Teacher Field Activity Supplement and Insect Fact Sheet for Introduction to Adult Insects and Their Adaptations

Transcription

1 Teacher Field Activity Supplement and Insect Fact Sheet for Introduction to Adult Insects and Their Adaptations How to make a kill jar Soak cotton ball in nailpolish with acetate, remove excess liquid, put in a glass jar, close the lid, and mark it as a kill jar. Kill jars are used mostly with butterflies and moths because their scales (which are used in most species identification) come off so easily. However, placing insects immediately in a freezer works even better. Do not put butterflies or moths in alcohol, they will loose all their scales in the liquid which will attach to the other insects and make a big mess. Two kill jars come in the SC LIFE Natural History Equipment Footlocker. If you would like to purchase your own kill jars, they sell them at Carolina Biological and Bioquip for about $6.00. Keep insects in the freezer instead of using alcohol It is easier to see all the parts of your specimen if they are dry (especially if an insect is hairy as many are). Keep in the freezer for at least an hour, but preferably overnight. How to use a beat sheet Open the wood supports to make an X, slip the ends of the X into the pockets of the sheet (located on the edges). Holding the sheet by the wooden "X", place the sheet under a woody shrub or tree then use another stick or wooden dowel or a whiffle-ball bat to beat the shrub or tree, dislodging the insects hidden in the vegetation. When the insects fall onto the sheet, the students can collect them. This method is good to use in woody vegetation and briars. A beat sheet comes in the SC LIFE Natural History Equipment Footlocker. If you would like to purchase your own beat sheet, the sell them at Bioquip for $ You can also construct a makeshift beat sheet by putting a white sheet on the ground and using a stick to beat the shrubbery. How to use a sweep net Attach the net by placing the loop s prongs into the holes found in the pole, then secure with the metal collar. Sweep to the left, then turn the net around to sweep to the right, in a figure eight motion. The motion prevents the insects from escaping as the net sweeps back and forth. This method is good to use in grassy areas. A sweep net comes in the SC LIFE Natural History Equipment Footlocker. There is not good alternative for making a sweep net; you can purchase your own sweep net from Bioquip for $ Using an aspirator or pooter - Collecting insects, especially those that fly, can be a tricky thing. Using an aspirator or pooter makes it much easier. Simply put the surgical tubing into your mouth, aim the metal tube at the insect and suck. There is a mesh screen that prevents the insect from being sucked into your mouth. The pooter comes with 2 plastic tubes for collecting insects (replacement tubes are available). Do not put alcohol in these tubes ever! You will never get the taste of alcohol out of the tubes and they turn cloudy so you cannot see the insect you collected. The surgical tubing can be boiled to sterilize it between use. I also recommend putting a small amount of foam at the bottom of the pooter tube to prevent the insects from going "splat" after a particularly strong inhaling. A pooter comes in the SC LIFE Natural History Equipment Footlocker. If you would like to purchase your own, the can be ordered from Bioquip for $6.95. Replacement tubes run $

2 How to get the insect out of the sweep net If you notice that you have collected a stinging insect and would prefer not to be stung, remember that insects have a desire to go up when confronted with an obstacle. Isolate the stinging insect in the net, reach in and place the collection jar or vial on top of it. When it climbs into the jar in an effort to go up, slip the cap on. Other sampling protocols that can be used - Have the students use both the beat sheet and sweep net, but also have them conduct a visual search for insects; under rocks and logs, on tree bark, etc. It is amazing the things you see when you stop and look. Internal environment - The scar pictured in slide 6 or the presentation is of Patrick McMillan, botanist extraordinaire here at Clemson University. He had a botfly lay its egg just under the skin where it hatched into a larva. After about 2 weeks, the larva died and the wound became infected. He had to go to the doctor to have the maggot removed and now has a faint scar which is shown in the red circle. Remember that only adult insects can have wings, but that not all adult insects have wings - Your students will probably collect immature insects which are not covered in the key (this key only refers to adult insects). Immature insects may look exactly like the adult, but not have any wings (Ex. immature Hemiptera)or they can look completely unlike the adult (Ex. caterpillars). Students can either not include these insects in the frequency table or they can list them under "unknown immature". There is also a listing for "other", in case you collect things other than insects. Insect legs - Insect legs are only attached to the thorax (wings, if present, are also only attached to the thorax). If there are any leglike appendages located anywhere else on the body, these are not true legs. 2

