Dr. Oscar E. Liburd
Professor of Fruit & Vegetable Entomology http://entnemdept.ufl.edu/Liburd/fruitnvegipm/teaching.htm Lecture 2: Biological Control
• Biological control the activity of one species that reduces the adverse effects of another species
• One of the oldest methods of insect control
• Earliest record 300 BC where the Chinese use ants to control citrus pests
Bamboo sticks connecting branches and trees to facilitate the movement of ants History of Biological Control in the US • Cottony cushion scale was introduced into southern California between 1873- 1876 • Threatened the citrus industry by 1885 • C.V. Riley (Chief
entomologist for US) DPI arrange a trip to Australia Cottony cushion scale • Albert Koebele subsequently Icerya purchasi traveled to Australia History of Biological Control in the US
Established in the US in 1888 Introduction of vedalia beetle for control of the cottony cushion scale
DPI Vedalia beetle Rodolia cardinalis Coccinellidae http://tolweb.org/Cryptochetidae/10588 Cryptochetum iceryae Cryptochetidae Success and Failures in Biological control Programs
Introduced into northern California from Europe 1944 covered over 2 m acres 2 species of beetles released
fs.usda.gov. A.Brousseau
Klamath weed (St. John’s wort)
• Chrysolina quadrigemina Chrysolina spp. adult • > 99% reduced in 10 years Chrysomelidae Success and Failures in Biological control Programs
Success • Prickly pear cactus (Genus Opuntia ) introduced into Australia in the 1920s. The cactus moth, Cactoblastis cactorum native to South America was introduced into Australia in 1925 and eradicated prickly pear cacti in a few years
Failures: • Introduced into Nevis in 1950, It was found in Florida in 1989 threatening the survival of native species of cacti and Mexico Cactoblastis cactorum m Strategies for Biological Control
• Introduction - referred to as ‘classical biological control’. Involves the deliberate introduction and establishment of natural enemies into areas where they did not previously exist
• Augmentation - Any biological control activity designed to increase the population of natural enemies
• Conservation and Enhancement - Activities designed to improve the survival, dispersal and reproduction of natural enemies Strategies for Biological Control
Introduction - Classical Biological Control
Identification of the pest and its native area
Conduct surveys for natural enemies of the pest in its native area
Shipment of species to a quarantine facility in the area where natural enemies will be released
Host evaluation studies in quarantine facility
Special permit for releasing in specific areas for further evaluation
If successful, final release Strategies for Biological Control
Augmentation releases
• Inundative releases - The release of large quantities of natural enemies with little or no impact expected from their progeny
Calphotos.berkely.edu Green lacewing Ladybird beetles Chrysoperla carnea Hippodamia convergens Strategies for Biological control
Inoculative releases - The release of natural enemies with the expectation that they will reproduce and spread throughout the area
Diadegma insularis Releasing Neoseiulus californicus
DBM Strategies for Biological control
Conservation and Enhancement of Natural Enemies
The use of selective insecticides to avoid natural enemy mortality
Increasing plant diversity
Providing resources including food, overwintering sites water
Strip harvesting Parasite
Parasite – is an animal that lives on or within a larger animal (host)
Requires one or a few host in its lifetime A parasite rarely kills its host, it can weaken the host that can eventually die
Nematodes are good examples of parasites that can be used to suppress insect populations
Steinernema carpocapsae Parasitoid • Parasitoid- an insect usually a wasp that develops within the body of another insect They generally have a narrow host range
Only one host is required to complete development
Host can live for a long time
They always kill their host
• Hyperparasite (secondary parasitoid) - a parasite that feeds on another parasitoid. Encarsia pergandiella and E. tricolor are hyperparasites of E. formosa. Common Parasitoids used in Fruit & Vegetable IPM
Aphelinidae Braconidae Encarsia formosa Aphelinidae Cotesia plutella Lysiphlebus testaceipes
Trichogrammatidae Braconidae Trichogramma spp. Diachasma alloeum
Univ. of Ca Predators • Predator - any organism that attack and feed on other animals (prey) and consumes more than one animal during its lifetime
Mite predators They are generally two feeding types: - Specialist Generalist
Predatory mites
Pytoseiulus persimilis Neoseiulus californicus Insect Orders with Predatory Significance
Coleoptera
- Coccinellidae; ladybird beetles aphids scale insects spider mites
- Carabidae; ground beetles
Cabbage maggot
Weed seeds
Lepidoptera eggs Insect Orders with Predatory Significance
Diptera Syrphidae; Hover or Flower flies
Larvae feed on aphids scale insects
Neuroptera: Chrysopidae Green lacewings
Larvae feed on aphids scale insects & thrips Insect Orders with Predatory Significance
Hemiptera Lygaeidae Anthocoridae
Bigeyed bug, Geocoris spp. Minute pirate bug, Orius spp.
Coccinellidae
Lady beetle Delphastus pusillus Insect parasitic nematodes • Nematodes are thin, un-segmented round-worms, which are parasitic on plants and other animals, or are free-living in soil or living water
• Important families in the class Nematoda
• Steinernematidae - Steinernema carpocapsae - beetle grubs
• Heterorhabditidae - Heterorhabditis bacteriophora - maggots
• They are used mostly as a bio-pesticides in high and medium value crops including cole crops, berry crops and turfgrass for control of borers, root maggots and cutworms