Anastrepha Fraterculus Research Articles

Native parasitoids (Hymenoptera: Braconidae) of fruit flies (Diptera: Tephritidae) in Serra da Bodoquena National Park-MS, Brazil

Abstract: Fruit flies are among the main groups of phytophagous insects. Their larvae, when feeding on the pulp or seeds of the host fruits, can cause rot and favor the entrance of pathogens. Thus, the objectives of this study was: (1) To know the trophic associations between species of parasitoids and fruit flies in the Parque Nacional da Serra da Bodoquena (PNSB)-MS, Brazil. (2) To inventory the parasitoid species associated with fruit flies in fruit trees in the Parque Nacional da Serra da Bodoquena. Monthly expeditions were carried out (From Jan 2017 to Feb 2018) in order to collect the fruits and obtain the fruit flies (Tephritidae) and their respective parasitoids. The collected fruits were transported to the laboratory of frugivorous insects (LIF) of the Universidade Federal da Grande Dourados (UFGD)-MS. The fruit fly larvae were daily collected and placed in transparent acrylic cups containing sterilized sand, where they remained till the emergence of adults and their parasitoids. Twenty-Three adult Tephritid parasitoids were recovered, represented by two species of Braconidae: Doryctobracon areolatus (18) and Utetes anastrephae (5), both infesting Anastrepha species: Anastrepha fraterculus, A. sororcula and A. striata in Myrtaceae: Psidium guajava and Eugenia myrcianthes. Doryctobracon areolatus and Utetes anastrephae are reported for the first time parasiting Anastrepha species in Eugenia myrcianthes.

Rearing two fruit flies pests on artificial diet with variable pH.

Fruit flies (Diptera: Tephritidae) are considered the main fruit pests worldwide. In Brazil, two species are predominant: the South American fruit fly, Anastrepha fraterculus and the Mediterranean fruit fly, Ceratitis capitata. In this study, we evaluated the effect of artificial diets with variable pH in their larval development and adult performance. The experiments were carried out in the laboratory at 25 ± 2 °C, 70 ± 10% RH and 12:12h (L:D) photoperiod. Semisolid diets with pH values of 6.0, 5.0, 4.0, 3.0, 2.0, 1.5, and 1.0, adjusted by adding hydrochloric acid were tested. Results indicated that the diet with pH 6.0 did not support larval development of both species of fruit fly. Diets with greater acidic pH values did not allow egg, larvae or pupae development and adult reproduction of A. fraterculus. For C. capitata , the pH of artificial diet exerts greater influence compared to A. fraterculus on the duration and viability of the larval stage, number of pupae, sex ratio and longevity of males.

Does Diachasmimorpha longicaudata (Hymenoptera: Braconidae) have a preferential instar to parasitize Tephritidae (Diptera)?

ABSTRACT Diachasmimorpha longicaudata (Ashmead, 1905) is a koinobiont parasitoid of Tephritidae larvae, the third instar larvae of which is considered preferential, but it is able to parasitize other larval stages and compete with native parasitoids. This study investigated the preference and parasitism capacity of D. longicaudata in larvae of different instar of Anastrepha fraterculus (Wiedemann, 1830) (AF) and Ceratitis capitata (Wiedemann, 1824) (CC). The experiments were carried out under laboratory conditions, one instar being offered at a time in parasitism units, with the following choices among the hosts: 25 AF larvae and 25 CC larvae (first, second and third instar were evaluated). The other test was a multiple-choice in relation to the instar, for larvae of the same host species, with three parasitism units being offered, with 15 larvae of each instar. The mean number of formed pupae, emerged parasitoids, parasitized pupae, unviable pupae and sex ratio were evaluated. In the first bioassay, the mean number of emerged parasitoids and parasitized pupae in the AF host were significantly higher in treatments with first and second instar larvae. For CC there was no difference between the instars tested. In the second bioassay, the mean value of emerged parasitoids and parasitized pupae, was higher in second and third instar larvae for CC, and for AF was in second instar larvae. The sex ratio was biased for males in all treatments in both bioassays. The results show that D. longicaudata can parasitize and be successful in all available larval instars, being able to compete with parasitoids of any instar.

