EFFECTIVENESS OF CYROMAZINE APPLICATION AND PARASITOIDS RELEASE FOR CONTROLLING AGAINST LEAFMINER FLY Liriomyza huidobrensis (BLANCHARD) (DIPTERA: AGROMYZIDAE)

Liriomyza huidobrensis is an invasive pest for various crops. Till now, the management of this pest is by the only use of pesticides which hence increased its resistance and decrease of its natural enemies. The objective of the study was to assess the effectiveness of cyromazine and parasitoids for reducing the population of leafminer fl y (L. huidobrensis) and to analyse the economic impact of the different treatments. The study was conducted in the Sirukem village, Kalibening sub district, Banjarnegara district, Central Java from July to November 2009. To address the objective, four treatment strategies were applied: no treatment, cyromazine, parasitoid release and cyromazine-parasitoid, and observa-tion of damage intensity, sampling of infested leaves, assessment of yield and an economic analysis were undertaken. The results found that cyromazine and parasitoids were effective to control against infestation of Liriomyza. Cyromazine was also harmless for parasitoids. The dominant parasitoid found were Opius chromatomyiae and Hemiptarsenus varicorni which preferred to parasitize the larvae of L.huidobrensis on Vicia faba than on Solanum tuberosum

Parasitoid serangga pengorok daun Liriomyza: intensitas parasitisasi, perubahan sebaran dan komposisinya

Serangga invasif lalat pengorok daun merupakan hama penting berbagai tanaman sayuran. Serangga ini berasosiasi dengan berbagai musuh alami sebagai agen pengendali populasinya. Penelitian ini bertujuan mengetahui potensi, perubahan sebaran dan komposisinya. Komposisi dan populasi musuh alami diamati dengan metode sampling daun yang terserang. Di masing-masing titik sampling, koleksi daun yang terserang dilakukan pada semua jenis tanaman dan gulma. Parasitoid serangga pengorok daun Liriomyza lebih menyukai untuk memarasit inang yang menyerang tanaman kacang buncis (50%), ceisin (55%), kentang (57%), kacang babi (70%), dan kacang merah (75%). Intensitas parasitoid meningkat (10,4% - 74,5%) menurut ketinggian tempatnya mulai dari 200 – 2200 m dpl. Sebaran dan komposisi parasitoid berubah dimana Opius chromatomyiae ditemukan di dataran rendah dan lebih dominan dibanding Hemiptarsenus varicornis. Opius chromatomyiae di dataran rendah mempunyai ukuran toraks yang lebih keci

Variation in Morphological Characters of Two Invasive Leafminers, Liriomyza huidobrensis and L. sativae, across a Tropical Elevation Gradient

Changes in morphological traits along elevation and latitudinal gradients in ectotherms are often interpreted in terms of the temperature-size rule, which states that the body size of organisms increases under low temperatures, and is therefore expected to increase with elevation and latitude. However other factors like host plant might contribute to spatial patterns in size as well, particularly for polyphagous insects. Here elevation patterns for trait size and shape in two leafminer species are examined, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) and L. sativae Blanchard, along a tropical elevation gradient in Java, Indonesia. Adult leafminers were trapped from different locations in the mountainous area of Dieng in the province of Central Java. To separate environmental versus genetic effects, L. huidobrensis originating from 1378 m and 2129 m ASL were reared in the laboratory for five generations. Size variation along the elevation gradient was only found in L. huidobrensis and this followed expectations based on the temperature-size rule. There were also complex changes in wing shape along the gradient. Morphological differences were influenced by genetic and environmental effects. Findings are discussed within the context of adaptation to different elevations in the two species

Lessons from the Mass Production of Wolbachia-infected Aedes aegypti for Egg Release in the Sleman and Bantul Districts of Yogyakarta

An efficacy study on wMel Wolbachia-infected Aedes aegypti technology conducted by the World Mosquito Program (WMP) Yogyakarta showed the reducing of dengue incidence in Yogyakarta City. Following this successful result, the intervention was scaled up into two neighbouring districts: Sleman and Bantul. This paper describes our experience in mass production for providing release material for a larger area to reach the deployment target, which includes insectary requirements, mass production protocols, and diagnostic screening. This review may serve as a reference guidance for national mass production for wMel Wolbachia-infected Ae. aegypti. 

Update to the AWED (Applying Wolbachia to Eliminate Dengue) trial study protocol: a cluster randomised controlled trial in Yogyakarta, Indonesia.

