Effects of borate on isomerization and yeast fermentation of high xylulose solution and acid hydrolysate of hemicellulose

d-Xylose has been isomerized by immobilized d-glucose isomerase (EC nomenclature is now d-xylose isomerase, d-xylose ketol-isomerase, EC 5.3.1.5; EC 5.3.1.18 is a deleted EC entry). Temperature has a profound influence on the equilibrium concentration of d-xylulose. When 1 md-xylose was isomerized in the presence of various concentrations of borate, maximum conversion (80%) was observed at 0.2 m sodium tetraborate. Temperature (40–69°C) and pH (6.0–7.5) had an insignificant effect on the equilibrium when borate was present. d-Xylose (0.5 m) was isomerized by d-glucose isomerase in the presence of various concentrations of sodium tetraborate (0.0125–0.25 m). Based on the initial rate of ethanol production and the fraction of total sugar converted into ethanol after 24 h of yeast fermentation, an optimum tetraborate concentration of 0.05 m was determined for both isomerization and fermentation. At an acidic pH, the rate of fermentation was faster than at neutral pH when borate was included in the d-xylose—d-xylulose system. Acid hydrolysate of bagasse hemicellulose could not be fermented at a pH lower than 5. Therefore, a compromise condition, pH 6.0, was chosen for fermentation.     

Field and laboratory efficacy studies of erythrosin B for Musca domestica (Diptera: Muscidae) and Drosophila robusta (Diptera: Drosophilidae) control

A 1.0% liquid bait formulation of erythrosin B was tested for house fly, Musca domestica L., control in one room of an environmentally controlled caged-layer poultry facility. Reduced fly numbers were recorded between day 14 and day 17 in the room treated with erythrosin B, after 17 d populations increased significantly in treatment and control rooms. Increasing the light intensity to 188 or 386 lm/m squared for 8 h a day or increasing bait stations from one station per 87 m3 to one station per 70 m2 had no effect on developing house fly populations. Annoying levels of a vinegar fly, Drosophila robusta group, developed in the poultry facility during the study. Populations increased to greater than 400 adults/m2 of wall surface by day 15, then declined in the treatment room to less than 1 adult/m2 by day 33. Mortality of house flies that had ingested a 1.0% liquid formulation of erythrosin B was recorded under laboratory light intensities of 51, 532, and 1,030 lm/m2. All three intensities resulted in mortality significantly higher than the control, but mortality among the light intensity treatments did not differ significantly. When house flies were supplied water with erythrosin B, mortality did not differ significantly from that of the control.     

House fly (Diptera: Muscidae) activity near baits containing (Z)-9-tricosene and efficacy of commercial toxic fly baits on a southern California dairy

Sticky card captures of house flies, Musca domestica L. (Diptera: Muscidae), were used to compare efficacy of screen-covered baits containing sugar, sugar and 0.1% (Z)-9-tricosene, sugar and 1.0% (Z)-9-tricosene, Golden Malrin [1.1% methomyl and 0.049% (Z)-9-tricosene], and Quick-Bayt [0.5% imidacloprid and 0.1% (Z)-9-tricosene]. The QuickBayt treatment caught more flies per hour (mean = 116.5) than sugar alone (mean = 81.0), but the addition of (Z)-9-tricosene to sugar did not increase fly capture compared with sugar alone. More males (65% of total) than females were collected on the sticky cards for all treatments. Fly kill by plain sugar (control) and the commercial baits Golden Malrin, QuikStrike Fly Abatement strips (1.0% nithiazine), and QuickBayt was tested over a 90-min period. An average of 1.4, 5.6, 363.0, and 1,266.0 flies were killed using sugar, Golden Malrin, QuikStrike, and QuickBayt, respectively. The similarity between Golden Malrin and plain sugar reflects severe resistance to this once effective methomyl bait. A no-choice feeding assay using lab-reared methomyl-susceptible and methomyl-resistant house flies was conducted with and without (Z)-9-tricosene. Adult mortality was significantly higher in the methomyl-susceptible strain exposed to treatments containing methomyl. Lower consumption of the methomyl treatments by resistant flies suggested resistance was behavioral and mortality was not influenced by (Z)-9-tricosene for either fly strain.     

