Sterile Insect Technique

Principles And Practice In Area-Wide Integrated Pest Management

Victor A. Dyck, Jorge Hendrichs, A.S. Robinson, Victor A. Dyck, Jorge Hendrichs, A.S. Robinson

• Publisher: CRC Press
• Year: 2021
• Print ISBN: 9780367474348
• eBook ISBN: 9781000377835
• Edition: 2
• Topic: Scienze biologiche
• Subtopic: Ecologia

The sterile insect technique (SIT) is an environment-friendly method of pest control that integrates well into area-wide integrated pest management (AW-IPM) programmes. This book takes a generic, thematic, comprehensive, and global approach in describing the principles and practice of the SIT. The strengths and weaknesses, and successes and failures, of the SIT are evaluated openly and fairly from a scientific perspective. The SIT is applicable to some major pests of plant-, animal-, and human-health importance, and criteria are provided to guide in the selection of pests appropriate for the SIT. In the second edition, all aspects of the SIT have been updated and the content considerably expanded. A great variety of subjects is covered, from the history of the SIT to improved prospects for its future application. The major chapters discuss the principles and technical components of applying sterile insects. The four main strategic options in using the SIT — suppression, containment, prevention, and eradication — with examples of each option are described in detail. Other chapters deal with supportive technologies, economic, environmental, and management considerations, and the socio-economic impact of AW-IPM programmes that integrate the SIT. In addition, this second edition includes six new chapters covering the latest developments in the technology: managing pathogens in insect mass-rearing, using symbionts and modern molecular technologies in support of the SIT, applying post-factory nutritional, hormonal, and semiochemical treatments, applying the SIT to eradicate outbreaks of invasive pests, and using the SIT against mosquito vectors of disease. This book will be useful reading for students in animal-, human-, and plant-health courses. The in-depth reviews of all aspects of the SIT and its integration into AW-IPM programmes, complete with extensive lists of scientific references, will be of great value to researchers, teachers, animal-, human-, and plant-health practitioners, and policy makers.

CHAPTER 3.1.


ROLE OF POPULATION AND BEHAVIOURAL ECOLOGY IN THE STERILE INSECT TECHNIQUE

Y. ITÔ¹. K. YAMAMURA² AND N.C. MANOUKIS³

¹Deceased

²Statistical Modeling Unit, Institute for Agro-Environmental Sciences, NARO, Tsukuba 305-8604, Japan

³Tropical Crop and Commodity Protection Research Unit, Daniel K. Inouye United States Pacific Basin Agricultural Research Center, United States Department of Agriculture —Agricultural Research Service Hilo, Hawaii 96720, USA Email: [email protected]

TABLE OF CONTENTS

1. INTRODUCTION

2. THEORETICAL POPULATION DYNAMICS

2.1. Logistic Model

2.2. Dynamics of Populations under Control by the SIT

2.3. Spatial Considerations

3. ESTIMATION OF POPULATION DENSITY AND MORTALITY BY MARK-RECAPTURE

3.1. Petersen Method

3.2. Yamamura Method

3.3. Jolly-Seber Method

3.4. Hamada Method (Modified Jackson Positive Method)

3.5. Jackson Negative Method

3.6. Fisher-Ford Method

4. ESTIMATION OF DISPERSAL DISTANCE BY MARK-RECAPTURE

4.1. Diffusion Equation

4.2. Random Correlated Walks

4.3. Distribution of Cumulative Recaptures

4.4. Empirical Distributions

5. BEHAVIOURAL ECOLOGY: SEXUAL COMPETITIVENESS OF RELEASED STERILE MALES IN THE FIELD

5.1. Effects of Long-Term Mass-Rearing more Important than the Effects of Sterilization

5.2. Competitiveness must be Measured in the Field

5.3. Inadvertent Selection of Mate-Choice when the SIT is Applied

5.4. How Can the Spread of an SIT-Resistant Strain be Overcome?

6. ACKNOWLEDGEMENTS

7. REFERENCES

SUMMARY

Important principles of population and behavioural ecology in relation to the application of the sterile insect technique (SIT) for the control of a pest are explained. These include: (1) a logistic population model for estimation of the population fluctuation of target animals and the number of sterile males to be released for successful eradication, (2) mark-recapture estimations of density and mortality rate of the target population, especially for remote areas, where repeated releases and recaptures are difficult, (3) models of dispersal to assess dispersal distance of target animals, and (4) equations for estimating the decrease of sexual competitiveness of mass-reared strains under field conditions. The method to estimate dispersal distance curves when attraction areas of traps are overlapping, and changes in mate-choice of wild females resulting from inadvertent selection when the SIT is applied, are explained. The necessity of field estimation of sexual competitiveness of released sterile males is also emphasized.

1. INTRODUCTION

In one of three seminal papers (Baumhover et al. 1955; Knipling 1955; Lindquist 1955) reporting the first success of the sterile insect technique (SIT) to eradicate insect pests, Knipling presented a table showing an example of model simulation for explaining the effect of sterile male releases. The model is

where N_g and N_g+1 are numbers of females at the gth and (g+1)th generation, and R and Q are rates of change in the population size per generation and the proportion of normal females (females which can lay hatchable eggs), respectively. This early model shows that population ecology theory and models have been an integral part of the SIT from the outset (Barclay, this volume; Barclay et al., this volume).