BACKGROUND: The AWED (Applying Wolbachia to Eliminate Dengue) trial is a parallel, two-arm, non-blinded cluster randomised controlled trial that is under way in Yogyakarta, Indonesia, with the aim of measuring the efficacy of Wolbachia-infected Aedes aegypti deployments in reducing dengue incidence in an endemic setting. Enrolment began in January 2018 and is ongoing. The original study protocol was published in April 2018. Here, we describe amendments that have been made to the study protocol since commencement of the trial. METHODS: The key protocol amendments are (1) a revised study duration with planned end of participant enrolment in August 2020, (2) the addition of new secondary objectives (i) to estimate serotype-specific efficacy of the Wolbachia intervention and (ii) to compare Ae. aegypti abundance in intervention versus untreated clusters, (3) an additional exposure classification for the per-protocol analysis where the Wolbachia exposure index is calculated using only the cluster-level Wolbachia prevalence in the participant's cluster of residence, (4) power re-estimation using a multinomial sampling method that better accounts for randomness in sampling, and (5) the addition of two trial stopping rules to address the potential for persistently low rates of virologically confirmed dengue case enrolment and Wolbachia contamination into untreated clusters. Additional minor changes to the protocol are also described. DISCUSSION: The findings from this study will provide the first experimental evidence for the efficacy of Wolbachia in reducing dengue incidence. Enrolment in the trial will conclude this year (2020) and results will be reported shortly thereafter. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT03055585. Registered on 14 February 2017. Last updated 22 March 2020

HUBUNGAN ANTARA KONDISI CUACA DENGAN DINAMIKA POPULASI NYAMUK DI KOTA YOGYAKARTA

Dinamika populasi nyamuk merupakan faktor penting untuk menentukan kejadian penyakit tular vektor. Penyakit tular vektor masih menjadi masalah kesehatan di Yogyakarta, namun belum ada kajian mengenai nyamuk vektor secara komprehensif. Analisis lingkungan terutama dari faktor temperatur udara dan curah hujan diperlukan dalam kajian monitoring nyamuk. Penelitian ini bertujuan untuk mendapatkan data primer dinamika populasi nyamuk di wilayah Kota Yogyakarta selama satu tahun (April 2015-Juli 2016). Pengumpulan sampel nyamuk dilakukan seminggu sekali dengan Biogents Sentinel trap (BG-S trap) yang dipasang di dalam rumah warga Kota Yogyakarta setiap jarak 500 m2. Data curah hujan dan temperatur udara diperoleh dari Badan Meteorologi Klimatologi dan Geofisika (BMKG) Yogyakarta. Analisis data menggunakan One Way-Anova SPSS 16 dan analisis regresi linear. Berdasarkan hasil penga-matan selama setahun menunjukkan bahwa populasi nyamuk didominasi oleh dua spesies, yaitu Aedes aegypti (L.) dan Culex quinquefasciatus (Say). Peningkatan populasi Ae. aegypti dan Ae. albopictus terjadi pada bulan November-Desember 2015 saat curah hujan dan temperatur tertinggi, berkebalikan dengan Cx. quiquefasciatus. Pengaruh faktor cuaca seperti temperatur serta curah hujan berkorelasi positif dengan populasi Ae. aegypti dan Ae. albopictus, namun berkorelasi negatif dengan populasi Cx. quinquefasciatus

The AWED trial (Applying Wolbachia to Eliminate Dengue) to assess the efficacy of Wolbachia-infected mosquito deployments to reduce dengue incidence in Yogyakarta, Indonesia: study protocol for a cluster randomised controlled trial.

BACKGROUND: Dengue and other arboviruses transmitted by Aedes aegypti mosquitoes, including Zika and chikungunya, present an increasing public health challenge in tropical regions. Current vector control strategies have failed to curb disease transmission, but continue to be employed despite the absence of robust evidence for their effectiveness or optimal implementation. The World Mosquito Program has developed a novel approach to arbovirus control using Ae. aegypti stably transfected with Wolbachia bacterium, with a significantly reduced ability to transmit dengue, Zika and chikungunya in laboratory experiments. Modelling predicts this will translate to local elimination of dengue in most epidemiological settings. This study protocol describes the first trial to measure the efficacy of Wolbachia in reducing dengue virus transmission in the field. METHODS/DESIGN: The study is a parallel, two-arm, non-blinded cluster randomised controlled trial conducted in a single site in Yogyakarta, Indonesia. The aim is to determine whether large-scale deployment of Wolbachia-infected Ae. aegypti mosquitoes leads to a measurable reduction in dengue incidence in treated versus untreated areas. The primary endpoint is symptomatic, virologically confirmed dengue virus infection of any severity. The 26 km2 study area was subdivided into 24 contiguous clusters, allocated randomly 1:1 to receive Wolbachia deployments or no intervention. We use a novel epidemiological study design, the cluster-randomised test-negative design trial, in which dengue cases and arbovirus-negative controls are sampled concurrently from among febrile patients presenting to a network of primary care clinics, with case or control status classified retrospectively based on the results of laboratory diagnostic testing. Efficacy is estimated from the odds ratio of Wolbachia exposure distribution (probability of living in a Wolbachia-treated area) among virologically confirmed dengue cases compared to test-negative controls. A secondary per-protocol analysis allows for individual Wolbachia exposure levels to be assessed to account for movements outside the cluster and the heterogeneity in local Wolbachia prevalence among treated clusters. DISCUSSION: The findings from this study will provide the first experimental evidence for the efficacy of Wolbachia in reducing dengue incidence. Together with observational evidence that is accumulating from pragmatic deployments of Wolbachia in other field sites, this will provide valuable data to estimate the effectiveness of this novel approach to arbovirus control, inform future cost-effectiveness estimates, and guide plans for large-scale deployments in other endemic settings. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT03055585 . Registered on 14 February 2017

