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