Can stable isotope markers be used to distinguish wild and mass-reared Anastrepha fraterculus flies?

The availability of accurate techniques to discriminate between marked laboratory-reared flies and unmarked wild flies captured in monitoring traps is essential for programs that integrate the Sterile Insect Technique (SIT) to manage fruit flies. In this study, the feasibility of using a stable isotope marking technique for the South American fruit fly, Anastrepha fraterculus (Wiedemann), was assessed. Wild flies were collected from apple orchards, which are a target of a SIT project in southern Brazil. To verify if adult flies could be labelled by the stable isotopes from larval diets, larvae were reared on two different C4-based diets and fruits in laboratory. To evaluate the influence of the two most common attractants applied to capture A. fraterculus (grape juice and CeraTrapTM) and the most common preservation method in fruit fly collections (ethanol), laboratory-reared flies were immersed in McPhail traps containing the respective treatments for two periods of time. Samples were analyzed in an elemental analyzer coupled to a Continuous Flow Isotope Ratio Mass Spectrometer (CF-IRMS) at CENA/USP. The δ13C signatures of flies reared on artificial diets differed significantly from the δ13C of flies whose larvae were reared on fruits and from wild flies. In contrast, the δ15N values were less conclusive and the technique could not rely solely on them. In all cases considered, the δ13C and δ15N signatures from males did not differ from females. Despite the alterations caused by the attractants tested and ethanol, laboratory-flies could be distinguished from the wild ones based on δ13C signatures. This is the first comprehensive study to demonstrate that it is possible to distinguish wild A. fraterculus from flies reared on larval diets containing C4 sugar. The first experimentally derived trophic discrimination factors were also obtained for this species. Thus, intrinsic isotope labelling can serve as a backup to conventional dye marking.

Understanding the dynamics underpinning the geographical distribution of the Anastrepha fraterculus complex in eastern Brazil

Understanding the dynamics underpinning the geographical distribution of the Anastrepha fraterculus complex in eastern Brazil

Response of two parasitoid species (Hymenoptera: Braconidae, Figitidae) to tephritid host and host food substrate cues

AbstractThe Neotropical‐native figitid Aganaspis pelleranoi (Brèthes) and the Asian braconid Diachasmimorpha longicaudata (Ashmead) are two parasitoids of Tephritidae fruit flies with long and recent, respectively, evolutionary histories in the Neotropics. Both species experienced a recent range of overlap. In Argentina, A. pelleranoi is a potential species in biological control programs against the pestiferous tephritid species, Anastrepha fraterculus (Wiedemann) and Ceratitis capitata (Wiedemann), whereas D. longicaudata is already used in open‐field releases against Medfly in central‐western Argentina. To characterize the host‐foraging strategies of A. pelleranoi and D. longicaudata, olfactometer experiments were conducted comparing responses to C. capitata and A. fraterculus larvae, in two kinds of food substrate: fruit and artificial larval medium. To control the possible influence of host larvae used for parasitoid rearing on olfactory response, two strains of both parasitoid species, reared on both tephrtid species, were studied. Volatiles directly emanating either from A. fraterculus or C. capitata larvae may be detected by both A. pelleranoi and D. longicaudata, although chemical stimuli originating from the combination of host larvae and the habitat of the host were preferred. However, olfactory cues associated with host larvae probably play a relevant role in host searching behaviour of A. pelleranoi, whereas for D. longicaudata, the host‐habitat olfactory stimuli would be highly essential in short‐range host location. The strain of the parasitoids did not affect host search ability on the two tephritid species evaluated. These evidences are relevant for mass production of both parasitoids and their impact following open‐field augmentative releases.

