Effect of carbon dioxide on the Oriental cockroach Blatta orientalis

Exposure to high concentrations of carbon dioxide (CO2) killed adult and nymphal stages of the oriental cockroach Blatta orientalis L. (Dictyoptera: Blattidae) with LT50 values of 11.5-16.2 h for 60% CO2 in air and 5.7-7.1 h for 100% CO2 at 20 degrees C; corresponding LT50s at 28 degrees C were 2.8-4.6 h for 60% CO2 in air and 2.3-3.6 h for 100% CO2. Complete kill of mobile stages was obtained within 24 h using 60% CO2 at 20 degrees C. Survivors of treatments with 100% CO2 at 28 degrees C remained completely paralysed for up to 3 days post-treatment and took up to 5 days to regain normal movement, but adult females then resumed production of oothecae with no significant loss in fecundity. Oothecae 5 or 30 days after deposition required 60-84 h exposure to 60% CO2 at 20 degrees C to prevent emergence of nymphs but less time using 100% CO2 at 28 degrees C. At 28 degrees C, when adult females were treated with 100% CO2 and 52% r.h. for 6 h (giving 100% mortality) loss of weight was significantly greater than that following treatment with air at 52% r.h. for 6 h (giving no mortality). However, significantly greater weight loss also occurred when they were treated with dried air (< 10% r.h.) for 6 h, also with no mortality. The toxicity of CO2 to mobile stages of the oriental cockroach appeared to result from irreversible effects on the nervous system, rather than from water loss during exposure.     

Effects of vacuum and controlled atmosphere treatments on insect mortality and lettuce quality

Laboratory studies were conducted to determine the effects of vacuum and controlled atmosphere on mortality of aphids, Nasonovia ribisnigri (Mosley) and Macrosiphum euphorbiae (Thomas), and leafminer, Liriomyza langei Frick, and on the visual quality of iceberg lettuce at three different temperatures. Vacuum at 50 mbar and controlled atmosphere with 6% CO2 were effective in controlling aphids and leafminer larvae. Complete control of N. ribisnigri and M. euphorbiae was achieved with vacuum treatments and 6% CO2 CA treatments at 5 degrees C in 4 d. Mortality was >96% when leafminer larvae were treated with vacuum and 6% CO2 CA treatments for 4 d. However, leafminer pupae were more tolerant to the treatments and highest mortality was close to 60% in 4 d with CO2 under vacuum. None of the treatments had negative effects on visual quality of iceberg lettuce. Results from this study are encouraging and warrant further and large-scale research.     

Metabolic response of Platynota stultana pupae during and after extended exposure to elevated CO(2) and reduced O(2) atmospheres

The metabolic response of Platynota stultana pupae to elevated CO(2) and reduced O(2) atmospheres was measured using microcalorimetry. Initial measurements at 20 degrees C immediately upon placement in controlled atmosphere indicated a decrease in metabolic heat rate (MHR) of 27, 45, 56, 56, and 72% in an atmosphere of 5, 10, 20, 40, and 79% CO(2), respectively, and a decrease of 20, 50, 66 and 100% under 6, 2, 1, and 0% O(2). With extended exposure to controlled atmospheres, MHR increased under 5, 10, and 20% CO(2) and 6 and 2% O(2); however, the increase was greater and occurred more rapidly with lower CO(2) and higher O(2) concentration. The MHR at 40 and 79% CO(2) remained at the initial reduced level for 8 and 6 days, respectively, then decreased with longer exposure. The MHR of pupae held under 1 and 0% O(2) remained at the initial reduced level for 22 days. Upon transfer to air, the MHR of pupae increased from the reduced levels and then decreased. When the MHR decreased by no more than 30%, as a result of controlled atmosphere treatment, the pupae still developed into adults. However, when the MHR decreased by more than 50%, the energy supply was insufficient and the pupae died. Pupa mortality was comparable between 5% CO(2) and 6% O(2), and 10% CO(2) and 2% O(2). The MHR was reduced less under 20% CO(2) than under 2 or 1% O(2); however, the pupae were more susceptible to 20% CO(2) than 2 or 1% O(2). These and other data indicate an increased toxicity of high CO(2) over low O(2) atmospheres that may be related to an increase in membrane permeability as a result of CO(2) treatment.     

