Genomes of the cosmopolitan fruit pest Bactrocera dorsalis (Diptera: Tephritidae) reveal its global invasion history and thermal adaptation.

INTRODUCTION: The oriental fruit fly Bactrocera dorsalis is one of the most destructive agricultural pests worldwide, with highly debated species delimitation, origin, and global spread routes. OBJECTIVES: Our study intended to (i) resolve the taxonomic uncertainties between B. dorsalis and B. carambolae, (ii) reveal the population structure and global invasion routes of B. dorsalis across Asia, Africa, and Oceania, and (iii) identify genomic regions that are responsible for the thermal adaptation of B. dorsalis. METHODS: Based on a high-quality chromosome-level reference genome assembly, we explored the population relationship using a genome-scale single nucleotide polymorphism dataset generated from the resequencing data of 487 B. dorsalis genomes and 25 B. carambolae genomes. Genome-wide association studies and silencing using RNA interference were used to identify and verify the candidate genes associated with extreme thermal stress. RESULTS: We showed that B. dorsalis originates from the Southern India region with three independent invasion and spread routes worldwide: (i) from Northern India to Northern Southeast Asia, then to Southern Southeast Asia; (ii) from Northern India to Northern Southeast Asian, then to China and Hawaii; and (iii) from Southern India toward the African mainland, then to Madagascar, which is mainly facilitated by human activities including trade and immigration. Twenty-seven genes were identified by a genome-wide association study to be associated with 11 temperature bioclimatic variables. The Cyp6a9 gene may enhance the thermal adaptation of B. dorsalis and thus boost its invasion, which tended to be upregulated at a hardening temperature of 38 °C. Functional verification using RNA interference silencing against Cyp6a9, led to the specific decrease in Cyp6a9 expression, reducing the survival rate of dsRNA-feeding larvae exposed to extreme thermal stress of 45 °C after heat hardening treatments in B. dorsalis. CONCLUSION: This study provides insights into the evolutionary history and genetic basis of temperature adaptation in B. dorsalis.

Characterization of Urinary Pesticide Metabolite Concentrations of Pregnant Women in Suriname.

Prenatal exposure to pesticides and the association with adverse health outcomes have been examined in several studies. However, the characterization of pesticide exposure among Surinamese women during pregnancy has not been assessed. As part of the Caribbean Consortium of Research in Environmental and Occupational Health research program, 214 urine samples were collected from pregnant women living in three regions in Suriname with different agricultural practices: capital Paramaribo, the rice producing district Nickerie, and the tropical rainforest, the Interior. We used isotope dilution tandem mass spectrometry to quantify urinary concentrations of biomarkers of three pesticide classes, including phenoxy acid herbicides and organophosphate and pyrethroid insecticides, all of which are commonly used in agricultural and residential settings in Suriname. We observed that participants residing in Nickerie had the highest urinary metabolite concentrations of 2,4-dichlorophenoxyacetic acid and pyrethroids compared to those from Paramaribo or the Interior. Paramaribo had the highest concentrations of organophosphate metabolites, specifically dialkyl phosphate metabolites. Para-nitrophenol was detected in samples from Paramaribo and the Interior. Samples from Nickerie had higher median urinary pesticide concentrations of 2,4-dichlorophenoxyacetic acid (1.06 µg/L), and the following metabolites, 3,5,6-trichloro-2-pyridinol (1.26 µg/L), 2-isopropyl-4-methyl-6-hydroxypyrimidine (0.60 µg/L), and 3-phenoxybenzoic acid (1.34 µg/L), possibly due to residential use and heavy rice production.

Exceptional larval morphology of nine species of the Anastrephamucronota species group (Diptera, Tephritidae).

Anastrepha is the most diverse and economically important genus of Tephritidae in the American tropics and subtropics. The striking morphology of the third instars of Anastrephacaballeroi Norrbom, Anastrephacrebra Stone, Anastrephahaplacantha Norrbom & Korytkowski, Anastrephakorytkowskii Norrbom, Anastrephanolazcoae Norrbom & Korytkowski, and three newly discovered and as yet formally unnamed species (Anastrepha sp. Peru-82, Anastrephasp.nr.protuberans, and Anastrepha sp. Sur-16), and the more typical morphology of Anastrephaaphelocentema Stone, are described using light and scanning electron microscopy. To contribute to a better understanding of the interspecific and intraspecific variation among species in the mucronota species group and facilitate phylogenetic studies, we integrate molecular and morphological techniques to confirm the identity and describe third instars. Larva-adult associations and the identification of described larvae were confirmed using DNA barcodes. We provide diagnostic characters to distinguish larvae among these nine species of the mucronota group and separate them from those of the 29 other Anastrepha species previously described. We introduce the vertical comb-like processes on the oral margin as a novel character, and the unusual character states, including position and shape of the preoral lobe, and dentate or fringed posterior margins of the oral ridges and accessory plates. Our comparative morphology concurs with most previously inferred phylogenetic relationships within the mucronota group.

New species and host plants of Anastrepha (Diptera: Tephritidae) primarily from Suriname and Par, Brazil.