Dynamics of soluble sugars and secondary metabolites in fruit of Juglans australis attacked by Anastrepha fraterculus and Ceratitis capitata (Diptera: Tephritidae)

The development and fitness of phytophagous insects are tightly linked to the nutritional quality of their host plants and many studies have examined the influence of primary and secondary metabolites of plants and their effects on the development of insects. Herbivore tactics to modify plant metabolic pathways to lower host toxicity need to be better understood as they are critical to a better understanding of herbivore–host plant relationships. To contribute to this end, in this study we analyzed temporal patterns of glucose, sucrose, fructose, and total soluble sugar contents, as well as tannins, phenols, and flavonoids in the mesocarp of fruit of native walnut (Juglans australis), uninfested and infested by Anastrepha fraterculus and Ceratitis capitata (sometimes simultaneously in a single fruit). Both fly species are polyphagous tephritids whose larvae feed on a wide variety of hosts. We observed a high correlation between infestation and adult emergence of these two insects which was positive in the case of sugar content and negative in the case of toxic secondary metabolites in fruit. At particular ripening stages, infested fruit contained higher levels of sugars and lower levels of phenols and tannins than non-infested fruit. We discuss the possibility that A. fraterculus and C. capitata, each with different egg-laying strategies, may modify metabolical pathways in the fruit for their own benefit through larval activity with the help of bacteria in their gut. Alternatively, the patterns observed may be simple side effects of larval feeding and associated growth of opportunistic microorganisms.

Effects of kaolin and limestone on infestation of South American fruit fly in citrus orchards

ABSTRACTThis study evaluated the effects of applying mineral films on infestations by Anastrepha fraterculus (Wied.) (Dip.: Tephritidae) in Céu and Valencia sweet oranges (Citrus sinensis). The treatments consisted of either kaolin or liquid limestone (calcium carbonate) at 20% concentrations, both with addition of 0.1% Break Thru® adhesive spreader, plus a control treatment (no applications). The spraying was performed in the Céu orchard in Pareci Novo, state of Rio Grande do Sul (RS), Brazil, from March to April 2015, and in the Valencia orchard in Taquari, RS, from May to August 2015. Each tree received 1.5 L of the respective formulations, applied by spraying. Fruits from the canopy and from the ground under each tree were harvested and arranged in containers with sand and stored in a chamber or a greenhouse for 30 days. The sand was then sieved and the fruits opened to remove the larvae and/or pupae. The physical-chemical attributes of the fruits harvested at the last sampling (during fruit harvest) were analysed. In both orchards, fruits collected from the canopy had similar numbers of pupae + larvae per canopy for kaolin and calcium carbonate treatments, and both were lower than in the control treatment. The fruits showed no physiological changes resulting from the treatments.

Evidence for Introgression Among Three Species of the Anastrepha fraterculus Group, a Radiating Species Complex of Fruit Flies.

Introgression should no longer be considered as rare a phenomenon as once thought, since several studies have recently documented gene flow between closely related and radiating species. Here, we investigated evolutionary relationships among three closely related species of fruit flies of the Anastrepha fraterculus group (Anastrepha fraterculus, A. obliqua and A. sororcula). We sequenced a set of 20 genes and implemented a combined populational and phylogenetic inference with a model selection approach by an ABC framework in order to elucidate the demographic history of these species. The phylogenetic histories inferred from most genes showed a great deal of discordance and substantial shared polymorphic variation. The analysis of several population and speciation models reveal that this shared variation is better explained by introgression rather than convergence by parallel mutation or incomplete lineage sorting. Our results consistently showed these species evolving under an isolation with migration model experiencing a continuous and asymmetrical pattern of gene flow involving all species pairs, even though still showed a more closely related relationship between A. fraterculus and A. sororcula when compared with A. obliqua. This suggests that these species have been exchanging genes since they split from their common ancestor ∼2.6 MYA ago. We also found strong evidence for recent population expansion that appears to be consequence of anthropic activities affecting host crops of fruit flies. These findings point that the introgression here found may have been driven by genetic drift and not necessary by selection, which has implications for tracking and managing fruit flies.

