Species Of Tephritids Research Articles

Comparative efficacy of a spider knottin insecticide, GS‐omega/kappa‐Hxtx‐Hv1a, against four species of invasive tropical tephritids

AbstractInvasive tephritid fruit flies collectively pose a significant economic challenge to agricultural pest management globally. Insecticide resistance to a number of previously effective chemical classes has increased the risk these pests pose as management options become limited. We evaluated the efficacy of a peptide‐based biorational insecticide with a unique mode of action, containing the active ingredient, GS‐omega/kappa‐Hxtx‐Hv1a (GS‐Hv1a), against four of tephritid species, oriental fruit fly (Bactrocera dorsalis), melon fly (Zeugodacus cucurbitae), Mediterranean fruit fly (Ceratitis capitata, ‘Medfly’), and Malaysian fruit fly (Bactrocera latrifrons). This assessment aimed to determine whether GS‐Hv1a has the potential for effective management of tropical tephritids, particularly in regions where insecticide resistance has developed to other products. We conducted two sets of screening assays with different methods of exposure, oral and topical and compared survival over time in response to increasing concentrations of GS‐Hv1a up to 3.86 mg/ml. We found that efficacy was species dependent: Ceratitis capitata was susceptible following topical exposure, while the other species of fruit fly were not. While Medfly survival decreased following oral ingestion as well, the amount required to achieve this was greater than the concentration used in the topical bioassay. We observed that survival continued to decline up to 72 h after exposure, indicating a delayed effect similar to other reduced‐risk insecticidal products such as fipronil. For this reason, GS‐Hv1a may be useful as a horizontal transfer tool in conjunction with C. capitata male pheromone lures.

First records of two species of Tephritidae and one species of Platystomatidae (Diptera) from Transcaucasia

Two species of Tephritidae, Tephritis conyzifoliae Merz, 1992 and Tephritomyia lauta (Loew, 1869), and one species of Platystomatidae, Platystoma dimidiatum Hendel, 1913, are recorded for the first time from Armenia and Transcaucasia at large. The larvae of T. conyzifoliae develop in two species of Crepis, C. pannonica (Jacq.) K. Koch and C. ciliata C. Koch. The latter species is recorded for the first time as a host plant of T. conyzifoliae. Tephritomyia lauta were reared from Echinops sp. The morphological details of all three species of flies are illustrated in colour photos, as well as the host plants of the two species of tephritids.

Effects of temperature on the activity of antioxidant enzymes in larvae of Bactrocera dorsalis (Diptera: Tephritidae) parasitized by Diachasmimorpha longicaudata (Hymenoptera: Braconidae): Optimizing the mass rearing of this braconid by varying the temperature

Diachasmimorpha longicaudata is the most widely used endoparasitoid in biocontrol programmes against various species of tephritids and is continuously mass-reared under laboratory conditions at a constant temperature; however, little is known about how varying the temperature might affect the effectiveness of the mass rearing of immature D. longicaudata. This study aimed to determine the optimum temperature for the development of larvae D. longicaudata the larvae of its host, Bactrocera dorsalis. Third-instar B. dorsalis were exposed for 4 h to five pairs of parasitoids, and then they were kept at one of six temperatures ranging from 19°C to 34°C. The activities of three major antioxidant enzymes (CAT, POX, SOD) were individually measured 4, 24, 48 and 72 h after exposure to each of the six temperatures. The results were as follows: for CAT the highest CAT activities were recorded at 25°C (intervals 5-24 h and 25-48 h), at 28°C (interval 0-4 h) and at 31°C (interval 49-72 h), and for POX and SOD identically at 25°C (intervals 0-4 h, 5-24 h) and at 31°C (intervals 25-48 h, 49-72 h), respectively. Subsequently, the effects keeping the parasitized larvae at these different temperatures on the biological attributes of D. longicaudata reared under laboratory conditions were investigated. The percentage of their eggs that hatched, percentage of adults that emerged, pupal weight and longevity were significantly greater than that recorded for the control when the parasitized host larvae were kept at 28°C for 4 h, 25°C for 5 and 48 h and 31°C for 49 and 72 h.