Laboratory environment effects on the reproduction and mortality of adult screwworm (Diptera: Calliphoridae)

The New World screwworm, Cochliomyia hominivorax Coquerel, is mass reared for screwworm eradication initiatives that use the sterile insect technique. New methods for rearing have helped to reduce the cost of the eradication program. We examined the effect and interaction of three temperatures (24.5, 29.5 and 34.5 degrees C), two diets (2% spray-dried blood plus 0.05% vitamins and corn syrup carrageenan) and three population densities (300, 400, and 500 flies/cage) on egg production, egg hatch, number of observable fertilized eggs, mortality (male and female) and ovarian development. The three population densities did not affect any of the parameters monitored. Using the protein diet increased egg production at all temperatures. Diet did not affect egg hatch or female mortality. Male mortality was significantly greater when fed the protein diet and reared at 24.5 degrees C and 34.5 degrees C. Egg hatch was significantly less when the flies were reared at 34.5 degrees C. When exposed to high temperatures (37 degrees C and 40 degrees C) egg production, egg hatch, fertility and mortality were adversely affected. At the higher temperatures, yolk did not adequately form during oogenesis. When compared to the normal rearing photoperiod (12 L:12 D), short photoperiod (1 L:23 D) increased egg production, egg hatch and fertility but lowered mortality.     

Transfer of toxicants from exposed nymphs of the drywood termite Incisitermes snyderi (Isoptera: Kalotermitidae) to unexposed nestmates

Two formulations of spinosad (NAF-85 and NAF-371) were evaluated to determine the effect of concentration, deposit condition (dried, wet, or topical), and exposure time (0.1-10 h) for toxicant transfer among nestmates in the drywood termite Incisitermes snyderi (Light). Spinosad treatments were compared with two formulations of disodium octaborate tetrahydrate (DOT) (10% aqueous dilution, 98% dust) and with 35% calcium arsenate dust. Termites were dyed and individually exposed to different treatments for 0.1, 1.5,1.0, 5.0, 10.0 h, or 0.1 and 1.0 h (DOT and calcium arsenate dust) and then placed with 10 unmarked, untreated nestmates in a petri dish. Spinosad formulations also were evaluated by topical application to dyed termites. Transfer of lethal doses of toxicants between termites was indicated by significant mortality of untreated termites in 25 of 28 treatments by 28 d after introduction of dyed, treated termites. Only three treatments, one spinosad treatment (NAF-371, wet, 1 h) and both DOT 10% solution treatments, resulted in mortality of untreated termites that was not significantly different than that of water-treated controls. Two spinosad treatments and both calcium arsenate dust treatments resulted in >90% (94-98%) mortality of untreated termites by 28 d after introduction. Mortality of untreated termites was significantly different from controls for the two spinosad formulations, depending on condition of deposit and duration of dyed termite exposure to treatments.     

Physiology of feeding-preference patterns of female black blowflies (Phormia regina Meigen): Modification in responsiveness to salts subsequent to salt feeding

Behavioural experimentation on Phormia regina shows that females previously fed only sucrose, and thus in a state of yeast preference, will ingest single-salt-sucrose mixtures in volumes similar to that of 10% yeast (Rachman et al., 1982). In particular, females will ingest NaCl 0.1 M in 0.2 M sucrose in volumes not statistically different from 10% yeast. In the experiments reported here, groups of females were given ad libitum access to both 0.2 M sucrose and NaCl 0.1 M in 0.2 M sucrose from days 0–4 after eclosion. Potassium and sodium salts were added to 0.2 M sucrose over a spectrum of concentrations and presented to the flies on day 6. The flies rejected all single-salt-sucrose mixtures offered. Even when the pre-test sodium salt was changed to a potassium salt during days 0–4, the flies still rejected the single-salt-sucrose mixtures offered subsequently. However, when sodium and potassium salts were mixed together in 0.2 M sucrose, females ingested the solutions in amounts similar to 10% yeast. Several different concentrations of the double-salt-sucrose solutions were ingested in volumes not statistically different from 10% yeast. Results support the underlying hypothesis that activity in the salt-sensitive chemosensory neurones is involved in protein preference.     

