The diverticulated crop is a unique and overlooked foregut organ in the Diptera that affects many physiological and behavioral functions. Historically, the crop was viewed simply as a reservoir for excess nutrients. The crop lobes and crop duct form an elaborate sphincter and pump system that moves stored nutrients to the crop lobes, oral cavity, and the midgut. The storage capacity of the crop lobes is significant when filled maximally and supplies sufficient carbohydrates to sustain prolonged activity and flight, and adequate protein and lipids to facilitate reproductive events. Crop emptying is under complex neuroendocrine and neural control and may be influenced by multiple neuromessengers, such as serotonin and dromyosuppressin. The crop lobes also serve as a site for the initial mixing of enzymes from the salivary glands and antimicrobials from the labellar glands with ingested food. These food-processing functions are associated with behaviors unique to dipterans, such as regurgitation (or bubbling), nuptial gift giving, and substrate droplet deposition or trap-lining.

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Hormesis is an adaptive response, commonly characterized by a biphasic doseresponse that can be either directly induced, or the result of compensatory biological processes following an initial disruption in homeostasis [Calabrese and Baldwin, Hum. Exp. Toxicol., 21 (2002), 91]. Low and environmentally relevant levels of dietary cadmium significantly enhanced the pupation rate of blowfly larvae, while higher doses inhibited pupation success. However, dietary cadmium at all exposure levels adversely affected the emergence of the adult fly from the pupal case. Such findings represent the first report of a heavy metal displaying a hormetic-like biphasic response for pupation success, while at the same time displaying stage-specific toxicity at a later developmental period. These conclusions are based on substantial experimentation of over 1750 blowflies, in seven replicate experiments, involving 10 concentrations per experiment. These findings indicate the need to assess the impact of environmental stressors over a broad range of potential exposures as well as throughout the entire life cycle. AbstractThis is the first report of a heavy metal displaying a hormetic-like biphasic response for early developmental success, while at the same time displaying stage-specific toxicity at a later developmental stage.

STOFFOLANO, J. G., JR. 1974. Influence of diapause and diet on the development of the gonads and accessory reproductive glands of the black blowfly, Phormia regina (Meigen). Can. J . Zool. 52: 981-988.Aspects of the reproductive biolo y, including mating, viteIIogenesis, and development of the accessory rcproductiw glands, offfoth nialc and fernalc Phormia regina were ~nvestigated. Non-diapausing adulis showed changes in Xhc female ovaries, plus in the Tat body and accessory rrproducuve gtantls ol' bo~lz sexes. t h a~ correlated a~th major reproductive events. The changes in these structures were influenced hy diet and diapause-~nducing condiltons. The irnpnrrance of protein in the diet of non-diaprtuslng. c~clorrlia houb ikmnles 1s ivelell tlocurnented;consequcntly. ympha~is has heen placed on the signil~cance oPprolein in [he dier of non-diapausing malts and ~t s fuilction m development of the accessory rcproduct~ve glands.STOFFOLANO, J. G . , JR. 1974.1~fluence of diapause and diet on the dcvrlopment of the onads and accessory rcproducUvc glands of ~h c black biotwfiy. Phorn~io rryinv (Meigen). ban. l. Zool. 52: 981-9SR.On .a CtudiC la biologie de la reproduction, chez les miles et les femelles de Ptrormia rednu, notammen1 sous les aspects dc I'accouplernent, la vitellogcnbe et le ddveloppment des glandes repraductrices accessoires. Chez les arlultes ne subissanl pas de diapausc, on observe des chan~ements dans Zes owires che7 la frmrlle, de m@mc clue dans le cor s gras et les glandes acce,soires rhei les devx rcxes: crr rhangmcotr son1 cn curr4larian a v e c k pnncipales phascr de la reproduction. Les changements opCrC.; dans ces structures sant houmls 21 I'mfluence du rtgime alimentalre et des condi~ions dc dPclenchement de In diapause. 1,'importance des pro-[Pines dans le rtglme alimentaire ries Femelles cyclorrhapl~es q u~ n'entren~ pas en diapause cst dcjh bicn connue; il est donc surtout quesuon ici de S~niportance des proteines d m Ir regime des males qui n'cntrcnt pas en diapar~se ct de 1c~1r rble dans le developpement des giancles rcproductrices accessoires.Fl.aduit par le journal]

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