The early success in eradicating the New World screwworm Cochliomyia hominivorax (Coquerel), in the area-wide integrated pest management (AW-IPM) programme in Florida in 1959, was not always replicated in subsequent AW-IPM programmes integrating the SIT (Krafsur 1998; Liebhold et al. 2016). In many cases this was because government officials thought about the SIT as an established technique consisting only of releasing sterile insects, with animal and plant health workers engaged in programmes releasing sterile insects without basic ecological and behavioural studies. Some early programmes did not include first estimating the number of wild females, simulating the process based on a population model incorporating the SIT, and evaluating in the field the mating competitiveness of the released sterile males. Thus, in some of those cases, many sterile males were released but eradication failed, and it was not possible to know the major reason for failure, in spite of overflooding the wild population with sterile males, e.g. ratios of the number of sterile to wild males were 112:1 in a Mediterranean fruit fly Ceratitis capitata (Wiedemann) programme in Nicaragua (Rhode et al. 1971), and 311:1 in another C. capitata programme in Procida Island (Cirio and de Murtas 1974). Without a full understanding of the population and behavioural ecology, the planning, implementation, and evaluation of programmes that release sterile insects become very difficult (FAO/IAEA 2016; Barclay, this volume; Barclay et al., this volume; Vreysen, this volume).

The goal of this chapter is to describe basic theory, models, and some mathematical techniques from population and behavioural ecology that are helpful for planning and executing the SIT component of an AW-SIT programme aimed at the control of pest insects — suppression, containment, prevention or eradication (Hendrichs, Vreysen et al., this volume).

2. THEORETICAL POPULATION DYNAMICS

2.1. Logistic Model

The most basic model of population increase is the Hale-Malthus model:

(1)

or, integrating equation 1,

(2)

where N_t, N₀, r and e are number of individuals at time t, number at the beginning of increase, intrinsic rate of increase, and the base of natural logarithms (= 2.71828), respectively. If population increase with discrete generations, as seen in many insects, is considered, equation 1 can be written as

(3)

or

(4)

the equation used by Knipling (1955), where lnR = r (Begon and Mortimer 1981).

In equations 1 and 3, the population size increases indefinitely, but the large N_t or N_g may result in a smaller rate of increase, due to density-dependency, and the population may reach an upper limit. The most widely used model of density-dependent population increase is the logistic model,

(5)

where h is the suppressive effect of existence of an individual on the intrinsic rate of increase. Here r/h is the upper limit of increase, and writing r/h = K,

(6)

or by integration,

(7)

where a is a constant.

To establish a population model of the melon fly Zeugodacus (formerly Bactrocera) cucurbitae (Coquillett) under control by the SIT, Itô (1977) used a discrete expression of equation 7 to calculate generation-based increase of a logistic population (Fujita and Utida 1953). We have the following relation from equation 7 of g generation: e^a—rg = (K/N ) — 1. By substituting this relation for equation 7 of (g + 1) generation, we obtain

(8)

where B = (e^r — 1)/K. In place of Itô’s procedure, we can use a logistic difference model, such as

(9)

where b and c are constants (Hassell 1975; Begon et al. 1996), in place of equation 4 for constant increase. Fig. 1 shows examples of Hale-Malthusian (dashed) and logistic increase of density (N_g).

2.2. Dynamics of Populations under Control by the SIT

In equations 8 or 9, the population size of the next generation can be expressed as

(10)

and when the SIT is applied

(11)

where H_g is the proportion of fertile (hatchable) eggs, and this value indicates the suppressive effect of sterile males on population increase. Thus, H_g is considered to be a function of the ratio of the number of sterile males, N_s, to fertile (normal) males, N_f in the field, that is,

(12)

Figure 1. Exponential (A) and sigmoidal (B) increase in the population. The equation giving a sigmoidal increase is the logistic model.

If the number of sterile males released in each generation is the same,

(12′)

how can f be determined? To establish a model of the SIT process for the melon fly on Kume Island, Okinawa, Itô (1977) adopted a Poisson distribution (mean number of matings = 1.61) for the frequency of matings per wild female. The probability that a female would mate with normal and/or sterile males was approximated by the binomial distribution. Based on this Poisson-binomial model, a curve showing the relationship between the expected hatchability of eggs and the N_s/N_f ratio was obtained (Fig. 2). The H_g values read from this graph are incorporated into equation 11 where R_g is derived from equation 8.

For the melon fly...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Preface
• Foreword
• Introductory Remarks
• Table of Contents
• Part II. Principles of the Sterile Insect Technique
• Part III. Technical Components of the Sterile Insect Technique
• Part IV. Supportive Technologies to Improve the Sterile Insect Technique
• Part V. Economic, Environmental, and Management Considerations
• Part VI. Application of the Sterile Insect Technique
• Part VII. Impact of Area-Wide Pest Management Programmes that Integrate the Sterile Insect Technique
• Part VIII. Future Development of the Sterile Insect Technique
• Author Index
• Subject Index