Functional Morphology of the Mouthparts of the Adult Mediterranean Fruit Fly, Ceratitis capitata

Food-based attractants incorporating an insecticide are an important component of area-wide control programmes for the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). This study was carried out to understand the feeding mechanism of adults of this species. Mouthparts of C. capitata are similar in general structure to those of another Tephritid genus, Bactrocera, and have specific structural modifications that determine what adult flies can ingest. The labellum has a series of fine tube-like structures, called pseudotracheae, on its inner surface. Each pseudotrachea leads from the outer margin of the labellum and ends at the prestomum to the oral opening. The pseudotracheae contain fine micropores about 0.5µm in size. During feeding, the oral opening is never exposed to the feeding substrate but the portions of the opposing labellar lobes proximal to the oral opening are flexed against each other and distal portions of the opposing labellar lobes are opened and pressed flat against the feeding substrate or surface. The prestomal spines at the base of each pseudotrachea interlock to form a barrier across the oral opening. Thus entry of large particles directly into the crop and gut through the oral opening is prevented by flexure of the opposing labellar lobes against each other and the interlocking prestomal spines across the oral opening. Only liquids and suspended particles less than 0.5µm in size are sucked through the micropores into the lumen of the pseudotracheae and then pass into the food canal and into the crop and gut. The pseudotracheae of adult C. capitata, particularly along the middle portion of the labellum, have prominent blade-like projections that Bactrocera do not have. These projections are probably an ancestral condition as they were not observed to use them to abrade the plant or feeding surface as has been reported for species in the Tephritid genus, Blepharoneura

Alimentary Tract Bacteria Isolated and Identified with API-20E and Molecular Cloning Techniques from Australian Tropical Fruit Flies, Bactrocera cacuminata and B. tryoni

Bacteria were isolated from the crop and midgut of field collected Bactrocera cacuminata (Hering) and Bactrocera tryoni (Froggatt) (Diptera: Tephritidae). Two methods were used, firstly isolation onto two types of bacteriological culture media (PYEA and TSA) and identification using the API-20E diagnostic kit, and secondly, analysis of samples using the 16S rRNA gene molecular diagnostic method. Using the API-20E method, 10 genera and 17 species of bacteria in the family Enterobacteriaceae were identified from cultures growing on the nutrient agar. The dominant species in both the crop and midgut were Citrobacter freundii, Enterobacter cloacae and Klebsiella oxytoca. Providencia rettgeri, Klebsiella pneumoniae ssp ozaenae and Serratia marcescens were isolated from B. tryoni only. Using the molecular cloning technique that is based on 16S rRNA gene sequences, five bacteria classes were dignosed — Alpha-, Beta-, Gamma- and Delta- Proteobacteria and Firmicutes — including five families, Leuconostocaceae, Enterococcaceae, Acetobacteriaceae, Comamonadaceae and Enterobacteriaceae. The bacteria affiliated with Firmicutes were found mainly in the crop while the Gammaproteobacteria, especially the family Enterobacteriaceae, was dominant in the midgut. This paper presents results from the first known application of molecular cloning techniques to study bacteria within tephritid species and the first record of Firmicutes bacteria in these flies

Survey of Opiine parasitoids of fruit flies (Diptera:Tephritidae) in Thailand and Malaysia

A survey of fruit flies (Diptera: Tephritidae) from wild and cultivated host plants was conducted in Thailand and Malaysia between 1986 and 1994. In addition to fruit flies, host samples also yielded parasites of those flies, predominantly opiine wasps (Hymenoptera: Braconidae: Opiinae). Although used extensively in classical biological control programmes, very little is known about the host relationships of these parasites in their native environment. From the survey work, host records are given for 13 described species (viz. Diachasmimorpha albobalteata [Cameron], D. dacusii [Cameron], D. longicaudata [Ashmead], Fopius arisanus [Sonan], F. deeralensis [Fullaway], F. persulcatus [Silvestri], F. skinneri [Fullaway], F. vandenboschi [Fullaway], Opius bellus Gahan, Psvtallia flelcheri [Silvestri], P. incisi [Silvestri], P. makii [Sonan] and Utetes bianchii [Fullaway]) and three undescribed opiines. The parasitoid species are listed in relation to the fruit fly species within fruit samples, and the plant species from which the flies and wasps were reared

Management of Melon Fly, Bactrocera cucurbitae (Coquillett) Infesting Gherkin:An Areawide Control Programme Adopted in Peninsular India

