LIBRO-CONGRESO-CITRUS

S13
With abundant production worldwide, Citrus spp. rank among fruit crops with the highest commercial value.
Citrus spp. have the distinction of encompassing extensive basic research and validation studies aimed at
developing acceptable and efficacious Probit 9 quarantine mitigations, including fumigation, high-temperature
forced-air, vapor heat, cold, and irradiation treatments. We will review and discuss conventional Probit 9
treatment schedules and alternative risk-based (e.g., conditional non-host, less than Probit 9) mitigation
approaches in achieving quarantine security for fruit flies in citrus.
S13P01
The transcriptome and protein baits of Bactrocera dorsalis (Diptera: Tephritidae).
Zheng W., Zhang W., and Zhang H.
Huazhong Agricultural University (HZAU), College of Plant Science and Technology, China. hongyu.zhang@mail.hzau.edu.cn
Bactrocera dorsalis is a destructive polyphagous pest feeding on more than 250 fruits and vegetables. To
understand molecular mechanisms of B. dorsalis’s behavior, to finally effectively control it, its extensive
transcriptome was produced using the Roche 454-FLX platform, and a new bait based on protein X was
developed. We obtained over 350 million bases of cDNA derived from the whole body of B. dorsalis at
different developmental stages. In a single run, 747,206 sequencing reads with a mean read length of 382 bp
were obtained. These reads were assembled into 28,782 contigs and 169,966 singletons. The mean contig
size was of 750 bp. Additionally, we identified a great number of genes that are involved in reproduction
and development, as well as genes that represent nearly all major conserved metazoan signal transduction
pathways. Furthermore, transcriptome changes during development were analyzed. A new bait based on
protein X was developed. Among 12 proteins tested, protein X was most attractive to both females and males
of B. dorsalis. After a series of lab bioassays, a mixture of protein X, brown sugar and white vinegar was
chosen as the bait to be used in the field bioassays. Methyleugenol (ME) and a sugar/vinegar mixture were
designed as the two controls. The results suggested that the protein X bait had the highest attractant rate,
and the number of trapped flies (83.5 males and 61 females) by this bait was 4.1 and 9.2 times of that in the
control of ME (35.5 males and 0 females)and sugar/vinegar mixture (5.7 males and 10 females), respectively.
Acknowledgements: This work is supported by the earmarked fund for Modern Agro-industry Technology
Research System of China (No. CARS-27), and Special Fund for Agro-scientific Research in the Public Interest
(no. 200903047).
S13P02
The potential benefits of using engineered Medfly to improve the efficacy and to reduce the cost
of the Sterile Insect Technique: RIDL strain OX3864A
Slade G. 1 , Koukidou M. 1 , Leftwich P.T. 1 , Rempoulakis P. 1 , Economopoulos A. 2 , Vontas J. 2 , and Alphey L. 1
1 Oxitec Limited (Oxitec), United Kingdom; and 2 University of Crete (UOC), Department of Biology, Greece. glen.slade@oxitec.com
The Mediterranean fruit fly (Medfly, Ceratitis capitata Wiedemann) is the most destructive insect pest
worldwide, infesting over 300 types of fruits, vegetables and nuts. Current control measures include
insecticides, lures and the Sterile Insect Technique (SIT). Traditional SIT involves releasing large numbers of
laboratory-reared, radiation-sterilized males into infested areas where they mate with wild females who then
produce non-viable progeny. The efficacy of SIT depends upon factors including the overall fitness and mating
competitiveness of the insects; cost drivers include production methods and required release numbers.
The engineered Medfly strain OX3864A incorporates a repressible female-specific lethality system enabling
population suppression without the cost or fitness penalty of irradiation. The female-specific nature of the trait
enables simple production of male-only release cohorts, while its heritability means that a given suppression
level can be achieved with fewer insects, compared to conventional SIT. The strain also has heritable genetic
fluorescence, making field monitoring more reliable. Laboratory and field trials with OX3864A showed 100%
efficacy in separating sexes, mating competitiveness comparable to wild type and the ability to suppress and
then eradicate a stable wild-type Medfly population in less than three months. Hence OX3864A can improve
the efficacy and financial viability of using SIT to control field populations of Medfly.
224 - VALENCIA CONFERENCE CENTER, 18th-23rd NOVEMBER 2012