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Industry and, Mauritius

Sookar P.,Agricultural Services | Alleck M.,Agricultural Services | Ahseek N.,Agricultural Services | Bhagwant S.,University of Mauritius
African Entomology | Year: 2014

Tephritid fruit flies are serious pests in Mauritius, of which Bactrocera zonata (Saunders) (Diptera: Tephritidae) is one. One of the pathogens of fruit flies is Beauveria bassiana (Balsamo) Vuillemin; the introduction of this entomopathogen into the wild fly population would be beneficial for suppression of fruit fly populations. Five releases were made to study the dispersal behaviour and survival of sterile B. zonata males either treated or untreated with dry conidia of B. bassiana, in vegetable plantations bordered with papaya and mango trees in northern Mauritius from April 2010 to December 2012. The flies used were reared for ≈172 generations in the laboratory. Results showed that the dispersal behaviour and post-release survival were different for the two types of sterile males. Recapture rates of B. bassiana-treated sterile males (2.0 ± 1.4 %) were significantly lower than those of untreated flies (6.2 ± 5.5 %). However, the recapture rates for both types of males were within acceptable limits for release-recapture studies with mass-reared and irradiated fruit flies. Up to day 4 after release the percentage recovery of sterile B. zonata males untreated and treated with B. bassiana was 76 % and 81 %, respectively; 90 % of the recovered sterile flies from both groups were recovered up to 100 m from the release point, and only 4 % at a distance between 150 m and 200 m from the release point. Our results suggest that sterile B. zonata males could potentially be used as vectors of B. bassiana to supplement suppression of this pest in a sterile insect release programme.

Sookar P.,Agricultural Services | Bhagwant S.,University of Mauritius | Khayrattee F.B.,Agricultural Services | Chooneea Y.,Agricultural Services
Journal of Applied Entomology | Year: 2014

Field cage tests were carried out to determine the mating compatibility of sterile and wild melon fly, Bactrocera cucurbitae (Coquillett), males that were treated or not treated with entomopathogenic fungi. The melon flies were irradiated at 70 Gy, and the adults were treated with dry conidia of either Beauveria bassiana (Balsamo) or Metarhizium anisopliae (Metchnikoff) Sorokin 1 day before the mating test. Our results demonstrate that sterile melon flies treated with either B. bassiana or M. anisopliae showed mating compatibility with the wild flies. Inoculation of the flies with the fungi did not significantly affect the mean time of copulation (323-567 min) as compared to mating involving only wild flies (407-518 min). Treatment of the flies with either B. bassiana or M. anisopliae did not significantly affect the propensity of mating. Wild females mated indiscriminately with sterile, sterile B. bassiana-treated or sterile M. anisopliae-treated males. Irrespective of the treatment combinations, mean percentage remating was significantly higher for sterile females with sterile males (7.72-27.12%) as compared to wild females with sterile males (0.76-14.90%). The possibility of using sterile melon flies as vectors of the entomopathogenic fungi to enhance an SIT programme is discussed. © 2013 Blackwell Verlag GmbH.

Sookar P.,Agricultural Services | Bhagwant S.,University of Mauritius | Allymamod M.N.,Agricultural Services
Journal of Insect Science | Year: 2014

In Mauritius, the peach fruit fly, Bactrocera zonata Saunders (Diptera: Tephritidae), and the melon fly, Bactrocera cucurbitae (Coquillett), are the major pest of fruits and vegetables, respectively. Fruit growers make use of broad-spectrum insecticides to protect their crops from fruit fly attack. This method of fruit fly control is hazardous to the environment and is a threat to beneficial insects. The entomopathogenic fungus, Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae), which was isolated from the soils of Mauritius, was used to investigate whether fungus-treated adult fruit flies could transfer conidia to non-treated flies during mating, and whether fungal infection could have an effect on mating behavior, fecundity, and fertility of the two female fruit fly species. When treated male flies were maintained together with non-treated female flies, they were able to transmit infection to untreated females, resulting in high mortalities. Similarly, fungus-infected female flies mixed with untreated males also transmitted infections to males, also resulting in high mortalities. Infection by M. anisopliae also resulted in the reduction of the number of eggs produced by females of B. cucurbitae. The results suggest that M. anisopliae may have potential for use in integrated control programs of B. zonata and B. cucurbitae using the sterile insect technique in Mauritius. © 2014, Library of the University of Arizona. All rights reserved.

Sookar P.,Agricultural Services | Haq I.,International Atomic Energy Agency | Jessup A.,International Atomic Energy Agency | Mcinnis D.,U.S. Department of Agriculture | And 3 more authors.
Journal of Applied Entomology | Year: 2013

Distinct host ranges of the melon fly, Bactrocera cucurbitae (Coquillett), have been reported among different island populations, suggesting significant genetic divergence. Thus, for the application of the sterile insect technique (SIT), it is important to ensure that released flies are sexually fully compatible with each other and with the laboratory strains. Mating tests among the following strains of the melon fly, B. cucurbitae: Mauritius laboratory-adapted (35 generations), Seychelles laboratory-adapted (24 generations), and Hawaii genetic sexing strain (90 generations), were conducted in field cages at the FAO/IAEA Agriculture and Biotechnology Laboratories in Seibersdorf, Austria during the months of August/September 2009. The genetic sexing strain, developed in Hawaii in 2001, allows separation of females and males on the basis of pupal colour. Two separate series of trials were run simultaneously. In the first, melon fly females from Mauritius were the target strain and the competing males were from Mauritius, Seychelles, and Hawaii (GSS). In the second trial, melon fly females from the Seychelles selected among competing males from the same three populations. Sexual activity was similar among the melon fly populations and no significant non-random, assortative mating was observed. Therefore, it is suggested that melon flies from Mauritius, Seychelles and the Hawaii are compatible, at least under semi-natural conditions. © 2010 Blackwell Verlag, GmbH.

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