Lecture 16

Question 1

Legs of surface insects vs ground-dwelling insects

Answer 1

• GROUND-DWELLING insects have shorter to no legs

- They have no need for these legs since the space is so cramped

Question 2

Morphological Adaptations for Soil Swelling Insects

Answer 2

• Reduced eyes
• Wings protected or lost
• Developed jumping mechanisms for protection (saltatorial legs and springtails)
• Fossorial legs (digging)

Question 3

Problems with living in soil

Answer 3

• Infection by microorganisms, like pathogenic fungi
  a. ants produce antibiotics secretions
  b. ants and bees have symbiotic bacteria that produce antibiotics
  c. earwigs produce antimicrobial chemicals from abdominal glands
  d. application in human medicine

Question 4

Feeding Habits of ground dwelling insects

Answer 4

• They are detritivores which means they eat dead/decaying plant/animal matter
• This also means that they are saprophages, obtaining nutrients by dead biomass
• This means they produce a lot of frass poop (because they also consume the soil)
• Break down larger particles
• Make micronutrients available to plants

Question 5

Ecosystem Engineering

Answer 5

• African termites
• Bare patch in a circle surrounded by perennial belt and then by a halo of grass
• Do this to collect water
• Perennial water accumulation
• Fair circles or Heuweltjies of southern harvester termite, Microhodotermes viator

Question 6

Termite mounds

Answer 6

• Nitrogen and Phosphorus produced
• Soil stays moist
• Plant get a boost, grow well

Question 7

Root Feeding Insects

Answer 7

• Periodical Cicadas
• Grape phylloxera
• Hemiptera (sternorrhyncha) Phylloxeridae
• Wireworms
• Coleoptera: Elateridae
• White grubs Coleoptera: Scarabaeidae
• Root orientation cues: CO2 and plant volatiles
• Weed Biological Control: 50% of root feeders successful vs 33% surface feeders
• Coleoptera: Curculionidae
• Coleoptera: Chrysomelidae
• Insects and decaying wood= Ambrosia beetles

Question 8

Coprophagous Insects

Answer 8

• Eat dung
• ex; cattle dung, rolling dung beetle
• Dung flies, dung beetles and fungi eat poop, then wasps, other flies, other beetles and mites eat those dung insects
• These interactions must happen before dung dries
• Bring dung balls in nest and put their eggs in the poop
• Found in trees making dung balls of primates
• Problem with chemicals used in animals

Question 9

Necrophagous Insects

Answer 9

• Decomposition in waves
• Useful for forensic Entomology
• Feed on corpsus

Question 10

Fungivorous (mycophagous) Insects

Answer 10

• Fructivores: Feast on fruit and yeast on fruit
• Fungus farming (leaf cutter ants)- take a bunch of leaves, cuts leaves, and grows fungus
• Atta sp. and Acromyrex use the same species of fungus (8-12 myo)
• Fungus Farming: termites

Question 11

Biology of Termites

Answer 11

• Higher termites (termitidae) and its subfamiliy (Macrotermitinae) grows fungus on there deigested faeces. The fungus (termitomyces) helps degrade materal
• Termites feed on the fruiting body of fungus which provides cellulase to digest cellulose
• The fungus will turn to a mushroom. We can see termite mushroom emerging from fungus comb on termite nest

Question 12

Cavernicolous (Troglobite) Insects

Answer 12

-Cave dwellers
-Environmental monitoring (flagship species)- ground dwelling insects not used since they don’t rate compared to vertebrates, difficult to sample, and difficult to identify
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