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Abstract The present study was conducted to investigate the array of hosts, distribution and to evaluate the toxicity of four insecticides: imidacloprid, fipronil, cypermethrin and chlorpyrifos alone and in combination against 3rd instar maggot and adult stage of fruit fly Bactrocera diversa Coquillett, 1904 (Diptera: Tephritidae) during 2021. B. diversa maggots were found vigorously feeding inside the cucurbit hosts (pumpkin, cucumber, bitter gourd, watermelon, round melon, bottle gourd) collected from different localities of Poonch division of Azad Jammu and Kashmir, Pakistan, and this species is reported for the first time as new record to this region. Susceptibilities of B. diversa to insecticides were evaluated using topical method. Mortality was checked after 3, 6, 8 and 24h of exposure. Cypermethrin was most effective to kill 50% of both larval and adult stage with least LC50 [7.2(1.040±0.214), 17.4(0.748±0.193)], respectively followed by imidacloprid. Imidacloprid most effectively killed 90% of both larval and adult population with least LC90 value [73.2 (3.013±0.708) 16.9 (1.886±0.437)] respectively after 24 hours. Cypermethrin with chlorpyrifos most effectively killed 50 and 90 percent of both larval and adult stage of B. diversa with least LC50 value [11.3 (1.085±0.245), 2.5 (0.759±0.252)] and least LC90 value [171.3 (1.085±0.245), 121.9 (0.759±0.252)], respectively after 24h of exposure. Toxicity of each insecticide increased with exposure for longer time and increased dose. Cypermethrin is suggested as most effective against both larval and adult stages of B. diversa in combination with chlorpyrifos followed by imidacloprid.

O presente estudo foi conduzido para investigar a variedade de hospedeiros, distribuição e avaliar a toxicidade de quatro inseticidas: imidaclopride, fipronil, cipermetrina e clorpirifós isoladamente e em combinação contra larva de 3º ínstar e estágio adulto da mosca-das-frutas Bactrocera diversa Coquillett, 1904 (Diptera: Tephritidae) durante 2021. Larvas de B. diversa foram encontradas se alimentando vigorosamente dentro dos hospedeiros de cucurbitáceas (abóbora, pepino, cabaça amarga, melancia, melão redondo, cabaça) coletados em diferentes localidades da divisão Poonch de Azad Jammu e Caxemira, Paquistão, e essa espécie é relatada pela primeira vez como novo registro para essa região. A suscetibilidade de B. diversa a inseticidas foi avaliada por método tópico. A mortalidade foi verificada após 3, 6, 8 e 24 horas de exposição. A cipermetrina foi mais eficaz para matar 50% do estágio larval e adulto com menos CL50 [7,2(1,040 ± 0,214), 17,4 (0,748±0,193)], respectivamente, seguido por imidaclopride. O imidaclopride matou mais efetivamente 90% da população larval e adulta com o menor valor de LC90 [73,2 (3,013 ± 0,708) 16,9 (1,886 ± 0,437)], respectivamente, após 24 horas. Cipermetrina com clorpirifós matou mais efetivamente 50% e 90% do estágio larval e adulto de B. diversa com valor mínimo de LC50 [11,3 (1,085 ± 0,245), 2,5 (0,759 ± 0,252)] e valor mínimo de LC90 [171,3 (1,085 ± 0,245), 121,9 (0,759 ± 0,252)], respectivamente, após 24 horas de exposição. A toxicidade de cada inseticida aumentou com a exposição por mais tempo e com o aumento da dose. A cipermetrina é sugerida como mais eficaz contra os estágios larval e adulto de B. diversa em combinação com clorpirifós seguido de imidaclopride.

