Tephritid Fruit Fly Species Research Articles

Reproductive aging in tephritid fruit flies

The broad objective of this paper is to present an overview and synthesis of selected studies on reproduction and aging in two model tephritid fruit fly species including the Mediterranean fruit fly, Ceratitis capitata, and the Mexican fruit fly, Anastrepha ludens. We summarize the research findings from empirical studies and modeling investigations involving reproduction in the two tephritid species. At the end we identify and discuss four general principles regarding reproductive aging in tephritids including reciprocity of reproductive and aging costs, qualitative tradeoffs, plasticity of lifespan and reproduction, and life history constraints and determinacy.

Immature Stages of Development in the Parasitoid Wasp,Diachasmimorpha longicaudata

The morphological changes experienced during the immature stages of the solitary parasitoid Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae: Opiinae) were studied. This natural enemy of several species of tephritid fruit flies is widely used in biological control strategies. Immature stages are poorly understood in endoparasitoids because they exist within the host. In the present work, developmental processes are described for this species, reared in Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) larvae under controlled environmental conditions. At 25° C, 85% RH, and with an 18:6 L:D photoperiod, preimaginal development takes about 16 days. Five preimaginal stages can be described: egg, three larval instars, prepupa, pupa, and pharate adult. Superparasitism was found in 20% of the host pupae, and the number of oviposition scars was positively correlated with the number of parasitoid larvae per host puparium. The results are compared and discussed with previous studies on related species.

Quality Testing of Three Species of Tephritid Fruit Flies After Embryo Cryopreservation

Abstract This study evaluates characteristics commonly used to define insect quality or fitness by using a complement of three species of tephritid fruit flies (Diptera: Tephritidae) obtained from cryopreserved embryos. Anastrepha ludens (Loew), Anastrepha suspensa (Loew), and Ceratitis capitata (Wiedemann) were used to assess embryo to adult emergence and adult longevity, flight ability, mating ability, fecundity, and genetic variability after cryopreservation. With the three species tested, embryo survival was reduced by 50–70% whereas adult eclosion seemed unaffected by cryogenic treatment. Laboratory cage survival of cryopreserved A. ludens paralleled that of controls when tested with or without food and water posttreatment. With C. capitata, field cage survival was also similar when the adult progeny of cryopreserved parents was compared with that of untreated flies of the same age. Assessment of flight ability of cryopreserved A. ludens over a 19-d period by using a flight mill showed no statistical difference when compared with the untreated groups over the same time period. Flight ability within field cages for newly emerged progeny of cryopreserved C. capitata also mirrored that of the controls. Observed matings occurring within laboratory cages containing equal numbers of A. ludens males and females did not differ from comparable control groups. Furthermore, male progeny obtained from cryopreserved C. capitata parents competed equally with untreated males for mates while housed in field cages. A laboratory analysis of fertility and fecundity of A. suspensa revealed that males mated with control females were unaffected by cryopreservation as embryos, whereas cryopreserved females exhibited a significantly reduced fecundity when mated with control males. The fecundity of C. capitata progeny of cryopreserved parents also did not differ from control levels while caged under laboratory conditions. A random amplified polymorphic DNA assay of the genetic diversity of A. ludens comparing cryopreserved males with control males showed that the coefficient of similarity was ≥85%. This study indicates that embryo cryopreservation had little or no effect on the reproduction, longevity and flight of the species tested and can be used to support maintenance of insect stocks and control programs supported by the mass-rearing process.

Old and new host-parasitoid associations: parasitism of the invasive fruit fly Bactrocera invadens (Diptera: Tephritidae) and five African fruit fly species by Fopius arisanus, an Asian opiine parasitoid

Fopius arisanus (Sonan), a solitary koinobiont endoparasitoid of fruit flies, was introduced for testing and final release against the recently discovered species Bactrocera invadens Drew, Tsuruta and White in Africa. Laboratory experiments were conducted to assess host preference, host acceptability for oviposition, and physiological suitability of B. invadens and five other indigenous tephritid fruit fly species, namely, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), C. cosyra (Walker), C. rosa Karsch, C. fasciventris (Bezzi), and C. anonae Graham. Females of F. arisanus visited all host egg patches, but showed a stronger preference to eggs of B. invadens, which was also most accepted for oviposition. Successful development of parasitoid progenies varied greatly across hosts, with B. invadens yielding the highest parasitoid progeny and C. fasciventris yielding no F. arisanus progeny. Most of the parasitoid eggs laid in C. rosa and C. fasciventris were encapsulated. Sex ratio was not influenced by host species and it was female biased in all hosts that produced parasitoid progeny. Fopius arisanus was able to establish a new association with C. capitata, C. cosyra and to a lesser extent C. anonae. The results are discussed in the light of the potential use of F. arisanus as a biological control agent of B. invadens.

