Potential of a fly gut microbiota incorporated gel-based larval diet for rearing Bactrocera dorsalis (Hendel)

Mahfuza Khan,Md Anwar Hossain,Shakil Ahmed Khan,Md Abdul Bari,Kajla Seheli,Khandokar Fahmida Sultana,Nahida Sultana

doi:10.1186/s12896-019-0580-0

Abstract

BackgroundThe Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is an important polyphagous pest of horticultural produce. The sterile insect technique (SIT) is a proven control method against many insect pests, including fruit flies, under area-wide pest management programs. High quality mass-rearing process and the cost-effective production of sterile target species are important for SIT. Irradiation is reported to cause severe damage to the symbiotic community structure in the mid gut of fruit fly species, impairing SIT success. However, studies have found that target-specific manipulation of insect gut bacteria can positively impact the overall fitness of SIT-specific insects.ResultsTwelve bacterial genera were isolated and identified from B. dorsalis eggs, third instars larval gut and adults gut. The bacterial genera were Acinetobacter, Alcaligenes, Citrobacter, Pseudomonas, Proteus, and Stenotrophomonas, belonging to the Enterobacteriaceae family. Larval diet enrichment with the selected bacterial isolate, Proteus sp. was found to improve adult emergence, percentage of male, and survival under stress. However, no significant changes were recorded in B. dorsalis egg hatching, pupal yield, pupal weight, duration of the larval stage, or flight ability.ConclusionsThese findings support the hypothesis that gut bacterial isolates can be used in conjunction with SIT. The newly developed gel-based larval diet incorporated with Proteus sp. isolates can be used for large-scale mass rearing of B. dorsalis in the SIT program.

Highlights

The Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is an important polyphagous pest of horticultural produce
Several gut bacteria have shown to act as lures [10] which may potentially be used as biocontrol agents [11, 12]
Abundant symbiotic communities in the digestive tract have been reported in fruit flies including Ceratitis capitata (Widemann) [6, 7], Bactrocera oleae (Gemlin) [4, 14, 15], Bactrocera tau (Walker) [16, 17], Zeugodacus (Bactrocera) cucurbitae (Coq.) [18], Bactrocera carambolae (Drew &Hancock) [19], Bactrocera cacuminata (Hering) Bactrocera tryoni (Froggatt) [20], the apple maggot fly, Rhagoletis pomonella (Walsh) [9], and the Mexican fruit fly, Anastrepha ludens (Loew) [21]

Summary

Introduction

The Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is an important polyphagous pest of horticultural produce. Irradiation is reported to cause severe damage to the symbiotic community structure in the mid gut of fruit fly species, impairing SIT success. Studies have found that target-specific manipulation of insect gut bacteria can positively impact the overall fitness of SIT-specific insects. The insect gut contains an array of microorganisms that influence its fitness [1, 2]. Such microbial partners contribute to host metabolism [3, 4], facilitate nutrient uptake [5], prolong host lifespan [6], strengthen mating competitiveness [7], defend against natural enemies [8], and help detoxify diets [9]. To characterize the gut symbiotic community structure of Tephritidae species, both culturedependent and culture-independent approaches have been used, in the med fly, which revealed a symbiotic bacterial community of different Enterobacteriaceae species from the genera Klebsiella, Enterobacter, Providencia, Pectobacterium, Pantoea, Morganella and Citrobacter [4, 22,23,24,25]

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