VL 9 Flashcards
Hwo is the food chain organised?
First Trophic level: Producers (plants)
Second Trophic level: Primary consumers (herbivores)
Third Trophic level: Secondary consumers (carnivores)
Fourth Trophic level: Tertiary consumers (top carnivores)
How much of the organic matter synthesized by plants remain unconsumed?
90 %
Passes to level of decomposers as plant material decaying on soil, together with the remains of animal corpses and the excretory products of producers and cosnumers of different levels
What is the mahor group of decomposers?
Artropods, present in nearly all terrestrial habitats
millions of individuals belonging to hundreds of species can be recorded in just one square meter
What are decomposers?
Decomposers are saprophytic organisms feeding on dead matter or decaying remians derived from producers and consumers
Life cycle of dung beetle
New adult -> emerges from soil and flies to fresh dung -> Male and female form a pair and bond to mate adn nest build -> Female lays an egg in each dung balls, nest of dung balls and tunnels dug beneath the soil surface (p. 11) -> Egg -> Larva -> Pupa -> New adult
Three main groups of dung beetles
Rollers (Scarabaeinae)
Tunnellers (Geotrupidae and most Scarabaeidae)
Dwellers (Aphodiidae)
Unique ecological function is of vital importance to the livestock sector and for the soil fertility of grasslands
Saprophytic beetles
Saprophytic beetles play a major role in decomposition of wood in ecosystems, thus recycling nutrients that would otherwise be locked in decay logs and branches. Some species are also involved in pollination
How do arthropods degradade cellulose and lignin?
most arthropodes lack the ability to develop enzymatic porcesses for degrading the fundamental components of any plant, lignin and cellulose.
Many insects have solved this problem by means of mutualistic relations with microorganisms, having bacteria or symbiotic protozoa in the intestinal tract. Others take advantage the cellulase produced by external microflora.
Termites - Isoptera
Life cycle and social organization
Eggs -> Nymphs -> Soldier, Worker, or developing winged form -> Winged reproductives (alates), Young King or Queens -> Male & Female wings shed -> King & Queen
Social organization similar to that of bees and ants in Hymenoptera, but with incomplete metamorphosis
Termites possess symbiotic bacteria and protozoa, and in their absence wood cannot be assimilated by these insects.
Megaponera analis is the sole ant species of genus Megaponera, they are strictly termite-eating and widely distributed in Sub-Saharan Africa
Diptera functional diversity
Syrphid flies: Pollinators/predators
Tachinid flies: parasitic
Flies that are decomposers of plant and animal tissues
How are the nutritional benefits of Insects?
53% proteins
35% fatty acids
13% carbohydrates
What are advantages of Insect farming?
Needs less space than traditional livestock, requires limited investment costs (per unit protein)
Breeding is practiced with simple technology
Allows fast returns on investment and high financial returns
Management of this farming is realtively simple and does not require in-depth training
