Article

Cold temperature disinfestation of bagged flour

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Abstract

We conducted studies using a commercial freezer maintained at −17.8 °C to determine the time needed to kill Tribolium castaneum eggs in a pallet of flour. Each bag weighed 22.7 kg, and there were 5 bags in each of 10 layers. The dimensions of the pallet were 109-cm wide by 132-cm long by 123-cm tall, and the weight of the stacked pallet was approximately 1152 kg. We conducted tests for nine internal goal temperatures of −12, −10, −8, −6, −4, −2, 0, 4 and 8 °C. Internal temperatures in the most central location of the flour pallet reached: −11.0, −9.4, −6.9, −5.0, −3.5, −1.6, −0.1, 3.3, and 5.6 °C and were achieved after 11.0, 9.1, 8.9, 7.2, 6.7, 5.8, 5.5, 5.2, and 4.2 days, respectively. For treatments where the goal temperature for the center bag ranged from −12 to 4 °C, egg mortality was 100% in bags located in both the periphery and in the center of the pallet. When the temperature goal for the center bag was 8 °C, 7 ± 2.5% of the eggs survived in bags located near the center of the pallet. Our data showed that temperatures that follow the dynamic temperature curve that takes place over 24.2 days (cool down and warm up for the 0 °C temperature goal) resulted in 100% mortality of T. castaneum eggs. The reason for the difference in mortality for a static compared to a dynamic temperature treatment may be due to the fact that the dynamic temperature treatment occurs over a much longer duration. The fact that the treatment only required 5.5 days in the freezer before it could be shipped makes it a practical method to disinfest pallets of flour, especially because the bags do not need to be removed from the pallet and no chemicals are used.

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... However, issues of cost, fumigant resistance, occupational health and environmental concerns have marred the continued use of most fumigants (Stejskal et al., 2019). With growing consumer consciousness and rapid changes in global trade policies against pesticides, safe and efficacious disinfestation techniques that meet regulatory standards and market demands are required (Flinn et al., 2015). Due to high insulation properties of grain, heat gain takes time once the grain is chilled (David et al., 1977), making extreme low temperatures ideal as a sustainable grain/commodity treatment method (Mullen and Arbogast, 1979;Fields et al., 2012). ...
... Similarly, C. ferrugineus was observed to have the ability to overwinter at low temperatures, including temperate winters (Fields, 1992;Fields et al., 2012) and depress its supercooling point (SCPs) to -20 ℃ when cold-acclimated (Smith, 1970;Fields, 1992). Tribolium castaneum was reported to succumb to -12 to 4℃ in flour pallets depending on duration of exposure (Flinn et al., 2015), e. g., -10 ℃ for 7-9 h could give 100 % mortality in both T. castaneum, and O. surinamensis (Mullen and Arbogast, 1979). Although various metrics are used to measure insect responses to low temperature, the SCPs have been extensively used (Baust and Rojas, 1985) and more recently, along with the chill comma recovery time (CCRT) (Nyamukondiwa and Terblanche, 2011). ...
... In addition, most laboratory experiments that use disinfested grain seem to lack a standard reference for low-temperature lethal thresholds of target species, resulting in excessive variations grain disinfestation methods (see Stejskal et al., 2019). For example, low-temperature disinfestation of different types of grain was reported, ranging from -18 ℃ (Brilinger et al., 2020), to +15 ℃ (Cui et al., 2020) at various chilling durations (Fields et al., 2002;Silva-Aguayo et al., 2004;Flinn et al., 2015). ...
Conference Paper
Safe and efficacious grain disinfestation techniques have become more important in the wake of production constrains and uncertainties, disruption of global supply chains, insecticide resistance, increasing consumer consciousness and associated changes in global trade policies. The use of extreme low temperature remains one of the most relevant techniques in meeting most of these changing sets of demands and standards, however, it remains unclear whether previously set 'blanket' low lethal temperature thresholds are applicable to other strains and different thermal acclimation contexts. We used, supercooling points (SCP), chill comma recovery time (CCRT) and exposure to extreme low temperature to reassess the low-temperature responses of four stored product beetle pests. Based on CCRT responses, Rhyzopertha dominica and Tribolium castaneum were significantly more cold tolerant than Oryzaephilus surinamensis and Cryptolestes ferrugineus. None of the species survived extreme low temperature exposure, however, SCP responses showed that C. ferrugineus was the most cold tolerant species with T. castaneum as the least. Our results show that stored beetles had depressed SCPs and thus more cold tolerant than reported in literature. This has implications on choice of low temperature lethal limits to improve the efficacy of grain disinfestation using cold treatments.
