Insect control and Insecticide

1- اسم المقرر سموم ومبيدات ومكافحة حشرات -402ش ورمزه الكودى 2- التخصص علم الحشرات 3- الفرقة الرابعة 4- عدد الوحدات )5 ساعات( نظرى + )5 ساعات( عملى History of Pest Management Lecture 1 World’s Worst Plant Pests Worst Historical Pest • Schistocerca gregaria (desert locust) a pest since biblical times, they in unexpectedly, strip a field bare in an hour and consume a very wide range of crops. Locust swarms may vanish for many years, only to break out of their endemic regions after periods of abnormally high rainfall.

﴿فَأَ ْر َس ْلنَا َعلَ ْي ِه ُم ال ُّطوفَا َن َوا ْل َج َرا َد َوا ْلقُ َّم َل َوال َّضفَا ِد َع َوال َّد َم آيَا ٍت ُّمفَ َّصالَ ٍت فَا ْستَ ْكبَ ُرواْ َو َكانُواْ قَ ْوماً ُّم ْج ِر ِمي َن﴾ ]األعراف: 133[. World’s Worst Plant Pests Most Expensive to Control • Diabrotica vergifera vergifera (western corn rootworm) In terms of the amount of pesticides once used to control and the expense of developing a resistant GM-strain, Diabrotica virgifera virgifera beetle is a strong contender. World’s Worst Plant Pests Greatest Human Impact • Phytophthora infestans (potato blight) Caused the Irish potato famine (1845-1852), one million people died and a further million emigrated from Ireland, causing the population to decrease by about 24%. World’s Worst Plant Pests Greatest Human Impact • Hemilaea vastatrix (coffee leaf rust) a fungus that devastated coffee production in Sri Lanka (Ceylon) in the 19th Century and famously led to a switch to tea drinking in the UK.

World’s Worst Plant Pests Worst Climate Change Threat

• Dendroctonus ponderosae (mountain pine beetle) The cumulative effect of the current outbreak of Dendroctonus ponderosae in British Columbia, Canada, has killed 13 million hectares of lodgepole pine forest and released an estimated 270 million tonns of carbon, converting the forest from a carbon sink to a large net carbon source. World’s Worst Plant Pests Most Resilient Pest • Leptinotarsa decemlineata (Colorado potato beetle) is a strong candidate for this award, having managed in the space of about 50 years to develop resistance to 52 different compounds belonging to all major insecticide classes (including cyanide). This beetle therefore has effectively beaten the chemists.

A Brief History of Pest Control

8000 BC – the beginnings of agriculture Pest Management History

• Era of traditional approaches (ancient-1938)

• Era of pesticides (1939-1975)

• Era of integrated pest management (1976-now)

3000BC in Egypt, cats were being used to control pests of grain stores such as rodents and it could kill snakes.

In 1939/40 a survey discovered that cats could keep a farm's population of rats down to a low level, but could not eliminate them completely. However, if the rats were cleared by trapping or poisoning, farm cats could stop them returning - at least from an area of 50 yards around a barn. Sumerians 5000 BC Chinese Great Age of Discovery (1200 BC – 400 AD) Passage from Chinese text, 3rd century AD:

“A factor which increases the abundance of a certain bird will indirectly benefit a population of aphids because of the thinning effect which it will have on the coccinellid beetles which eat the aphids but are themselves eaten by the bird.”

History of Biological Control:

Intentional manipulation of to suppress insects goes back to ancient China in 400 BC

• gathered, sold and established colonies of predatory weaver ants in citrus orchards to control caterpillars and boring beetles.

• moved nests around in the orchard and created overhead “ant highways” between trees using bamboo

• DeBach observed this practice still being used in Burma in the 1950’s 17 Biological control in China 400 AD

Greeks and Romans (300 BC-19th century) Habitat/cultural manipulation:

950 BC - Homer 450 BC - Herodotus Pest proof granary – 13 BC

A Step Backwards: The Dark Ages (500 AD)

Roman text suggested the following for protection from caterpillars:

“a woman ungirded and with flying hair must run barefoot around the garden, or a crayfish must be nailed up in different places in the garden.”

