Connected on 2014-02-04 09:30:00 from Cook, Illinois, United States
- Bugscope Team sample for today's session with St Matthias is pumping down
- Bugscope Team now we're making presets for today's session.
- Bugscope Team good morning!
- Bugscope Team welcome to Bugscope!
- Teacher Good morning! We are almost ready here.
- Bugscope Team we are ready to roll
- Bugscope Team this is a serious aphid predator
- Teacher We are ready!
- Bugscope Team so you have control of the microscope, and we welcome any questions you have about the insects/arthropods or the microscope or anything else
- Teacher Thank you! We were just discussing aphids and were curious about the larva's mouth
- Bugscope Team you can change the mag, click on a part of the screen to center the image there, change the contrast and brightness, and focus
- Bugscope Team here we can see that the ladybug larva has a small mandible visible from here
- Bugscope Team it also has four palps, two mandilbular and two maxillary, that help it taste and also manipulate its food
- Teacher What is a mandible? Is it like teeth?
Bugscope Team the mandible is the jaw
- Bugscope Team in people, the lower jaw is the mandible and the upper jaw, part of the head, is called the maxilla
- Bugscope Team with insects the mandibles open side to side, like a gate
- Bugscope Team the palps have tips with chemosensors that are like tastebuds
- Teacher What is the actual size of a larva mandible?
Bugscope Team we can estimate by using the scalebar on the lower left of the screen
- Bugscope Team it is likely about 200 micrometers long, 200 microns
- Bugscope Team a microsm
- Bugscope Team oops
- Teacher Very cool!
- Bugscope Team a micrometer is a millionth of a meter, or a thousandth of a millimeter
- Teacher Now we are going to look at the larva's legs
- Bugscope Team micron = micrometer
- Bugscope Team an easier way for us to think of 200 microns is as a fifth of a millimeter
- Bugscope Team to us, a larva is a simplified adult
- Bugscope Team for example its eyes are not very good, and it has single claws at the tips of its legs, whereas an adult ladybug has compound eyes and articulated claws
- Teacher Besides the wings, does a larva have any different body parts than an adult?
Bugscope Team I think it has most of the same parts but they are to us more primitive
- Bugscope Team like the eyes, of which there are maybe 5 per side of the head, called stemmata, are hardly there in a larva
- Teacher Very cool
- Teacher What are we looking at on this side of the larva? What is the purpose of this part?
- Bugscope Team this is the antenna
- Bugscope Team in the back we can see two wrinkled stemmata
- Teacher okay
- Bugscope Team antennae help the insect sense the environment; often one of the main things they do is help collect chemical scents from the air'
- Teacher we are going to switch images
Bugscope Team super cool
- Teacher We are interested in spiders, so we want to see the eye up close
- Teacher Can you describe what we are seeing here?
- Bugscope Team this is really interesting because we see the same pattern of folded setae in front of the eye on two sides of the cephalothorax
- Teacher What are setae?
- Bugscope Team the dome is one of the eight spider eyes, and the things that are like very long pine trees are plumose setae, which are vibration sensitive in this case
- Bugscope Team setae are the things that look to us like hairs. they are very important because the help insects and comparable arthropopds sense their environment
- Bugscope Team insects have an exoskeleton, which is like a shell, or like having armor. the setae stick through the exoskeleton and help with touch, wind, chemical, hot/cold, and other sensing
- Teacher What part of the eye is behind the dome?
Bugscope Team that is the lens, I guess you could say. spider eyes are often not very good
- Teacher Also, what kind of spider is this sample?
Bugscope Team not sure, but probably a wolf spider
- Bugscope Team spiders have this interesting function in which if they are bitten by another spider and sense venom entering their body, for example through a leg, they can just let that leg fall off
- Bugscope Team normally the plumose setae are standing up
- Teacher Do they grow a new one?
Bugscope Team not unless they are the kind of spiders that molt, like large tarantulas
- Teacher Very interesting
- Bugscope Team we are not very good with identifying spiders beyond the more obvious ones
- Bugscope Team tarantulas have setae that are called urticating hairs that they can actually fire at something that is bothering them
- Bugscope Team urticaria means 'itching'
- Bugscope Team but the urticating hairs can actually get stuck in the surface of your eye
- Bugscope Team we can see 7 eyes here; one is obscured at the top of the screen
- Teacher What part of the spider is this?
Bugscope Team this is the cephalothorx, which is a combination head and thorax
- Bugscope Team spiders do not have separate heads and thoraxes
- Bugscope Team your thorax is your chest, or your trunk
- Teacher How can you tell which parts are the eyes?
Bugscope Team they are the round bumps that are kind of in a circle
- Bugscope Team we have done this a few times and have practice seeing them
- Teacher Are the lines on the right side the setae again?