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Bactrocera zonata (Saunders) as one of the most devastating species of the genus Bactrocera is a notorious polyphagous fruit fly pest attacking lots of commercially important host plant species in many parts of the world including Iran. Despite economic importance, the population genetics of B. zonata have remained relatively unexplored in the country. In this study, the genetic structure, genetic diversity, and demographic history of this pest in Iran were investigated on the basis of cytochrome oxidase c subunit 1 (COI) sequences. A total of 21 haplotypes were identified from 66 individuals collected from seven locations. Genetic diversity indices (number of haplotypes, haplotype diversity, and nucleotide diversity) revealed high genetic diversity without any isolation by distance among the geographic areas. An overall low level of genetic differentiation between populations revealed by genetic structure analysis reinforces the hypothesis of free movement of flies throughout the geographic areas. Non-significant correlation between genetic distances and geographic distances was an indication of a high level of gene flow among the studied populations of the pest. In addition, the recent population expansion following a recent past bottleneck could be a factor that might be contributed to the overall low level of the genetic structure. Mismatch distribution analysis as well as Tajima's D and Fu's FS tests strengthens the likelihood of a recent expanded population following a population bottleneck.

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Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) is an important pest of vegetables in Asia, the Middle East, Africa, and Hawaii. High temperature can significantly influence B. cucurbitae reproduction. The effect of short-term high-temperature exposure on proteins that affect oviposition was analyzed by proteomics. Among six key target genes for oviposition, the expression of Vitellogenin-1, Vitellogenin-2, and Vitellogenin receptor was similar in B. cucurbitae exposed to higher temperature compared to controls. However, levels of Vitellogenin-3 were reduced. Juvenile hormone (Jh)-inducible protein was downregulated and then upregulated, while the expression of Jh-epoxide hydrolase-2 showed the opposite Jh-inducible protein trend. Therefore, short-term high-temperature stress can cause differential expression of proteins related to oviposition in B. cucurbitae, which in turn further triggers the hormesis of oviposition. High-temperature conditions have become more frequent because of climate warming and are predicted to continue. The data indicate that climate effects on insect reproduction pose a significant threat to agriculture in a world of increasing population.

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Understanding spatio-temporal distribution of pest in orchards can provide important information that could be used to design monitoring schemes and establish better means for pest control. In this study, the spatial and temporal distribution of Bactrocera minax (Enderlein) (Diptera: Tephritidae) was assessed, and activity trends were evaluated by using probability kriging. Adults of B. minax were captured in two successive occurrences in a small-scale citrus orchard by using food bait traps, which were placed both inside and outside the orchard. The weekly spatial distribution of B. minax within the orchard and adjacent woods was examined using semivariogram parameters. The edge concentration was discovered during the most weeks in adult occurrence, and the population of the adults aggregated with high probability within a less-than-100-m-wide band on both of the sides of the orchard and the woods. The sequential probability kriged maps showed that the adults were estimated in the marginal zone with higher probability, especially in the early and peak stages. The feeding, ovipositing, and mating behaviors of B. minax are possible explanations for these spatio-temporal patterns. Therefore, spatial arrangement and distance to the forest edge of traps or spraying spot should be considered to enhance pest control on B. minax in small-scale orchards.

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The study of sexual behavior and the identification of the signals involved in mate recognition between con-specifics are key components that can shed some light, as part of an integrative taxonomic approach, in delimitating species within species complexes. In the Tephritidae family several species complexes have received particular attention as they include important agricultural pests such as the Ceratitis fasciventris (Bezzi), Ceratitis anonae (Graham) and Ceratitis rosa Karsch (FAR) complex, the Bactrocera dorsalis (Hendel) complex and the Anastrepha fraterculus (Wiedemann) complex. Here the value and usefulness of a methodology that uses walk-in field cages with host trees to assess, under semi-natural conditions, mating compatibility within these complexes is reviewed, and the same methodology to study the role of chemical communication in pre-mating isolation among Anastrepha fraterculus populations is used. Results showed that under the same experimental conditions it was possible to distinguish an entire range of different outcomes: from full mating compatibility among some populations to complete assortative mating among others. The effectiveness of the methodology in contributing to defining species limits was shown in two species complexes: Anastrepha fraterculus and Bactrocera dorsalis, and in the case of the latter the synonymization of several established species was published. We conclude that walk-in field cages constitute a powerful tool to measure mating compatibility, which is also useful to determine the role of chemical signals in species recognition. Overall, this experimental approach provides a good source of information about reproductive boundaries to delimit species. However, it needs to be applied as part of an integrative taxonomic approach that simultaneously assesses cytogenetic, molecular, physiological and morphological traits in order to reach more robust species delimitations.