Kajian aspek keamanan nyamuk Aedes aegypti Linnaeus ber-Wolbachia di Yogyakarta, Indonesia

Dengue prevention efforts are limited to the control strategies of its vector and the management of breeding sites. New alternatives for dengue vector control that are sustainable and more environmentally friendly are needed to complement the government’s current efforts. Research on Wolbachia-infected Aedes aegypti Linnaeus mosquitoes as an alternative biocontrol strategy has been performed in Yogyakarta City. However, one of the concerns of the community members and stakeholders about this technology is the safety aspect regarding the transmission of Wolbachia to other species and the possibility that humans will contract Wolbachia. This study aimed to address these concerns, namely to find out whether horizontal transmission of Wolbachia occurred from A. aegypti that were released to other species and whether residents living in the released areas were infected with Wolbachia. The research was conducted in Dusun Nogotirto and Dusun Kronggahan (Sleman Regency), as well as in Dusun Jomblangan and Dusun Singosaren (Bantul Regency), Yogyakarta Special Province. Wolbachia qPCR screening using the target gene WD0513 was performed on 922 Culex quinquefasciatus Say and 331 Aedes albopictus (Skuse). ELISA test was carried out on 190 pairs of plasma samples, namely the sample before the Wolbachia frequency was established (still 80%). The results showed no evidence of Wolbachia transfer from Wolbachia-infected A. aegypti to other mosquito species coexisting in the same habitat or to humans. This study corroborates the safety evidence of Wolbachia-infected A. aegypti technology as an alternative to control dengue virus transmissio

Efficacy of Wolbachia-Infected Mosquito Deployments for the Control of Dengue.

BACKGROUND: Aedes aegypti mosquitoes infected with the wMel strain of Wolbachia pipientis are less susceptible than wild-type A. aegypti to dengue virus infection. METHODS: We conducted a cluster-randomized trial involving releases of wMel-infected A. aegypti mosquitoes for the control of dengue in Yogyakarta, Indonesia. We randomly assigned 12 geographic clusters to receive deployments of wMel-infected A. aegypti (intervention clusters) and 12 clusters to receive no deployments (control clusters). All clusters practiced local mosquito-control measures as usual. A test-negative design was used to assess the efficacy of the intervention. Patients with acute undifferentiated fever who presented to local primary care clinics and were 3 to 45 years of age were recruited. Laboratory testing was used to identify participants who had virologically confirmed dengue (VCD) and those who were test-negative controls. The primary end point was symptomatic VCD of any severity caused by any dengue virus serotype. RESULTS: After successful introgression of wMel into the intervention clusters, 8144 participants were enrolled; 3721 lived in intervention clusters, and 4423 lived in control clusters. In the intention-to-treat analysis, VCD occurred in 67 of 2905 participants (2.3%) in the intervention clusters and in 318 of 3401 (9.4%) in the control clusters (aggregate odds ratio for VCD, 0.23; 95% confidence interval [CI], 0.15 to 0.35; P = 0.004). The protective efficacy of the intervention was 77.1% (95% CI, 65.3 to 84.9) and was similar against the four dengue virus serotypes. The incidence of hospitalization for VCD was lower among participants who lived in intervention clusters (13 of 2905 participants [0.4%]) than among those who lived in control clusters (102 of 3401 [3.0%]) (protective efficacy, 86.2%; 95% CI, 66.2 to 94.3). CONCLUSIONS: Introgression of wMel into A. aegypti populations was effective in reducing the incidence of symptomatic dengue and resulted in fewer hospitalizations for dengue among the participants. (Funded by the Tahija Foundation and others; AWED ClinicalTrials.gov number, NCT03055585; Indonesia Registry number, INA-A7OB6TW.)