Desmoscolecids (Nematode) from New Georgia,Solomon Islands

Two new desmoscolecid species are described: Desmoscolex koloensis sp. nov. and D. parakoloensis sp. nov. Additional information is given on Desmoscolex (Desmolorenzenia) montana, D. sieverti and D. fennicus. The genus Desmolorenzenia is considered a subgenus of Desmoscolex. Pareudesmoscolex lacustris represents a juvenile state of Desmocolex dussarti. Some reflections are made on terrestrial and freshwater desmoscolecids.     

New contributions towards the understanding of the phylogenetic relationships among economically important fruit flies (Diptera: Tephritidae)

Fruit flies (Diptera: Tephritidae) are a species-rich and economically important group. The phylogenetic relationships among the many taxa are still to be fully resolved and the monophyly of several groups is still to be confirmed. This paper reports a study of the phylogenetic relationships among 23 economically important tephritid species (representing several major lineages of the family) which examines the sequence of a region of mitochondrial DNA encompassing the cytb, tRNA(Ser) and ND1 genes. Substitutions characteristic of particular taxa were found that could help classify members of the family at any developmental stage. The trees obtained by the maximum parsimony, neighbour joining and maximum likelihood methods were generally compatible with present morphological classification patterns. However, the data reveal some characteristics of the phylogenetic relationships of this family that do not agree with present classifications. The results support the probable non-monophyletic nature of the subfamily Trypetinae and suggest that Bactrocera cucurbitae (Coquillet) is more closely related to the genus Dacus than to other species of Bactrocera.     

Effectiveness of thiamethoxam-coated spheres against blueberry maggot flies (Diptera: Tephritidae)

Studies were conducted to evaluate the mortality of blueberry maggot, Rhagoletis mendax Curran, flies exposed to thiamethoxam- and imidacloprid-coated biodegradable (8-cm-diameter) red spheres, under both laboratory and field conditions. Laboratory studies with spheres coated with 0.1-2.0% (AI) of thiamethoxam indicated that they are effective against R. mendax; however, no dose-dependent response was observed. Studies on the effect of visitation time on thiamethoxam-coated spheres showed a decrease in R. mendax mortality as the duration of visitation time decreased from 60 to 10 s. Under field conditions, significantly more flies were captured on Plexiglas panes below the 2% (AI) thiamethoxam-coated spheres when compared with similar panes below untreated spheres. In field evaluations of thiamethoxam- and imidacloprid-coated spheres, imidacloprid-coated spheres (2.0% [AI]) were found to be significantly more effective than thiamethoxam-coated spheres (0.5-4.0% [AI]). Field trials to characterize the levels of mortality associated with aging pesticide-coated spheres revealed that the effectiveness of treated spheres decreased with increasing age of sphere, and this reduction in effectiveness is greater in thiamethoxam-coated spheres than in imidacloprid-coated spheres. These results provide comparative data on the effectiveness of thiamethoxam- and imidacloprid-coated spheres and support the potential of using pesticide-treated spheres for control of blueberry maggot flies.     

Microsatellite loci from the Caribbean Fruit Fly,Anastrepha suspensa (Diptera: Tephritidae)

The lack of polymorphic genetic markers suitable for genotyping sperm, eggs, and all life stages of the important agricultural pest, Anastrepha suspensa, have prevented detailed genetic studies of its breeding system, reproductive dynamics, and population dynamics. We describe polymerase chain reaction (PCR) primers and reaction conditions for amplifying nine polymorphic microsatellite DNA loci isolated from this species. The PCR primers were tested on four to five individuals each collected from five geographically distant locations in Florida. Heterozygosity values and the number of alleles per locus varied from 0.11 to 0.89, and from two to 12, respectively.     

A new genus in the tribe Acidoxanthini (Diptera: Tephritidae: Trypetinae) from India,with a discussion of its phylogenetic relationships

Gibbifronta pavoniae David, Hancock and Han, gen. et sp. nov., is described from India. The current status of the subtribe Acidoxanthina is scrutinized based on both morphological characters and DNA barcoding analysis, and this taxon is formally proposed as the tribe Acidoxanthini within the subfamily Trypetinae in order to accommodate the genera Gibbifronta, Acidoxantha Hendel, Craspedoxanthitea Hardy and Acidoxanthopsis Hering. We found that the members of the Acidoxanthini possess a unique characteristic within the family Tephritidae, the short and broadly truncate lateral surstylus with reduced prensisetae and 1–3 pairs of strong dorsal setae on epandrium. Even though comparable information is not available for Acidoxanthopsis, it is retained in Acidoxanthini. Gibbifronta is distinguished from other genera of the tribe by the presence of a high gena and prominent hump-like projection on the frons. Phylogenetic analysis based on DNA barcodes revealed that Gibbifronta is closely related to Acidoxantha and support its placement in Acidoxanthini. COI sequences of Gibbifronta pavoniae, Nitrariomyia lukjanovitshi Rohdendorf, Acidoxantha galibeedu David and Ramani and an undescribed Acidoxantha species have been obtained and reported. A key to the genera of Acidoxanthini is also provided.http://zoobank.org/100D010D-21D3-4F0B-B38E-1F72DC8E9BF3.     