... Earlier studies with the application of cold treatment directly on amylaceous commodities (grains, flour, etc.), showed the efficacy of the method against insects that occur at the post-harvest stages of agricultural commodities (Smith 1970;Nakakita and Ikenaga 1997;Burks and Hagstrum 1999;Andreadis et al. 2014;Flinn et al. 2015). Low temperatures have been successfully implemented for the protection of stored tobacco against the cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae) (Imai and Harada 2006). ...
... Here, our results showed all eggs died at − 5 °C before 24 h of exposure, and survival at the 8-h exposure was only 3%, which was much lower than the respective figures of larvae and pupae. Regarding T. castaneum eggs, Flinn et al. (2015) noted that in bagged flour mortality was 100%, when the temperature of flour was between − 12 and 4 °C. Arthur et al. (2015) reported than 8 h of exposure at − 18 °C were required to kill the eggs of T. castaneum, which was identified as the most cold-tolerant life stage of this species. ...
... For example, for P. interpunctella larvae, the decrease in temperature from − 10 to − 15 °C reduced the time that was needed for 100% mortality from 1 day to only 2 h. From the available literature, we can conclude that temperatures at this level or even lower can be utilized successfully for the rapid disinfestation of stored-products (Fields 1992;Flinn et al. 2015;Arthur et al. 2015). However, efficacy alone should not be the only indicator for the viability of cold treatments for stored-products in "real world" industrial applications, as slightly higher temperatures, e.g., − 10 °C instead of − 15 °C, may be more economically feasible, even if these temperatures have to be applied for longer time periods. ...
Article
Full-text available
The insecticidal effect of low temperatures for the control of all life stages of two stored-product insects, Plodia interpunctella and Liposcelis bostrychophila, was evaluated under laboratory conditions. The temperatures tested were 0, − 5, − 10 and − 15 °C, and, at these temperatures, the insects were exposed for 2, 4 and 8 h and also for 1, 2, 3 and 7 days. Regarding P. interpunctella, the most cold-tolerant life stage was larvae, given that 2 days of exposure were needed for complete (100%) mortality at − 10 °C. Moreover, all larvae were dead at − 15 °C even after 2 h of exposure. Eggs of P. interpunctella were susceptible to cold, as mortality was complete after 7, 1 day, 2 and 2 h at 0, − 5, − 10 and − 15 °C, respectively. L. bostrychophila was by far less susceptible than P. interpunctella. For this species, adults were still alive even after 7 days at − 10 °C, while complete mortality was achieved only after 1 day at − 15 °C. Eggs of L. bostrychophila were the most cold-tolerant life stage, as survival was observed even after 3 days at − 15 °C. The results of the present study provide the first data set on which all life stages of P. interpunctella and L. bostrychophila are evaluated for their susceptibility to cold treatments in a standardized series of exposures and temperatures. These results are expected to further encourage the “real world” application of cold treatments for the disinfestation of durable stored-products.
... The differences in cold susceptibility depend on behavioral, physiological and biochemical adaptations of insects and mites to cold (Fields, 2001). Species that are most easily controlled by cold temperatures include the red flour beetle, T. castaneum, the confused flour beetle, T. confusum Jacquelin Du Val (Coleoptera: Tenebrionidae), and the merchant grain beetle, Oryzaephilus mercator (Fauvel) (Coleoptera: Silvanidae) (Nagel and Shepard, 1934;Howe, 1965;Sinha and Watters, 1985;Arthur et al., 2015;Flinn et al., 2015), whereas the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), the larger cabinet beetle Trogoderma inclusum (LeConte) (Coleoptera: Dermestidae), T. variabile, S. granarius, E. kuehniella and P. interpunctella are less vulnerable to cold temperatures and thus more difficult to control (Mathlein, 1961;Fields, 1992;Mason and Straight, 1998;Somme, 1968;Abdelghany et al., 2015;Arthur et al., 2015). Furthermore, the susceptibility to low temperatures can also be affected by developmental stage. ...