3 The order Collembola (coll = glue, embola = bolt or wedge, referring to the collophore, a tube-like appendage located on the ventral side of the first abdominal segment, see dotted arrow) contain the springtails. The common name is derived from the furcula or spring located at the end of their abdomen that propels them through the air (see solid arrow). A springtail 3 to 6mm in length can jump 75 to 100mm. The order Odonata (from the Greek meaning tooth, referring to the teeth on the mandibles) contain the dragonflies and damselflies. These insects spend their juvenile life in the water, then emerge as winged adults. They have large eyes (excellent eyesight), a small thorax, and a long, slender abdomen. Their distinctive wings are elongated and membranous with many veins. Dragonflies range in size from 28 to 150mm, while damselflies range in size from 25 to 65mm The order Diptera (di = two, ptera = wing) contain the flies. They, too, have three pair of legs and two pair of wings; however, the second pair have evolved into halteres, which look like little balls on the end of short stalks located just behind the first pair of wings (see red arrow in presentation). They also have short, V shaped antennae located between their eyes (see blue arrow in presentation). Beware some flies are very good mimics of bees and wasps, however, unlike bees and wasps, they cannot sting. Their size ranges from 6-65mm. The order Ephemeroptera (ephemera = for a day or short-lived, ptera = wings) contain the mayflies. These insects also spend their juvenile life in the water, then emerge as winged adults. They have membranous wings, the front pair being larger, with lots of veins and 2 to 3 long, threadlike tails attached to their abdomen. The wings are held at rest together above the body (as seen in the picture). Their size ranges from 5-35mm. 3

4 The order Hemiptera (hemi = half, ptera = wing) contain the true bugs. They have three pair of legs and two pair of wings, the first pair having a partial leathery covering on the top half, while being membranous on the bottom half. They fold the second pair across their back forming an X shape (see dotted arrows). They also have a beak-like mouthpart (looks like a straw), which begins at the top of their head (see solid arrow). Their size ranges from 3-40mm. The order Homoptera (homo = alike, ptera = wing, referring to the fact that the wings are uniform in texture throughout) include the leafhoppers, cicadas, and aphids. They have two pair of wings (when they have wings, you might see a whole lot of immature aphids), three pair of legs, variable antennae, and a beak-like mouthpart (looks like a straw), that begins at the lower part of the head (see arrow). Their size ranges from 2-60mm. 4

5 The order Orthoptera (ortho = straight, ptera = wing) includes the grasshoppers, katydids, and crickets. They have three pair of legs, chewing mouthparts, and hind legs that are modified for jumping. They have four wings (when they have wings), the first pair being elongated, and somewhat thickened covering the second pair which are membranous and folded like a fan beneath the front wings (see red and blue arrows in the presentation). Their size ranges from 9-80mm. The order Phasmida contain the walkingsticks and leaf insects. Walkingsticks (found around here) resemble twigs or sticks and have greatly reduced or entirely absent wings. The leaf insects (found in the tropics) usually have well developed hindwings and resemble leaves. They can reach up to 150mm in length. The order Mantodea (from the Greek, meaning soothsayer or a kind of grasshopper) contain the mantids. They have large eyes, large bodies, and modified front legs which have spines on them. They hold their front legs in a bent praying position, hence their common name, praying mantis them (see arrow). They can reach up to 150mm in length. The order Blattaria contain the cockroaches. These insects are flattened and oval in shape with a protective head covering (pronotum see arrow). They have four wings, although in some species, the wings are reduced. They can reach up to 60mm in length. 5

