genetic control group doan thien thanh bt070134 ho thi phuong thao bt070132 vietnam national university ho chi minh city international university biotechnology department applied entomology lecturer d

“The Sterile Insect Release Method and Other Genetic Control Strategies”. Rechcigl.“Biological and biotechnological control[r]

GROUP:

DOAN THIEN THANH

VIETNAM NATIONAL UNIVERSITY HO CHI MINH CITY- INTERNATIONAL UNIVERSITY BIOTECHNOLOGY DEPARTMENT

APPLIED ENTOMOLOGY

OUTLINE

1. What is genetic insect control?

 Definition  Purposes

 Advantages and disadvantages

 How?

 Factors affect on genetic insect control

2. Sterile insect technique – SIT.

Definition

Basic principle: utilize factors which will

lead to reproductive failure

“The use of any condition of treatment that

can reduce the reproductive potential of

Purposes

• Control the growth and development of insect.

• Regulation insect population.

 Control pest infestation

 Protecting commercial crops

 Protect human health from harmful insects (like

mosquitoes)

Advantages and disadvantages

ADVANTAGES DISADVANTAGES

•Friendly with environment.

•Not harmful for

beneficial insect in the same field.

•Not harmful for human health.

•Knowledgeable.

•Require well trained investigators.

•Can not be applied

How?

Based on the induction of dominant lethal mutations in the sperm:

By ionizing radiations or chemical

sterilants

By physical methods

Factors affect on genetic insect control

• Natural density levels. • Cost of rearing.

• Releasing the number of insects required.

• Degree of annoyance or damaged causes by

Sterile insect technique (SIT)

• 1950s - Dr Raymond C Bushland and Dr

Edward F Knipling (Received the 1992 World Food Prize)

• Most widely - most successful.

• Sterile male technique or sterile insect release

method

• Against insect disease vector.

• Suit for insect species that mate only once or

if there is multiple mating, sperm from the

How?

Principle:

Sterile insects + “wild” insects  infertile eggs.

How frequently?

Applications

• Pink Bollworm (Pectinophora gossypiella

Saunders)/USA (California)

• Control Culex quinquefasciatus in Sea Horse

Key, Florida coast

• Screwworm fly /USA, Mexico, Libya.

• Mediterranean Fruit Fly (Ceratitis capitata

Advantages/ disadvantages

ADVANTAGES DISADVANTAGES

•Hight cost initial but the control of vector species in an area with a low

population density of the species may be

comparatively

•Saving money in control of year to year where

species can be

•Repeated treatment is required to exterminate the population

•Sex separation is difficult

•Radiation treatment effects health male

Other Genetic Approaches to Insect Control

Inherited sterility

Inherited sterility

Referred to as delayed sterility, F1 sterility,

partial sterility…

Suiting for insects that contain polycentric

chromosomes

Involving the transmission of aberrant

Inherited sterility

2 ways:

Radiation therapy  break chromosomes

sterility

Culturing stocks of the target species which

contains homozygous translocations (depend on number and size of the translocations

Chromosomal translocations in an F1 male whose

Inherited sterility- advantages

enhanced reproductive competitiveness of

the partially sterilized individuals compared to the fully sterilized individual used in SIT

The production have higher numbers than

Cytoplasmic incompatibility

• Between insects of the same species with

different Wolbachia infection status

• Sterility is due to a cytoplasmic factor

transmitted through the egg → kill the sperm of the incompatible male after its entry into the

egg

Either unidirectional or bidirectional:

 Unidirectional CI : an infected male mates with an uninfected female

Bidirectional CI : in mating between infected

Cytoplasmic incompatibility

• Achieving by mass production

Other genetic approaches

• Principle:

Release not sterile insects produce

sex-ratio distorters (SRDs) meiotic drive

decline population.

• SRDs: heritable elements > modify the sex

ratio > promote transmission

Example

Drosophila melanogaster

D willistoni X ♀ D melanogaster ♂

F1 primarily ♀

D melanogaster X rare F1 ♀ ♂ BC1 primarily ♀

References

• Alan C Bartlett and Robert T Staten USDA, ARS, Western

Cotton Research Laboratory, APHIS, PPQ, Phoenix Methods Development Center Phoenix, AZ 85040 “The Sterile Insect Release Method and Other Genetic Control Strategies”

From http://ipmworld.umn.edu/chapters/bartlett.htm.

• Nancy A Rechcigl.“Biological and biotechnological control

of insect pests” Published by CRC Press, 1999

• Sex ratio- concepts and research methods Cambridge

University Press.

• George Davidson Genetic control of insect pests Published

by Academic Press, 1974 Original from the University of California