... Low temperatures are also used to control insects in finished products or bulk grain, provided that moisture levels of the air are not high enough to wet the grain (Mason and Strait, 1998;Fields et al., 2012;Flinn et al., 2015). Packaged finished products often require extremely low temperatures or extremely long durations to reach temperatures required to kill insects (Mullen and Arbogast, 1979). ...
... Likewise, relatively brief storage of bins or packages with dried fruits and nuts in commercial freezers, at temperatures below À15 C for at least 48 h, also shows potential as a disinfestation treatment for both the Indian meal moth and the navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae) (Johnson, 2007). Moreover, Flinn et al. (2015) noted that low temperatures were able to control T. castaneum inside flour bags, suggesting that low temperatures are able to penetrate the flour mass. In that study, the authors noted that the dynamic temperature change (cool down and then warm up) was more effective than the continuous application of freezing, probably due to the fact that this dynamic change takes more time, which means that insects are exposed for a longer interval. ...
... The application of low temperatures for control of stored-product insects has been extensively evaluated over the past three decades for many species of the orders Coleoptera, Lepidoptera and Psocoptera [1][2][3][4][5][6][7][8]. These studies show that stored-product insects vary remarkably in their susceptibility to low temperatures. ...
... A recent review by Andreadis and Athanassiou [4] underlines the lack of paradigms of cold tolerance of stored-product insects as compared with field crop pests. In addition, most of the data available for stored-product insects'cold tolerance are largely focused on non-acclimated individuals [1,3,5,7,9]. Athanassiou et al. [7] show that acclimation of stored-product insects prior to actual treatment has dissimilar effects depending on species and acclimation conditions, and is not always related to increased tolerance. ...
... Still, this post-acclimation approach has not been tested in detail, either as a stand-alone scenario or in conjunction with preacclimation. Practically, post-acclimation is very likely to occur when durable commodities are treated with subzero temperatures, as temperature increases very gradually after the termination of the cold treatments [5], which may allow insects to have a considerable adjustment period. Hence, in these scenarios, insect mortality may not be solely caused by the cold treatment itself, but by a combination of cold treatment with post-acclimation. ...
Article
Full-text available
Insect survival after exposure to 0 °C for 7 days was examined in laboratory bioassays for control of adults of six major stored-product beetle species, Oryzaephilus surinamensis (L.), the sawtoothed grain beetle, Cryptolestes ferrugineus, (Stephens), the rusty grain beetle, Dermestes maculatus DeGeer, the hide beetle, Sitophilus oryzae (L.), the rice weevil, Tribolium castaneum (Herbst), the red flour beetle, and T. confusum Jacquelin DuVal, the confused flour beetle In this test there were four different acclimation treatments, insects that had been subjected to a pre-acclimation period to 0 °C, a post-acclimation period, both a pre and post-acclimation period, and adults that were not acclimated. Insect survival for all species except S. oryzae was not affected by the exposure to 0 °C, regardless of the acclimation scenario. In contrast, exposure to 0 °C drastically reduced survival of S. oryzae. Moreover, adults that were exposed to the post-acclimation only and un-acclimated adults had lower survival rates than those that had either exposure to pre-acclimation, or to both pre- and post-acclimation. Results of this experiment show that acclimation played a limited role in adult survival of five of the six tested species, and that exposure of adults to 0 °C for 7 d had no effect in survival of these species as well.
... Given that cold treatments are being evaluated for the disinfestation of commodities, experiments that are based on treatment of infested product may be more realistic than treatment of insects alone, since the presence of food around the insect may act as an "insulating material" reducing the lethal effect of low temperatures. Flinn et al. (2015) exposed palletized bagged flour infested with the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) to −17.8°C and found that the temperature cooled much more quickly in the peripheral areas of the stacked pallet compared to the internal center, resulting in survival of T. castaneum eggs as the pallet stack cooled, but mortality was complete when temperature reached −17.8°C. More recently, Athanassiou and Arthur (2020) found that a temperature of 0°C did not produce complete mortality of adults of several stored-product beetle species, despite their pre-or post-conditioning. ...
