Mating success depends on rearing substrate in cactophilic Drosophila

Drosophila buzzatii and D. koepferae coexist in the arid lands of southern South America and exploit different types of cactus as breeding hosts. The former prefers to lay eggs on the rotting pads of prickly pears (genus Opuntia) whereas D. koepferae exhibits greater acceptance for columnar cacti (e. g., Echinopsis terschekii). Here, we demonstrate that the rearing cacti affect male mating success, flies reared in each species' preferred host exhibited enhanced mating success than those raised in secondary hosts. Opuntia sulphurea medium endows D. buzzatii males with greater mating ability while D. koepferae males perform better when flies develop in Echinopsis terschekii. These effects are not mediated through body size, even in D. buzzatii whose body size happens to be affected by the rearing cacti. This scenario, which is consistent with the evolution of host specialization and speciation through sensory drive, emphasizes the importance of habitat isolation in the coexistence of these cactophilic Drosophila. © 2011 Springer Science+Business Media B.V.

Evaluating irradiation dose for sterility induction and quality control of mass-produced fruit fly Bactrocera tryoni (Diptera : Tephritidae)

The sterile insect technique has been routinely used to eradicate fruit fly Bactrocera tryoni (Froggatt) incursions. This study considers whether fly quality in a mass-rearing facility can be improved by reducing irradiation doses, without sacrificing reproductive sterility. Pupae were exposed to one of five target irradiation dose ranges: 0, 40-45, 50-55, 60-65, and 70-75 Gy. Pupae were then assessed using routine quality control measures: flight ability, sex ratio, longevity under nutritional stress, emergence, and reproductive sterility. Irradiation did not have a significant effect on flight ability or sex ratio tests. Longevity under nutritional stress was significantly increased at 70-75 Gy, but no other doses differed from 0 Gy. Emergence was slightly reduced in the 50-55, 60-65, and 70-75 Gy treatments, but 40-45 Gy treatments did not differ from 0 Gy, though confounding temporal factors complicate interpretation. Reproductive sterility remained acceptable (> 99.5%) for all doses--40-45 Gy (99.78%), 50-55 Gy (100%), 60-65 Gy (100%), and 70-75 Gy (99.99%). We recommend that B. tryoni used in sterile insect technique releases be irradiated at a target dose of 50-55 Gy, providing improved quality and undiminished sterility in comparison with the current 70-75 Gy standard while also providing a substantial buffer against risk of under dosing.

Singh v The Queen: A Path Toward Confusion, Redundancy and Doctrinal Inconsistency

In Walkington v The Queen, the English Court of Criminal Appeal enunciated criteria fordetermining whether a building contains parts thereof for purposes of ss 76 and 77 of the CrimesAct 1958 (Vic): burglary and aggravated burglary respectively. In Singh v The Queen, the VictorianCourt of Appeal was confronted with a situation in which a trespassory entry had been made into abuilding that, according to the principles enunciated in Walkington, did not consist of any part orparts. Recognizing that there was scant evidence with which to prove that the accused’s entry hadbeen accompanied by an intention to commit one of the crimes specified in ss 76 and 77, the courtnonetheless affirmed the applicant’s conviction for aggravated burglary under s 77. In so doing,the court reaffirmed its earlier decision in The Queen v Chimirri which held that a trespassoryentry into a building results in continuing trespass for as long as the accused remains in thebuilding. In Chimirri, it was further held that if an accused forms an intention to commit one ofthe specified crimes subsequent to the initial trespassory entry and enters a part of the buildingwith that intention, he or she has committed burglary, aggravated burglary, or both by virtueof the continuing trespass doctrine. The discussion to follow will demonstrate that the court’sreasoning in both Chimirri and Singh is not only flawed, but flies in the face of the very passagesfrom the judgment of Lane LJ in Walkington that were quoted with apparent approval in Singh.The discussion will further demonstrate that the continuing trespass doctrine adds nothing of valueto the law of burglary as it existed prior to Chimirri and Singh; rather, its only effect is to addconfusion and uncertainty to what had been a settled area of the law.

Male sexual behaviour and ethanol consumption from an evolutionary perspective: a comment on "Sexual deprivation increases ethanol intake in Drosophila"

Shohat-Ophir et al. (1) demonstrate a connection between sexual behaviour and ethanol consumption in male Drosophila flies, and how the neuropeptide F system regulates ethanol preference. Their results are rightly discussed only in a physiological context, but this has facilitated erroneous anthropomorphic interpretations by the media. Here we discuss the link between male sexual behaviour and ethanol consumption from an evolutionary perspective, providing a broader context to interpret their results.

Hygienic practices among food vendors in educational institutions in Ghana: the case of Konongo

With the booming street food industry in the developing world there is an urgent need to ensure food vendors adhere to hygienic practices to protect public health. This study assessed the adherence to food hygiene practices by food vendors in educational institutions in Konongo, Ghana. Structured questionnaires, extensive observation and interviews were used for the study involving 60 food vendors from 20 basic schools. Attributable to the influence of school authorities and the level of in-training of food vendors, the study points out that food vendors in educational institutions generally adhered to good food hygiene practices, namely, regular medical examination (93%), protection of food from flies and dust (55%); proper serving of food (100%); good hand hygiene (63%); and the use of personal protective clothing (52%). The training of food vendors on food hygiene, instead of the level of education had a significant association (p < 0.05) with crucial food hygiene practices such as medical examination, hand hygiene and protection of food from flies and dust. Further, regulatory bodies legally mandated to efficiently monitor the activities of food vendors lacked the adequate capacity to do so. The study proposes that efforts should be geared towards developing training programmes for food vendors as well as capacity building of the stakeholders.