6 The order Thysanoptera (thysano = fringe, ptera = wing) contain the thrips (singular or plural). These are mostly seen in the juvenile stage (without wings). Their mouthpart is modified for sucking, forming an off-center, asymmetrical conical structure (see red arrow in presentation). Thrips can give a remarkably strong bite for such a small insect. In fact, during the summer, if you feel a bite, but can only see a very small, orange object, chances are it was a thrips. By the way, singular or plural, it is thrips. They can reach up to 4mm in length. The order Neuroptera (neuro = nerve, ptera = wing) for the purposes of this lesson contain the alderflies, dobsonflies, fishflies, snakeflies, lacewings, and antlions. They have four membranous wings with lots of veins which gives them their name. Males and females can have mandibles which are usually sickle-shaped, the males being larger on size (see arrow). Their size ranges from 9-70mm. The order Plecoptera (pleco = folded, ptera = wing, referring to the fact that the anal region of the hind wing is folded when the wings are at rest) contain the stoneflies. These insects spend their juvenile life in the water, then emerge as an adult. They have four wings, the first pair being elongated with lots of veins, the second being shorter than the first and lobed (see arrow). This is the area that is folded when at rest. Their size ranges from 6-64mm. The order Mecoptera (meco = long, ptera = wing) contain the scorpion flies; however, they do not sting. The males have a reproductive organ that resembles the tail of a scorpion, see solid arrow (hence the common name). All Mecoptera have this distinctive face and three pair of legs. They also have a distinctive banded wing pattern, see dotted arrows (wide, black bands across a clear wing). Their size ranges from 5-25mm. 6

7 The order Dermaptera (derma = skin, ptera = wing, referring to the texture of the front wings) contain the earwigs. They are flattened, elongated, and have a forcep-looking cerci located at he end of their abdomen (see arrow). When they have wings, they can have either 2 or 4, with the front wings being short, leathery, and veinless. The hindwings are membranous and rounded and are folded under the first pair of wings. While the common name suggests that they crawl into people s ears, this is just an old wive s tale. Their size ranges from 5-25mm. The order Lepidoptera (lepido = scale, ptera = wing) contain the butterflies, moths, and skippers. They have three pair of legs, two pair of wings, long antennae, and usually a coiled proboscis with which they use to drink nectar (see red arrows in presentation). They get their name because of the scales on the wings which come off when you handle it. These scales look like glitter or iridescent dust left on your fingertips. It is hypothesized that this group evolved the scales as a way of escaping spider webs. When caught in a web, the insect can escape leaving its scales still attached. Their size ranges from mm. The order Coleoptera (coleo = sheath, ptera = wing, referring to the elytra) includes the beetles. They have three pair of legs, two pair of wings (the first of which has evolved into a hard covering called the elytra which protects the second pair), and variable mouthparts. The elytra comes together and forms a line down the middle of the back (see arrows), compared to other orders whose wings overlap. Previously, students have described the antennae as looking like stacked balls, but they, too, are highly variable in size and shape. Their size ranges from mm. 7

8 The order Trichoptera (tricho = hair, ptera = wing) contain the caddisflies. These insects spend their juvenile life in the water, then emerge as winged adults. They look like moths, but hold their wings rooflike over their body (see arrows). Their four wings are membranous and hairy (hence their name). Their size ranges from 7-25mm. The order Isoptera (iso = equal, ptera = wings, referring to the fact that the forewings and hindwings look alike and are the same size, see dotted arrows) contain the termites. They are highly social insects with distinct forms that perform different functions for the colony. Only the reproductive adults have wings, while the workers and soldiers look alike, except that soldiers have a larger head. Termites look like ants and are sometimes called white ants ; however, termites are wider in the waist (see solid arrow), white, and their antennae are not elbowed (see dashed arrow). Their size ranges from 5-20mm. The order Hymenoptera (hymeno = god of marriage, ptera = wing, referring to the union of the front and hind wings which sometimes makes them look like they have only 1 pair of wings) include the ants, wasps, and bees. They have three pair of legs, two pair of wings (if they have wings), long, elbowshaped antennae, and three definite body regions. Again, when looking at this group, it may look like they have only one pair of wings because the front and hind wings are still attached. Look for the lobes (see arrows) to decide if the wings are just attached or if indeed there are only one pair of wings. Remember, they have many mimics, so be aware. The females, by the way, are the only ones that can sting because the stinger is actually a modified ovipositor (egg layer). Their size ranges from 3-55mm. 8

