Explore the vast range of titles available.

Well-adapted and abundant insect pests can negatively affect agricultural production. We modeled the abundance of two Rhagoletis fly (Diptera: Tephritidae) pests, apple maggot fly, Rhagoletis pomonella (Walsh), and western cherry fruit fly, Rhagoletis indifferens Curran, in Washington State (WA), U.S.A. using biologically relevant environmental variables. We tested the hypothesis that abundance of the two species is influenced by different environmental variables, based on the fact that these two species evolved in different environments, have different host plants, and that R. pomonella is an introduced pest in WA while R. indifferens is native. We collected data on fly and host plant abundance at 61 randomly selected sites across WA in 2015 and 2016. We obtained land-cover, climate, and elevation data from online sources and used these data to derive relevant landscape variables and modeled fly abundance using generalized linear models. For R. pomonella, relatively high winter mean minimum temperature, low elevation, and developed land-cover were the top variables positively related to fly abundance. In contrast, for R. indifferens, the top variables related to greater fly abundance were high Hargreaves climatic moisture and annual heat-moisture deficits (indication of drier habitats), high host plant abundance, and developed land-cover. Our results identify key environmental variables driving Rhagoletis fly abundance in WA and can be used for understanding adaptation of insects to non-native and native habitats and for assisting fly quarantine and management decisions.

The gut microbiome of insects directly or indirectly affects the metabolism, immune status, sensory perception and feeding behavior of its host. Here, we examine the hypothesis that in the oriental fruit fly (Bactrocera dorsalis, Diptera: Tephritidae), the presence or absence of gut symbionts affects foraging behavior and nutrient ingestion. We offered protein-starved flies, symbiotic or aposymbiotic, a choice between diets containing all amino acids or only the non-essential ones. The different diets were presented in a foraging arena as drops that varied in their size and density, creating an imbalanced foraging environment. Suppressing the microbiome resulted in significant changes of the foraging behavior of both male and female flies. Aposymbiotic flies responded faster to the diets offered in experimental arenas, spent more time feeding, ingested more drops of food, and were constrained to feed on time-consuming patches (containing small drops of food), when these offered the full complement of amino acids. We discuss these results in the context of previous studies on the effect of the gut microbiome on host behavior, and suggest that these be extended to the life history dimension.

Oviposition holds crucial significance for insect reproduction. Nevertheless, the research on the neural conduction mechanism of oviposition is still rather limited in most agricultural pests. Here, we demonstrate that the conserved Kainate receptors (KARs) expressed in the glutamatergic neurons (GNs) and the ovipositor neuromuscular junctions (NMJs) regulate the oviposition behavior in Bactrocera dorsalis . We identified two KARs (Grik2b and Grik2c), which control the oviposition behavior by influencing both oviposition preference and egg-laying quantity. Protein-ligand interaction indicated that glutamate serves as the neurotransmitter of Grik2b and Grik2c. Knockdown glutamate-coding genes adversely impacted oviposition preference and egg-laying quantity. Specific knockdown Grik2b (or Grik2c) in the GNs and NMJs could respectively influence oviposition preference and egg-laying quantity. Finally, inhibitors of KARs were screened for their ability to inhibit oviposition. Our study provides strong supporting evidence that a novel neural conduction mechanism for oviposition by uncovering the diverse roles of KARs and provides potential molecular target controlling insect oviposition.

The oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae), is a widespread pest in Bangladesh. Sterile Insect Technique (SIT) offers a solution for effectively suppressing this fruit fly species. However, SIT involves mass rearing of fruit fly species in a laboratory where a standardized artificial rearing diet is crucial for ensuring uniform growth, development, and reproduction. In this study, we assessed efficacy of a new formulated gel-based meridic larval diet as well as protein and carbohydrate rich adult diets for the rearing of B. dorsalis in laboratory conditions. Proximate analysis was conducted for our formulated rearing diets to determine the content of moisture, protein, fat, carbohydrate, and ash. For our formulated diets, several key biological parameters, including egg hatching rate, pupation rate, pupal weight, adult emergence, adult growth, sex ratio, and flight capacity, were assessed. Statistical analysis using Tukey box plots revealed a significant improvement for the laboratory reared body parameters of adults while maintained in meridic diets, as compared to their wild counterparts. Adults fruit flies reared on our formulated meridic adult diets exhibited sufficient longevity, especially when compared to those provided with only water. In addition, our study presents survival analysis using non-parametric Kaplan–Meier estimator and Weibull parametric model. Our findings indicate that the formulated diets presented in this study can be effectively incorporated into B. dorsalis laboratory mass-rearing, meeting the required standard quality parameters outlined in the FAO/IAEA/USDA mass-rearing guideline of tephritid fruit flies.

