Laboratory longevity and competitiveness of Dacus ciliatus Loew (Diptera: Tephritidae) following sub-sterilizing gamma irradiation (original) (raw)
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Anais da Academia Brasileira de Ciências
Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae) is a major fruit pest, which is basicaly controlled using insecticides, which represents a risk to benefi cial arthropods, human health and food contamination. The sterile insect technique (SIT) is a potential alternative tool for the management of this pest, however, only confl icting data is found regarding the optimal dose to achieve sterility. Thus, this study evaluated the effect of gamma radiation doses (0, 40, 50, 60 and 70 Gy) on male and female reproductive sterility, gonads morphometry, emergence, fl ight ability, and longevity under nutritional stress of A. fraterculus. Full female sterility was achieved at 50 Gy, while full male sterility was achieved at 70 Gy. Both ovarian and testicular sizes were affected by irradiation, while no infl uence was observed on the quality parameters evaluated. Our results suggest that 70 Gy applied 48 h before adult emergence can be used to sterilize A. fraterculus in a SIT programme.
Induction of Sterility in Anastrepha Fraterculus (Diptera: Tephritidae) by Gamma Radiation
Florida Entomologist, 2007
In relation to the application of the sterile insect technique (SIT) for the South American fruit fly Anastrepha fraterculus (Wiedemann), we analyzed the effect on adult fertility of different doses of gamma irradiation and the age of pupae at the time of irradiation. In a first experiment, we applied doses of 50, 70, and 90 Gy to pupae at 24, 48, 72, and 96 h before adult emergence. In a second experiment we irradiated pupae 48 h before emergence with 20, 40, and 60 Gy and estimated male and female fertility and sperm transfer by irradiated males. The results indicated pupal age at irradiation does not significantly affect male fertility. If males irradiated with 60 Gy are crossed to non-irradiated females the fertility is about 1%. Females irradiated with 40 Gy did not lay eggs independently of the male to which they mated. No significant effects of radiation were observed with respect to the ability of males to transfer sperm. A dose of 70 Gy applied 48 h before adult emergence induces 100% sterility in both males and females.
In this study, laboratory and field cage experiments were conducted to assess the performance of sterile mass-reared Mexican fruit fly Anastrepha ludens (Loew) irradiated at various doses. In small laboratory cages, the radiation dose was found to have no effect on adult emergence, flying adults or survival at 25 days. In field cages, non-irradiated males and males irradiated at 20 and 40 Gy were found to exhibit greater mating propensity than males irradiated at 60 and 80 Gy. In large field cages in competition with wild males, cohorts of flies (male and female) irradiated at the low dose of 40 Gy and wild non-irradiated flies mated randomly, while flies irradiated at the high standard dose of 80 Gy mated assortatively. Irrespective of the radiation dose, laboratory flies courted and attempted copulation significantly earlier in the day than wild flies. In large field cages, cohorts of flies irradiated at low doses, e.g. 40 Gy, tended to induce greater sterility into a cohort of wild flies than those irradiated at 80 Gy, but the difference was not significant. Our results suggest that lowering the radiation dose currently applied to mass-reared flies in the Mexican fruit fly eradication campaign would substantially improve male mating performance. This could result in greater sterility induction without posing a risk in areas where target pest populations naturally prevail and are under suppression during the early stages of eradication programmes.
Radiation doses for sterilization of tephritid fruit flies
2004
In a database cataloguing radiation doses for arthropod sterilization and disinfestation, out of 65 entries on Diptera species from 16 families and 22 genera, 21 species belong to the Tephritidae, confirming the importance of this group in pest management and international trade in agricultural commodities. Following Tephritidae are Culicidae (15 species), Glossinidae (6), Muscidae (6), Calliphoridae (5), Drosophilidae (1), Anthomyiidae (1), Oestridae (2), Agromyzidae (2), Chloropidae (1), Piophilidae (1), Cuterebridae (1), Psilidae (1), Sarcophagidae (1), Sciaridae (1) and Tachinidae (1). The 21 species of Tephritidae belong to five genera, with Bactrocera having the largest number of species (9) being the subject of studies on sterility induction for pest control,followed by Anastrepha (6 species), Rhagoletis (3), Ceratitis (2) and Dacus (1). The mean dose to induce sterilization in Tephritidae is 65 Gy, which reflects an intermediate sensitivity to radiation compared toother Dipt...