Estrogen effects on osmotic regulation of AVP and fluid balance

To determine estrogen effects on osmotic regulation of arginine vasopressin (AVP) and body fluids, we suppressed endogenous estrogen and progesterone using the gonadotropin-releasing hormone (GnRH) analog leuprolide acetate (GnRHa). Subjects were assigned to one of two groups: 1) GnRHa alone, then GnRHa + estrogen (E, n = 9, 25 +/- 1 yr); 2) GnRHa alone, then GnRHa + estrogen with progesterone (E/P, n = 6, 26 +/- 3). During GnRHa alone and with hormone treatment, we compared AVP and body fluid regulatory responses to 3% NaCl infusion (HSI, 120 min, 0.1 ml. min(-1). kg body wt(-1)), drinking (30 min, 15 ml/kg body wt), and recovery (60 min of seated rest). Plasma [E(2)] increased from 23.9 to 275.3 pg/ml with hormone treatments. Plasma [P(4)] increased from 0.6 to 5.7 ng/ml during E/P and was unchanged (0.4 to 0.6 ng/ml) during E. Compared with GnRHa alone, E reduced osmotic AVP release threshold (275 +/- 4 to 271 +/- 4 mosmol/kg, P < 0.05), and E/P reduced the AVP increase in response during HSI (6.0 +/- 1.3 to 4.2 +/- 0.6 pg/ml at the end of HSI), but free water clearance was unaffected in either group. Relative to GnRHa, pre-HSI plasma renin activity (PRA) was greater during E (0.8 +/- 0.1 vs. 1.2 +/- 0.2 ng ANG I. ml(-1). h(-1)) but not after HSI or recovery. PRA was greater than GnRHa during E/P at baseline (1.1 +/- 0.2 vs. 2.5 +/- 0.6) and after HSI (0.6 +/- 0.1 vs. 1.1 +/- 1.1) and recovery (0.5 +/- 0.1 vs. 1.3 +/- 0.2 ng ANG I. ml(-1). h(-1)). Baseline fractional excretion of sodium was unaffected by E or E/P but was attenuated by the end of recovery for both E (3.3 +/- 0.6 vs. 2.4 +/- 0.4%) and E/P (2.8 +/- 0.4 vs 1.7 +/- 0.4%, GnRHa alone and with hormone treatment, respectively). Fluid retention increased with both hormone treatments. Renal sensitivity to AVP may be lower during E due to intrarenal effects on water and sodium excretion. E/P increased sodium retention and renin-angiotensin-aldosterone stimulation.     

Mortality and oviposition of western cherry fruit fly (Diptera: Tephritidae) exposed to different insecticide baits for varying periods in the presence and absence of food

Spinosad bait is used to control western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), by killing flies before they oviposit. However, effects of different insecticide baits on management of reproductively mature flies are largely unknown. Objectives here were to determine mortality and oviposition of reproductively mature R. indifferens exposed to different insecticide baits for varying periods in the presence and absence of dried yeast extract and sucrose food. Spinosad bait (spinosad in a mix of protein, sugar, and other ingredients) was compared with acetamiprid, thiamethoxam, and imidacloprid in sucrose or Nu-Lure + sucrose bait. When flies were exposed to treatments and then offered cherries, Prunus avium (L.) L., for oviposition or when they were exposed to treatments and cherries simultaneously, both thiamethoxam bait and imidacloprid bait resulted in higher mortality and lower oviposition than spinosad bait and acetamiprid bait. Exposures to thiamethoxam bait and imidacloprid bait for six and 24 h were similarly effective, but 6-h exposures to spinosad bait and acetamiprid bait were less effective than 24-h exposures. There was little difference between sucrose and Nu-Lure + sucrose baits. When food was present, thiamethoxam bait and imidacloprid bait caused greater mortality and lower oviposition than spinosad bait and acetamiprid bait, but when food was absent, patterns were less consistent. Because of its ability to kill flies sooner after it is exposed to flies when food is present or absent, thiamethoxam or imidacloprid in sucrose or Nu-Lure bait may reduce infestations in cherries more than spinosad bait when mature R. indifferens are present in orchards.     

