Male Fruit Flies Research Articles

Attraction of feral Bactrocera dorsalis males (Diptera: Tephritidae) to natural versus commercial sources of methyl eugenol

• Bulbophyllum cheiri flowers contain methyl eugenol (ME) and attract Oriental fruit fly males. • The flower attracts more flies than an equivalent quantity of synthetic ME in traps. • When flanked by traps with higher doses of ME, flowers still attract flies though in lower numbers. Males of Bactrocera dorsalis (Hendel) are strongly attracted to methyl eugenol (ME), which occurs in over 450 plant species. Given this powerful attraction, ME is commonly used in surveillance and eradication programs against this invasive agricultural pest. Preliminary observations revealed that B . dorsalis males visited ME-bearing flowers of the fruit fly orchid (FFO) Bulbophyllum cheiri subsp. cheiri even when these occurred near traps baited with far greater quantities of ME. Based on this evidence, we undertook field experiments to assess the attraction of feral B . dorsalis males to FFO flowers relative to commercial sources of ME. At the edge of a secondary forest, an FFO flower was placed midway between two ME sources located 20 m apart, and attracted flies were collected over an entire day. When the ME sources were unenclosed (not in traps), the relative attractiveness of FFO flowers to B . dorsalis males varied with the amount of ME placed nearby. The FFO flower (i) attracted a similar proportion of males when 1 g ME was placed at the flanking sites but (ii) captured significantly smaller proportions when the nearby sites had 6 or 10 g commercial ME sources. Similar tests with the commercial sources enclosed in traps showed that (i) 6 g ME sources in Steiner traps attracted significantly more B . dorsalis males than FFO flowers but (ii) 10 g sources in Clear traps (1 L buckets with 4 entrance holes) did not outperform the FFO flowers, presumably owing to limited dispersion of volatiles from the trap. Implications of these results for surveillance programs are discussed.

Single-cell RNA-sequencing reveals pre-meiotic X-chromosome dosage compensation in Drosophila testis.

Dosage compensation equalizes X-linked expression between XY males and XX females. In male fruit flies, expression levels of the X-chromosome are increased approximately two-fold to compensate for their single X chromosome. In testis, dosage compensation is thought to cease during meiosis; however, the timing and degree of the resulting transcriptional suppression is difficult to separate from global meiotic downregulation of each chromosome. To address this, we analyzed testis single-cell RNA-sequencing (scRNA-seq) data from two Drosophila melanogaster strains. We found evidence that the X chromosome is equally transcriptionally active as autosomes in somatic and pre-meiotic cells, and less transcriptionally active than autosomes in meiotic and post-meiotic cells. In cells experiencing dosage compensation, close proximity to MSL (male-specific lethal) chromatin entry sites (CES) correlates with increased X chromosome transcription. We found low or undetectable levels of germline expression of most msl genes, mle, roX1 and roX2 via scRNA-seq and RNA-FISH, and no evidence of germline nuclear roX1/2 localization. Our results suggest that, although dosage compensation occurs in somatic and pre-meiotic germ cells in Drosophila testis, there might be non-canonical factors involved in the dosage compensation mechanism. The single-cell expression patterns and enrichment statistics of detected genes can be explored interactively in our database: https://zhao.labapps.rockefeller.edu/gene-expr/.

Pengaruh formulasi metil eugenol block plus terhadap tangkapan lalat buah Bactrocera spp. pada tanaman cabai