The β2-tubulin gene from three tephritid fruit fly species and use of its promoter for sperm marking

To isolate testis-specific regulatory DNA that could be used in genetically transformed insect pest species to improve their biological control, β2-tubulin genes and their proximal genomic DNA were isolated from three economically important tephritid pest species, Anastrepha suspensa, Anastrepha ludens, and Bactrocera dorsalis. Gene isolation was first attempted by degenerate PCR on an A. suspensa adult male testes cDNA library, which fortuitously isolated the 2.85 kb β1-tubulin gene that encodes a 447 amino acid polypeptide. Subsequent PCR using 5′ and 3′ RACE generated the 1.4 kb Asβ2-tubulin gene that encodes a 446 amino acid polypeptide. Using primers to conserved sequences, the highly similar A. ludens and B. dorsalis β2-tubulin genes, encoding identical amino acid sequences, were then isolated. To verify Asβ2-tubulin gene identification based on gene expression, qRT-PCR showed that Asβ2-tubulin transcript was most abundant in pupal and adult males, and specific to the testes. This was further tested in transformants having the DsRed.T3 reporter gene regulated by the Asβ2-tubulin 1.3 kb promoter region. Fluorescent protein was specifically expressed in testes from third instar larvae to adults, and fluorescent sperm could be detected in the spermathecae of non-transgenic females mated to transgenic males.To confirm these matings, a PCR protocol was developed specific to the transgenic sperm DNA.

Effect of Metarhizium anisopliae inoculation on the mating behavior of three species of African Tephritid fruit flies, Ceratitis capitata, Ceratitis cosyra and Ceratitis fasciventris

Bioassays were carried out in the laboratory to investigate the effect of inoculation by Metarhizium anisopliae on mating behavior of three species of fruit flies, Ceratitis cosyra, C. fasciventris and C. capitata. In all three species, inoculation by the fungus resulted in significant delay in the commencement of calling and mating of treated males as they spent substantial amount of time in grooming activity. In fungus-treated male flies, calling and mating started at 70.0–80.0 min after exposing them to untreated females. However, when females were treated, calling and mating started from 15.0 to 16.0 min. Fungus-treated males competed equally with untreated males for virgin female flies from day 0 to day 2 post-inoculation. There were, however, significant differences on day 3, with untreated males of the three fruit fly species having higher percentage of paring than fungus-treated males. There was no significant difference in the duration of pairing of fungus-treated males and untreated male of the three fruit fly species at day 0, 1 and 2 post-inoculation. However, on day 3 post-inoculation, there was a significant difference in the duration of mating with fungus-treated males having the lowest duration of mating. No significant differences in the percentage of mating between fungus-treated male and female flies; and the untreated flies at day 0, 1 and 2 days post-inoculation, except on day 3. The results are discussed with regard to application in autodissemination, baiting and the sterile insect techniques.

Insecticidal Activity of Basil Oil, <I>trans</I>-Anethole, Estragole, and Linalool to Adult Fruit Flies of <I>Ceratitis capitata</I>, <I>Bactrocera dorsalis</I>, and <I>Bactrocera cucurbitae</I>