实蝇共生菌研究进展

实蝇类昆虫(双翅目Diptera:实蝇科Tephritidae)是重要的农业害虫,为害农作物茎秆和水果,严重影响农业生产和果蔬贸易,被许多国家列为重要的检疫性有害生物。实蝇共生菌对宿主实蝇的取食、生殖、发育及环境适应能力具有重要作用。目前,已有21个属的共生细菌(Enterobacter、Klebsiella、Citrobacter、Pseudomonas、Providencia、Erwinia、Acetobacter、Serratia、Proteus、Hafnia、Cedecea、Arthrobacter、Lactobacillus、Micrococcus、Streptococcus、Staphylococcus、Vibrio、Hafnia、Deinococcacea、Bacillus、Wolba-chia)以及1个属的共生真菌(Candida)被鉴定。其中,肺炎杆菌Klebsiella pneumoniae、产酸克雷伯氏菌Klebsiella oxytoca、成团泛菌Pantoea agglomerans、费氏柠檬酸杆菌Citrobter freundii、阴沟肠杆菌Enterobacter cloaca...     

Visual responses of apple maggot flies, Rhagoletis pomonella (Diptera: Tephritidae): Orchard studies

Apple maggot flies, Rhagoletis pomonella, were found to be highly responsive to visual stimuli, with maximum responses dependent upon color, shape, and size characteristics of the stimulus. Each sex had a significant preference for yellow 30×40 cm rectangles over green, orange, red, blue, violet, black, white and clear rectangles of the same size. On the other hand, each sex had a significant preference for red, blue, violet, dark organge, and black spheres 7.5 cm in diameter over green, light orange, yellow, white, and clear spheres of the same size. Both sexes had a significant preference for 7.5 cm spheres over equivalent-sized cubes, cylinders and rectangles. As the diameter of a sphere was increased from 7.5 to 45 cm, there was an orderly and significant decrease in the attractiveness of those that were darkcolored (red) but a progressive and significant increase in the attractiveness of those that were yellow. The flies did not congregate on trees with apples or respond strongly to 7.5 cm, darkcolored spheres until they were sexually mature (at least in the case of females). Relative to other colors, females were often significantly more attracted than males to yellow. The attractiveness of an olfactory stimulus eliciting feeding-type reactions was enhanced to a substantial degree when employed in conjunction with a 30×40 cm yellow rectangle, but to only a very slight degree when in conjunction with a 7.5 cm red sphere.Evidence presented suggests the following explanation for these findings. The flies are attracted to large surfaces of yellow because they react to yellow, on the basis of true color discrimination, as if it were foliage on which to find food. On the other hand, they are attracted to small, dark-colored spheres because they react to such spheres as they react to apples, which are the oviposition site and which also appear to serve as a rendezvous site for the sexes in mating activity. Once the flies have arrived on apple trees, they detect apples solely through vision. Red, blue, violet, dark orange, and black small spheres are preferred over small spheres of other colors on the basis that they stand out in strongest contrast against the background and not on the basis of true color discrimination. Large, dark-colored spheres are unattractive because the range of sphere sizes eliciting positive responses is near the size of an apple.These findings have proven useful in designing effective devices for sampling orchard populations of the flies and may also prove useful in fly control.

