escaping danger.

Crickets and long-horned grasshoppers, like the katydids, have an “eardrum” or tympanum at the basal end of their tibia. We have been enjoying the raucous sound penetrating the blackness of night. It is essential for noise making insects to hear the sexual calls at night for successful breeding. Instead of hearing in their heads like us, they hear in their legs.

There are more specialized leg structures than described here so consider visiting the library, the web, and spend time outdoors exploring. One very important feature not mentioned is tarsal claws. Most insects have small claws that aid gripping surfaces. When an insect stands on your arm, you often feel the claws grip.

The front legs of the praying mantis have a long femur and tibia lined with stiff spines that allow it to grip insect prey firmly. Its coxa that connects the femur to the body is long instead of small and round. It allows greater mobility for capturing prey. Each insect species has unique adaptations that meet its lifestyle. If you have been grabbed by a mantis, its spines might have penetrated your skin and even caused some bleeding.

Inside the exoskeleton leg, is where the muscles are attached. Our leg muscles extend across joints so when contracted they cause the leg to bend. If both ends were attached to the same bone, contraction would not result in movement. Insects are similar in muscle attachment except their muscles are inside the hollow exoskeleton but they stretch across joints. You will not find an insect with bulging muscles because they are hidden inside.

Beetles have interesting legs. They are sometimes quite easy to observe in fall because they frequently stand on flower heads for extended periods. Visit a goldenrod or New England Aster to watch. Notice how the front pair of legs reaches forward and the second and third pair of legs extend backwards. Some insects only use four legs (two pairs) when walking so watch to discover them. Observe leg movement and notice if the front and back legs on one side are used with the middle leg on the opposite side when walking.

Some insects like the blister beetle ooze a substance from their leg joints when disturbed. The fluid can cause skin blisters. There are thousands of insects with interesting leg joints. Take time to observe nature’s wonders.

Natural history questions or topic suggestions can be directed to Ranger Steve (Mueller) at odybrook@chartermi.net – Ody Brook Nature Sanctuary, 13010 Northland Dr. Cedar Springs, MI 49319 or call 616-696-1753.

Posted in Outdoors, Ranger Steve's Nature NicheComments (0)

Repelling Insects 


Ranger Steve Mueller

Ranger Steve Mueller

By Ranger Steve Mueller

 

Biting insects can drive us indoors. Wildlife are not as fortunate as we are in escaping biting critters. They find ways to reduce the nuisance by selecting breezy locations that keep mosquitoes and black flies away. Deer flies arrive later in the season and provide a painful bite but not as bad as a horse fly bite.

Black flies swarm in early spring. A friend said black flies were in thick swarm around me. I did not receive a single bite. When black flies first emerge, they do not seem to bite. I need to study that more. Maybe males emerge first. They do not need blood for egg development. When tiny black fly females arrive, they crawl around on skin looking for edges like hairline or bite at clothing edges.

When I wore a swimsuit, black flies couldn’t find a place to bite except at the suit’s edge. I treated that edge with repellent and I remained bite free while fishing. Large numbers of these small humpbacked flies landed on me and crawled about but they are so small I did not feel them. We do not feel their bite either. It is not until later that bite sites become red, itchy, and painful.

Avoid insect repellent chemicals as much as possible. Many repellants are not healthy for us when applied to skin. Place repellent on clothes. When biting insects are numerous, keep your body covered for protection and apply a safe repellent to limited exposed skin. Insect head nets are better than chemicals for protection.

Be careful not to get the chemical on the palms of hands because it will get on things you touch. I touch plants, insects I study, frogs, or other life. I do not want to injure anything I handle or leave chemical traces on leaves that are beneficial for insects to eat. Apply repellent to the back of hand and wipe it on face or neck. Do not spray your face because some might get in eyes. Avoid applying to forehead. When you sweat, it will to run into your eyes.

Mary Miller, who worked with me at the Howard Christensen Nature Center, taught me that wearing a bracken fern worked well to keep deer flies from biting and swarming my face. These flies circle our heads and are disturbing beyond their bite. Pick the fern and place its stem in hair or hat. The leafy portion of the fern rises above your head. Flies swarm that instead of our face. It is a simple repellent.

Wearing cologne, perfume, or hair gels attract biting insects and even irritated stinging wasps. We might want to smell great for people but it will attract unwanted insects. It has been difficult to get some students to appreciate the natural world if they use hair gels. They are bothered too much by insects to enjoy the outdoors.