Fruit fly Bactrocera spp. is one of important pests in chili pepper. The use of methyl eugenol (ME) block plus as an attractant in traps is one method of controlling fruit flies populations. This study aims to find out the appropriate formulation of ME block plus formulation in increasing fruit fly catches on chili pepper. The experiment was carried out from January to April 2018 in Lembang Village, Lembang District, West Bandung Regency. The experiment used a randomized block design consists of eight treatments and three replications. The treatments tested were ME 2 ml was applied to all treatments using cotton; block; chili essence 4 ml block; 4 ml block of guava essence; orange essence 4 ml block; starfruit essence 4 ml block; mango essence 4 ml block; an attractant block product with the active ingredient ME. Although the results showed that all the treatments tested could not attract female fruit flies, the essence formulation was successful in attracting male fruit flies by 87%. The 4 ml chili essence in the 2 ml ME block formulation was the most effective treatment to increase male fruit fly catches by as much as 377 fruit flies/traps/week specifically the species Bactrocera dorsalis (Hendel), Bactrocera carambolae Drew & Hancock, Bactrocera umbrosa Fabricius, and hybrid fruit flies B. dorsalis x B. carambolae.

UJI DAYATARIK TIGA MERK ATRAKTAN UNTUK PENGENDALIAN HAMA LALAT BUAH (Bactrocera spp.) PADA TANAMAN SAYURAN DAN BUAH-BUAHAN

Fruit flies are an insect whose existence is very detrimental because of their role and function as the main pests for vegetable and fruit farmers. For that, we need technology that can suppress the population to increase crop production. The purpose of this study is to obtain information about the ability of three attractant brands on the market to attract male fruit flies, namely Ferokop, Petrogenol, and Milabu. This research used a quantitative exploratory method with collecting data on the number of male fruit fly imago trapped and harvested. The treatment for each type of attractant was repeated four times so that there were 12 bottles of traps in total. The harvest of fruit flies is carried out every day and counted manually using a hand counter. This data obtained were then tabulated and analyzed with ANOVA at the level significant of 5%. If there is a significant difference, then a further test is carried out with the Least Significance Different (LSD) test. The identification results showed that the Ferokop attractant had the highest attractiveness, at 337.38 catches per day, followed by the Petrogenol brand with 225.52 catches, and finally the Milabu brand with 83.05 catches. The conclusion is that the three types of attractant brands have different abilities in attracting male fruit flies.

Monitoring of fruit fly, Bactrocera zonata (Diptera: Tephritidae) population by installing traps in mango orchard Bahawalnagar, Pakistan.

Mango is king of fruits and grown in various countries including Pakistan. The production of mango fruits in Pakistan is low due to attack of various insect pests especially fruit flies. Fruit flies are the major issue in the mango production. Fruit flies are considered as quarantine and key pests of Agricultural and horticultural crops causing huge losses in crop production. The current study was conducted at a farmer field in Bahawalnagar, to monitor the population of fruit flies installing different traps like bottle, jar, and pheromones traps (methyl eugenol) in mango orchards. Data were recorded from January, 2020-December, 2020. The results showed that maximum population of male fruit flies was captured in pheromones traps while minimum in jar traps. The population of fruit flies was emerged in month of April and no population was recorded in first three month and last one month of study. The June and July were the most favorable months for fruit fly attack on mango while December was least. Pheromones traps which are installed at 12 feet height from the ground surface captured 99% fruit fly population while lowest 30% population were captured at 4 feet height. Methyl eugenol trap were more effective to capture maximum population of fruit flies among tested traps. It can prove effective trap in controlling pest population in the mango orchards globally especially in Pakistan.

Encapsulation of Basil Essential Oil by Paste Method and Combined Application with Mechanical Trap for Oriental Fruit Fly Control.

Simple SummaryEssential oils of the Ocimum spp. comprised of the volatile phenylpropanoids known for the Oriental fruit fly attractant property. However, fully exposing the essential oils in the field limited their ability. Therefore, we proposed a cheap yet effective paste encapsulation technique combined with a plastic trap for controlling tropical fruit fly in tropical fruit orchard. In this work, the chemical compositions of basils oils, including those of lemon basil, white holy basil, Thai basil, tree basil and red holy basil, were analysed. Methyl eugenol was detected in all types of basils. The essential oils of red and white holy basils possessed a comparable ability (~25%) to attract male Oriental fruit fly to the synthesised fruit fly attractant in the laboratory experiment. To control the release of the active ingredients, the white holly basil oil (WBO) was encapsulated with maltodextrin (MD) and gum arabic (GA) by paste method. The essential oil is retained in the wall complex much longer with the addition of MD. The results also revealed that the combination of the MD:GA (25:75) had the highest loading efficiency of the oil (9.40%) as observed by the numerous porous structures by scanning electron microscopy. Fourier-transform infrared spectra of the encapsulated polymer confirmed traces of essential oil functional groups. The field test study advised that WBO-encapsulated products improved fruit fly attractive efficiency by maintaining the release rate of basil essential oil.