Hydroprene prolongs developmental time and increases mortality in wandering-phase Indianmeal moth (Lepidoptera: Pyralidae) larvae

Wandering phase Indianmeal moth, Plodia interpunctella (Hübner), larvae were exposed to the label rate of hydroprene (1.9 x 10(-3) mg [AI] /cm2) sprayed on concreted petri dishes. Larvae were exposed for 1, 3, 6, 12, 18, 24, and 30 h and maintained at 16, 20, 24, 28, and 32 degrees C and 57% RH until adult emergence. Larval developmental time and mortality were significantly influenced by temperature and exposure intervals. Maximum developmental time (47.2 +/- 1.3 d) occurred at 16 degrees C, and the minimum developmental time (7.0 +/- 0.5 d) occurred at 32 degrees C. Larval mortality generally increased at all of the five tested temperatures as exposure period increased. The greatest mortality (82.0 +/- 0.1%) occurred when larvae were exposed for 30 h at 28 degrees C, and minimum mortality (0.0 +/- 0.5%) occurred at 16 degrees C when larvae were exposed for 1 h. The relationships between temperature, exposure period, and developmental time were described by polynomial models, based on lack-of-fit tests. Hydroprene has potential to be an effective alternative to conventional insecticides in surface treatments for Indianmeal moth management. Response-surface models derived from this study can be used in simulation models to estimate the potential consequences of hydroprene on Indianmeal moth population dynamics.     

The susceptibility of the giant freshwater prawn Macrobrachium rosenbergii to Lactococcus garvieae and its resistance under copper sulfate stress.

Addition of copper sulfate (0.1 to 0.4 mg l(-1)) to tryptic soy broth (TSB) had no effect on growth rate of the bacterial pathogen Lactococcus garvieae. Giant freshwater prawns Macrobrachium rosenbergii were injected with L. garvieae (4 x 10(6) colony-forming units [cfu] prawn(-1)) grown in TSB or TSB containing copper sulfate at 0.1, 0.2, 0.3 or 0.4 mg l(-1). After 48 h, the cumulative mortality was significantly (p < 0.05) higher for prawns exposed to L. garvieae grown in 0.4 mg l(-1) copper sulfate than at the lower concentrations examined. In other experiments, prawns were injected with TSB-grown L. garvieae (4 x 10(6) and 2 x 10(5) cfu prawn(-1)), then held in water containing copper sulfate. After 8 h the mortality of L. garvieae-exposed prawns held in water containing 0.4 mg l(-1) copper sulfate was significantly higher than prawns held in water containing 0.2 and 0.3 mg l(-1) copper sulfate. At the lower L. garvieae density, cumulative mortality of prawns increased directly with ambient copper sulfate concentrations in the range of 0.2 to 0.4 mg l(-1). All prawns survived a 168 h exposure to 0.1 mg l(-1) copper sulfate. Prawns exposed to different concentrations of copper sulfate were examined for hemocyte density, phenoloxidase activity and respiratory burst. No significant differences in hemocyte density were observed among treatments. In prawns following a 48 h exposure to 0.1 mg l(-1) copper sulfate, phenoloxidase activity was decreased, but respiratory burst was increased. In conclusion, copper sulfate increased the virulence of L. garvieae to M. rosenbergii and modulated its immune system. Copper sulfate at 0.1 mg l(-1) decreased susceptibility of M. rosenbergii to L garvieae infection, whereas at 0.2 mg l(-1) the susceptibility was increased. The generation of superoxide anion by M. rosenbergii exposed to copper sulfate at a concentration higher than 0.2 mg l(-1) was considered to be cytoxic.     