Heated-controlled atmosphere postharvest treatments for Macchiademus diplopterus (Hemiptera: Lygaeidae) and Phlyctinus callosus (Coleoptera: Curculionidae)

Nonchemical, environmentally friendly quarantine treatments are preferred for use in postharvest control of insect pests. Combined high temperature and controlled atmosphere quarantine treatments for phytosanitary fruit pests Macchiademus diplopterus (Distant) (Hemiptera: Lygaeidae) and Phlyctinus callosus (Schoenherr) (Coleoptera: Curculionidae) were investigated to determine the potential of such treatments for quarantine security. Field-collected, aestivating M. diplopterus adults and P. callosus adults were treated using a controlled atmosphere waterbath system. This system simulates the controlled atmosphere temperature treatment system (CATTS) used to control a number of phytosanitary pests in the United States and allows for a rapid assessment of pest response to treatment. Insects were treated under regular air conditions and a controlled atmosphere of 1% oxygen, 15% carbon dioxide in nitrogen, at two ramping heat rates, 12 and 24 degrees C/h. Treatment of both species was more effective under both heating rates when the controlled atmosphere condition was applied. Under these conditions of controlled atmospheres, mortality of P. callosus was greater when the faster heating rate was used, but the opposite was true for M. diplopterus. This could be due to the physiological condition of aestivation contributing to metabolic arrest in response to the stresses being applied during treatment. Results indicate that the potential for the development of CATTS treatments for these phytosanitary pests, particularly P. callosus, is promising.     

Potential of temperature, controlled atmospheres, and ozone fumigation to control thrips and mealybugs on ornamental plants for export

Ozone (O3) fumigation is a potential quarantine treatment alternative for controlling stored-product pests and surface insect pests on fresh agricultural commodities. We explored the effects of temperature, treatment time, controlled atmospheres, and vacuum in combination with O3 to control two important pests of ornamental crops: western flower thrips, Frankliniella occidentalis (Pergande), and longtailed mealybug, Pseudococcus longispinus Targioni Tozzetti. Treatment parameters tested were O3 concentrations from 0 to 3,800 ppm, treatment durations were from 30 to 120 min, vacuums were from 0 to 0.41 bar below ambient, temperatures were from 32.2 to 40.6 degrees C, and controlled atmospheres were composed primarily of nitrogen, carbon dioxide, or breathing air [BA]. Treatment efficacy was enhanced by higher O3 concentration and temperature, lower oxygen, and longer treatment times. Reduced pressure was not an important factor. Mealybugs were more difficult to kill than thrips. A 30-min treatment of O3 at approximately 200 ppm in 100% CO2 at 37.8 degrees C killed 47.9 and 98.0% of mealybugs and adult female thrips, respectively. All of the ornamentals tested were damaged to some degree by O3 treatments. However, crops with thick leaves such as orchids exhibited little damage, and the waxy portions of certain flowers were not damaged. The results suggest that O3 has potential as a quarantine treatment to control thrips and mealybugs on selected commodities.     

