Genetic elimination of field-cage populations of Mediterranean fruit flies.

Aris Economopoulos,Antigoni Zacharopoulou,Martha Koukidou,Luke Alphey,John Vontas,Guoliang Fu,Tracey Chapman,Polychronis Rempoulakis,Hong-Fei Gong,Philip T Leftwich

doi:10.1098/rspb.2014.1372

Abstract

The Mediterranean fruit fly (medfly, Ceratitis capitata Wiedemann) is a pest of over 300 fruits, vegetables and nuts. The sterile insect technique (SIT) is a control measure used to reduce the reproductive potential of populations through the mass release of sterilized male insects that mate with wild females. However, SIT flies can display poor field performance, due to the effects of mass-rearing and of the irradiation process used for sterilization. The development of female-lethal RIDL (release of insects carrying a dominant lethal) strains for medfly can overcome many of the problems of SIT associated with irradiation. Here, we present life-history characterizations for two medfly RIDL strains, OX3864A and OX3647Q. Our results show (i) full functionality of RIDL, (ii) equivalency of RIDL and wild-type strains for life-history characteristics, and (iii) a high level of sexual competitiveness against both wild-type and wild-derived males. We also present the first proof-of-principle experiment on the use of RIDL to eliminate medfly populations. Weekly releases of OX3864A males into stable populations of wild-type medfly caused a successive decline in numbers, leading to eradication. The results show that genetic control can provide an effective alternative to SIT for the control of pest insects.

Highlights

The Mediterranean fruit fly is a globally distributed agricultural pest, infesting over 300 types of cultivated and wild fruits, vegetables and nuts—the widest known host range of any pest fruit fly [1]
Stable populations of wt medfly were established in four large field cages with two cages chosen at random to be ‘treatment’ cages into which, in addition to the normal number of pupae added to the cages, approximately 1500 Release of insects carrying a dominant lethal (RIDL) males per week were released
We investigated the OX3864A and OX3647Q homozygous fsRIDL lines of the medfly

Summary

Introduction

The Mediterranean fruit fly (medfly, Ceratitis capitata Wiedemann) is a globally distributed agricultural pest, infesting over 300 types of cultivated and wild fruits, vegetables and nuts—the widest known host range of any pest fruit fly [1]. Stable populations of wt medfly were established in four large field cages with two cages chosen at random to be ‘treatment’ cages into which, in addition to the normal number of pupae added to the cages, approximately 1500 RIDL males per week were released. This protocol was based on that of Valdez et al [30]. The Cox’s Proportional Hazards model was run in R [44], all other tests were performed using SPSSv14 (SPSS Inc., Chicago, IL, USA)

Results

Findings

Discussion