how to draw….. a beetle in 20 steps. what you’ll need: piece of paper or sketch book sharp...
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HOW to DRAW…..
a beetle in 20 steps
what you’ll need:
• piece of paper or sketch book
• sharp pencil and a good eraser
• straight edge ruler
note: some teachers may wish to demonstrate on a large sketchpad, a black/white board or with overhead transparencies.
Step 1. Have students place papervertically. In the center of the page,draw a small equilateral triangle, pointing down (towards bottom of page).
note: teachers can also use this to discuss ‘triangles’. Also, althoughit doesn’t yet look like a beetle:this triangle will become your beetle’s scutellum, which is part of the meso-thorax
8 x 11.5 piece of paper
Step 2. Draw four straight linesfrom your triangle as shown below.Two short lines, and two long lines.Notice that TWO lines originate at
a right angle from the upper right corner of the triangle
note: teachers can also use this to discuss RIGHT ANGLES
Step 3. Connect the left short lineto the downward facing line witha long curved line. Do the samewith the upper and right hand lines.
these two shapes will become your beetle’s elytra
Step 4. add one more long curvethat originates to the right of the triangle, and extends down, curving towards the bottom-mostpoint.
this line defines a region that will become 2 parts in your finished drawing: (1) the metathorax and (2) the abdomen
ADDED mathematical subject: variables
teachers may wish to use variables to illustratethe similarities in some of the lengths.
xx x
x
Step 4. draw a longer line, parallelto the long horizontal line drawn instep 2. At the end, draw a curvedline down and back towards thecenter of the page. The shape drawnshould look like the front of a canoe or a blade.
this region will define the beetle’s flight or hind wing, also called the metathoracic wing.
Step 5. draw 5 parallel lines and little circles above each oneas shown below.
these lines define the abdominal segments and thecircles are the spiracles
Step 6. draw a line, parallel to the topof the original triangle (step 1) that extends left almost (but not quite) to the left hand edge of the drawing. Thenconnect it to the upper left corner with a curved line
the region defined by these two lines will be the prothorax
Step 7. The next few steps dealwith the beetle’s HEAD. To begin, draw three horizontal parallel lines above your drawing. The distance above should be approximately equal to one sideof the original triangle and they should be positioned directly overthe triangle from step 1.
Step 8. add two small ovals oneach side of the lower line drawnin step 7. The ovals should connectthis line to the line drawn in step 6.
these two shapes will become your beetle’s compound eyes
Step 9. connect the parallel linesdrawn in step 7
these two trapezoids will become your beetle’s clypeusand labrum
Step 10 (halfway there). Add twozig-zag lines up from the top of thebeetle.
these two shapes will become your beetle’s mandibles
Step 11. Connect the zig zags tothe lines drawn in step 9 with twocurved lines.
Step 12. we’re going to focus inon the head and add a set ofantennae and some palpi
start by adding two rectangles thatemerge from the head above thecompound eyes. Add a smallersquare or rectangle on top of each
these will be the first two segments of the antennae.The larger segment is the scape and the smaller oneis the pedicel
Step 12. we’re going to focus inon the head and add a set ofantennae
start by adding two rectangles thatemerge from the head above thecompound eyes. Add a smallersquare or rectangle on top of each
these will be the first two segments of the antennae.The larger segment is the scape and the smaller oneis the pedicel
Step 13. beetle antennae are verydiverse – but most have 8-30 moresegments on each antennae. The simplest one to draw is the filiformantenna.
add a ‘tail’ like shape to the end ofeach pedicel and then subdivide thiswith lots of lines to make thesegments. repeat on other side.
this entire part of the antennae iscalled the flagellum
Step 14. palpi. Under the mandibleof most insects (including beetles)is a small pair of what looklike little antennae called maxillary palpi
to add maxillary palpi- draw threecontiguous ovals between the scape and the mandible.
this entire part of the antennae iscalled the flagellum
Step 15. legs. All insect legshave 6 legs, each with 6 parts. But only 5 parts are usually visible from above. We’re onlygoing to illustrate the LEFT legsin this drawing.
each of these shapes is the femur of one leg. The plural of femurisn’t “femurs”…it’s: femora
draw three rectangular shapeson the side of your beetle.