Courtship in Two Morphotypes of the Anastrepha fraterculus (Diptera: Tephritidae) Cryptic Species Complex and their Implications for Understanding Mate Recognition

Ritualized courtship behaviors are used to recognize potential mates and behavioral patterns are inevitably different among populations that demonstrate reproductive incompatibility. We characterized and compared the courtship behaviors of two morphotypes of the cryptic species complex Anastrepha fraterculus: Brazil-1 morphotype and Brazil-3 morphotype. Courtship behaviors were filmed to analyze the behavioral sequences of these two morphotypes during homotypic crossings. The behavioral units Alignment (AL) and Abdominal movements (AB and AB-call) were newly recognized in the courtship ethogram of Anastrepha fraterculus males. The two morphotypes show distinct behavioral sequences leading up to copulation. Some behaviors were repeated frequently during the courtship process, while others were more restricted to the final moments of courtship. The three behavioral units that contributed most to copulation success were Contact, Alignment, and Arrowhead 1 in the Brazil-1 morphotype and Alignment, Arrowhead 1, and Fanning in the Brazil-3 morphotype. Some behavioral routines differed across the two morphotypes. Significant differences were also noted between the frequencies of the behavioral units displayed during courtship in the two morphotypes. The relationships between the pre-zygotic incompatibilities of the Brazil-1 and Brazil-3 morphotypes and the differences between the courtship behaviors of their males are discussed. Our results indicate that behavioral isolation is involved in the process of pre-zygotic reproductive isolation of Brazil-1 and Brazil-3 morphotypes.

Fruit fly (Diptera: Tephritidae) assemblage in a feijoa orchard in Santa Catarina State, Brazil

Fruit flies cause economically important damage on several cultivated and native South American fruit trees. Hence, it is important to understand the population dynamics of these insects. This study aimed to characterize the assemblage and population fluctuations of fruit flies in a feijoa (Acca sellowiana) orchard in Lages, Santa Catarina State, Brazil from September 2009 to May 2012. Captures of flies were made with McPhail traps baited with hydrolyzed protein. Evaluations and bait change were performed weekly. A total of 2,197 flies were captured (957 males and 1,240 females). Analysis of abundance, constancy, dominancy and frequency showed that Anastrepha fraterculus was the main species captured; it was considered to be very frequent, constant and highly dominant throughout the study period. The orchard presented low equitability, low diversity, and high dominance of A. fraterculus during the three fruit seasons evaluated. No correlation was found between climatic factors and population levels of A. fraterculus.

Optimization of the sterilizing doses and overflooding ratios for the South American fruit fly.

The Sterile Insect Technique (SIT) is an autocidal control method that relies on inundative releases of sterilized mass-reared insects. This technology has been used in several area-wide programmes for the suppression/eradication of fruit fly populations. Choosing the optimum sterilizing dose and the sterile release density is an essential step of the SIT. Considering unsolved issues related to the application of this technique against Anastrepha fraterculus (Wiedemann), this study aimed to define accurately the central target dose for both sexes of this species and to verify the induction of sterility in fertile flies at different sterile:fertile ratios. The results from the regression analyses proved that the sterilization process for the A. fraterculus Brazilian-1 morphotype (the most common in southern Brazil and Argentina) could consist of irradiating pupae 72 h before adult emergence at 40 Gy, with no detrimental effects to standard quality control parameters. The ovarian development in irradiated females was characterized, demonstrating that doses equal to or higher than 25 Gy cause complete and irreversible ovarian atrophy. The laboratory and field cage tests showed that the sterility induction increased with the proportion of sterile flies, and a sterile:fertile ratio of 50:1 should be appropriate in SIT field trials. The sterile females apparently did not distract the sterile males, despite of the slightly higher reductions in pupal yield for all ratios in their absence. The data generated in this study have a great practical value and will help decision-makers in planning field trials to evaluate the efficacy of the SIT against A. fraterculus populations.