The Effect of Methyl Eugenol Block Plus on Bactrocera dorsalis Complex Total Captured in Chili Plantation

Fruit flies (Bactrocera spp.) are an important pest for horticultural crops, especially fruits and vegetables. One of the most effective and eco-friendly methods to control male and female fruit flies is by usingtraps that use Methyl Eugenol (ME) block plus fruit essence as an attractant. The purposes of this research were to acquire the most effective formulation of ME Block plus fruit essence to catch the most male and female fruit flies on the chili plantation and to detremine the increase in total of fruit flies caught. This research started from December 2017 to January 2018 at Cibeureum Village, Sukamantri District, Ciamis Regency, West Java Province. The research was conducted using a randomized block design consisting of 8 treatments and 3 repetitions. The treatments consisted of adding fruit essence to the ME block: 2 ml of ME on cotton; 2 ml of ME block; 2 ml of ME block + 4 ml of mango essence; 2 ml of ME block + 4 ml of orange essence; 2 ml of ME block + 4 ml of guava essence; 2 ml of ME block + 4 ml of star fruit essence; 2 ml of ME block + 4 ml of chili essence; Antilat (Organic pesticide) as a comparison. The results showed that ME block plus fruit essence has increased the total of male fruit flies caught, but it did not attract female fruit flies. The best combinations with the highest average of male fruit flies caught were ME block plus orange essence with 750.67/5 week, followed by ME block plus chili essence with 746.00/5 week

Extended holding period and yeast hydrolysate in pre-release diet increase abundance of mature sterile Queensland fruit fly males in the field

Extended holding period and yeast hydrolysate in pre-release diet increase abundance of mature sterile Queensland fruit fly males in the field

Fermented Neem (Azadirachta indica) leaves-metal nanoparticles and their insecticidal properties against Bactrocera dorsalis (Hendel)

Objectives: To investigate the potential of nanoparticles synthesized from neem leaves in pest management for Bactrocera dorsalis. Methods: This study involves extracting the insecticidal properties of neem (Azadirachta indica) by fermenting air-dried leaves with rice wash. The crude fermented neem extract (FNE) was applied as a biopesticide against male B. dorsalis in an improvised olfactometer. The remaining crude extract was utilized in the green synthesis of silver nanoparticles (AgNP) and copper nanoparticles (CuNP). The insecticidal activities of FNE and the extracts with AgNP and CuNP were tested against B. dorsalis. Findings: The experimental treatments 100% FNE and 20% FNECuNP have the same effect as the positive control, causing the death of adult male fruit fly of 83.33% mortality rate after 24 h. The treatment 20% FNE-AgNP showed a higher mortality rate, 100%, after 24 h. Likewise, the results of the larvicidal activities infer that the most effective treatment with a mortality rate of 100% after 24-h exposure is the extract with silver nanoparticles. Moreover, the neem extract, FNE-AgNP, and FNE-CuNP exhibited ovicidal properties, suppressing the development of eggs into third instar larvae. Fermented neem extract can be used to formulate biopesticide enhanced with nanoparticles for controlling B. dorsalis. Novelty: This study showed that the fermented neem leaves extract using rice wash is effective in the green synthesis of silver and copper nanoparticles. The prepared biopesticide metal nanoparticles can be used in the management of B. dorsalis. Keywords: Silver nanoparticles; Copper nanoparticles; Insecticidal; Bactrocera dorsalis; Azadirachta indica