Development of Spalangia cameroni and Muscidifurax raptor (Hymenoptera: Pteromalidae) on live house fly (Diptera: Muscidae) pupae and pupae killed by heat shock, irradiation, and cold

The objective of this study was to evaluate the suitability of killed house fly (Musca domestica L) pupae for production of two economically important pupal parasitoids. Two-day-old fly pupae were subjected to heat shock treatments of varying temperatures and durations in an oven at >or=70% RH; exposure to temperatures of 55 degrees C or higher for 15 min or longer resulted in 100% mortality. Exposure to 50 degrees C resulted in 40 and 91% mortality at 15 and 60 min, respectively. All (100%) pupae placed in a -80 degrees C freezer were killed after 10-min exposure; exposure times of <5 min resulted in <21% mortality. Progeny production of Spalangia cameroni Perkins and Muscidifurax raptor Girault and Sanders (Hymeoptera: Pteromalidae) from pupae killed by heat shock or 50 kR of gamma radiation was not significantly different from production on live hosts on the day when pupae were killed. Freeze-killed pupae produced 16% fewer S. cameroni than live pupae and an equivalent amount of M. raptor progeny on the day when pupae were killed. When killed pupae were stored in freezer bags at 4 degrees C for 4 mo, heat-killed, irradiated, and freeze-killed pupae remained as effective for production of M. raptor as live pupae. Production of S. cameroni on heat-killed and irradiated pupae was equal to parasitoid production on live pupae for up to 2 mo of storage, after which production on killed pupae declined to 63% of that observed with live pupae. Production of S. cameroni on freeze-killed pupae was 73-78% of production using live pupae during weeks 2-8 of storage and declined to 41 and 28% after 3 and 4 mo, respectively. Killing pupae by heat shock provides a simple and low-cost method for stockpiling high-quality hosts for mass-rearing both of these filth fly biological control agents.     

The effect of modified atmospheres on the survival of the eggs of four storage mite species

The results of a laboratory investigation into the effects of modified atmospheres (MA) on the eggs of mite pests of grain and cheese are presented. Four species of astigmatid mite were tested; Acarus farris (Oudemans). A. siro L., Lepidoglyphus destructor (Schrank) and Tyrophagus longior (Gervais). All are found in many habitats including grain and cheese stores. Three low oxygen (O2) MA mixtures were used, based on carbon dioxide (CO2), nitrogen (N2) or simulated burner gas (0.5 or 2% O2, 10% CO2, balance N2) plus 60% CO2 in air (8% O2). The mites were exposed at 15 degrees C and 80% r.h., a combination of conditions that occurs at the surface of stored grain during the autumn which promotes mite population growth. The exposure periods required to prevent egg hatch for each species in every mixture are given. Tyrophagus longior was the most tolerant species, followed by A. siro and A. farris, with L. destructor the most susceptible. Burner gas was the most effective mixture overall with 0.5% O2 but with an increase in the O2 level to 2% for all the mixtures, CO2 became the more effective control agent. With 60% CO2 in air some loss of efficacy was observed against the three most tolerant species and even more so for L. destructor. Sublethal exposures to MAs for at least 4 days in L. destructor, 6 days in A. farris and A. siro and 8 days for T. longior caused a delay in egg hatch.     

The Effect of Storage in Various Gaseous Atmospheres on the Microflora of Lamb Chops Held at—1°C

The effect of different gaseous atmospheres on the development of the bacterial flora on lamb chops stored at –1°C was examined. The atmospheres were air, nitrogen, hydrogen, and mixtures of air + carbon dioxide, oxygen + nitrogen, oxygen + carbon dioxide, nitrogen + carbon dioxide and hydrogen + carbon dioxide (gas ratio = 80:20, v/v). Storage life of chops ranged from two weeks in air to eight weeks in oxygen-free atmospheres. At the end of storage life Microbacterium thermosphactum was present as a major constituent of the bacterial flora in all atmospheres. In oxygen + carbon dioxide it was the predominant organism. In all other oxygen containing atmospheres, Pseudomonas spp. made up a large proportion of the flora. Strains of Enterobacteriaceae occurred in low-oxygen and oxygen-free atmospheres, and Lactobacillus spp. occurred in oxygen-free atmospheres.     

Growth and survival of uninjured and sublethally heat-injured Escherichia coli O157:H7 on beef extract medium as influenced by package atmosphere and storage temperature.