An area-wide control (AWC) programme was undertaken for management of melon fly, Bactrocera cucurbitae(Coquillet), in 3 km2 area in Kashapura village of Gauribidanur taluk, Chickaballapura District, Karnataka State in peninsular India from 52nd week of 2007 to 30th week of 2010. Implementation of the AWC programme included field sanitation, male annihilation technique (MAT) through para-pheromone, Cue lure, and bait application technique (BAT). This AWC programme resulted in steady decline of melon fly population in the grid area, and corresponding reduction in per cent fruit fly infested gherkin fruits. In the AWC (grid) area, flies trapped per day (FTD) led to attaining suppression (1 to 0.1 FTD) and eradication levels (<0.1 FTD), which is acceptable to the Indian gherkin processing industry. Whereas, in the non-grid area, fruit fly populations perpetuated at infestation level (>1 FTD) during majority of weeks under observation

Multiple mating by females of two Bactrocera species (Diptera: Tephritidae: Dacinae)

Abstract Multiple mating was investigated in two tephritid species when females were under minimal male pressure because they were each confined with a single male in cages 20r20r20 cm and observed daily until they died. Laboratory-reared females of Bactrocera cucumis (French) lived up to 274 days and refractory periods averaged 59-63 days. However, the distribution of matings among B. cucumis females was not significantly different to that expected by chance. Wild females of Bactrocera cacuminata (Hering) reared from field-collected fruits of Solanum mauritianum Scopoli lived for up to 134 days and mated up to three times with refractory periods between matings averaging 27-39 days. The distribution of the number of matings among females of B. cacuminata was non-random because of the high proportion of non-maters (50%); but, when only females mating more than once were considered, there was no significant departure from random expectation

Mouthpart structure, feeding mechanisms, and natural food sources of adult Bactrocera (Diptera: Tephritidae)

Mouthpart structure, feeding mechanisms, and natural sources of food of the adults of 4 species of fruit flies in the genus Bactrocera - B. tryoni (Froggatt), B. jarvisi (Tryon), B. cacuminata (Hering), and B. cucumis (French) - were studied. When exposed to dry or semisolid food, adult flies always regurgitated fluid from their crop to liquefy and dissolve the food substrate. The regurgitated liquid, along with the dissolved food, was then reingested. Flies without fluid in their crops were unable to liquefy and feed on dry and semisolid food. Liquids were always imbibed without fluids being regurgitated from the crop. Food particles and liquids were ingested only through fine micropores

Mouthpart structure, feeding mechanisms, and natural food sources of adult Bactrocera (diptera: tephritidae)

Mouthpart structure, feeding mechanisms, and natural sources of food of the adults of 4 species of fruit flies in the genus Bactrocera-B. tryoni (Froggatt), B. jarvisi (Tryon), B. cacuminata (Hering), and B. cucumis (French)-were studied. When exposed to dry or semisolid food, adult flies always regurgitated fluid from their crop to liquefy and dissolve the food substrate. The regurgitated liquid, along with the dissolved food, was then reingested. Flies without fluid in their crops were unable to liquefy and feed on dry and semisolid food. Liquids were always imbibed without fluids being regurgitated from the crop. Food particles and liquids were ingested only through fine micropores (<0.5 µm) on the pseudotracheae. Particles larger than 0.5 µm were not ingested because the opposing oral lobes were held together tightly during feeding so that the oral opening was never exposed to the food substrate. In addition, interlocking prestomal spines project across the oral opening and also may help prevent the entry of large particulate matter. Particles larger than bacteria, such as yeasts, fungal spores, and pollen grains that are commonly found on fruit and leaf surfaces where adult flies commonly forage, were thus excluded by the labellar filtering mechanism. This interpretation, together with the results of field observations on their feeding behavior and laboratory and field-feeding experiments (reported elsewhere), suggest that adult fruit flies in the genus Bactrocera use a combination of their fluid-centered mode of feeding and their labellar filtering mechanism to feed on fruit juices, leachates, and bacteria (Enterobacteriaceae), which constitute their primary source of food in nature

Mating activity of Bactrocera cacuminata (Hering) (Diptera: Tephritidae) on its larval host plant Solanum mauritianum Scopoli in southeast Queensland

A detailed study was conducted on the mating behaviour of Bactrocera cacuminata (Hering) (Diptera: Tephritidae) in nature. Plant tissues from Solanum mauritianum Scopoli, the primary larval host for B. cacuminata, were also analysed for methyl eugenol content. In the field, over a 15 month period, 44,171 observations of adult B. cacuminata individuals were made including 1109 mating pairs on S. mauritianum. Calling behaviour consisting of wing fanning and anus beating by males was also consistently observed on the underside of leaves of S. mauritianum after sunset. Female flies that arrived into these groups of 10–15 calling males were mated and often remained coupled until dawn. No methyl eugenol was detected from the analysis of leaves, flowers and fruits of S. mauritianum. Thus, B. cacuminata does not need to aggregate at sites where methyl eugenol is present and the hypothesis that this chemical plays a role in the selection of mating sites by B. cacuminata is not supported by the current study. It is concluded that S. mauritianum is the primary site of mating for B. cacuminata in nature and that the concept that the larval host plant is the centre of activity for dacine fruit flies remains robust, being fully supported by the results of this study