DISTRIBUTION AND IDENTIFICATION OF FRUIT FLIES (DIPTERA: TEPHRITIDAE) ATTRACTED ON METHYL EUGANOL AND CUE LURE IN CENTRAL BANGKA REGENCY, BANGKA BELITUNG

Not all fruit flies species of Dacini tribe were pests to fruit and fleshy vegetables. CentralBangka Regency is one of the citrus producer in the Bangka Belitung Islands Province. Information about this fruit flies in this area was limited. This study aimed to make inventory and identification of fruit flies species of the Dacini tribe in Central Bangka Regency, Bangka Belitung. The research was conducted in Nibung, Penyak, and Terentang Villages in Central Bangka Regency, Bangka Islands. Lynfield traps were installed in a citrus cultivation area about 1.5 m above ground level. Lynfield traps were treated with the attractant and deltamethrin (2: 1; v / v) on dental cotton. Methyl eugenol and cue lure were used to attract the male fruit flies. In Central Bangka Regency, 3 genera and 14 species of fruit flies were obtained from the tribe Dacini. The fruit fly species of Bactrocera atrifemur, B. carambolae, B. dorsalis, B. occipitalis, and B. umbrosa were caught in the methyl eugenol attractant trap. Meanwhile, the fruit fly species of B. albistrigata, B. fuscitibia, B. melastomatos, B. neocognata, B. nigrotibialis, Dacus nanggalae, Zeugodacus apicalis, Z. caudatus, and Z. cucurbitae were caught in the cue lure attractant trap. The fruit flies obtained from the two different attractants were used to develop dichotomous keys.

The influence of male dominance in female Anastrepha curvicauda mate selection

Males of the papaya fruit fly, Anastrepha curvicauda Gerstaecker (former Toxotrypana curvicauda), defend a papaya fruit from rivals and males release their sex pheromone to attract and mate with females and offer them an oviposition site. While some aspects of the biology of A. curvicauda are known, such as its reproductive biology, its sex pheromone, and host selection, there is currently no information on the species mate selection process. This paper describes the precopulatory mating behavior of A. curvicauda and elucidates how intrasexual selection affects the mate selection process. We studied the precopulatory mating behavior of dominant and subordinate males and ethograms were devised. The effect of hierarchy was studied in non-choice and choice experiments. Male’s repertoire includes 15 behavioral elements, 12 precopulatory, one mating, and two postcopulatory (tandem and encounter). In non-choice experiments, dominant and subordinate males were accepted by females, but when females had the opportunity to choose among males, dominant males were significantly preferred over subordinate ones. The presence of a rival male modified the courting behavior of males and agonistic behavior among males was observed before and during mating.

Rectal bacteria produce sex pheromones in the male oriental fruit fly

Volatile molecules produced by the microbiota play a primary role in chemical communication between insects,1 and direct production of pheromone components by the microbiota is one of the most obvious mechanisms.2 Here, we investigated the production of male-borne sex pheromones of the oriental fruit fly, Bactrocera dorsalis. As observed in previous studies,3,4 2,3,5-trimethylpyrazine (TMP) and 2,3,5,6-tetramethylpyrazine (TTMP) are sex pheromones produced in the male rectum. Mature virgin females are strongly attracted to TMP and TTMP. 16S rRNA sequencing results show that the rectal bacteria are dominated by Bacilli that harbor the pathway to produce TMP and TTMP.5-8 The levels of Bacilli, TMP, and TTMP in the male rectum can be significantly decreased by feeding male flies with antibiotics. Invitro assays show that Bacillus species isolated from the male rectum can produce TMP and TTMP when provided with the substrates glucose and threonine, the levels of which are significantly higher in the rectum of mature males. These findings highlight the influence of microbial symbionts on insect pheromones and provide an example of direct bacterial production of pheromones in insects.