The effect of atmospheric composition and storage temperature on growth and survival of uninjured and sublethally heat-injured Escherichia coli O157:H7, inoculated onto brain heart infusion agar containing 0.3% beef extract (BEM), was determined. BEM plates were packaged in barrier bags in air, 100% CO2, 100% N2, 20% CO2: 80% N2, and vacuum and were stored at 4, 10, and 37 degrees C for up to 20 days. Package atmosphere and inoculum status (i.e., uninjured or heat-injured) influenced (P < 0.01) growth and survival of E. coli O157:H7 stored at all test temperatures. Growth of heat-injured E. coli O157:H7 was slower (P < 0.01) than uninjured E. coli O157:H7 stored at 37 degrees C. At 37 degrees C, uninjured E. coli O157:H7 reached stationary phase growth earlier than heat-injured populations. Uninjured E. coli O157:H7 grew during 10 days of storage at 10 degrees C, while heat-injured populations declined during 20 days of storage at 10 degrees C. Uninjured E. coli O157:H7 stored at 10 degrees C reached stationary phase growth within approximately 10 days in all packaging atmospheres except CO2. Populations of uninjured and heat-injured E. coli O157:H7 declined throughout storage for 20 days at 4 degrees C. Survival of uninjured populations stored at 4 degrees C, as well as heat-injured populations stored at 4 and 10 degrees C, was enhanced in CO2 atmosphere. Survival of heat-injured E. coli O157:H7 at 4 and 10 degrees C was not different (P > 0.05). Uninjured and heat-injured E. coli O157:H7 are able to survive at low temperatures in the modified atmospheres used in this study.     

Tolerance of pupae and pharate adults of Callosobruchus subinnotatus Pic (Coleoptera: Bruchidae) to modified atmospheres: a function of metabolic rate

Three developmental stages (pupae, early pharate and late pharate adults) of Callosobruchus subinnotatus (Pic.) were investigated for their tolerance or susceptibility to four modified atmospheres. Two of these atmospheres were hypercarbic and two were hypoxic. The hypercarbic atmospheres were found to cause mortality earlier than hypoxic atmospheres. Late pharate adults died earlier than pupae or early pharate adults. Late pharate adults that survived the exposure took a longer time to eclose than the pupae or early pharate adult.Using high resolution microrespirometric techniques, it was possible to record the oxygen consumption rate and CO(2) output of different developmental stages in air. The metabolic rate was determined manometrically as the oxygen uptake rate at an ambient temperature of 25 degrees C. The oxygen uptake rate differed significantly between groups of 20 individuals of different stages (p<0.01; t-test). The lowest rate of oxygen uptake (510.6+/-52.2 &mgr;l g(-1) h(-1)) was recorded in pupae. Higher oxygen uptake rates were found in early pharate adults (668.4+/-45.6 &mgr;l g(-1) h(-1)) and late pharate adults (1171.2+/-45.0 &mgr;l g(-1) h(-1)), and adult beetles (1310.4+/-53.4 &mgr;l g(-1) h(-1)). The patterns of CO(2) release were similar to those of oxygen uptake. CO(2) release was highest in eclosed adults and late pharate adults followed by early pharate adults, and lowest in pupae. The mode of CO(2) release ranged from continuous CO(2) release in pupae to discontinuous CO(2) release in late pharate and eclosed adults. Thus, high metabolic rates, and perhaps, in conjunction with discontinuous CO(2) of late pharate adults are responsible for their higher susceptibility to modified atmospheres than pupae and early pharate adults.     