Step 16. now add a longer rectangular to each of these
each of these is the tibia of one leg.
Step 17. on each tibia, we add5 rectangles or ovals, that looklike beads on a string.
each of these strings is a tarsusand each segment (bead) is a tarsomere
Step 18. on each tarsus, addtwo little claws
each claw is called a pretarsus or tarsal claw
Step 19. add parallel lines to elytra
grooves on the elytra are called striae
Step 20. (optional) add remaininglegs.
YOU’RE DONE!!!! CONGRATULATIONS YOU HAVE DRAWNA BEETLE!!!!
step 1. draw a lightvertical line about 1”from the RIGHT edgeof you piece of paper.
we’re going to erase this line in the next step
add 13 horizontal linesbeginning about 1” from top and about ½”apart.
NOW erase the line from the preceding step
lightly letter these ‘A’through ‘M’ (we’llerase these letters at theend..so do them lightly).
A
B
C
D
E
F
G
H
I
J
K
L
M
draw a line from theoutstretched elytronto line F and write‘Elytron’
A
B
C
D
E
F
G
H
I
J
K
L
M
Elytron
place the word ‘Wing’inside the outstretchedwing
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
draw a line from oneeye to line C andwrite ‘compound eye’
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
draw a line from the right mandible to line Aand write ‘mandible’
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
Mandible
draw a line from the right mandible to line Aand write ‘mandible’
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
Mandible
Maxillary palpus
draw a line from the right mandible to line Aand write ‘mandible’
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
Mandible
Maxillary palpus
Antenna
Either write the word‘Pronotum’ inside theregion to the left of theelytron OR draw a lineto line D and write the word ‘Pronotum’ there.
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
Mandible
Maxillary palpus
Antenna
Pronotum
Pronotum
draw a line from the central triangle to lineE, and write ‘Scutellum’
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
Mandible
Maxillary palpus
Antenna
Pronotum
Scutellum
Metanotum will go inline G with a line drawnto the region directlyright of the central triangle
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
Mandible
Maxillary palpus
Antenna
Pronotum
Scutellum
Metanotum
Metanotum will go inline G with a line drawnto the region directlyright of the central triangle
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
Mandible
Maxillary palpus
Antenna
Pronotum
Scutellum
Metanotum
Abdominalsegments
Metanotum will go inline G with a line drawnto the region directlyright of the central triangle
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
Mandible
Maxillary palpus
Antenna
Pronotum
Scutellum
Metanotum
Abdominalsegments
Spiracle
The parts of the legcan all be done at oncewith a line to thetop segment going toJ, the next to K, the clawsat the bottom to M andthen a bracket for thelittle segments leadingto line L
these are labeled: Femur (J),Tibia (K), Tarsus (L) & Tarsal Claw (M)
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
Mandible
Maxillary palpus
Antenna
Pronotum
Scutellum
Metanotum
Abdominalsegments
Spiracle
Femur
Tibia
Tarsus
Tarsal Claw
Body regions are denotedby large square bracketsas shown here.
A
B
C
D
E
F
G
H
I
J
K
L
M
ElytronWing
Compound Eye
Mandible
Maxillary palpus
Antenna
Pronotum
Scutellum
Metanotum
Abdominalsegments
Spiracle
Femur
Tibia
Tarsus
Tarsal Claw
HEAD
THORAX
ABDOMEN
last step is to erase the letters we put on the linesto the right…and the linesthemselves if you like
you now have a scientificillustration of generalizedbeetle anatomy!!!
ElytronWing
Compound Eye
Mandible
Maxillary palpus
Antenna
Pronotum
Scutellum
Metanotum
Abdominalsegments
Spiracle
Femur
Tibia
Tarsus
Tarsal Claw
HEAD
THORAX
ABDOMEN
A legend can be added toto finish it off
ElytronWing
Compound Eye
Mandible
Maxillary palpus
Antenna
Pronotum
Scutellum
Metanotum
Abdominalsegments
Spiracle
Femur
Tibia
Tarsus
Tarsal Claw
HEAD
THORAX
ABDOMEN
Scientific IllustrationBeetle Anatomy (dorsal view)
Student NameSeptember, 2009