Masculinized Drosophila females adapt their fighting strategies to their opponent.

Many animal species show aggression to gain mating partners and to protect territories and other resources from competitors. Both male and female fruit flies of the species Drosophila melanogaster exhibit aggression in same-sex pairings, but the strategies used are sexually dimorphic. We have begun to explore the biological basis for the differing aggression strategies, and the cues promoting one form of aggression over the other. Here, we describe a line of genetically masculinized females that switch between male and female aggression patterns based on the sexual identity of their opponents. When these masculinized females are paired with more aggressive opponents, they increase the amount of male-like aggression they use, but do not alter the level of female aggression. This suggests that male aggression may be more highly responsive to behavioral cues than female aggression. Although the masculinized females of this line show opponent-dependent changes in aggression and courtship behavior, locomotor activity and sleep are unaffected. Thus, the driver line used may specifically masculinize neurons involved in social behavior. A discussion of possible different roles of male and female aggression in fruit flies is included here. These results can serve as precursors to future experiments aimed at elucidating the circuitry and triggering cues underlying sexually dimorphic aggressive behavior.

Dietary antioxidants reduce damage and rescue sperm viability and fertility following oxidative stress in Drosophila melanogaster

AbstractReactive oxygen species (ROS) in large amounts have been shown to cause peroxidative damage to tissues, thereby influencing life‐history trade‐offs such as between reproduction and survival. Reactive oxygen species production is heightened in stressful environments, such as after exposure to toxins. Our study analyzes the effects of antioxidants in reducing the damaging effects of ROS to rescue pre‐ and post‐copulatory reproductive efforts in Drosophila melanogaster Meigen (Diptera: Drosophilidae). We hypothesized that if male fruit flies were fed antioxidant‐enriched diets prior to environmental stress, then the antioxidants would quench the ROS. This would then reduce the lipid peroxidative damage to male sperm, resulting in increased pre‐ and post‐copula reproductive efforts. Two groups of fruit flies were fed antioxidant‐rich diets of lipoic acid (2.15 mM) or melatonin (0.43 mM). Males from all treatments were then fed an herbicide, paraquat (10 mM), which functions as an environmental stressor to shock their immune systems and increase ROS production. All males were then mated to virgin females and copula behavior, sperm viability, male fertility, and total antioxidant capacity were assessed. Our results showed significantly longer mating latencies, higher levels of viable sperm, and more offspring sired in antioxidant‐fed treatments compared to controls. Antioxidant assays reveal that post‐paraquat challenge, males up‐regulate the amount of antioxidants produced. These results draw light on the basis of life‐history trade‐offs such as between reproduction and survival under the context of the molecular mechanisms that govern them, such as pre‐ and post‐copulatory behavior, ROS production, fertility, and sperm viability.

DISTRIBUTION AND IDENTIFICATION OF FRUIT FLIES (DIPTERA: TEPHRITIDAE) ATTRACTED ON METHYL EUGANOL AND CUE LURE IN CENTRAL BANGKA REGENCY, BANGKA BELITUNG

Distribution and identification of fruit flies (Diptera: Tephritidae) attracted on methyl euganol and cue lure in CentralBangka Regency, Bangka Belitung. Not all fruit flies species of Dacini tribe were pests to fruit and fleshy vegetables. CentralBangka Regency is one of the citrus producer in the Bangka Belitung Islands Province. Information about this fruit flies in thisarea was limited. This study aimed to make inventory and identification of fruit flies species of the Dacini tribe in CentralBangka Regency, Bangka Belitung. The research was conducted in Nibung, Penyak, and Terentang Villages in Central BangkaRegency, Bangka Islands. Lynfield traps were installed in a citrus cultivation area about 1.5 m above ground level. Lynfieldtraps were treated with the attractant and deltamethrin (2: 1; v / v) on dental cotton. Methyl eugenol and cue lure were usedto attract the male fruit flies. In Central Bangka Regency, 3 genera and 14 species of fruit flies were obtained from the tribeDacini. The fruit fly species of Bactrocera atrifemur, B. carambolae, B. dorsalis, B. occipitalis, and B. umbrosa were caughtin the methyl eugenol attractant trap. Meanwhile, the fruit fly species of B. albistrigata, B. fuscitibia, B. melastomatos,B. neocognata, B. nigrotibialis, Dacus nanggalae, Zeugodacus apicalis, Z. caudatus, and Z. cucurbitae were caught in thecue lure attractant trap. The fruit flies obtained from the two different attractants were used to develop dichotomous keys.