Phenotypic Structure of Colombian Populations ofAnastrepha fraterculusComplex (Diptera: Tephritidae)

Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) is one of the principal quarantine pests in Colombian fruit production. Studies have shown that the nominal species is a complex of cryptic species and that the more common biological entity that exists in Colombia, the “Andean morphotype,” is a species, different from others on the continent. The bioecological information available for this morphotype is scarce, yet it is essential for establishing integrated pest management programs and for defining the insect's quarantine status. Knowledge of the pest's population structure, whether biological, genetic or morphological, is a valuable tool in making management decisions. The goal of this study was to gain information on the phenotypic structure of the Colombian populations of this species complex through the morphometric study of the eggs, larvae, and adults. Populations of A. fraterculus s.l. from 2 fruit species widely known as hosts for this insect (coffee, Coffea arabica L. [Rubiaceae], at medium altitudes; feijoa, Acca sellowiana (O. Berg) [Myrtaceae]) at high altitudes) were collected at 9 Colombian localities from the south of the country (Narino) to the northeast (Santander). Adults were obtained from the collected fruits, which were then used to rear insects in feijoa fruits. Significant variables were selected using a discriminant analysis, and the differences between the populations were analyzed using a multivariate analysis of variance. The variability of each significant variable was studied with a Kruskal-Wallis nonparametric analysis. The morphological variables studied were 21 for adult females, 7 for adult males, 24 for third-instar larvae, and 2 for the eggs. Intraspecific variability was found in the Colombian populations of the A. fraterculus Andean morphotype. In populations from higher altitudes, the adults and larvae are larger, whereas the eggs are smaller, compared to populations from lower altitudes. Variability might have a genetic component and be due to the limited movement of the individuals, which may favor the application of management activities in selected areas.

Spatial and temporal dispersal patterns of Diachasmimorpha longicaudata (Hymenoptera: Braconidae) reared on Ceratitis capitata and Anastrepha fraterculus (Diptera: Tephritidae)

The dispersal and parasitism abilities of Diachasmimorpha longicaudata, reared on the larval hosts Ceratitis capitata and Anastrepha fraterculus, were evaluated in a guava orchard. Eleven releases of approximately 3000 parasitoids were conducted in a 15-ha orchard and wasp dispersal was monitored from 6 to 272 m away from a central release point. At each monitoring point, larvae of C. capitata and A. fraterculus were offered as hosts for the parasitoids. In five releases, parasitoids were offered only one host species, and in six releases, they were given a choice. In total, 10,351 parasitoids were recovered from these hosts, all of which were D. longicaudata. Both parasitoid strains dispersed in all directions, but showed a slight bias towards the east. Both strains of the parasitoid survived and parasitized larvae of A. fraterculus and C. capitata for up to 15 days after release, with maximum activity during the first 7 days, but more individuals of the Anastrepha strain were recovered after 15 days. Although the highest rates of parasitism by both wasp strains occurred close to the release point, the Anastrepha strain parasitized more hosts at greater distances from the release point, whereas the Ceratitis strain parasitized more hosts close to release points. Releases of the Anastrepha strain of D. longicaudata are therefore recommended, as this strain yields high rates of parasitism further away from release points and appears to survive longer in the field.

Strategies for Establishing a Rearing Technique for the Fruit Fly Parasitoid: Doryctobracon brasiliensis (Hymenoptera: Braconidae).

Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) is the most important pest in South American orchards. When control measures are not adopted, this pest can cause losses of up to 100%. Doryctobracon brasiliensis (Szépligeti) (Hymenoptera: Braconidae) is a larval-pupal endoparasitoid that can be used as a native biological control agent against A. fraterculus. This study aimed to develop a rearing technique for D. brasiliensis in larvae of A. fraterculus. Trials were carried out to: 1) determine the optimal instar for parasitism, 2) define the exposure time of larvae to parasitoids, 3) determine the density requirements of A. fraterculus larvae offered to each parasitoid, and 4) evaluate the effect of diet on adults of D. brasiliensis. In all trials, we evaluated the number of offspring, parasitism rate, and sex ratio. Moreover, in the experiment to investigate the effects of diet, we determined the longevity of males and females. In both choice and nonchoice parasitism tests, the parasitoids preferred third-instar larvae of A. fraterculus over second- and first-instar larvae. An exposure time of 12 h of A. fraterculus larvae produced larger numbers of parasitoids and higher parasitism rates. The density of 15 larvae of A. fraterculus to each female of D. brasiliensis produced a larger number of offspring. A supply of honey solution (20 and 50%) to the parasitoids yielded the highest number offspring and resulted in greater longevity. Our findings can be used to support the development of a mass rearing protocol for D. brasiliensis.