Reproductive, neuroendocrine, and immune consequences of acute exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in the Siberian hamster

The present study tested the hypothesis that acute treatment with 2, 3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) impairs fertility, disrupts the nocturnal melatonin rhythm, and suppresses lymphocyte function. Adult Siberian hamsters administered 2 or 100 microg TCDD/kg body weight/0.2 ml sesame oil had a delayed latency to first litter and an increased adult mortality compared to hamsters given 0.1 microg/kg or vehicle. Within 75 days of TCDD treatment, full reproductive capabilities were achieved. Moreover, the nocturnal melatonin rhythm was not disrupted in adults administered TCDD or in their progeny. Lymphocyte activity varied with respect to time of day and treatment. Lymphocyte proliferation was enhanced at night irrespective of TCDD treatment; during the day, 2 wk after the 2-microg/kg treatment, blastogenesis was reduced compared to that in the 0.1-microg/kg group or in vehicle-treated controls. In contrast, TCDD did not affect the mixed lymphocyte reaction in response to allogeneic antigen when assessed at 2 and 20 wk post-treatment. Thus, findings indicate that TCDD produced acute effects on fertility, mortality, and systemic lymphocyte proliferation, but long-lasting effects on specific aspects of reproductive, neuroendocrine, and immune cell functions were not observed.     

Sodium selenite stimulates neurobehavior and neurochemical activities in rats

The effect of 0.05, 0.1, and 0.2 mg sodium selenite/kg body weight ip on the activities of neurobehavioral, acetyl cholinesterase, monoamine oxidase, and the content of dopamine and its metabolites in circadian rhythm centers of male Wistar rats was studied after 7 d of treatment. The results show an appreciable increase in locomotion, stereo-events, distance traveled, and average speed at the dose of 0.1 and 0.2 mg sodium selenite/kg. The data have shown hyperactivity of animals with various doses of sodium selenite, and it was significant and dose-dependent after 3 d of treatment. The activity of acetylcholinesterase (AChE) was inhibited dose dependently, and it was significant in preoptic area with 0.1 or 0.2 mg sodium selenite/kg. Conversely, in the posterior hypothalamus its activity was significantly elevated with the dose of 0.2 mg sodium selenite/kg, but its alteration in brain stem was not significant. Monoamine oxidase (MAO) activity was increased in preoptic area with the dose of 0.1 mg sodium selenite/kg, but its alteration in posterior hypothalamus and brain stem was not significant. The content of dopamine (DA), 3,4-dihydroxyphenyl acetic acid (DOPAC), and homovanilic acid (HVA) was elevated dose dependently and it was significant with the doss of 0.1 and 0.2 mg sodium selenite/kg, but the content of DOPAC and HVA in posterior hypothalamus was not significant with the dose of 0.1 mg sodium selenite/kg.     

水母雪莲体细胞胚胎发生及其植株再生

水母雪莲（Saussurea medusa Maxim.)茎和叶片的切段接种于MS＋2mg/L NAA 0.5mmg/L 6-BA的培养基上,20d后产生黄褐色的愈伤组织,经过几个月的继代培养,愈伤组织仍保持旺盛的增殖能力,但部分由黄褐色逐渐变为红色,将红色愈伤组织转到MS＋0．1mg/L NAA＋0．2mg/L 6-BA 5mg/L GA3的培养基上,30d后可分化出大量的体细胞胚,体细胞胚成熟后转到1／2MS＋0．2mg/L IAA 0.5%活性炭的培养基上,30d后可长出2－4cm的根,带根的小苗经锻炼后移栽到土壤中,成活率达76％,细胞组织学观察表明,发育成熟的体细胞胚具有胚根,胚轴和胚芽的完整结构,具有独立的维管系统。     

A partial modification of the carbazole method of Bitter and Muir for quantitation of hexuronic acids.

The carbazole method of T. Bitter and H. M. Muir (1962, Anal. Biochem.4, 330–334)for quantitation of hexuronic acids was modified partially. In this modification (procedure g), 0.2 m anhydrous sodium tetraborate was used instead of 0.025 m sodium tetraborate decahydrate. The color intensity of d-glucuronolactone was slightly diminished by this modification, however, that of l-iduronolactone significantly increased. Thus, the difference in color intensity between d-glucuronolactone and l-iduronolactone became very small. When evaluated by procedure g, the hexuronic acid content of dermatan sulfate was comparable to that of chondroitin sulfate A.     

