Bactrocera papayae Drew & Hancock, Bactrocera philippinensis Drew & Hancock, Bactrocera carambolae Drew & Hancock, and Bactrocera invadens Drew, Tsuruta & White are four horticultural pest tephritid fruit fly species that are highly similar, morphologically and genetically, to the destructive pest, the Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). This similarity has rendered the discovery of reliable diagnostic characters problematic, which, in view of the economic importance of these taxa and the international trade implications, has resulted in ongoing difficulties for many areas of plant protection and food security. Consequently, a major international collaborative and integrated multidisciplinary research effort was initiated in 2009 to build upon existing literature with the specific aim of resolving biological species limits among B. papayae, B. philippinensis, B. carambolae, B. invadens and B. dorsalis to overcome constraints to pest management and international trade. Bactrocera philippinensis has recently been synonymized with B. papayae as a result of this initiative and this review corroborates that finding; however, the other names remain in use. While consistent characters have been found to reliably distinguish B. carambolae from B. dorsalis, B. invadens and B. papayae, no such characters have been found to differentiate the latter three putative species. We conclude that B. carambolae is a valid species and that the remaining taxa, B. dorsalis, B. invadens and B. papayae, represent the same species. Thus, we consider B. dorsalis (Hendel) as the senior synonym of B. papayae Drew and Hancock syn.n. and B. invadens Drew, Tsuruta & White syn.n. A redescription of B. dorsalis is provided. Given the agricultural importance of B. dorsalis, this taxonomic decision will have significant global plant biosecurity implications, affecting pest management, quarantine, international trade, postharvest treatment and basic research. Throughout the paper, we emphasize the value of independent and multidisciplinary tools in delimiting species, particularly in complicated cases involving morphologically cryptic taxa. Bactrocera (Bactrocera) dorsalis (Hendel)

In Queensland, three tomato ( Lycopersicon lycopersicum ) cultivars, Grosse Lisse, Roma and Cherry, are infested by Queensland fruit fly, Bactrocera tryoni (Froggatt). In this study, we examined if there was a correlation between oviposition preference and offspring performance of B. tryoni among the three tomato cultivars. We also investigated host plant traits that may explain any variation in preference and performance. Choice and no-choice experiments were carried out under laboratory conditions. A positive correlation between oviposition preference and offspring performance of B. tryoni was observed in the three tomato cultivars. Grosse Lisse and Roma cultivars were highly preferred by B. tryoni over Cherry cultivar. Performance (measured as proportion of eggs developing to the pupal stage) was significantly higher in Grosse Lisse and Roma cultivars than in Cherry cultivar. The pericarp toughness of Cherry cultivar appears responsible for its low rate of infestation, while the presence of 2-butanol and 1,4-butanediamine in Roma and Grosse Lisse, respectively, may partly be responsible for the high oviposition preference shown by B. tryoni towards these cultivars.

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.

Mouthpart structure, feeding mechanisms and natural sources of food of the adults of four species of Bactrocera fruit flies (Tephritidae: Diptera) endemic to Queensland, viz. Bactrocera tryoni (Froggatt), Bactrocera jarvisi (Tryon), Bactrocera cacuminata (Hering) and Bactrocera cucumis (French), were stnjdied. When exposed to dry food, adults always regurgitated fluid from their crop to liquefy and dissolve the food substrate. Regurgitated liquids and dissolved food were then reingested but only through fine micropores (< 0.5 ^jim) on the feeding tubules (pseudotracheae). Large particles (> 0.5 | jLm) were prevented from being ingested by prestomal spines, which project across the oral opening, as well as by t±ie flexure of tiie oral lobes to form the prestomal sulcus. The intake of food by Bactrocera adults was thus restricted to fluids and firuit fiy-type bacteria. Larger particles, such as pollen grains, fungal spores and even yeasts, commonly found on the surfaces, were excluded by the micropores.Studies on the infiuence of diet on the development of the gonads, accessory glands and ability to mate in B. tryoni provided previously unavailable information on the development of the accessory glands in both sexes, and the erecting and pumping organ of males in relation to diet. The current view, that male flies do not require proteins for normal sexual activity, is inaccurate. Although males deprived of proteins could mate and inseminate females, they had a smaller erecting and pumping organ, and were less competitive compared with males fed proteins.Systematic field observations on the diet pattern of activity of adult B. tryoni and B. cacuminata in their native environments: (i) identified the major feeding and mating sites of B. tryoni and B. cacuminata; (ii) established that adult flies fed primarily on the surfaces of host fruits; and (iii) confirmed the importance of the host plant as a centre of activity of tropical tephritids.

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.

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 20 x 20 x 20 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.

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.

Fruit flies (Diptera: Tephritidae) are major pests of fruits and vegetables in many countries, including Indonesia. Knowledge of the fruit fly host range in a specific area is an important part of the area-wide pest management program to reduce the pest problem. The aim of this study was to extend and update the information on the host range of fruit flies in the Regency of Sleman, Yogyakarta. This area is one of the centers of fruit production, particularly snake fruit in Indonesia. Fruit sampling was conducted from August 2019 to February 2020 in four sub-districts in Sleman consisting of different types of agro-ecosystems. Fruit rearing was carried out in the laboratory followed by identification of the fruit and fruit flies that emerged to species level. From the 23 species of fruits belonging to 14 different families that were collected, the following 6 species of fruit flies emerged: Bactrocera dorsalis, B. carambolae, B. umbrosa, B. albistrigata, B. mcgregori, and Zeugodacus cucurbitae. Bactrocera dorsalis and B. carambolae utilized the widest range of hosts, 12 and 11 species of fruits, respectively. Syzygium cumini, Malpighia emarginata, and Phaleria macrocarpa were recorded for the first time as new hosts of B. carambolae in Indonesia. Additional data of B. dorsalis and B. carambolae infesting salak cv. pondoh is also reported.