Fruit flies belonging to Tephritidae family are highly destructive agricultural pests, posing a significant threat to various fruits and vegetables grown in Bangladesh. A comprehensive year-round survey was conducted at Atomic Energy Research Establishment (AERE) campus located in the central region of Bangladesh. Three types of male lures (methyl eugenol, cue-lure and zingerone) were used to detect and assess the diversity of pest fruit fly species. A total of seventeen species of Tephritidae fruit flies were detected in this survey. The Bactrocera carambolae fruit fly has been discovered for the first time in our survey area, indicating spread of its range towards the north-west region from its previous detection sites (Chattogram and Sylhet Divisions) in Bangladesh. Among the detected pest species, we identified six abundant species: Bactrocera dorsalis , Zeugodacus cucurbitae , Zeugodacus tau , Bactrocera rubigina , Bactrocera zonata , and Dacus longicornis . The most abundant species was the polyphagous fruit pest B. dorsalis , comprising 76.83% of the total captured flies. The species Z. cucurbitae was the second most abundant, representing 13.82% of the total trapped flies. The fitted curve to survey data using Gaussian mixture model revealed the existence of overlapped subgroups in the temporal population distribution of B. dorsalis and Z. cucurbitae . In addition, our statistical analysis of the six abundant Tephritidae fruit fly species revealed correlation of population dynamics with several factors including temperature, rainfall, humidity, photoperiod, and fruiting time of host plant species in the selected area.

Since 1954, when the first tropical tephritid fruit fly was detected in California, a total of 17 species in four genera and 11 386 individuals (adults/larvae) have been detected in the state at more than 3348 locations in 330 cities. We conclude from spatial mapping analyses of historical capture patterns and modelling that, despite the 250+ emergency eradication projects that have been directed against these pests by state and federal agencies, a minimum of five and as many as nine or more tephritid species are established and widespread, including the Mediterranean, Mexican and oriental fruit flies, and possibly the peach, guava and melon fruit flies. We outline and discuss the evidence for our conclusions, with particular attention to the incremental, chronic and insidious nature of the invasion, which involves ultra-small, barely detectable populations. We finish by considering the implications of our results for invasion biology and for science-based invasion policy.

Bactrocera tau (Walker) (Diptera: Tephritidae) is an economically important invasive pest, that is capable of seriously reducing the quality and yield of vegetables and fruits, it was first recorded from Fujian province in 1849 and later introduced to Yunnan province in 1912 as a result in trade fruits and vegetables of China. In recent years, with the onset of global climate change and the accompanying increase in the greenhouse effect, elevated climatic temperatures have become one of the main environmental factors affecting growth and reproduction in insects, and the optimal developmental temperature of B. tau was found to be from 25 °C to 31 °C, the growth, development and reproduction of B. tau are normal under the optimal temperature conditions. In order to determine the repercussions that elevated temperature have on B. tau , we assessed the effects that short-term (12 h) high-temperature exposures (34 °C, 36 °C, 38 °C, 40 °C, 42 °C, 44 °C, 46 °C, and 48 °C) had on the growth, development and reproduction of B. tau at different developmental stages of the fly. The results showed that the survival rate of B. tau gradually decreased in all stages following exposure to short-term high-temperatures. The pupal stage was the least sensitive to increased temperatures. The pupae withstood the highest lethal temperature, having an LT 50 of 42.060 °C, followed by female adults (40.447 °C), male adults (40.013 °C), and larvae (36.740 °C). The egg stage, which was the most susceptible to heat increases, had the lowest LT 50 (38.310 °C). No significant effects were observed in the developmental stages of B. tau at temperatures from 24 °C to 38 °C. The development duration was significantly prolonged at 40 °C ( P  < 0.05) in the eggs (2.830d), larvae (7.330d), and pupae (8.170d) ( P  < 0.05). B. tau was unable to survive at temperatures above 42 °C. The pre-oviposition of female adults was extended, the average egg number per female showed a downward trend, the longevity of adults gradually shortened, and the ratio of female to male offspring increased as temperature increments were increased. In summary, short-term high-temperatures over 42 °C were not suitable for successful development of B. tau , while short-term high-temperatures over 40 °C were not suitable for successful reproduction in B. tau .