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The melon fly, Bactrocera cucurbitae (Coquillett), and the pumpkin fly, Bactrocera tau (Walker), are economically important pests that attack mainly cucurbitacean fruits. The two fruit fly species have similar natural distributions, host ranges, and population growth capacities. This study was designed to assess the asymmetrical competitions through resource exploitation between the larvae of B. cucurbitae and B. tau at different density levels and temperatures, and on different hosts by comparing the relative effects of interspecific and intraspecific interactions on four life history parameters: survival rate, puparial mass, puparial duration, and developmental duration. Our results showed that intraspecific and interspecific competitions occurred under some laboratory conditions, and B. cucurbitae took advantage over B. tau at the high-density level and at low and high temperatures on pumpkin, bitter gourd, and bottle gourd when interspecific competition took place. Intraspecific and interspecific competitions mainly affected the puparial mass and the survival rate of the two fruit fly species but had no marked effect on the puparial duration or development duration.

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The use of irradiated hosts in mass rearing tephritid parasitoids represents an important technical advance in fruit fly augmentative biological control. Irradiation assures that fly emergence is avoided in non-parasitized hosts, while at the same time it has no appreciable effect on parasitoid quality, i.e., fecundity, longevity and flight capability. Parasitoids of fruit fly eggs, larvae and pupae have all been shown to successfully develop in irradiated hosts, allowing a broad range of species to be shipped and released without post-rearing delays waiting for fly emergence and costly procedures to separate flies and wasps. This facilitates the early, more effective and less damaging shipment of natural enemies within hosts and across quarantined borders. In addition, the survival and dispersal of released parasitoids can be monitored by placing irradiated sentinel-hosts in the field. The optimal radiation dosages for host-sterility and parasitoid-fitness differ among species, and considerable progress has been made in integrating radiation into a variety of rearing procedures.

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The peach fruit fly, Bactrocera zonata, is a significant pest of fruit and vegetable crops in South East Asia and Pacific region. Ccontrol strategies of fruit flies, relying chiefly on insecticides, have serious environmental consequences, disturbing the agro-ecosystem as well as eliminating natural enemies. This study was oriented at exploring the potential of turmeric, Curcuma longa, extracts to control the peach fruit fly. Freshly emerged female adults of Bactrocera zonata were continuously fed for 16 days on diet containing 1000, 500 and 250 ppm of acetone extract of Curcuma longa separately in laboratory cages. The extract caused 85.00, 66.67 and 56.67 percent mortality at 1000, 500 and 250 ppm respectively. The surviving females were mated and allowed to reproduce on clean guava fruits in separate cages. The inhibition in pupal progeny was 67.90, 60.74 and 51.96 percent in the flies fed on 1000, 500 and 250 ppm, the inhibition observed in adult progeny was 84.68, 79.03 and 67.74 percent, respectively.

A mosca do pêssego, Bactrocera zonata, é uma importante praga das frutas e produtos hortícolas no Sudeste Asiático e Pacífico. As estratégias de controle de moscas-das-frutas, que se baseia principalmente no uso de inseticidas, têm consequências ambientais graves, perturbando o agroecossistema, bem como eliminando os inimigos naturais. Este estudo foi orientado a explorar as potencialidades dos extratos de açafrão Curcuma longa para controle de B. zonata. Após a emergência, adultos de fêmeas de B. zonata foram continuamente alimentados, durante 16 dias, com dieta contendo 1000, 500 e 250 ppm de extrato acetônico de C. longa separadamente em gaiolas no laboratório. O extrato causou 85,00, 66,67 e 56,67 por cento de mortalidade em 1000, 500 e 250 ppm, respectivamente. As fêmeas foram acasaladas e postas para ovipositar separadamente em goiabas dentro das gaiolas. A inibição na progênie pupal foi 67,90, 60,74 e 51,96 por cento nos insetos alimentados em 1000, 500 e 250 ppm, a inibição observada na progênie adulta foi 84,68, 79,03 e 67,74 por cento, respectivamente.