Laboratory study on the effects of temperature and three ventilation rates on infestations of Varroa destructor in clusters of honey bees (Hymenoptera: Apidae)

In this study, reduced levels of ventilation were applied to small clusters of bees under controlled conditions to determine whether lowered ventilation rates and the resulting increased levels of CO2 could increase the mortality rates of varroa. Two experiments were performed at two different temperatures (10 degrees C and 25 degrees C). Both experiments compared varroa mortality among high (360 liters/h), medium (42.5 liters/h), and low (14 liters/h) rates of ventilation. The clusters of bees (approximately 300 worker bees) in bioassay cages with 40 introduced varroa mites were placed into self-contained glass chambers and were randomly assigned to one of the three ventilation treatments within incubators set at either of the two temperatures. Bee and varroa mortality and the levels of CO2 concentration were measured in each of the experimental chambers. In both experiments, CO2 levels within the chamber increased, with a decrease in ventilation with CO2 reaching a maximum of 1.2 +/- 0.45% at 10 degrees C and 2.13 +/- 0.2% at 25 degrees C under low ventilation. At high ventilation rates, CO2 concentration in chamber air was similar at 10 degrees C (1.1 +/- 1.5%) and 25 degrees C (1.9 +/- 1.1%). Both humidity and CO2 concentration were higher at 25 degrees C than at 10 degrees C. Bee mortality was similar within all ventilation rate treatments at either 10 degrees C (11.5 +/- 2.7-19.3 +/- 3.8%) or 25 degrees C (15.2 +/- 1.9-20.7 +/- 3.5%). At 10 degrees C, varroa mortality (percentage dead) was greatest in the high ventilation treatment (12.2 +/- 2.1%), but only slightly higher than under low (3.7 +/- 1.7%) and medium ventilation (4.9 +/- 1.6%). At 25 degrees C, varroa mortality was greatest under low ventilation at 46.12 +/- 7.7% and significantly greater than at either medium (29.7 +/- 7.4%) or low ventilation (9.5 +/- 1.6.1%). This study demonstrates that at 25 degrees C, restricted ventilation, resulting in high levels of CO2 in the surrounding environment of small clusters of honey bees, has the potential to substantially increase varroa mortality.     

Effect of high-carbon dioxide atmospheres on infestations of apple maggot (Diptera: Tephritidae) in apples

Short-term storage regimens containing elevated atmospheres of carbon dioxide (CO2) were evaluated for their ability to disinfest newly harvested 'McIntosh' apples of apple maggot, Rhagoletis pomonella (Walsh). Infested fruits containing newly laid eggs were either placed directly into the high-CO2 atmosphere at 10 degrees C to expose this life stage, or else held first for 7 d at room temperature, to allow development to the neonate larval stage. Treatment combinations consisted of three different CO2 levels (10.6, 14.9, and 19.0% CO2) and two periods of exposure (7 and 14 d). Apple maggot eggs subjected to the treatments always exhibited some survival, which was lower for the 14-d than the 7-d exposure periods. In contrast, newly hatched larvae were less able to survive the treatments. The 7-d exposure allowed low levels of survival of this life stage, but virtually none survived the 14-d exposure period. To determine the age at which eggs become more susceptible to high-CO2 atmospheres, infested fruits containing eggs three or 3d old were submitted to a 14-d exposure to 19.0% CO2. Survival of 3-d old eggs was similar to that of eggs exposed at an age of 1 d or less, but this dropped to near zero for 5-d old eggs, indicating an increase in susceptibility sometime during the 3-5-d age range. Fruits exposed to 19.0% CO2 for 14 d were significantly firmer than untreated fruits. No apparent browning, internal breakdown or other fruit defects were detected in any of the treatments.     

Microculture model studies on the effect of various gas atmospheres on microbial growth at different temperatures

A microculture technique, employing 96-well tissue culture plates in plastic bags, was used to test the effect of different gas atmospheres (vacuum, air, nitrogen, and carbon dioxide) on the growth of Escherichia coli, Bacillus macerans, Salmonella typhimurium. Candida albicans, Lactobacillus plantarum, Pseudomonas/Acinetobacter/moraxella-group, Brochothrix thermosphacta and Yersinia enterocolitica at 2, 6, and 20 degrees C. In general, carbon dioxide was the most effective inhibitor. The inhibition increased with decreasing temperature. Only the combination of carbon dioxide and 2 degrees C provided complete inhibition of Broch. thermosphacta and Y. enterocolitica.     