Basil oil and its three major active constituents (trans-anethole, estragole, and linalool) obtained from basil (Oscimum basilicum L.) were tested on three tephritid fruit fly species [Ceratitis capitata (Wiedemann), Bactrocera dorsalis (Hendel), and Bactrocera cucurbitae (Coquillett)] for insecticidal activity. All test chemicals acted fast and showed a steep dose-response relationship. The lethal times for 90% mortality/knockdown (LT90) of the three fly species to 10% of the test chemicals were between 8 and 38 min. The toxic action of basil oil in C. capitata occurred significantly faster than in B. cucurbitae but slightly faster than in B. dorsalis. Estragole acted faster in B. dorsalis than in C. capitata and B. cucurbitae. Linalool action was faster in B. dorsalis and C. capitata than in B. cucurbitae. trans-Anethole action was similar to all three species. Methyl eugenol acted faster in C. capitata and B. cucurbitae than in B. dorsalis. When linalool was mixed with cuelure (attractant to B. cucurbitae male), its potency to the three fly species decreased as the concentration of cuelure increased. This was due to linalool hydrolysis catalyzed by acetic acid from cuelure degradation, which was confirmed by chemical analysis. When methyl eugenol (B. dorsalis male attractant) was mixed with basil oil, trans-anethole, estragole, or linalool, it did not affect the toxicity of basil oil and linalool to B. dorsalis, but it did significantly decrease the toxicity of trans-anethole and estragole. Structural similarity between methyl eugenol and trans-anethole and estragole suggests that methyl eugenol might act at a site similar to that of trans-anethole and estragole and serve as an antagonist if an action site exists. Methyl eugenol also may play a physiological role on the toxicity reduction.

Evaluation of the impact of Diachasmimorpha longicaudata on Bactrocera invadens and five African fruit fly species

Abstract Diachasmimorpha longicaudata (Ashmead), a solitary koinobiont larval–prepupal endoparasitoid of fruit flies, was introduced into Kenya for testing and final release against the recently discovered invasive species, Bactrocera invadens Drew, Tsuruta and White in Africa. Laboratory experiments were conducted to determine host preference, host acceptability for oviposition and physiological suitability of B. invadens and five other indigenous tephritid fruit fly species –Ceratitis capitata (Wiedemann), Ceratitis cosyra (Walker), Ceratitis rosa Karsch, Ceratitis fasciventris (Bezzi) and Ceratitis anonae Graham – for the development of D. longicaudata. Females of D. longicaudata visited all host‐larval patches, and were also attracted to these hosts at comparable levels. Acceptability, successful development of parasitoid progenies and their sex ratio varied widely across hosts. C. capitata yielded the highest parasitoid numbers whereas B. invadens was the only host that yielded a female‐biased sex ratio. Larvae of B. invadens, C. rosa, C. fasciventris and C. anonae mounted differential immune reaction towards D. longicaudata eggs. Although, the parasitoid performed poorly on the target host B. invadens, it was able to form new association with C. cosyra and C. capitata. The prospect of using this parasitoid in biological control of African indigenous fruit flies is discussed.

Do Methyl Eugenol-fed Males of the Oriental Fruit Fly (Diptera: Tephritidae) Induce Female Re-mating?

Abstract Polyandry has been reported for various species of tephritid fruit flies, and efforts to explain this phenomenon have focused primarily on the respective roles of sperm stores and male accessory gland fluids. However, recent research on the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), demonstrated that female re-mating propensity was influenced by the “suitability” of available mates; preferred males were more likely to induce female re-mating than were less attractive males. The goal of this study was to determine whether male attractiveness similarly influenced female re-mating in the oriental fruit fly, Bactrocera dorsalis (Hendel). Females of this species are known to mate preferentially with males that previously ingested methyl eugenol (ME), a plant-borne compound whose metabolites are used in the synthesis of the male sex pheromone. Females were mated initially (with males denied ME), held isolated from males with access to oviposition substrate, and then offered ME-fed or non-...

Natural establishment of a parasitoid complex on Bactrocera latifrons (Diptera: Tephritidae) in Hawaii