Spatio-temporal distribution of sexual calling behaviour in domesticated, sterile and wild Queensland fruit fly males under field cage conditions.

The sterile insect technique (SIT) is used in Australia to contain and eradicate outbreaks of Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) in fruit-fly-free regions, and to manage populations in some endemic regions. To assess the likely impact of SIT on wild B. tryoni populations it is important to assess the colocation and synchrony of male calling between sterile and wild flies. We observed the location and timing of calling behaviours of marked mass-reared (fertile and sterile) and wild B. tryoni males in walk-in field cages. We found that wild males called further from the canopy centre than mass-reared (fertile or sterile) males. Mass-reared (fertile or sterile) males called earlier in the evening than wild males and, consequently, mass-reared males called when temperature and light intensity were higher than when wild males called. Male calling is a prerequisite to mating among dacine fruit flies. Therefore, our observations of spatio-temporal divergence in male calling behaviour may lead to assortative mating between mass-reared and wild B. tryoni in SIT applications. The importance of these spatio-temporal differences warrants further inquiry, with particular focus on how environmental conditions modify calling behaviour and avenues to ameliorate differences between sterile and wild flies. © 2021 Society of Chemical Industry.

Field Capture of Male Oriental Fruit Flies (Diptera: Tephritidae) in Traps Baited with Solid Dispensers Containing Varying Amounts of Methyl Eugenol

Detection of invasive populations of Bactrocera dorsalis relies on traps baited with the male-specific attractant methyl eugenol. Standard protocol involves applying 5 mL of liquid methyl eugenol (1% naled) to a cotton wick, which is then placed inside a Jackson trap. Because of the lure's high volatility, the lure is replaced every 6 wk. Prolonging the lure's longevity would increase trap servicing intervals and reduce associated costs. Conducted at 2 sites in Hawaii, the present study investigated the performance of weathered solid dispensers containing 3, 6, or 10 g of methyl eugenol, deployed with solid insecticidal strips, relative to freshly baited liquid-bearing cotton wicks. At the cooler site, the solid lure/toxicant combination captured as many males as the fresh liquid formulation for as long as 12 wk. At the warmer site, the solid lure/toxicant system had shorter longevity, apparently owing to the reduced effectiveness of the insecticidal strip over time.

Edible Mushroom Protein Content and Antioxidant Capacity Increase the Longevity of Anastrepha ludens Fruit Flies.

This study aimed to determine the effect of the protein and antioxidant contents of edible mushrooms on the longevity of the fruit fly (Anastrepha ludens). The contents of protein (Bradford assay), antioxidants (DPPH and ABTS assays), total phenols, and flavonoids in nine strains of different edible mushroom species were determined. Freeze-dried and finely ground complete mushroom fruiting bodies were used to feed the flies, with a concentration of 0.5% in the diet. Male and female fruit flies, both fertile and sterile, were used in this study. Two controls were used: the standard fly diet and a diet supplemented with cinnamon as a food rich in antioxidants. Differences in protein and antioxidant contents were found among the evaluated strains. Differences were also observed in the responses of female and male flies as well as between the responses of fertile and sterile flies. Overall, the sterile flies lived longer. The addition of mushrooms in the diet resulted in greater longevity than in the controls. The use of sterile flies allowed observation of the effect of proteins and antioxidants on reproduction and the subsequent effect of reproduction on longevity.