Some people have their own natural repellents. My youngest daughter and I are not bothered by insects as much as Karen and my older daughter. I think it is because Julianne and I have more vitamin B. The four of us were hiking Five Lakes trail near Strongs in the UP and it was 80 F. Karen and Jenny Jo wore sweatshirts with hoods and covered all but face and hands. Biting insects were so thick around them they could not enjoy the hike. Julianne and I wore light weight clothes with skin exposed and insects were not thick around us.

A world of natural chemicals in nature niches attract, irritate, or repel insects. Plant chemicals protect them from insects and we extract those to use as commercial repellents. Native Americans historically rubbed sweetfern leaves on themselves because the chemical in leaves repels insects.

Biting insects are most problematic from May to late June. It is wonderful to be outside but bugs can drive us indoors. Find ways to be outside during all seasons. Staying in open sunlit breezy areas works well to avoid biters. Shaded wet areas have more mosquitoes. Camping in mid to late summer and fall has fewer irritating insects and makes for a better family experience.

Natural history questions or topic suggestions can be directed to Ranger Steve (Mueller) at odybrook@chartermi.net – Ody Brook Nature Sanctuary, 13010 Northland Dr. Cedar Springs, MI 49319 or call 616-696-1753.

Posted in Ranger Steve's Nature NicheComments (0)

Winter sleeping


 

By Ranger Steve Mueller

By Ranger Steve Mueller

Chipmunks emerge from underground burrows in mid winter when conditions warm, the sun shines, water trickles, or warmth penetrates deep into their bodies.

During my naturalist career, we shared the best evidence-based scientific discoveries about hibernators, deep sleepers, and those that stay active all winter. Insects hibernate, diapause, or even stay active all winter but they are excluded from this discussion, as are birds that also have some hibernators. Those groups like reptiles and amphibians will merit their own nature niche adaptation stories.

Within the Class Mammalia, we taught Michigan has four groups with true hibernators, including some bats, the 13-lined ground squirrel, woodchuck, and jumping mice. Bears are deep sleepers but are not considered true hibernators. Chipmunks that periodically pop out of the ground during winter were reported as deep sleepers.

An authoritative book I depend on is Michigan Mammals by William Burt (1957). It referred to chipmunks as hibernators. Despite the rigorous scientific scrutiny used in making the text accurate, questions were raised regarding chipmunks’ winter behavior in regards to sleeping or hibernating. I was not greatly concerned with the issue and referred to the small striped mammals as deep sleepers.

I should have pursued the issue with more vigor but information seemed conflicting and I had other scientific controversies to address that seemed more pertinent and meaningful for society’s welfare. Things like climate change or animal species origins related to Earth’s biodiversity, for ecological sustainable conditions that people need, took precedence.

Recently my naturalist friend, Greg, spoke about chipmunk hibernation and I challenged the idea. It stimulated me to examine peer-reviewed research. New technology developments during recent decades make it easier to study winter sleep for various species. Small monitoring devices can be implanted in animals to monitor breathing, heart rate, and temperature on a 24-hour basis.

Studies supported chipmunks are true hibernators but there are still unknowns. Hibernators’ breathing and heart rate become extremely slow and body temperature drops to near freezing. Bears do not experience such dramatic reduction and are considered deep sleepers. Bear body temperature only drops from about 100 to 90 F. Respiration and heart rate slow but are not so reduced that it is difficult to arouse the bear.

Chipmunk heart rate slows from 350 beats per minute to about 4, temperature drops from 94 F to 40 F, and respiration changes from 60 to about 20 breaths per minute. It is difficult to arouse them. The adaptations merit the designation of true hibernation but other factors are not consistent with what is normally considered true hibernation.

Chipmunks awake periodically instead of remaining in deep torpor for months. The triggers causing them to periodically waken are unknown. They become active, eat cached food in burrows or even venture outside. Other true hibernators do not defecate or urinate for months, but chipmunks do.

I learned long ago that it is not either/or in nature. Most everything is on a gradation from one end of a continuum to another. It is not either hibernate or not hibernate. Different species demonstrate behaviors and adaptations along a continuum. Most might show a particular adaptation, such as hibernation, but all are experimenting through the process of natural selection and evolution for survival.

Natural history questions or topic suggestions can be directed to Ranger Steve (Mueller) at odybrook@chartermi.net – Ody Brook Nature Sanctuary, 13010 Northland Dr. Cedar Springs, MI 49319 or call 616-696-1753.

Posted in Ranger Steve's Nature NicheComments (0)


advert
Kent Theatre
Cedar Car Co
Advertising Rates Brochure
Ensley Team Five Star Realty

Get the Cedar Springs Post in your mailbox for only $35.00 a year!