Bactrocera latifrons (Hendel) (Diptera: Tephritidae) is the most recent of four tephritid fruit fly species accidentally introduced into Hawaii. Although parasitoids have been released against other tephritid fruit fly species and have shown partial success in Hawaii, no parasitoids were released until 2004 to suppress populations of B. latifrons. The present study was conducted to document the parasitoid complex that has naturally established against B. latifrons in Hawaii and to assess whether there is a need for improving the biological control of this species. Based on ripe turkeyberry (Solanum torvum Sw) fruit collections over three consecutive years B. latifrons was the dominant tephritid fruit fly infestating turkeyberry at all four sites surveyed, across three major islands in Hawaii. The overall percentage parasitism of B. latifrons ranged from a low of 0.8% (Hana, Maui) to a high of 8.8% (Kahaluu, Oahu). Five primary parasitoid species were recovered from individually held B. latifrons puparia: Fopius arisanus (Sonan), Psyttalia incisi (Silvestri), Diachasmimorpha longicaudata (Ashmead), D. tryoni (Cameron), and Tetrastichus giffardianus Silvestri. F. arisanus was the predominant parasitoid at three of the four sites. Low levels of parasitism suggest that there is a need to improve biological control of B. latifrons, to minimize chances of this species causing economic impacts on crop production in Hawaii. We discuss the possibility of improving biological control of B. latifrons through augmentative releases of F. arisanus or introduction and release of specific and efficient new parasitoid species.

Acceptance and suitability of different host stages of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) and seven other tephritid fruit fly species to Tetrastichus giffardii Silvestri (Hymenoptera: Eulophidae)

Abstract Tetrastichus giffardii Silvestri is a gregarious eulophid endoparasitoid of several tephritid fruit fly species. Host stage suitability was studied using nine age groups of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), namely, eggs less than 24 h and between 24 and 48 h old, and 1- to 7-day-old larvae. Life table studies for T. giffardii using C. capitata as host were done at 26 ± 5 °C and 55–60% RH. Egg load in relation to age of the female parasitoid was also assessed as was the effect of host deprivation on adult longevity. Host acceptance and suitability were examined with respect to eight species of tephritids. Potential hosts so tested were five Ceratitis species, the Medfly, C. capitata , the mango fruit fly, Ceratitis cosyra (Walker), the Natal fruit fly, Ceratitis rosa Karsch, Ceratitis fasciventris (Bezzi), and Ceratitis anonae Graham; two Bactrocera species, the melon fruit fly, Bactrocera cucurbitae (Coquillett) and the newly invasive Bactrocera invadens Drew, Tsuruta, and White; and one Dacus species, the lesser pumpkin fly, Dacus ciliatus Loew. No parasitoids were obtained from eggs while all larval stages were suitable though at varying degrees. Parasitism and number of progeny was related to host age in a curvilinear manner with maxima at 4- to 5-day-old larvae. By contrast, development time decreased with age of host larvae while sex ratio was not affected. The intrinsic rate of increase was 0.17 ± 0.01; gross and net reproductive rates were 64.9 ± 4.3 and 44.9 ± 3.8, respectively. Non-ovipositing females lived significantly longer than ovipositing ones. The females accepted all host species tested, but only C. capitata , D. ciliatus and, to a much lesser extent, C. cosyra were suitable. In the remaining host species, most eggs were encapsulated. In C. capitata and D. ciliatus , percent parasitism was similar, but number of progeny was lower and the sex ratio, as the proportion of females, was higher when the parasitoid was reared on D. ciliatus . Progeny per puparium were also similar for the two hosts. In the light of these results it can be concluded that T. giffardii has a narrow host range, but it attacks and successfully develops in larvae representing a wide range of ages.

Male Diachasma alloeum parasitoids from two host species of tephritid fruit flies respond equally to female-produced sex pheromone

. Diachasma alloeum is a braconid wasp that parasitizes hawthorn-infesting Rhagoletis pomonella and blueberry-infesting Rhagoletis mendax, both tephritid fruit fly sibling species. The behavioural responses of male D. alloeum originating from both fruit fly host species to hexane extracts of conspecific females originating from both host species and females of various mating status are investigated in a laboratory Y-tube olfactometer. Male D. alloeum originating from either R. mendax or R. pomonella respond to one whole-body, female equivalent hexane extract in equal frequency as to a live, virgin female; this response is at least 7.5-fold greater than to solvent controls. Male D. alloeum originating from R. mendax or R. pomonella are attracted to hexane extracts of female D. alloeum abdomens but not to extracts of the head and thorax regions. Virgin D. alloeum females attract significantly more male D. alloeum originating from either host species compared with mated females of the same age. Copulation behaviour between same host and mixed host pairs appears to be identical. Male D. alloeum are equally responsive to the female-produced sex pheromone of female D. alloeum, irrespective of females' host-species origin, suggesting that these host-specific populations can potentially interbreed.

