Course content? What to study and format of written tests.

Picture Shows: lectures are slightly refined after delivery and posted within a day or so; lecture content you should make your own includes the notes that accompany each ‘picture’ [slide], even if I didn’t say it during the lecture. I intend that you understand both the information in the notes and what I say in lecture and I never adhere to my own notes.Labs for download: Preambles of the labs contain lots of information together with your own labwork and obviously this sort of information can help deal with test questions.Source paper essays: In a some cases an assigned reading paper could require more detailed discussion. At the moment there is only one essay there involving membracids.Sources: See Assigned Reading – Short Papers; here we will accumulate particular papers that you should access online via the library and read in as much detail as you can muster.Try to understand topics to at least the level presented in lecture; but if possible beyond. This is where Vogel comes in. Lecture syllabus: I plan to change some of these topics if an interesting paper appears or just a new idea. topics given there are mostly those that will be addressed but not on the dates given at present; we are already at odds with what is there and I reserve the right to change timing: I will come back after the fact and restore accuracy.

See under Special Topics on the website for an example of the sort of question asked on tests; the tentorium is used here as the basis of a sample question and answer. Typically one describes structure and demonstrates intelligent thought about how it might behave mechanically. I try from time to time to be creative.

Taxa, diversity, systematics

aA B

For information on cuticle as a material see: Vincent J.F.V., Wegst U.G.K. 2004. Design and mechanical properties of insect cuticle. Arthropod Structure & Development 33: 187-199.

Insect cuticle is a composite material of crystalline chitin nanofibres embedded in a protein matrix.

Locust tentorium from above

Cross-bracing supports a bridge

Family Tettigoniidae (katydids) Tettigonia viridissima

Evolution of the gula

Gula

The ‘text’ Vogel, See Appendix 2 Motion and Direction, p. 547

• Keeping d large increases the moment of force that the mandible can apply.

• Axis of rotation of the mandible is a line joining the articulation points with the lower margin of the cranium.

• The mandible turning about this axis, completes an arc of a circle, which can crush a leaf or seed against the opposing mandible.

Spiders: orb-weaver

silk fibres only 1 micrometre in diameter: adaptation to reduce visibility?

Spiders and silk

• Spiders produce their silk from glands located at the opisthosoma posterior.

• Silks are proteins with great tensile strength, good extensibility and ability to store strain energy.

silk spigots: spinneretsMicroangela

Argiope: garden spider

Ted McRae

MuhammedMahdi Karim

Eisner T. 1983. Spider web protection through visual advertisement: role of the stabilimentum. Science 219: 185-187.

Hypotheses to explain the selective advantage of stabilimenta: 1. Reinforcement2. Tension adjustment 3. Camouflage4. Visual marker

Notice leg allignment of this spider re stabilimentum: consistent with camouflage Ho.

Tested preserving capacity of visual web markers: triangular strips of white paper

forming an X

• 30 natural webs without stabilimenta (control).

• 30 comparable webs adorned with artificial equivalents of stabilimenta.

• Webs with artificial stabilimenta survived “intact through the early morning period when birds are on the wing”.

Some spiders keep their webs up night & day, and some spin anew each evening,

taking their web down again at dawn; this latter group don’t make stabilimenta and

their webs were used in Eisner’s experiment, the spider residents having been captured and removed from their

webs.

Orb-weaver spider webs include a ‘viscid spiral’ of silk with beaded sticky droplets to: glue for prey. The shingle-like moth wing scales are shown adhering to a strand in the middle right picture.