Pattern of association between endemic Hawaiian fruit flies (Diptera, Tephritidae) and their symbiotic bacteria: Evidence of cospeciation events and proposal of “Candidatus Stammerula trupaneae”

Several insect lineages have evolved mutualistic association with symbiotic bacteria. This is the case of some species of mealybugs, whiteflies, weevils, tsetse flies, cockroaches, termites, carpenter ants, aphids and fruit flies. Some species of Tephritinae, the most specialized subfamily of fruit flies (Diptera: Tephritidae), harbour co-evolved vertically transmitted, bacterial symbionts in their midgut, known as “Candidatus Stammerula spp.”. The 25 described endemic species of Hawaiian tephritids, plus at least three undescribed species, are taxonomically distributed among three genera: the cosmopolitan genus Trupanea (21 described spp.), the endemic genus Phaeogramma (2 spp.) and the Nearctic genus Neotephritis (2 spp.). We examined the presence of symbiotic bacteria in the endemic tephritids of the Hawaiian Islands, which represent a spectacular example of adaptive radiation, and tested the concordant evolution between host and symbiont phylogenies.We detected through PCR assays the presence of specific symbiotic bacteria, designated as “Candidatus Stammerula trupaneae”, from 35 individuals of 15 species. The phylogeny of the insect host was reconstructed based on two regions of the mitochondrial DNA (16S rDNA and COI-tRNALeu-COII), while the bacterial 16S rRNA was used for the symbiont analysis. Host and symbiont phylogenies were then compared and evaluated for patterns of cophylogeny and strict cospeciation. Topological congruence between Hawaiian Tephritinae and their symbiotic bacteria phylogenies suggests a limited, but significant degree of host–symbiont cospeciation. We also explored the character reconstruction of three host traits, as island location, host lineage, and host tissue attacked, based on the symbiont phylogenies under the hypothesis of cospeciation.

Presence of the endosymbiont Wolbachia among some fruit flies (Diptera: Tephritidae) from Iran: A multilocus sequence typing approach

Wolbachia is a widespread endosymbiont of insects with a diverse range of biological effects on its hosts. We studied the prevalence of Wolbachia in some important species of tephritids in Iran. Among different populations of five fruit fly species, Dacus ciliatus (cucurbit fly), Rhagoletis cerasi (cherry fruit fly), Ceratitis capitata (Mediterranean fruit fly), Myiopardalis pardalina (melon fly) and Carypomya vesuviana (jujube fly), two species, R. cerasi and C. vesuviana, showed infection with separate Wolbachia strains, namely wCer6 and wVes1, respectively. C. vesuviana is introduced here as a novel host for Wolbachia. Genotyping of Wolbachia strains in 12 populations of five fruit fly species, using multilocus sequence typing (MLST) and the wsp gene sequence showed the occurrence of two new strains as well as a new strain type (ST) belonging to the A supergroup. On the basis of the results of this study, 12 barcodes under five species of Iranian tephritids have been added to the database of DNA barcodes. Inter- and intra-specific differences among COI sequences showed a clear gap in barcoding among most fruit flies.

Primeiro registro de Tomoplagia reimoseri Hendel e Xanthaciura mallochi Aczél (Diptera: Tephritidae) para o Estado de Santa Catarina, Brasil

O presente trabalho tem como objetivo levantar as espécies de tefritídeos endófagos associados a capítulos de asteráceas em Chapecó, Santa Catarina. Para tanto, foram efetuadas coletas quinzenais no município de Chapecó, Santa Catarina, durante o período de setembro de 2005 a setembro de 2006, concentradas na primavera e no verão. Os capítulos foram destacados diretamente das plantas, no campo, e acondicionados em sacos plásticos. Este trabalho constitui o primeiro registro de Tomoplagia reimoseri Hendel e Xanthaciura mallochi Aczél coletados em capítulos de Asteraceae no município de Chapecó, elevando para 72 espécies de tefritídeos registradas para o referido Estado.

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.

Flowerhead-infesting fruit flies (Diptera: Tephritidae) on thistles (Asteraceae), in Lebanon

A survey of flowerhead-infesting tephritids on thistles was conducted in Lebanon during 1995–1998. Twenty thistle species belonging to the Asteraceae yielded 18 species of tephritids. Out of the 18 reared tephritids, 15 are reported for the first time to occur in Lebanon. Seventeen new host species and 11 new host genera for those tephritids are also reported for the first time.

Acoustic component and social context of the wing display of the walnut fly Rhagoletis juglandis

Courtship signaling via wing vibration, accompanied by sound production, has been reported in several species of tephritids. In this large family of flies, sound communication as well as complex courtship displays appears to be restricted to species with lekking mating systems (i.e., Mediterranean fruit fly, Anastrepha and Dacus species). In contrast, in tephritid species with resource-defense mating systems, such as species in the genus Rhagoletis, little or no courtship behavior, acoustical or otherwise, has been described. Wing displays in Rhagoletis species have been considered to play a visual role. This study describes a distinctive wing display performed by males of the walnut fly, Rhagoletis juglandis. Laboratory experiments and field observations demonstrate that the male wing display plays a role in courtship. We used sound and vibration detectors to record the signals produced by this wing display. Using a combination of techniques, we were able to record both the very low-frequency vibration and its accompanying airborne infrasound (12–22 Hz) produced by the males.