Bugscope Team those are -- yes! -- setae that are lying down
- Bugscope Team the setae help the spider sense vibration, which is very important to it; noise is vibration transmitted through the air
- Bugscope Team the things that look like flat blades are scales from insects
- Teacher Very cool
- Bugscope Team insects like butterflies, moths, mosquitoes, and silverfish has scales on their wings and bodies, and one purpose of the scales, which are modified setae, is to protect them from spiderwebs
- Bugscope Team 'have' scales on their wings and bodies
- Bugscope Team when you rub a butterfly's wings, the stuff like powder that comes off is the scales
- Bugscope Team there is a scale lying on some of the spider's setae
- Teacher Is this a scale on the spider?
Bugscope Team yes but it is not from the spider
- Teacher That is very cool
- Teacher Right
Bugscope Team sorry
- Bugscope Team scales have ridges that make them more rigid, just like Ruffles potato chips
- Bugscope Team the ridges also interfere with light, with the wavelengths of light, and thus they can produce color
- Bugscope Team that is, they can produce both color from pigment and color from their shape, which is called structural color
- Teacher What are the small dots on the ridges?
Bugscope Team some of those are dirt, but right on the ridges we are seeing how the scale formed; those dots are part of the structure
- Bugscope Team this is another scale, on the head of a millipede
- Bugscope Team sometimes some sort of liquid will get on them and dry and they will look like little numps
- Teacher Wow!
- Bugscope Team we can see that the scale is pretty small, because the millipede itself is small
- Teacher How many legs does this millipede have?
- Bugscope Team milli means 1000, and ped means foot, but that isn't really how many legs they have
- Bugscope Team it should have four per segment, so we can couny segments and get pretty close to the true number
- Bugscope Team maybe if it were a really long one from the tropics
- Bugscope Team so there should be 40 legs among the ten segments we see here
- Teacher Yes, we were just counting too!
- Bugscope Team but the millipede was at least twice as long before it broke
- Teacher That is a lot of legs!
- Bugscope Team centipedes have only one pair of legs per segment
- Teacher Why would an insect need that many legs?
Bugscope Team insects have only six legs, so we know this is not an insect; but I think its a necessity of having a very long body
- Teacher Okay
- Bugscope Team so if you think about a caterpillar, then, with its own long body, and it's an insect so should have only six legs -- we find that they have what are called 'prolegs' that fulfill some of the leg function
- Teacher It looks like the legs have joints. How many joints do millepede legs have?
Bugscope Team i think there are 6 per leg. You can try to count them by looking where it is bending
- Bugscope Team this is something odd we are not sure about
- Bugscope Team usually, on insects, we find two spiracles per segment -- one on each side
- Bugscope Team this looks like a spiracle, but there are two on each side or four on each body segment. so it's good this is not an insect...
- Teacher What are spiracles?
Bugscope Team they are breathing ports that supply oxygen to the body. they are connected to a trachea that runs through the body
- Bugscope Team they dont have noses like we do and they don't breathe in their mouths
- Bugscope Team rolypolies are similar to millipedes, but they are crustaceans, actually related to crabs and lobsters
- Teacher Very cool - we see a lot of roly polies in Chicago
- Bugscope Team roly polies like dark damp places. You can usually find one under a rock
- Bugscope Team we can see that many of the insect and comparable arthropods in the sample today have scales on their bodies
Bugscope Team it is because when we collect insects we have them in the same place, together, sometimes, so the scales get on everything
- Bugscope Team the part that looks like a raspberry is the compound eye of the ant
- Teacher We also had a question about the neck of an ant - if it is connected like the spider or separated
- Bugscope Team we can see that the mandibles are serrated like pinking shears
- Bugscope Team and there are lots of setae on the mandibles that help the ant sense when she is biting something
- Bugscope Team it is difficult for us, sometimes to know where the eyes are because the antennae usually take that place on the head -- the place we would expect eyes to be
- Teacher Very cool
- Bugscope Team the individual facets of the compound eye are called ommatidia
- Teacher Can you tell us more about the antennae?
Bugscope Team ants, for one, have that long nonflexible component of the antenna close to the head, whereas wasps and bees, which are closely related, have antennae that are flexible much closer to the head -- the antennae are fully flexible
- Teacher Does an ant mandible chew side to side or up & down?
Bugscope Team side to side
- Bugscope Team here we see an antenna that broke off; we were hoping to find more chemosensory setae
- Bugscope Team you can see how the mandibles cut, side to side, maybe here
- Teacher Very cool. We had a question about the ant's feet if they have sensors too
- Bugscope Team insects do not have teeth, but the toothlike elements of the mandibles are hardened, often, with zinc and calcium
- Bugscope Team the mandibles open out like a gate
- Bugscope Team some insects do indeed have chemosensors on their feet; there are so many species of ants that it is likely we could find some that, like Monarch butterflies, have that capability on the setae on their feet.
- Bugscope Team thank you for joining us for bugscope
- Teacher We are out of time here.
Bugscope Team Thank You!
- Teacher Thank you very much! We really enjoyed talking with you!
- Bugscope Team https://bugscope.beckman.illinois.edu/members/2013-079 is where you can access your images and chat from today
- Bugscope Team Bye!