Lecture 1 Flashcards
Invertebrate
-No back bone
-1.4 million (80%)
Vertebrates
-Backbone
-62,000 (3%)
Plants
-310,000 (17%)
Irelands Invertebrates
-Almost 20,000 invertebrates
-11,500 insects
-8000 other invertebrates
Arthropods
-Myriapods
-Trilobites
-Chelicerates
-Crustaceans
-Insects
(All have common ancestor)
What percentage of insects in the world are ants
1%
Biomass Number
-Biomass exceeds that of all humans that have ever existed (approx 90 billion)
- More insects in one square mile of empty field than there are people in the world
- New beetles are discovered at a rate of one an hour
Irelands largest Insect population
Wasps, bees, ants (3,194
What is an insect?
-3 body segments (head, thorax, abdomen)
-Generally 1-2 pairs of wings
-Expskeleton
Insects as predators and parasites
-Keep ecosystems in balance
-Predators, parasites, parasitoids, pathogenic agents
-Feed on other insect groups
-Natural population regulation
-Insects, mites, spiders
Corn Borer
- One of the largest pests of corn in USA
-Larvae of moth
-Lay their eggs on corn
-Borer eggs, where the wasp larvae develop, killing the corn borers in the eggs
Trichogramma
-Parasitic wasps of the genus Trichogramma
-Have been avalibale on the North American market since the 90’s
-Introducing Trichogramma ostriniae significantly reduced the corn borer population and the damage to the ears of corn
-Further, biological control with trichogramma was considerably more cost-effective than the application of chemical insecticides.
-The main effect was that the corn borer’s natural enemies were maintained, thus reducing secondary pest populations.
Insects as decomposers
-Plant matter, dead animals, dung
-Insects very good at decomposing solid waste
-Enhances forage palatability
-Recycle nitrogen
-Reduce pest habitat
How much solid waste does a cow produce every year?
900kg
Dung Beetles
-Approx 35 species in Ireland
-Rollers, tunnellers, dwellers
-Family Scarabidae- over 5000 species
Dung Beetles in Australia
- Cattle brought to continent in 1788
-No native insect to process dung
-Slowly decomposing dung, issues with pests
When were dung beetles introduced in Australia?
- 1965-1985
How many species of Dung Beetles in Australia
-43 species released
-23 now established
What did Dung Beetles in Australia reduce?
-80% reduction in pestiferous bush fly
-Bush fly transmits disease to cattle
How much can a dung beetle drag?
- One dung beetle can drag 1,141 times its weight
Avermectin
-Treats internal parasites of cattle
-Ends up in dung
-Toxic to dung beetles
-Cow pat on rangeland in US untreated: 23 months
-Cow pat on rangeland in US treated with pesticide: 28 months
Total losses averted by Dung Beetle
$380 million
Insects as pollinators
-Plants= sessile
-Visit flowers to feed on nectar and pollen
-At same time, they help the plant to reproduce
What percentage of leading food crops rely on animal pollination?
75%
What percentage of the worlds flowering plants rely on animal pollination?
90%
How much is pollination by insects responsible for?
- 1 in 3 bites of food
-39 of 57 leading crops
Is insect pollination needed by grains
- No
-Use wind pollination
What can insect pollination do?
-May improve the quality or quantity of fruit.
-It can increase genetic diversity -Necessary for many crops not to produce the edible part but to produce seed for replanting afterwards (e.g. cabbage, lettuce etc)
What does insect pollination improve?
-Quality and quantity
-Seed production viability
-Genetic diversity
Who are pollinators?
-Honeybees (50%)
-Wild insects (50%)
What percentage of pollinators are honeybees?
-50%
Pollination in Ireland
-Oilseed rape (€4 million pa)
-Apples
-Field beans
-Peas
-Berries
-Clover
=Total value €53 million pa
Insects as food
Insects = based of food chain
Food for other insects, birds, mammals
Food for humans
Value of insects as food
-Commercial fishing in the US: $225 million
-Birdwatching: $19.8 billion, which is 61% of the $32.4 billion spent on bird observation annually in the United States
Entomophagy
-Eating insects
-Food source for humans in 80% of countries worldwide