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Zusammenfassung Imagines von Rhagoletis pomonella reagieren positiv auf visuelle Reize, wobei Farbe, Form und Grösse des Stimulus von ausschlaggebender Bedeutung sind. Beide Geschlechter zeigten in den Versuchen eine signifikante Präferenz für gelbe Rechtecke (30×40 cm), die sie häufiger anflogen als grüne, orange, rote, blaue, violette, schwarze, weisse und farblose Flächen gleicher Grösse. Ebenso zeigte es sich, dass Kugeln von 7.5 cm Durchmesser von den Fliegen eindeutig Kuben, Zylindern und Rechtecken gleicher Grössenordnung für den anflug bevorzugt wurden. Mit zunehmendem Durchmesser der Kugeln von 7.5 cm bis 45 cm konnte eine abnehmende Anziehung von dunkel gefärbten Kugeln, jedoch eine zunehmende Anziehung von gelben Kugeln auf die Fliegen beobachtet werden. Vor der Geschlechtsreife reagierten die Weibchen nicht in ausgeprägtem Maße auf die 7.5 cm dunkel gefärbte grossen Kugeln, sondern wurden mehr als die Männchen von Gelb angezogen. Die Wirkung eines Nahrungsköders wurde in Kombination mit einer gelben Fläche von 30×40 cm signifikant erhöht, während die Kombination des Köders mit einer roten Kugel von 7.5 cm Durchmesser die Anziehung von Weibchen nur unwesentlich erhöhte.Die Resultate lassen sich damit erklären, dass die Fliegen durch gelbe Flächen angezogen werden, weil sie dank Diskriminierung der Farbe auf Gelb reagieren als wäre es Blattwerk, auf dem sich die Nahrungsquellen befinden. Auf der anderen Seite werden sie von dunklen Kugeln in den Dimensionen eines Apfels angezogen, da im Freiland Äpfel Orte für die Eiablage und offenbar Treffpunkte für die Geschlechter darstellen. Sobald die Fliegen den Apfelbaum beflogen haben, orientieren sie sich allein mit dem Gesichtssinn gegen die Früchte. Kleinere rote, blaue, dunkel orange, violette und schwarze Kugeln werden anders gefärbten vorgezogen, weil sie den grössten Kontrast gegenüber dem Hintergrund bilden und nicht auf Grund echter Farbdiskriminierung. Grosse dunkle Kugeln verlieren ihre Wirkung auf die Fliegen, weil nur Kugeln in der Grössenordnung eines Apfels positive Reaktionen auslösen.Diese Befunde haben sich als nützlich erwiesen in der Ausarbeitung von Sammelmethoden für Freilandpopulationen und dürften auch in der Bekämpfung der Apfelfliegen Anwendung finden.

     

Fruit flies (Diptera: Tephritidae) and their parasitoids (Hymenoptera: Braconidae) associated to host plants in the southern region of Bahia State

The association among Anastrepha species, braconid parasitoids and host fruits in southern Bahia is recorded. Doryctobracon areolatus (Szépligeti) was associated with A. serpentina (Wied.) in Pouteria caimito, A. bahiensis Lima in Helicostylis tomentosa, A. sororcula Zucchi in Eugenia uniflora, and A. obliqua (Macquart) in Spondias purpurea. Anatrepha obliqua was unique in fruits of Averrhoa carambola, but associated with D. areolatus, Asobara anastrephae (Muesebeck) and Utetes anastrephae (Viereck). In Achras sapota, A. serpentina was associated with A. anastrephae and D. areolatus, while in Psidium guajava, A. fraterculus (Wied.) and A. sororcula were associated with D. areolatus and U. anastrephae.     

Management of Fruit Flies (Diptera: Tephritidae) of the Most Perishable Fruits

We investigated to minimize the dependency on the use of chemicals and thus develop safe and environmental friendly control program for the most perishable fruits i.e., apple,‘ber’, guava and mango. Our findings on the composition of fruit fly species reveal that Bactrocera dorsalis was dominant on apple (33.96% existence), Corpomya incompleta on‘ber’(51.91% existence) and Bactrocera zonata on guava (49.62% existence) and mango (74.66% existence). The correlation between population and infestation percentage was non‐significant in apple orchards, whereas positive and highly significant in between population and infestation, as well as on the cumulative basis in‘ber’, guava and mango orchards during 1998‐1999. Hoeing, baiting and methyl eugenol were statistically equal resulting about 77% decrease in infestation. The maximum control of 91.68% was observed where all four‐control operations including Dipterex® were integrated together. Weather factors, when computed together, had maximum effect on population fluctuation and infestation with rainfall contributing the major role. For guava fruits, the months of August (14.06A individuals/trap/day) and September (13.81A individuals/trap/day) were important, resulting in maximum infestation percentage of 10.76 to 14.74%, respectively.     

Effect of trap position, habitat, and height on the capture of pepper maggot flies (Diptera: Tephritidae)

Trapping results indicate that pepper maggot, Zonosemata electa (Say), flies occupy tree canopies adjacent to fields when not on host plants. Several in- and near-field trap positions were used to find a reliable monitoring system for adult pepper maggots. Traps baited with liquid ammonium hydroxide (Stills-style trap), hung in the canopy of trees on the edges of pepper fields, caught significantly more Z. electa flies than when positioned lower along the treeline or in the field. In a second experiment, significantly more pepper maggot flies were captured in sugar maples compared with choke cherry trees, which indicates a pest preference for certain nonhost habitats. The lowest trap height tested (2.1 m) failed to capture Z. electa flies in either tree species when the pest population level was low. These studies demonstrated that pepper maggot flies can be reliably detected with Stills-style traps positioned at approximately 6.4 m height within the canopy of sugar maple trees adjacent to pepper fields. Fruit oviposition scars also are useful site-specific indicators of pepper maggot presence/absence and may aid in determining if insecticide applications are necessary and in timing sprays.