9 Potential Answers to the Quiz Image 1: Insect because it has 3 pairs of legs (dragonfly) can infer that the large eyes on the front of its head may indicate that it is a predator or hunter can infer that because it has wings, it can fly can infer that because it has wings, it is an adult Image 2: not an insect because it has 4 pairs of legs (6 legs and 2 pinchers) (scorpion) can infer that because it is flattened dorsa-ventrally that it could get into tight places or in crevices can infer that because it has its eyes on top of its head that it looks at its environment the way a fish might look through the surface of the water Image 3: Insect because it has 3 pairs of legs (beetle) can infer that because it is flattened dorsa-ventrally that it could get into tight places or in crevices can infer that because it looks like the bark it is sitting on, that maybe it is camouflaged to look like bark and as a result may be found in a forest setting Image 4: not an insect because it has 4 pairs of legs (spider) can infer that the yellow coloring might indicate danger Image 5: Insect because it has 3 pairs of legs (cockroach) can infer that the long antennae might give an indication of what s happening in the world around it can infer that the long antennae and small eyes might indicate bad eyesight can infer that because it is flattened dorsa-ventrally that it could get into tight places or in crevices can infer that the spikes on its legs might aid it in capturing food or might help in deciphering what is going on in the world around it can infer that because it has wings, it can fly can infer that because it has wings, it is an adult Image 6: Insect because it has 3 pairs of legs (walking stick) can infer that because it looks like a twig or stick, it is a twig mimic can infer that because it looks like a twig or stick, it might be found in trees or shrubs can infer that long antennae might give an indication of what s happening in the world around it can infer that long antennae and small eyes might indicate bad eyesight Image 7: Insect because it has 3 pairs of legs (beefly) can infer that because it is black and yellow, that might be an indication of danger can infer that because it has wings, it can fly can infer that because it has wings, it is an adult can infer that because it has only 1 pair of wings while the second pair are halteres that it is in fact a fly can infer that because it is a fly that looks like a bee, that it is a bee mimic 9

10 Image 8: Insect because it has 3 pairs of legs (grasshopper) can infer that because it has large, muscular hind legs, it can use these for jumping can infer that because it is green, it likes to hang out in vegetation can infer that long antennae might give an indication of what s happening in the world around it can infer that having eyes on the side of the head might indicate that it is prey, not a predator can infer that the ovipositor located at the end of its abdomen indicates that it is a female Image 9: not an insect because it has multiple legs on multiple segments (millipede) can infer that because it is black and yellow, that might be an indication of danger Image 10: Insect because it has 3 pairs of legs (leafhopper) can infer that because it has wings, it can fly can infer that because it has wings, it is an adult can infer that because it is green, it likes to hang out in vegetation can infer that the spikes on it back look like thorns and might indicate that it tries to mimic a thorn on a bush can infer that these spikes might be used for protection against predators 10

11 Example of Graphs Class Results number of insects per order run pool riffle Coleoptera Diptera Ephemeroptera Hemiptera Neuroptera Odonata Plecoptera Trichoptera Unknown insect orders Insect Distribution in the Field by the School number of insects per order Blattaria Dermaptera Hemiptera Isoptera Mecoptera Orthoptera Trichoptera Other insect orders 11

12 References Arnett, Ross H. Jr. and Richard L. Jacques, Jr Insect Life: A Field Entomology Manual for the Amateur Naturalist. Prentice-Hall, Inc. Englewood Cliffs, New Jersey. Borror, Donald J., Charles A. Triplehorn, and Norman F. Johnson An Introduction to the Study of Insects. Harcourt Brace College Publishers, New York. Castner, James L Photographic Atlas of Entomology and Guide to Insect Identification. Feline Press, Pittsburg, Kansas. Imes, Rick The Practical Entomologist. Simon & Schuster, Inc. New York. Image References for the Handout Folsom, Justus Watson Entomology with Special References to its Ecological Aspects. 3rd Edition. P. Blakiston s Son & Co, Philadelphia. Miall, L.C The Natural History of Aquatic Insects. McMillan and Co, New York. Osborn, Herbert Agricultural Entomology. Lea and Febeger, Philadelphia. Ross, Herbert H How to Collect and Preserve Insects. Circular 39. Natural History Survey Division, Urbana, Illinois. Wellhouse, Walter Housley How Insects Live: An Elementary Entomology. McMillan and Co, New York. 12