Bactrocera (Notodacus) xanthodes ( Broun, 1905 )

Leblanc, Luc, 2022, The dacine fruit flies (Diptera: Tephritidae: Dacini) of Oceania, Insecta Mundi 2022 (948), pp. 1-167 : 147-149

Bactrocera (Notodacus) xanthodes ( Broun, 1905)

Pacific fruit fly

Figure 89

Distribution ( Fig. 121 ). Fiji ( Viti Levu, Vanua Levu, Lau Group, Rotuma). Futuna. Wallis. Samoa (Savai’i, Manono, Upolu). American Samoa. Tonga (Tongatapu Group, Ha’apai Group, Vava’u Group, Niuas Group). Niue. Cook Islands (Rarotonga, Mangaia, Mauke, Mitiaro, Atiu, Aitutaki; introduced early 1970’s). French Polynesia (Austral Islands: Raivavae, Rimatara, Rurutu; detected 1998). Nauru (detected 1992, eradicated 2000).

Male lure. Methyl eugenol (weak attractant), methyl-isoeugenol (strong attractant: Royer et al. 2019b).

Host plants. Category B polyphagous fruit pest ( Vargas et al.2015) bred from 34 host species in 20families.Records in American Samoa, Cook Islands, Fiji, Nauru, Samoa, Tonga, and Wallis: ANACARDIACEAE : Mangifera indica . ANNONACEAE : Annona cherimola , A. muricata . APOCYNACEAE : Cerbera manghas , Ochrosia oppositifolia . CALOPHYLLACEAE : Calophyllum inophyllum . CARICACEAE : Carica papaya . COMBRETACEAE : Terminalia catappa , T. samoensis . CONVOLVULACEAE : Stictocardia tiliifolia . CUCURBITACEAE : Citrullus lanatus . EBENACEAE : Diospyros ferrea . EUPHORBIACEAE : Excoecaria agallocha . FABACEAE : Inocarpus fagifer . LAU- RACEAE: Persea americana . LECYTHIDACEAE : Barringtonia edulis , B. racemosa , B. seaturae . MALVACEAE : Theobroma cacao . MORACEAE : Artocarpus altilis , A. heterophyllus . PASSIFLORACEAE : Passiflora edulis , P. ligularis , P. quadrangularis . RUTACEAE : Citrus japonica , C. maxima , C. reticulata , C. sinensis . SANTALACEAE : Santalum yasi . SAPOTACEAE : Burckella richii , Chrysophyllum cainito , Pouteria caimito . SOLANACEAE : Solanum lycopersicum , S. mauritianum .

Edible hosts common names. Abiu, avocado, breadfruit, cherimoya, cocoa, giant granadilla, jackfruit, kumquat, mango, orange, papaya, pomelo, purple granadilla, soursop, star-apple, sweet granadilla, Tahitian chestnut, tangerine, tomato, tropical almond, watermelon.

Biology. Adults mate at dusk (Allwood 1997). Rate of development was studied by Kassim (1993). At 27° C in papaya, egg hatch starts after 36 hours, 40% of larvae have reached second instar by 72 hours, and 76% have reached third instar by 120 hours. Larval popping starts at 156 hours, and 67% have pupated by 168 hours. Adult longevity is 21 weeks under laboratory conditions. A female lays on average 143 eggs over 112 days, starting two weeks after emergence, with egg laying peak egg laying at weeks 9 to 12. Pacific fruit fly is commonly found in the village, suburban and coastal environments, where breadfruit and mango are common, and is absent in forest habitats ( Leweniqila et al. 1997b). Monthly trapping data is illustrated on Figures 133 , 134 , and was published in Litsinger et al. (1991), Leweniqila et al. (1997b), and Tora Vueti et al. (1997c). This species is parasitized by Fopius arisanus in the Cook Islands, Fiji, Tonga and Samoa, and also by Diachasmimorpha longicaudata in Fiji ( Vargas et al. 2012a).

Notes. Heat tolerance was studied in Fiji, Tonga, Samoa and Cook Islands ( Foliaki and Armstrong 1997; Tora Vueti et al. 1997b; Waddell et al. 1997a; Tunupopo et al. 2019). It is less heat tolerant than B. passiflorae , B. facialis , B. kirki and B. melanotus . The eradication of this species in Nauru took a lot longer than initially expected, in great part due to weak attraction to methyl eugenol ( Allwood et al. 2002). Methyl-isoeugenol, a more potent attractant than methyl eugenol for this species, should preferably be used for monitoring, control and eradication of B. xanthodes ( Royer et al. 2019b) .

Figures

Figure 89. Bactrocera (Notodacus) xanthodes (Broun). A) Head. B) Head and scutum. C) Abdomen, female. D) Abdomen, male. E) Abdomen apex of male, ventral view. F) Wing. G) Lateral view.

Figure 121. Distribution and invasion and eradication history of fruit flies in the Bactrocera xanthodes complex in Oceania: Bactrocera paraxanthodes Drew and Hancock, B. neoxanthodes Drew and Romig, B. xanthodes (Broun), and undescribed species near B. paraxanthodes in Samoa. Photos of B. neoxanthodes and B. xanthodes by Steve Wilson.

Figure 133. Mean (±SE) daily captures of Bactrocera xanthodes (Broun) in methyl eugenol traps maintained: A) In coastal, inland and forest trapping sites on Rarotonga Island (Cook Islands) between May 1991 and September 1992, based on 18 trapping sites (n = 306, mean FTD = 0.48), and B) in Fiji (Viti Levu, Vanua Levu) between September 1991 and August 1992, based on seven trapping sites (n = 81, mean FTD = 6.06).

Figure 134. Mean (±SE) daily captures of Bactrocera xanthodes (Broun) in methyl eugenol traps maintained: A) in Samoa (Upolu Island) between January 2000 and June 2001, based on eight trapping sites (n = 139, mean FTD = 1.88), and B) in Tonga (Tongatapu and Vava’u Islands) between January and December 1995 and 1999, based on 15 trapping sites (n = 209, mean FTD = 1.13).