Coexistence between two fruit fly species is supported by the different strength of intra‐ and interspecific competition

1. Unravelling the strength and modes of interspecific interactions between resident and introduced species is necessary in order to understand the basis of their coexistence or the displacement of the former by the latter. In Argentina, the indigenous Tephritidae fly Anastrepha fraterculus overlaps its distribution and host fruit with the introduced species Ceratitis capitata.2. This study focused on the relative strength of intra‐ and interspecific competition during the larval stage as a potential factor supporting coexistence. Classical competition experiments (addition and substitution) were conducted between larvae of the two species reared in artificial larval diet. The study evaluated whether a temporal separation between oviposition events affects the outcome of the competition.3. When both species started to consume the resource at the same time, A. fraterculus experienced a negative effect in larval survival, pupal weight and duration of larval stage, while for C. capitata, pupal weight decreased. When A. fraterculus started feeding 1 day earlier than C. capitata, the negative effects became milder, and when the temporal separation increased, these effects were reversed. Substitution experiments showed an increase in pupal weight when larvae had to share the resource with heterospecific larvae, and showed negative effects suffered for both species when they shared the resource with conspecific individuals.4. These results suggest that intraspecific competition is stronger than interspecific competition, and a differential oviposition preference could generate an asynchrony of these species in nature. Such mechanisms could favour coexistence between A. fraterculus and C. capitata in an environment previously occupied only by the former.

Toxicity and residual effects of toxic baits with spinosyns on the South American fruit fly

Abstract: The objective of this work was to assess the lethal concentration and lethal time (LC and LT) of spinosad and spinetoram, combined with different food lures, and their residual effects on South American fruit fly (Anastrepha fraterculus). The toxic baits were offered in eight concentrations (2, 6, 14, 35, 84, 204, 495, and 1,200 mg L-1), combined with the following food lures: 7% sugarcane molasses, 3% Biofruit, 1.5% CeraTrap, 1.25% Flyral, 3% Samaritá Bait, and 3% Samaritá Tradicional; diluted food lures in water were used as controls. The residual effect of the formulations at 96 mg L-1 concentration were evaluated for 21 days and were compared with that of the commercial bait Success 0.02 CB. Both insecticides were toxic to adults of A. fraterculus, and mortality varied with the food lure used. The LC50and LT50ranged from 15.19 to 318.86 mg L-1and from 11.43 to 85.93 hours, respectively. Spinosad was 2 to 36 times as toxic as spinetoram when combined with different hydrolyzed proteins. Toxic baits formulated with spinosad and spinetoram (96 mg L-1) caused mortality equivalent to the one by Success 0.02 CB (90.2%), when assessed on the day of application. Toxic baits formulated with 3% Biofruit + spinosad and 3% Samaritá Bait + spinetoram are effective for managingA. fraterculusand provide up to seven days of residual effect in the absence of rain; however, only Success 0.02 CB caused more than 80% mortality for up to 21 days.

Biological Activity of Bacillus thuringiensis (Bacillales: Bacillaceae) in Anastrepha fraterculus (Diptera: Tephritidae).

Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) is considered to be one of the major pest insects in fruit orchards worldwide. Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) strains are widely used as biological control agents and show high biological activity against different insect species. The objective of this study was to evaluate the biological activity of different strains of B. thuringiensis against A. fraterculus larvae and adults. Bioassays were performed using suspensions of bacterial spores/crystals of B. thuringiensis var. israelensis (Bti), kurstaki (Btk), and oswaldocruzi (Bto) strains at three concentrations [2 × 107, 2 × 108, and 2 × 109 colony-forming units per ml (CFU ml-1)]. At a concentration of 2 × 109 CFU ml-1, a significant larval effect (mortality 60%) was observed when compared with the control treatment. Larvae that ingested spore/crystal suspensions of Bti, Btk, or Bto bacterial strains exhibited significant larval and pupal deformations, leading to a significant decrease (~50%) in the completion of the insects' biological cycle (egg to adult). The B. thuringiensis strains (Bti, Btk, or Bto) at a concentration of 2 × 109 CFU ml-1 in combination with one food attractant (BioAnastrepha 3% or CeraTrap 1.5%) in formulations of toxic baits provided high mortality (mortality > 85%) of A. fraterculus adults 7 d after treatment. However, the Btk strain in combination with CeraTrap 1.5% caused mortality of 40%. On the basis of these results, the native bacterial strains Bti, Btk, and Bto were considered to be promising candidates as biological control agents against A. fraterculus.

Evidence of Adaptive Evolution and Relaxed Constraints in Sex-Biased Genes of South American and West Indies Fruit Flies (Diptera: Tephritidae).

Several studies have demonstrated that genes differentially expressed between sexes (sex-biased genes) tend to evolve faster than unbiased genes, particularly in males. The reason for this accelerated evolution is not clear, but several explanations have involved adaptive and nonadaptive mechanisms. Furthermore, the differences of sex-biased expression patterns of closely related species are also little explored out of Drosophila. To address the evolutionary processes involved with sex-biased expression in species with incipient differentiation, we analyzed male and female transcriptomes of Anastrepha fraterculus and Anastrepha obliqua, a pair of species that have diverged recently, likely in the presence of gene flow. Using these data, we inferred differentiation indexes and evolutionary rates and tested for signals of selection in thousands of genes expressed in head and reproductive transcriptomes from both species. Our results indicate that sex-biased and reproductive-biased genes evolve faster than unbiased genes in both species, which is due to both adaptive pressure and relaxed constraints. Furthermore, among male-biased genes evolving under positive selection, we identified some related to sexual functions such as courtship behavior and fertility. These findings suggest that sex-biased genes may have played important roles in the establishment of reproductive isolation between these species, due to a combination of selection and drift, and unveil a plethora of genetic markers useful for more studies in these species and their differentiation.

Effect of food lures for monitoring of Anastrepha fraterculus (Diptera: Tephritidae) in Acca sellowiana (Myrtaceae)

The South American fruit fly, Anastrepha fraterculus (Diptera: Tephritidae) stands out for its polyphagous habit of damaging the production of several fruits in southern Brazil. This study aimed to evaluate the capture efficiency of A. fraterculus using grape juice at different periods of decomposition and aging as well as to test the capture efficiency of the enzymatic hydrolyzed protein Cera Trap® in feijoa crops. The work was conducted in a commercial feijoa orchard in São Joaquim, SC, Brazil during the 2014 growing season. Undiluted Cera Trap®, fresh grape juice and grape juice that had aged for 7 and 14 days were evaluated. All of the treatments with grape juice were used at the recommended concentration of 25 %. McPhail traps were used with 300 mL for each lure. On a weekly basis, the number of adults and the percentage of female fruit flies captured were evaluated, using identification and counting. Cera Trap® was the lure that captured the highest number of fruit flies, with a high percentage of females and with a higher frequency of captures during the season. Cera Trap® also showed the highest number of action thresholds compared to grape juice treatments. The 25 % fresh and aged grape juice showed a low number of captures and a low number of action thresholds. We conclude that fresh and aged grape juice were not effective for capturing and monitoring A. fraterculus in feijoa orchards. The Cera Trap® lure proves to be an alternative to improve monitoring of A. fraterculus in orchards in southern Brazil.