Consequences of Agricultural Revolution (19th century):

• The potato blight in Ireland, England, and Belgium (late 1840’s)

• Fungus leaf spot disease in coffee

• Powdery mildew outbreak in European grapes (1850’s)

• Grape phylloxera invades Europe from the US (1848-1878)

Grape phylloxera Grape powdery mildew History of Biological Control:

Parasitoids are less obvious than large predators - first observation was 1602 (Aldrovandi on butterflies - thought they were another life stage)

1st correct interpretation was in 1685, Martin Lister in the Philosophical Transactions of the Royal Society of London described parasitism by Ichneumonid wasps on caterpillars

Insect disease - first to experimentally show was Agostino Bassi of Italy with Beauveria on silkworm, 1835

24 In Europe, R. Réaumur (in 1734), is thought to be the first to propose biocontrol: he advised the release of lacewings in greenhouses for the control of aphids. R. Réaumur

1752 Carl Linneus suggested “every pest has a natural enemy, we should capture and use them to dis-infest crops”

In 1840’s predators were released for control of gypsy moth and garden pests in Italy

25 North America - rapidly expanding agriculture in 1800’s

1855 Asa Fitch N.Y. state entomologist proposed importing parasites from England - didn’t happen Asa Fitch

Wheat midge Sitodiplosis mosellana was known to come from Europe

26 In 1865, the first successful international importation for weed control took place, when a cochineal insect (Homoptera) was transferred from India (originally from Argentina) to Sri Lanka, where it effectively controlled the prickly pear cactus within a few years

27 C. V. Riley - the “Father of modern biological control”

1873 first international movement of an insect natural enemy - Missouri state entomologist C.V. Riley sent predatory mite Tytoglyphus phylloxera to France for grape phylloxera - establishment but no control

1879 C.V. Riley appointed Chief entomologist for USDA - soon after imported internal parasite of cabbage butterfly. Established, but not very effective agent

28 Cottony Cushion Scale: California Success

Cottony Cushion Scale () discovered in Menlo Park 1868 on acacia CA’s new citrus industry was mostly around LA - took 3-4 yrs before it appeared on citrus in LA

By 1880 it was throughout CA - almost wiped out the citrus industry

Chemical measures (cyanide fumigation) had only limited effect

29 Cottony Cushion Scale

30 C.V. Riley speculated and confirmed that CCS was from Australia

Riley procured funds and sent Albert Koebele to AU in 1888

Keobele found a parasitic fly ( iceryae) and a predacious lady bird beetle (Rodolia cardinalis) [formerly Vedalia]

31 Cryptochetum iceryae

32 Rodolia cardinalis

33 Rodolia cardinalis larvae

34 Shipped to SF, reared, then released in tents in LA

Beetle quickly established, spread, and provided complete control within 2 years

Parasitic fly also became established and is primary control agent in coastal areas

35 Saved citrus industry in CA

Dramatic success lead to: • further federal government support • State support through the University of California • willingness of public/growers to consider BC

By WWII 13 pests controlled in all or part of California.

Unfortunately CCS project also lead to a great deal of focus on coccinelids for BC in California and Hawaii with little success.

36 Cottony Cushion Scale Biological Control (late 19th century)

Rodolia cardinalis Early 20th Century – 5 major approaches to pest control are well established:

1) Biological control 2) Cultural/Mechanical control 3) Chemical control 4) Resistant varieties

5) Legal control, through the use of inspections and quarantines, is established in the US in 1912 by the Plant Quarantine Act. Insecticide Era (1939)

• Development of new synthetic insecticidal compounds.

1939 Discovery of the insecticidal properties of DDT

1940s Organophosphates in Germany Carbamates in Switzerland DDT (dichlorodiphenyltrichloroethane):

• First synthesized in 1873 by a German grad student • Paul Müller, a Swiss chemist with the Geigy Corporation, discovered its insecticidal properties in 1939

The End of the Insecticide Era

• The beginning of the end… the earliest hint of impending disaster was the evolution of resistance.

• 1946 - The first reported case of tolerance to DDT in the house fly in Sweden.

• Within 20 years 224 species of insects and mites were resistant to at least one major insecticide.

The End of the Insecticide Era

• The beginning of the end…

• Pest resurgence following applications of broad- spectrum pesticides due to the elimination of natural enemies.

• Secondary pest outbreak – herbivores which were previously not a pest outbreak following pesticide applications.

The End of the Insecticide Era

• The nail in the coffin… the publication of Silent Spring by Rachel Carson in 1962.

Rachel Carson quotes “I believe natural beauty has a necessary place in the spiritual development of any individual or any society. I believe that whenever we substitute something man-made and artificial for a natural feature of the earth, we have retarded some part of man’s spiritual growth” Lessons from history

• Important advances in pest management have occurred independently across cultures throughout history… we have much to learn from other societies.

• The roots of integrated pest management have existed for centuries, but social and political factors have resulted in the loss of knowledge that must be re- learned.

• The discovery of the insecticidal properties of DDT changed the trajectory of pest management for decades to follow.