Selenium altered the levels of lipids, lipid peroxidation, and sulfhydryl groups in straitum and thalamus of rat

The effect of sodium selenite (0.05, 0.1, and 0.2 mg/kg body weight, ip) on the lipid levels (total lipids, phospholipids, cholesterol, gangliosides), thiobarbituric acid reactive substance (TBARS), and sulfhydryl group (-SH) in the straitum and thalamus of a male Wistar rat was studied after 7 d of treatment. The level of total lipids and cholesterol was significantly and dose-dependently elevated in the straitum and thalamus with 0.1 and 0.2 mg/kg of sodium selenite. However, the cholesterol level was significantly increased only with 0.2 mg/kg of sodium selenite in the thalamus. The level of phospholipids and gangliosides was more significant with 0.1 mg/kg of sodium selenite as compared to 0.2 mg. No significant alteration on the gangliosides level was observed in the thalamus with various doses of sodium selenite although the elevation with 0.2 mg dose was 25.9%. The content of TBARS was elevated dose dependently in straitum, but its level was depleted significantly with 0.1-mg/kg dose of sodium selenite in the thalamus. The level of the -SH group was significantly depleted in the straitum with 0.1-mg/kg dose of sodium selenite; conversely, this dose has significantly elevated the levels of-SH group in the thalamus.     

Additive interaction of <Emphasis Type="Italic">Helicoverpa armigera</Emphasis> Nucleopolyhedrovirus and Azadirachtin

Mortality of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) was higher in the combined treatment of Nucleopolyhedrovirus (NPV) and Azadirachtin (AZA) and mortality was increased when AZA concentration was doubled. Larval mortality decreased as the age of the larvae increased in all the treatments. The time for 100% kill of third instar larvae was significantly reduced to 72 h when AZA (0.1 ppm) was combined with NPV (10³ PIB/ml) when compared to 168 and 120 h for the same dose NPV and AZA individual treatments, respectively. The average leaf disc consumption, consumption index (CI), relative growth rate (RGR), the efficiency of conversion of ingested (ECI) and digested (ECD) food values were drastically reduced in the combined treatment of NPV and AZA than in the individual treatments. Larval as well as pupal durations were significantly extended and the adult longevity and fecundity were significantly reduced in the combined treatment of NPV and AZA. Weight of 14 day old control larvae was 420 mg and it was reduced to 299 and 248 mg after NPV (5 × 10² PIB/ml) and AZA (0.025 ppm) treatments, respectively. The larval weight was drastically decreased to 99 mg after the combined treatment at the same dose. The additive interaction between both the treatments, AZA and NPV, was found to be in a dose dependent manner and were highly compatible in disrupting the survival, feeding and biology of H. armigera.     

Pathogenicity ofBeauveria bassiana for adults ofTribolium castaneum (Col.: Tenebrionidae) in stored grains

Conidia ofBeauveria bassiana were evaluated for activity against adults ofTribolium castaneum, under laboratory conditions closely resembling the stored-grain conditions. Three doses of the fungus were applied in the treatments: 0.1 g, 0.5 g and 1 g per 20 insects/dose/flask. Treated insects and untreated were incubated in broken wheat. There were 5 replications for each test. A total of 1600 treated and control insects used were kept in a climatic chamber (70±5% and 27±2°C) for 45 days. Observations were performed daily and the recording of infected cadavers began when the percentage of mortality exceeded 50%. The evaluation of the efficiency of each dose ofB. bassiana was made 14, 21, 28 and 45 days after inoculation. Mortality of adults that were exposed to the beetles treated with 0.5 g and 1 g of conidia ofB. bassiana / 20 adults was 87 and 85% respectively, within 21 days of exposure. Onset of mortality was further delayed at lower dosage of the fungus; 55% after 21 days. After 28 days there were no difference in mortality between the 0.5 g and 1 g dosages ofB. bassiana. The most efficient treatment was 0.5 g/20 insects, which resulted in a control higher than 50% 14 days post treatment.     

