Agricultural Entomology

What is Agriculture? The cultivation of plants/animals for Human

Use Includes plants used for :

Food (Fruits, vegetables, grains and oil seeds) Animal Feed Fiber products (like wood or cotton)

Tarrant Co. Agriculture Factoids In 1997, There were 1048 farms covering 184,081

acres of land. These farms produce over $40 Million worth of ag.

Products each year. Major Tarrant Co. Crops include:

Seed Corn Sorghum Wheat Grass and alfalfa hay

What Role Do Insects Play in Agriculture?

Harmful insects: Eat parts of plant, causing weakened growth and

production Eat parts of plant that we eat, spoiling crop Spread diseases that weaken or kill the plant

Beneficial Insects: Eat or parasitize harmful insects, keeping

their populations in check. Pollinate Produce Marketable Products (honey, wax,

silk)

One Plant, Many Pests Apple Trees:

Plum Curculio – Fruit Damage

Apple Pests Codling Moth-fruit damage

Apple Pests Apple Maggot Fly – Fruit Damage

Apple Pests Rosy apple aphid – Foliage and Fruit

Damage

Apple Pests Flat-Head Apple Tree Borer – Wood

Damage

Cotton Pests Cotton Aphid

Cotton Pests Cotton Bollworm

Cotton Pests Cotton Leaf Perforator

How Do Farmers Deal With Pest Insects?

Chemical Control

Biological Control

Integrated Pest Management (IPM)

Chemical ControlPesticides: Synthetic or Natural Chemicals used to interrupt the

normal physiological processes of insects.Timing is important!

Some applications may make the problemworse in the long run.

Some pesticides can harm people, too!

BioControl Natural Enemies: Insects that prey upon or

parasitize pest insects, keeping their populations at a minimal level

Pheromone Trapping: using chemical signals to trap adults before they can lay eggs

Bt transgenic plants – are toxic to Lepidopteran pests.

Natural Enemies Come in 2 categories:

Generalists – eat a variety of pest and beneficial species.

Specialists – Have specific prey or hosts.

Frequently Released GeneralistsGreen Lacewings

Frequently Released Generalists Ladybird Beetles

Frequently Released Generalists Mantids

Specialists Mealybug Destroyer

Predatory Thrips

Specialists Parasitoids

Pheromone Trapping

Transgenic Crops Bacillus thuringiensis genes inserted into

genome of many different crops. B. thuringiensis is a naturally occuring bacteria

that produces a protein that is lethal to Lepidoptera.

Bt Plants produce their own pesticide, and aren’t harmful to people.

Selection for plants that don’t produce the protein in their pollen reduces the risk to non-target species.

How Bt Crops Work

Pollinators In order to produce fruit, vegetables, or

seed, many plants need insect pollinators.

Insect Products Apis millifera, The Honey Bee

Silkworms

Silkworm Production

Scale Insect Products Shellac Cochineal dyes

The End