Functional analysis of CG8005 gene in Drosophila testis

The processes of self-renewal and differentiation of germ cells are crucial to the development of male infertility and germ cell tumors. CG8005 gene is one of the regulatory factors of the testicular germ stem cells in Drosophila melanogaster, and its functional mechanism is still unknown. To explore the biological function(s) of CG8005 gene in the germ cell niche of Drosophila testis, first, the UAS-gal4 system was used to drive the expression of UAS-CG8005 RNAi in Drosophila testicular germ cells and cyst cells. Fertility tests were then performed to determine the fertility rate of male flies. Second, the expression patterns of Vasa, IBI, Zn finger homeodomain 1 (Zfh1), eyes absent (Eya), DE-cad, FasIII and Phospho-Histone H3(PH3), and TUNEL were analyzed by immunofluorescence staining in both control and CG8005 RNAi testes. Lastly, small interfering RNA (siRNA) was used to silence the CG8005 gene expression in Drosophila S2 cells; and PH3 was used to detect the proliferation ability of Drosophila S2 cells in the control group and CG8005 siRNA group. Apoptosis of Drosophila S2 cells was analyzed with TUNEL and flow cytometry. To observe the relative expression of the spliceosome, the mRNA levels of the spliceosome subunits were detected by fluorescence quantitative RT-PCR. As compared with the control group, the results showed that deletion of the CG8005 gene in the germ cells and cyst cells of the testis reduced or even completely abolished the fertility of male fruit flies. In addition, nos-gal4 driven UAS-CG8005 RNAi led to loss of fusomes and reduce the proliferative ability of germ cells. Noticeably, tj-gal4-directed UAS-CG8005 RNAi knockdown of CG8005 gene in the testis led to germ cell tumor development. Knockdown of CG8005 gene in Drosophila S2 cells resulted in increase in apoptosis and inhibition of proliferation. Further, the silencing of the CG8005 gene in Drosophila S2 cells caused increases in the mRNA levels of the spliceosome subunits. Hence, CG8005 gene is essential for the self-renewal and differentiation of germ cells in Drosophila testis. Its deletion may lead to restricted germ cell survival and the formation of germ cell-like tumors. CG8005 gene can participate in the regulation of proliferation and apoptosis of Drosophila S2 cells, which is essential for the maintenance of cell life, and might competitively regulate the mRNA levels of spliceosome subunits.

Raspberry ketone supplements provided to immature male Queensland fruit fly, Bactrocera tryoni (Froggatt), increase the amount of volatiles in rectal glands

Raspberry ketone (RK) supplements provided together with sugar and yeast hydrolysate accelerate sexual maturation and increase mating success of Queensland fruit fly (‘Qfly’) males. However, the mechanisms underlying this enhanced mating ability are currently unknown. Volatiles are an important element of Qfly sexual calling and courtship and so changes in volatiles quantity or quality may be involved, and the present study investigated this possibility. Flies were fed a diet of sugar only (S) or yeast hydrolysate mixed with sugar (YH + S) (1:3) that contained 0% RK (control) and 5% RK (treated) for 2 days after emergence. Volatile compounds were extracted from rectal glands when flies were 6, 8, 10, 20, and 30 days old. Males fed on RK exhibited a significant increase in total volatile production in rectal glands compared to RK-unfed males (control). Males fed on RK with YH + S produced significantly higher amount of volatiles than males fed on RK with sugar only. Males fed on YH + S diet produced more volatiles in the presence of RK compared to males fed on YH + S diet only. Two compounds, N-(3-methylbutyl)acetamide and N-(3-methylbutyl)propanamide were dominant in endogenously produced rectal gland volatiles comprising ca. more than 90% of the total amount in both RK-fed and control males. Considering exogenous and endogenous compounds together, unaltered RK was dominant along with these two endogenous compounds in RK-fed males in rectal gland until 30 days of age in both diet groups.