Use of Symbiotic Bacteria to Reduce Mass-rearing Costs and Increase Mating Success in Selected Fruit Pests in Support of SIT Application

Closed for Proposals

Project Type

Coordinated Research Project

Project Code

D41024

CRP

1816

Approved Date

2011/03/14

Project Status

Closed

Start Date

2012/02/10

Expected End Date

2018/01/26

Completed Date

2018/01/26

Description

The sterile insect technique (SIT) is a sustainable and environment-friendly control method against some major pests of fruits and vegetables world wide. One of the main obstacles to the widespread implementation of the SIT is the cost relative to other, less sustainable alternatives. In recent years there has been a major paradigm shift in understanding the intimate relationship between microorganisms and their hosts, be they humans, animals or plants. Specifically, studies on insects have revealed seminal contributions of microorganisms to the nutrition, health and reproductive success of their hosts. ?Furthermore, there is evidence that during the mass-rearing and radiation processes, the native microflora of the insects is disrupted and its contribution to the host diminished. Accordingly, the objective of this CRP is to characterize the microorganisms associated with the major fruit pests targeted by the SIT and to harness these symbionts to decrease production costs and increase sterile insect quality.

Objectives

The objective of the project is to understand and harness the role that microorganisms play in the larval and adult biology of selected key fruit and vegetable pests to improve the SIT component as part of area-wide integrated pest management programmes applied against such pests.

Specific Objectives

To determine the effect of radiation on the symbiotic communities in target species.

To develop methods of using beneficial bacteria to replace costly ingredients in larval diets in SIT applications.

To explore the use of symbionts as probiotics provided to adult sterile males before their release to significantly improve sterile male performance.

To harness symbiotic microorganisms as reproductive manipulators and determine their ability to suppress target populations.

Impact

The systematic study of the symbionts associated with pest Tephritid species has resulted in several important breakthroughs:
1. The bacteria associated with most of the Tephritid pests have been identified for the first time.
2. The role of bacteria in mass rearing facilities has been elucidated for several key pest species.
3. The effect of sterilizing radiation on the microbiota of several mass reared species has been documented.
4. The use of symbionts as probiotic supplements to improve larval rearing and adult quality has been studied in several species of Anastrepha, Bactrocera, and Ceratitis capitata.
5. The utility of harnessing symbiotic associations towards the reproductive manipulation and suppression of target populations has been investigated. Specifically, the effect of Wolbachia infection on Ceratitis capitata has been studied, revealing the practical potential for introducing this bacterium into mass reared and wild populations.
6. An online portal has been established describing protocols and techniques for culture-dependent and independent approaches (PCR protocols, symbiont screening etc).
7. An online tool for calculating distribution of operational taxonomic units generated from new generation sequencing approaches has been developed (Rbplot).
8. Electronic version of a database of all microorganisms identified during the CRP has been established and is available online

Overall, the research performed under this CRP has resulted in 22 publications in peer reviewed publications, numerous presentations in international and national scientific meetings, and several theses written by undergraduate and graduate students. Outcomes from the CRP sponsored research are implemented in the major mass rearing facilities worldwide. Finally, the collaborative research undertaken has forged lasting interdisciplinary working groups, bridging basic and applied approaches, engaged in furthering the research initiated during the CRP.

Relevance

The CRP pioneered the study of symbiotic bacteria associated with pest Tephritids. The results of the research undertaken during the CRP have provided novel information regarding the symbiotic bacteria of Tephritid flies, and the role of these and other bacteria in the mass rearing facilities has been revealed and investigated. Furthermore the utility of providing bacteria as probiotic supplements has been examined critically, with specific recommendations tailored to the needs and constraints of the varied species targeted for SIT. Finally, introducing Wolbachia to mass rearing colonies has proven to be an additional strategy to be deployed against pest tephritids.

CRP Publications

Bangladesh/ IFRB, AERE, Bangladesh Atomic Energy Commission

Scientific Article

2014

Pramanik, K., A-Al-Mahin, Khan, M. & A.B. Miah. 2014. Isolation and identification of mid-gut bacterial community of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). Research Journal of Microbiology. 9(6):278-286