Irradiation of Anastrepha ludens (Diptera: Tephritidae) Revisited: Optimizing Sterility Induction
Journal of Economic Entomology, 2007
Irradiation doses currently applied to sterilize Mexican fruit ßies, Anastrepha ludens (Loew) (Diptera: Tephritidae), for release under the sterile insect technique eradication campaign in Mexico, were reviewed in an effort to increase sterile male performance in the Þeld. A dose maximizing sterility induction into wild populations was sought by balancing somatic Þtness with genetic sterility. Doses of 40, 60, and 80 Gy induced 95% or more sterility in all males, which in turn induced similar degrees of sterility into a cohort of wild ßies in the laboratory. However, a low dose of 40 Gy was sufÞcient to completely suppress egg production in females. Similarly, a mild carryover of genetic damage might have been transferred to the F1 progeny of males irradiated at 40 Gy crossed with fertile wild females. Our results suggest that the 80-Gy dose currently applied in Mexico can be lowered substantially without jeopardizing program goals. This view could be strengthened by comparing performance of males irradiated at different doses under more natural settings. In general, we discuss the value of determining irradiation doses for pest species where females are more radiosensitive than males, by selecting the dose that causes 100% sterility in females.
1989
Tupac of the oriental fruit lly, Ducus tlnnalis Hi-ndcl. which had been exposed as larvae to the parasiloid, Bimlnrs Itmpraudatia (Ashmead), were subjected to 10 krad gamma radiation in nitrogen atmosphere on the eleventh clay after parasili/alioii. The irradiation treatment caused sterility in the adult parasitoids of both sexes. Camilla irradiation slightly enhanced longevity ol treated females when compared with un treated parasitoids. However, longevity of treated males decreased significantly. The sterile insect and the augmentative parasitoid release techniques are two ecologically acceptable methods for the suppression of tephritid fruit fly populations in Hawaii (Wong et al. 1984). The integration of both suppression methods is proposed to be more effective and less costly than the use of either of these methods alone, or the use of insecticide sprays (E. F. Knipling, personal communication). During the laboratory rearing of tephritid fruit fly parasitoids, over 50% of the h...
Irradiation of Anastrepha obliqua (Diptera: Tephritidae) Revisited: Optimizing Sterility Induction
Journal of Economic Entomology, 2004
The effects of irradiation doses increasing from 0 to 100 Gy (1 Gy is energy absorbed in J kg Ϫ1 of irradiated material) on fertility, ßight ability, survival, and sterile male mating performance were evaluated for mass-reared Anastrepha obliqua (Macquart). High sterility values (Ͼ98.2%) for irradiated males were obtained for doses as low as 25 Gy. Egg hatch was inhibited for irradiated males crossed with irradiated females at a low dose of 20 Gy. However, we estimated that to achieve 99.9% sterility (standard goal of many sterile insect technique programs), irradiation doses had to be increased to a dose between 50 and 75 Gy. At doses of 25 Gy and greater, we observed a decreasing trend in adult ßight ability and an increasing trend in adult mortality. Such differences were greater for pupae irradiated at a young age compared those irradiated 24 h before emergence. Our single most relevant Þnding was that sterility induction (i.e., oviposition of nonfertilized eggs) was two times greater for males irradiated at low doses (40 Gy) than for males irradiated at high doses (80 Gy) when used at a 3:1:1 sterilized male to fertile male to fertile female ratio. Males irradiated at high doses may have been outcompeted by unirradiated males when courting unirradiated females. Implications of our Þndings for sterile insect technique programs are discussed.
Journal of Applied Entomology, 2008
Queensland fruit fly (Bactrocera tryoni; Q-fly) pupae are routinely irradiated to induce reproductive sterility in adults released in a sterile insect technique programme. Although there have been some studies of how total dose influences fly quality, dose rate has not been considered. In the present study, pupae were irradiated at a target dose range of 70-75 Gy at dose rates of approximately 5, 7, 26, 57 and 80 Gy/min and were then subjected to routine IAEA/FAO/USDA quality control tests including emergence, flight ability, mortality under stress and sterility induction. No significant effects of dose rate were found on emergence or flight ability. Sterility induction was also found to be independent of dose rate, a result conforming to a 'one-hit' ionizing event hypothesis. Flies irradiated at higher dose rates suffered increased mortality under stress. This appears to stem from an increased tendency to over-shoot the target dose when irradiating at high dose rates. We recommend that, to reduce potential error in total target dose, the lowest practical dose rate be used when irradiating Q-fly pupae for use in the sterile insect technique. Relationship between irradiation dose rate (Gy/min) and total dosage absorbed by the pupae (Gy).
Journal of economic entomology, 2018
Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) is a widely distributed pest of soft-skinned and stone fruits that is controlled mainly with pesticides. An alternative to the chemical control is the sterile insect technique (SIT), an ecologically friendly method of pest management that could be used against D. suzukii. The objective of the present study was to evaluate the effects of gamma radiation on reproductive sterility, ovarian morphometry, and quality parameters of D. suzukii. Full female sterility was achieved at 75 Gy, while an adequate level of male sterility (99.67%) was obtained at 200 Gy. The ovarian size showed an exponential decay in function of irradiation dose increase. There was no significant influence of irradiation dose on the quality parameters evaluated. Our data suggest that gamma radiation can be recommended to be used in an SIT program for D. suzukii.