Confirmation and efficacy tests against codling moth and oriental fruit moth in peaches and nectarines using combination heat and controlled atmosphere treatments

Two high-temperature, forced air treatments under controlled atmosphere conditions, called CATTS for controlled atmosphere/temperature treatment system, were developed for control of all life stages of codling moth, Cydia pomonella (L.), and oriental fruit moth, Grapholita molesta (Busck), infesting peaches and nectarines (both Prunus spp.). These treatments were used in efficacy and confirmation tests to kill > 5,000 fourth instar oriental fruit moths and > 30,000 fourth instar codling moths with zero survivors. The treatments consist of linear heating rates of either 12 or 24 degrees C/h to a final chamber temperature under a 1% O2, 15% CO2, and > 90% RH atmosphere with air speed between 1.2 and 2.0 m/s. At a 12 degrees C linear chamber heating rate, treatment takes approximately 3 h to reach a final chamber temperature of 46 degrees C. The average lowest core temperatures of the fruit reached 43.8 degrees C within the last 30 min of the treatment. At a 24 degrees C linear chamber heating rate, it takes approximately 2.5 h to reach a final chamber temperature of 46 degrees C. The average lowest core temperatures of the fruit reached 44.6 degrees C for the last 15 min of the treatment. It also was determined that both treatments did not significantly alter the quality parameters that were evaluated to a degree that would have negatively influenced the marketability of the fruit. Positive benefits of treatment included a slower ripening of treated fruit and an inhibition of the loss of juiciness during storage in some cultivars. These treatments may be used to replacement to methyl bromide fumigation for conventional fruit or as a new treatment for organic fruit contingent upon importing country approval.     

Combined heat and controlled atmosphere quarantine treatments for control of western cherry fruit fly in sweet cherries

Nonchemical quarantine treatments, using a combination of short duration high temperatures under low oxygen, elevated carbon dioxide atmospheric environment were developed to control western cherry fruit fly, Rhagoletis indifferens Curran, in sweet cherries, Prunus avium (L.). The two treatments developed use a chamber temperature of 45 degrees C for 45 min and a chamber temperature of 47 degreesd C for 25 min, both under a 1% oxygen, 15% carbon dioxide, -2 degrees C dew point environment. Both these treatments have been shown to provide control of all life stages of western cherry fruit fly while preserving commodity market quality. There was no definitive egg or larval stage, which was demonstrated to be the most tolerant to either controlled atmosphere temperature treatment system treatment. Efficacy tests for both treatments resulted in 100% mortality of >5000 western cherry fruit flies in each treatment. These treatments may provide, with further study, quarantine security in exported sweet cherries where western cherry fruit fly is a quarantine concern and fumigation with methyl bromide is not desired.     

Effect of various gas atmospheres on the growth and survival of Campylobacter jejuni on beef

Pieces of fresh beef were inoculated with three strains of Campylobacter jejuni. The meat was then allocated to three treatments: (a) vacuum packaged, (b) packaged in an atmosphere of 20% CO2 + 80% N2, and (c) packaged into sterile Petri dishes in anaerobic cultivation boxes, which were filled with a gas mixture of 5% O2 + 10% CO2 + 85% N2. The packaging material in the first two treatments was PA 80/PE 100-PE 100/PA 80/PE 100. The survival of Campylobacter cells was followed at 37 degrees C, 20 degrees C and 4 degrees C for 48 h, 4 days and 25 days, respectively. At 37 degrees C the counts of two Campylobacter strains increased in each package treatment for 48 h. At 20 degrees C and at 4 degrees C the counts of the same two strains decreased by 1 to 2 log units and 0.5 to 1 log unit, respectively, during storage. The survival of the two strains was about the same in all package treatments. The third strain was the most sensitive of the strains studied. At 37 degrees C its numbers increased only in the optimal gas atmosphere; at 20 degrees C the strain was not detectable after 24 to 48 h storage and at 4 degrees C after 4 days storage. The aerobic plate counts were determined for all samples at the same time as Campylobacter counts. The high indigenous bacterial numbers of the meat samples did not appear to have a great effect on the survival or growth of campylobacters.     