Natural Occurrence of Parasitoids ofAnastrephaspp. Schiner, 1868 (Diptera: Tephritidae) in Different Host Plants, in Itaguai (RJ), Brazil

The relationship amongAnastrephaspp. flies, their parasitoids, and host plants in Itaguai (RJ), Brazil, is described. Samples of mature fruit were taken from 12 different host plant species. Four species of braconid parasitoids and four species of tephritids subsequently emerged from the collections.Anastrepha fraterculus(Wiedemann) was parasitized by all of the braconids, i.e.,Doryctobracon areolatus(Szepligeti),D. brasiliensis(Szepligeti),Utetes (Bracanastrepha) anastrephae(Viereck), andOpius bellusGahan.A. obliqua(Macquart) andA. distinctaGreene were attacked by all the parasitoids, exceptD. brasiliensis. A. sororculaZucchi was parasitized byD. areolatusandU. anastrephae. A. obliquawas the most common fly species.D. areolatusaccounted for 89.23% of the total parasitization. The overall rate of parasitism ofAnastrephaspp. was 10.4%. However, parasitism varied considerably among host plants. Flies fromEugenia uniflora, E. brasiliensis, Spondias purpurea,andPsidium guajavawere the most heavily parasitized at 59.64, 23.27, 17.47, and 16.02%, respectively. Some tropical fruit host plants for theAnastrephaflies markedly facilitate parasitoid multiplication and deserve attention both as reservoirs of natural enemies and as targets for biological control within integrated fruit fly control programs.

Microbial gut floras of eight species of tephritids

The gut bacteria of eight tephritid species were isolated and characterized. Larvae of the genus Urophora and Tephritis dilacerata proved to house no microorganisms in their digestive organs. Bacteria were isolated from adults of five fruit fly species. Most of the bacterial strains were enterobacteria. Fruit-infesting tephritid species, flower-head species and gall formers had similar gut floras consisting of bacteria widespread in the soil and on the phylloplane.

Morphology of the Reproductive System in Anastrepha suspensa (Loew) and Notes on Related Species

Male and female reproductive systems of Anastrepha suspensa (Loew) are described and illustrated. Examination of ovarioles showed them to be polytrophic. A survey of available literature and dissections of preserved specimens provided a comparison of the number of spermathecae present in 25 species of tephritids.

Laboratory Assessment of 73 Insecticides Against the Oriental Fruit Fly, Melon Fly, and Mediterranean Fruit Fly13

From 1952 to 1968, several hundred insecticides were assayed in the laboratory (by topical applications to the thoracic mesonotum) for toxicity to the 3 species of tephritids found in Hawaii: oriental fruit flies, Dacus dorsalis Hendel; melon flies, D. cucurbitae Coquillett; and Mediterranean fruit flies, Ceratitis capitata (Wiedemann). The results with 73 insecticides are reported by computed dosemortality curves LD50 levels in εg toxicant/fly, the upper and lower limits at the 95% confidence level, and the slopes. Malathion was the standard for comparison. LD50’s were not established for chlorobenzilate, dicofol, Zinophos® O, O-diethyl O-pyrazinyl phosphorothioate), and tetradifon. At any dose tested, no LD50 against oriental fruit flies was established for carbaryl; no LD50 against the melon fly was established for DDT, methoxychlor, and Pyrazoxon® (diethyl 3-methylpyrazol-5-yl phosphate); and no LD50 against oriental fruit flies and melon flies was established for Terbeno® (polychlorinated terpene). Dimethoate and naled were generally the most toxic of the insecticides against all 3 species when they were applied in this manner.

Suspected Sex Pheromone Glands in Three Economically Important Species of Dacus12

Recent work demonstrated the presence of a sex pheromone gland associated with the rectum of the male Queensland fruit fly, Dacus tryotni (Froggatt), which produced substances attractive to female files. Similar rectal gland complexes, which are described, also are present in at least 2 other species of male tephritids, the oriental fruit fly, D. dorsalis Hendel, and the olive fruit fly, D. oleae (Gmelin), which correspond closely in their anatomical and histological makeup to that described for D. tryoni . The gland consists of a reservoir occupying the right lateral posterior one-third of the rectal sac, and a small bulbular secretary sac opening into the reservoir at its base. Both structures are lined by folded layers of large epithelial cells. In a 3rd species, the melon fly, D. cucurbitae Coquillett, a rectal gland also is present, hut is situated ventro-laterally off of the rectal sac. It forms a distinct chamber connected to the rectal sac but remains separated from the lumen of this structure by bands of longitudinal and circular muscles. Internally, the epithelial lining consists of large epithelial cells greatly folded upon one another.