Bactrocera zonata

<i>Bactrocera zonata</i>

The cryptochrome (cry) Gene and a Mating Isolation Mechanism in Tephritid Fruit Flies

Two sibling species of tephritid fruit fly, Bactrocera tryoni and Bactrocera neohumeralis, are differentiated by their time of mating, which is genetically determined and requires interactions between the endogenous circadian clock and light intensity. The cryptochrome (cry) gene, a light-sensitive component of the circadian clock, was isolated in the two Bactrocera species. The putative amino acid sequence is identical in the two species. In the brain, in situ hybridization showed that cry is expressed in the lateral and dorsal regions of the central brain where PER immunostaining was also observed and in a peripheral cell cluster of the antennal lobes. Levels of cry mRNA were analyzed in whole head, brain, and antennae. In whole head, cry is abundantly and constantly expressed. However, in brain and antennae the transcript cycles in abundance, with higher levels during the day than at night, and cry transcripts are more abundant in the brain and antennae of B. neohumeralis than in that of B. tryoni. Strikingly, these results are duplicated in hybrid lines, generated by rare mating between B. tryoni and B. neohumeralis and then selected on the basis of mating time, suggesting a role for the cry gene in the mating isolation mechanism that differentiates the species.

NATIVE HYMENOPTERAN PARASITOIDS ASSOCIATED WITH FRUIT FLIES (DIPTERA: TEPHRITIDAE) IN SANTA CATARINA STATE, BRAZIL

A survey of tephritid fruit fly species and their parasitoids was conducted in the western portion of Santa Catarina state, Brazil. A total of 9,197 fruits belonging to 46 plant species in 24 families was collected. The parasitoids recovered were Aganaspis pelleranoi (Brethes), Lopheucoila anastrephae (Rhower) (Figitidae), Doryctobracon areolatus (Szepligeti), Doryctobracon brasiliensis (Szepligeti), Odontosema anastrephae Borgmeier, Opius bellus Gahan, Opius sp., Utetes (Bracanastrepha) anastrephae (Viereck) (Braconidae), and Trichopria anastrephae Lima (Diapriidae). Agasnaspis pelleranoi is the most frequent parasitoid species found in the west region of Santa Catarina. We recorded the first occurrence of L. anastrephae in Santa Catarina. Parasitism ranged from 1.2 to 46.9%.

Sperm Storage Patterns in Singly Mated Females of the Caribbean Fruit Fly, &lt;I&gt;Anastrepha suspensa&lt;/I&gt; (Diptera: Tephritidae)

Insemination and fertilization are temporally dissociated in most insects thus creating conditions for female-mediated processes to influence paternity. One possible response to copulatory and postcopulatory sexual selection may be to increase the number of sperm-storage organs allowing for differential storage and use of sperm from multiple males. Differential sperm storage was tested in singly mated females of the tephritid fruit fly species, Anastrepha suspensa, which has four sperm-storage organs with separate entries to the bursa. Females mate multiply, and males display copulatory courtship. Copulation duration was examined in relation to female size, male size, and the quantity and distribution of spermatozoa in the four storage organs. Sperm quantity stored in females ranged from 141 to 2,617 spermatozoa, and the time spent in copulation ranged from 6 to 45 min. Spermatozoa were present in the ventral receptacle after all copulations, although this was not the case for the spermathecae. There was no significant correlation between body size and the duration of copulation or the quantity of sperm stored, but copulation duration was positively correlated to the quantity of sperm stored (r = 0.38, P = 0.02).

Effect of constant temperatures on germination, radial growth and virulence of Metarhizium anisopliae to three species of African tephritid fruit flies

The effect of temperatureon conidial germination, mycelial growth, andsusceptibility of adults of three tephritidfruit flies, Ceratitis capitata(Wiedemann), C. fasciventris (Bezzi) andC. cosyra (Walker) to six isolatesof Metarhizium anisopliae were studied inthe laboratory. There were significantdifferences among the isolates in the effect oftemperature on both germination and growth.Over 80% of conidia germinated at 20, 25 and30°C, while between 26 and 67% conidiagerminated at 35°C and less than 10% at15°C within 24 hours. Radial growth was slowat 15°C and 35°C with all of theisolates. The optimum temperature forgermination and mycelial growth was 25°C. Mortality caused by the six fungal isolatesagainst the three fruit fly species varied withtemperature, isolate, and fruit fly species.Fungal isolates were more effective at 25, 30and 35°C than at 20°C. The LT90values decreased with increasing temperature upto the optimum temperature of 30°C. Therewere significant differences in susceptibilitybetween fly species to fungal infection at allthe temperatures tested.