Insect mitogenome organisation is highly conserved, yet, some insects, especially with parasitic life cycles, have rearranged mitogenomes. Furthermore, intraspecific mitochondrial diversity can be reduced by fitness-affecting bacterial endosymbionts like Wolbachia due to their maternal coinheritance with mitochondria. We have sequenced mitogenomes of the Wolbachia-infected endoparasitoid Dipterophagus daci (Strepsiptera: Halictophagidae) and four of its 22 known tephritid fruit fly host species using total genomic extracts of parasitised flies collected across > 700 km in Australia. This halictophagid mitogenome revealed extensive rearrangements relative to the four fly mitogenomes which exhibited the ancestral insect mitogenome pattern. Compared to the only four available other strepsipteran mitogenomes, the D. daci mitogenome had additional transpositions of one rRNA and two tRNA genes, and a single nucleotide frameshift deletion in nad5 requiring translational frameshifting or, alternatively, resulting in a large protein truncation. Dipterophagus daci displays an almost completely endoparasitic life cycle when compared to Strepsiptera that have maintained the ancestral state of free-living adults. Our results support the hypothesis that the transition to extreme endoparasitism evolved together with increased levels of mitogenome changes. Furthermore, intraspecific mitogenome diversity was substantially smaller in D. daci than the parasitised flies suggesting Wolbachia reduced mitochondrial diversity because of a role in D. daci fitness.

Fruit volatiles play a crucial role in the host localization by the oriental fruit fly, Bactrocera dorsalis Hendel (Diptera:Tephritidae).This study focused on identifying the fruit volatiles from Sanyue plum and Sanhua plum (Prunus salicina Lindl.), which are 2 varieties of the same species, and examined their impact on the behavior of B. dorsalis by using aY-olfactometer. A total of 35 and 54 volatiles from Sanyue plum and Sanhua plum were identified, respectively. Among these, 23 volatiles elicited electroantennographic (EAG) responses by B. dorsalis adults, showing concentration-dependent effects in males and females. Ethyl butyrate, butyl acetate, butyl hexanoate, ethyl caproate, ethyl hexanoate, and hexyl acetate significantly attracted B. dorsalis compared to liquid paraffin, while nonaldehyde was avoided.There was no significant difference in the behavioral responses of both sexes to sorbitol esters, hexyl isobutyrate, and 1-tetradecene compared with the control liquid paraffin group. Interestingly, (3Z)-C-3-hexenyl acetate significantly attracted females, but not males.The above findings suggest that plum fruit volatiles are likely to facilitate the localization of host fruit by B. dorsalis adults and may even aid in mate-finding. This study opens up new avenues for exploring novel plant-based attractants that might be of value for the integrated management of B. dorsalis.

Climate change affects the distribution of insects, such as pests and parasitoids. Species Distribution Models (SDMs) have been developed to determine distribution patterns and risk areas for pests and biological control agents under different climate change scenarios. The South American fruit fly, Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae), is an important pest of cultivated fruits throughout the Americas that can be controlled by natural enemies, such as the native parasitoid Doryctobracon areolatus (Szépligeti) (Hymenoptera: Braconidae) and the introduced parasitoid Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae). However, the control efficacy and parasitism performance of these organisms could be affected by changing environmental conditions. SDMs were conducted using Random Forest to predict suitable areas for the establishment of A . fraterculus , D. areolatus , and D. longicaudata under different climate scenarios or Representative Concentration Pathways (SSPs) (SSP 2–4.5 and 5–8.8) in two different periods (2021–2040 and 2041–2060). Our results predicted an increase in suitable areas for A. fraterculus in the Americas, especially in some South American countries such as Colombia and Brazil. Moreover, the projected distribution of these species is intricately linked to the regional climatic patterns. Temperate and tropical areas were more suitable for the establishment of A. fraterculus ; D. areolatus was better suited to temperate climates; while tropical climates were more suitable for D. longicaudata. Suitable areas for the establishment of both parasitoid species were predicted to increase in future climate scenarios, with D. longicaudata having a greater geographical expansion than D. areolatus. These parasitoids could be used as biocontrol agents in almost all areas suitable for the establishment of A. fraterculus .