Antifertility effect of gossypol in male Japanese quail

Conventionally housed 130-160 g adult male Japanese quail were given gossypol acetic acid (gossypol) im at 25 mg/kg in 0.5 ml of 10% EtOH for 12 and 24 days (Groups 1 and 2), respectively. One day after treatment was terminated they were allowed to mate with laying females individually for 20 days. Fertility was 0% from mating of the Group 1 birds on days 1-2 and increased to 25, 35, 55 and 65% on days 3-6 after cessation of gossypol treatment. At day 11, fertility was 80 vs 84% in controls, whereas hatchability was 70% for both. By comparison, eggs from Group 2 mated quail were infertile for up to 20 days after the termination of gossypol treatment. In a parallel experiment, the percent testes to body weight ratio in control and 7, 14, 21, and 28-day gossypol-treated quail was 2.5, 2.2, 1.8, 0.5, and 0.2%, respectively. In 12 vs 24-day treated birds, 7, 14, 21, and 28 days after gossypol treatment, the ratios were 1.0 vs 0.5%, 2.0 vs 0.8% and 2.8 vs 1.9%, respectively. The decreased fertility and hatachability, and testicular atrophy resulting from gossypol given to male quail was dose-time related. Furthermore, the androgen-dependent cloacal gland was drastically reduced in size by the treatment with gossypol. The mode of action of gossypol in male quail is different than it is in mammals in that the testicular size of mammals remains unchanged with long-term gossypol treatment. It is concluded that quail may be a useful avian animal model for investigating the antifertility effects of gossypol.     

Physiology of feeding-preference patterns of female black blowflies (Phormia regina Meigen): Alterations in responsiveness to salts

Electrophysiological recordings of tarsal and labellar contact chemosensilla in Phormia regina females demonstrate activation of sugar-, cation-, and possibly anion-sensitive cells in response to 10% yeast extract. Yeast extract is a proteinaceous food source that supports full egg development. Though some protein is required for egg maturation in Phormia, a blowfly not normally autogenous, purified proteins alone neither activate the chemosensilla nor promote egg development. In experiments reported here, groups of females were given ad lib access to either 0.2 M sucrose or 0.2 M sucrose and 10% yeast for four days after eclosion. The sucrose diet induced a ‘protein’ preference but no egg development. Potassium and sodium salts were added to 0.2 M sucrose and presented to the flies on day six. The volumes of salt-sucrose mixtures taken were greater than those of 0.2 M sucrose for flies raised on 0.2 M sucrose, though yeast was preferred over all but one salt solution. For sucrose-and-yeast-fed flies, volumes of 0.05 and 0.1 M salt mixtures consumed did not differ from 0.2 M sucrose; however, sucrose alone was favoured over more concentrated salt mixtures. All salt-sucrose mixtures tested were significantly more effective stimuli for sucrose-and-yeast-fed flies than yeast. It is suggested that varying sensitivity in the salt-sensitive contact chemosensilla plays a role in reported food preference shifts associated with reproduction.     

Effect of glucose on Listeria monocytogenes biofilm formation,and assessment of the biofilm’s sanitation tolerance

Listeria monocytogenes is an important cause of human foodborne infections and its ability to form biofilms is a serious concern to the food industry. To reveal the effect of glucose conditions on biofilm formation of L. monocytogenes, 20 strains were investigated under three glucose conditions (0.1, 1.0, and 2.0% w v^–1) by quantifying the number of cells in the biofilm and observing the biofilm structure after incubation for 24, 72, and 168 h. In addition, the biofilms were examined for their sensitivity to sodium hypochlorite. It was found that high concentrations of glucose reduced the number of viable cells in the biofilms and increased extracellular polymeric substance production. Moreover, biofilms formed at a glucose concentration of 1.0 or 2.0% were more resistant to sodium hypochlorite than those formed at a glucose concentration of 0.1%. This knowledge can be used to help design the most appropriate sanitation strategy.