Seventeen new species of Anastrepha, primarily from Suriname, French Guiana and Par, Brazil, are described and illustrated: A. aithogaster Norrbom from Brazil (Par), French Guiana, and Suriname; A. aliesae Norrbom from Suriname; A. brownsbergiensis Norrbom from Suriname; A. crassaculeus Norrbom Rodriguez Clavijo from Colombia (Magdalena, Norte de Santander) and Suriname; A. curvivenis Norrbom from Brazil (Amazonas), Ecuador (Zamora-Chinchipe), Peru (San Martn), and Suriname; A. fuscoalata Norrbom from Brazil (Par), French Guiana, and Suriname; A. gangadini Norrbom from Suriname; A. juxtalanceola Norrbom from Brazil (Par) and Suriname; A. microstrepha Norrbom from Brazil (Bahia) and Suriname; A. mitaraka Norrbom from French Guiana; A. neptis Norrbom from Brazil (Par), Ecuador (Orellana), Peru (Loreto) and Suriname; A. sobrina Norrbom from Brazil (Par), French Guiana, and Suriname; A. surinamensis Norrbom from Suriname; A. tenebrosa Norrbom from Brazil (Par) and Peru (Loreto); A. triangularis Norrbom from Suriname; A. wachiperi Norrbom from French Guiana and Peru (Cusco); and A. wittiensis Norrbom from Suriname. The following host plant records are reported: A. aithogaster from fruit of Parahancornia fasciculata (Poir.) Benoist (Apocynaceae); A. aliesae from fruit of Passiflora coccinea Aubl. and P. glandulosa Cav. (Passifloraceae); A. crassaculeus from fruit of an undetermined species of Pouteria (Sapotaceae); A. fuscoalata from fruit of Trymatococcus oligandrus (Benoist) Lanj. (Moraceae); A. sobrina from fruit of Eugenia lambertiana DC. (Myrtaceae); and A. wittiensis from fruit of Manilkara bidentata (A. DC.) A. Chev. (Sapotaceae).

Τhe Complete Mitochondrial Genome of Bactrocera carambolae (Diptera: Tephritidae): Genome Description and Phylogenetic Implications.

Bactrocera carambolae is one of the approximately 100 sibling species of the Bactrocera dorsalis complex and considered to be very closely related to B. dorsalis. Due to their high morphological similarity and overlapping distribution, as well as to their economic impact and quarantine status, the development of reliable markers for species delimitation between the two taxa is of great importance. Here we present the complete mitochondrial genome of B. carambolae sourced from its native range in Malaysia and its invaded territory in Suriname. The mitogenome of B. carambolae presents the typical organization of an insect mitochondrion. Comparisons of the analyzed B. carambolae sequences to all available complete mitochondrial sequences of B. dorsalis revealed several species-specific polymorphic sites. Phylogenetic analysis based on Bactrocera mitogenomes supports that B. carambolae is a differentiated taxon though closely related to B. dorsalis. The present complete mitochondrial sequences of B. carambolae could be used, in the frame of Integrative Taxonomy, for species discrimination and resolution of the phylogenetic relationships within this taxonomically challenging complex, which would facilitate the application of species-specific population suppression strategies, such as the sterile insect technique.

Analysis of Pesticides and Toxic Heavy Metals Contained in Mosquito Coils.

In this study, 10 mosquito coils manufactured in China were obtained in Suriname, South America, where they are used extensively. The coils were analyzed for organics (allethrin, permethrin, and butylated hydroxytoluene) and heavy metals (Cr, Co, As, Cd, and Pb) by GC-MS and ICP-MS, respectively. Allethrin was the only target organic compound detected in all mosquito coils with concentrations ranging from ~1900 to ~4500 µg/g. The concentrations of heavy metals varied as follows (in µg/g): Cr: 2.9-9.4, Co: 0.1-1.2, Cu: 0.7-16.1, Se: 0.10-0.4, Ni: 2.1-5.8, As: 0.10-2.2, Cd: 0.10-0.2, and Pb: 1.1-3.6.

Host plants of the carambola fruit fly, Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae), in Suriname, South America

Fruits were collected over a 12-year period to determine the host status for the Carambola fruit fly, Bactrocera carambolae Drew & Hancock, and other tephritid species in Suriname, South America. Over 11,000 fruit samples were collected from many locations and the total of 20 fruit species were recorded as host, ranging in infestation from heavy to occasional. Over 650 samples of 188 fruit species, including many wild species, were collected and no fruit flies were reared. This work, which started specifically to obtain information on the Carambola fruit fly, resulted also in detailed information regarding the importance, distribution and host preferences of several Anastrepha species, and the status of fruit fly parasitoids.

Durante um periodo de 12 anos foram coletados frutos para determinar as plantas hospedeiras da mosca-da-carambola, Bactrocera carambolae Drew & Hancock, e outras espécies de tefrítidos que ocorrem no Suriname, América do Sul. Mais de 11.000 amostras de frutos foram coletadas de diversas localidades e somaram o total de 20 espécies de frutos tidos como hospedeiros, classificados como infestação entre forte e até ocasional. Mais de 650 amostras de 188 espécies de frutos, incluindo várias espécies selvagens, foram coletadas porém não foram encontradas as moscas nas frutas. Este trabalho, que começou especificamente para obter informações sobre a mosca-da-carambola, resultou também em informações sobre a importância, distribuição e preferência de diferentes espécies de Anastrepha para as plantas hospedeiras e a importância de parasitóides de moscas-das-frutas.