Effect of temperature on the microbial flora of herring fillets stored in air or carbon dioxide

The microbial development on fillets of herring from the Baltic Sea was studied at temperatures from 0-15 C in air or 100% carbon dioxide (96-100% CO2). The shelf-life of the fillets , defined as the time for the 'total aerobic count' to reach 1 X 10(7) c.f.u./g increased with decreased temperature from 1 d at 15 degrees C to 7 d at 0 degrees C (air). The corresponding values in CO2 were 3 d and 33 d, respectively. The initial flora of the herring fillets was dominated by Alteromonas putrefaciens and Pseudomonas spp. and so was the spoilage flora after storage in air (together 62-95% of the flora: all temperatures). Alteromonas putrefaciens predominated slightly at 2 degrees C to 15 degrees C, while Pseudomonas spp. dominated at 0 degrees C. The Pseudomonas flora was mainly split between Ps. fragi , Ps. fluorescens and a heterogenous group of unidentified Pseudomonas spp. The proportions were not influenced by temperature. In 100% CO2 at the time of spoilage the flora consisted of a significant number of Lactobacillus spp. Below 4 C the domination was almost complete while at 10 degrees C and 15 degrees C. Enterobacteriaceae, Vibrionaceae and Alt. putrefaciens was also found. It was concluded that the microbiological shelf-life of herring fillets is improved by refrigeration storage in 100% CO2 but for good results the temperature should not exceed 2 degrees C.     

Time-mortality relationships for Tribolium castaneum (Coleoptera: Tenebrionidae) life stages exposed to elevated temperatures

The use of elevated temperatures (> or = 40-60 degrees C) or heat treatments for managing insects in food-processing facilities is a viable alternative to space fumigation with methyl bromide. Quantitative data are lacking on the responses of life stages of the red flour beetle, Tribolium castaneum (Herbst), an important pest of food-processing facilities worldwide, to elevated temperatures used during heat treatments. We determined time-mortality relationships for eggs, young (neonate) larvae, old larvae, pupae, and adults of T. castaneum, exposed to constant temperatures of 42, 46, 50, 54, 58, and 60 degrees C. Generally, mortality of each stage increased with an increase in temperature and exposure time. Young larvae were the most heat-tolerant stage, especially at temperatures > or = 50 degrees C. Exposure for a minimum of 7.2 h at > or = 50 degrees C was required to kill 99% of young larvae, whereas the other stages required < or = 1.8 h. Heat treatments that control young larvae should control all other stages of T. castaneum, and young larvae should be used as test insects to evaluate efficacy against T. castaneum during an actual facility heat treatment. These results provide the basis for successful use of elevated temperatures for management of T. castaneum life stages associated with food-processing facilities.     

Hydrolysis technology of biomass waste to produce amino acids in sub-critical water

Hydrolysis of biomass waste (such as fish waste, chicken waste, hair and feather) to produce amino acids was studied in sub-critical water, with reaction temperatures from 180 to 320 degrees C and reaction pressures from 3 to 30 MPa. The product of amino acid was determined by Amino Acid Analyzer (BioLC), and 18 kinds of amino acid were obtained. The results show that the controlling of reaction atmosphere, pressure, temperature and time of hydrolysis is very important to obtain high yield of amino acid; most of amino acids reached maximum yield at reaction temperature range of 200-290 degrees C and reaction time range of 5-20 min. There are obvious changes of amino acids yield at reaction pressures of 6-16 MPa and reaction temperature around 260 degrees C, owing to the homogeneousness of the first two phases of water in the formation of vapor and liquid. There are different yields of the same amino acid in different reaction atmospheres (e.g. air, carbon dioxide and nitrogen).