The Effects of Selection for early (day) and late (dusk) Mating lines of Hybrids ofBactrocera tryoniandBactrocera neohumeralis

Bactrocera neohumeralis and Bactrocera tryoni are closely related tephritid fruit fly species. B. neohumeralis mates throughout the day (in bright light) and B. tryoni mates at dusk. The two species can also be distinguished by the colour of their calli (prothoracic sclerites) which are brown and yellow, respectively. The F1 hybrids can mate both in bright light just before dusk and during dusk and have calli that are partly brown and partly yellow. The F2 hybrids have a wider range of callus patterns and mating occurs more widely in the day as well as at dusk. We directly selected hybrid stocks for mating time, creating 'early' (day-mating) and 'late' (dusk-mating) lines. As an apparently inadvertent consequence, the two types of line respectively had predominantly brown and predominantly yellow calli and thus came to closely resemble the original two species in both behaviour and appearance. Lines that were evenly selected (half for day and half for dusk) essentially retained the mating pattern of F2 hybrids. Selection for callus colour alone also affected the distribution of mating times in a predictable way. We propose a genetical model to account for the results and discuss them in the light of the apparent maintenance of species integrity in nature.

Host species, age and sex as factors affecting the susceptibility of the African Tephritid fruit fly species, Ceratitis capitata, C. cosyra and C. fasciventris to infection by Metarhizium anisopliae

The effect of host age and sex on the susceptibility of 3 tephritid fruit fly species, Ceratitis capitata (Wiedemann), C. cosyra (Walker) and C. fasciventris (Bezzi) to the entomopathogenic fungus Metarhizium anisopliae (Metchnikoff) Sorokin was studied in the laboratory. Three adult host ages, 0 (<1 day-old), 7-day-old and 14-day-old, were used. All 3 species were susceptible to fungal infection, although there were differences in the levels of susceptibility among the hosts. Age accounted for the largest variability in mortality followed by species, while sex had the lowest variability. Of the 3 host ages tested, the 0- and 7-day-old flies were more susceptible to fungal infection than the 14-day-old flies. Male and female C. fasciventris flies generally succumbed earlier to fungal infection than the other two species. Female flies of C. cosyra and C. fasciventris were also generally more susceptible to fungal infection than the males, although differences were apparent at 3 and 4 days after treatment but not 5 days after treatment. Age accounted for the largest variability in lethal time mortality values (LTs). Mean LT-values generally indicated that the speed of kill was faster among younger flies than the older flies. LT95 ranged between 3.9–4.9 days in the 0-day-old flies, 4.3–6.1 days in the 7-day-old flies and 4.6–6.1 days in 14-day-old flies in the different species and sexes. The implication of this study for the management of fruit flies is discussed.

Assessment of Corn Pollen as a Food Source for Two Tephritid Fruit Fly Species

The melon fly, Bactrocera cucurbitae (Coquillett) is a serious pest of cucurbit crops. Although melon fly females oviposit in cucurbit crops, both males and females are frequently associated with a range of nonhost plants, including both crops such as corn (Zea mays C. Linnaeus) and wild plants such as castor bean (Ricinus communis C. Linnaeus) that occur within the cropping area or along the crop borders. This association with nonhost plants has been used for control purposes through the technique of spraying protein baits incorporating a toxicant on these nonhost plants. Association of melon flies to corn has not been reported to be tied to any phenological stage of corn. We report field studies that show that melon flies, as well as oriental fruit flies, B. dorsalis (Hendel), may show increased population levels in corn at the time of, and subsequent to, flowering and pollen shed and suggest that this population increase may be tied to pollen consumption. Before this, pollen had not been reported to be an important food source for the tropical Bactrocera spp.