... However, we did not find this to be true in our study. Other studies, such as Flinn et al. (2015), documented effects of an insulating mass of bagged flour, but this study used much larger quantities of flour than our study. But, in a similar laboratory study, Arthur et al. (2015) exposed different life stages of T. castaneum and the larger cabinet beetle, Trogoderma inclusum LeConte (Coleoptera: Dermestidae) to −18°C and did see indications that even a small amount of food material gave an insulating effect. ...
Article
The efficacy of low temperatures ranging from 0 to -15 oC, was evaluated against all life stages of Tribolium confusum, adults of Oryzaephilus surinamensis and adults of Liposcelis bostrychophila. All species/life stages were exposed in empty vials or vials containing 5 g of flour, for time intervals of 2 to 7 d. Eggs and pupae were the least susceptible life stages of T. confusum, as these life stages had the highest survival at – 15 oC. Nevertheless, at this temperature, an exposure of 4 and 8 h for eggs and pupae, respectively, resulted in no survival. In most combinations, the presence of flour did not affect survival of T. confusum exposed to any temperature. There was no survival of O. surinamensis adults after exposure to -5 oC for 7 d or to -10 oC for 8 h, and the presence of flour had no effect on survival. Adults of L. bostrychophila were the most-cold tolerant among the species and life stages tested; at -10 oC, mortality was 100 % only after 7 d of exposure. For this species, the presence of flour had some effect on adult survival, but results were not consistent with temperature. The results of this study can be utilized to develop control programs for using low temperatures as a disinfestation strategy for infested commodities.
... The storage of grains and their products at low temperatures is one of the most reliable alternative methods for disinfestation of storage and processing facilities against stored product insects (Smith 1970;Nakakita and Ikenaga 1997;Burks and Hagstrum 1999;Flinn et al., 2015;Athanassiou et al., 2018b). Recent studies showed that low temperatures can control many key stored-product insects, particularly beetles and weevils (Nakakita and Ikenaga 1997;Arthur et al. 2015Arthur et al. , 2017Flinn et al., 2015). ...
... The storage of grains and their products at low temperatures is one of the most reliable alternative methods for disinfestation of storage and processing facilities against stored product insects (Smith 1970;Nakakita and Ikenaga 1997;Burks and Hagstrum 1999;Flinn et al., 2015;Athanassiou et al., 2018b). Recent studies showed that low temperatures can control many key stored-product insects, particularly beetles and weevils (Nakakita and Ikenaga 1997;Arthur et al. 2015Arthur et al. , 2017Flinn et al., 2015). For example, T. castaneum and Trogoderma inclusum were completely controlled, and 100% mortality was observed between 0.5 and 64 h under low-temperature treatment, depending on the species and its life stage . ...
Article
Insects face several (environmental) abiotic stressors, including low temperature, which cause the failure of neuromuscular function. Such exposure leads insects toa reversible comatose state termed chill-coma, but the consequences of this state for the organism biology were little explored. Here, the consequences of the chill-coma phase were investigated in two of the main stored product pest species-the red flour beetle Tribolium castaneum (larvae and adults) and the rice weevil Sitophilus oryzae (adults). For this purpose, a series of low-temperature shocks were used to estimate the chill-coma recovery time (CCRT), survival, nutrition and weight gain/ growth of T. castaneum (larvae and adults) and S. oryzae, as well as the development of T. castaneum life stages. The relatively long CCRT was characteristic of beetle larvae, at different low-temperature shocks, and CCRT increased with decreasing temperatures and increasing exposure intervals for both pest species. The survival was little affected by the low-temperature shocks applied, but such shocks affected insect feeding and growth. Tri-bolium castaneum larvae was more sensitive than adults of both insect species. Moreover, the relative consumption and weight gain of S. oryzae adults were lower than those of T. castaneum adults and mainly larvae, while feeding deterrence was not affected by low temperature shocks, unlike food conversion efficiency. Low-temperature shocks, even under short duration at some temperatures, significantly delayed development. The lower the temperature and the higher the exposure period, the more delayed the development. Thus, the physiological costs of chill-coma are translated into life-history consequences, with potential implications for the management of this insect pest species in stored products and even more so on red flour beetles and rice weevils.
... We did not include food in our treatment vials because we wanted to determine the time required to kill insects using freezing independent of the commodity infested. Thus, our results are applicable to any commodity by measuring temperature in the commodity until À18 C is reached or by using models that predict cooling temperatures of commodities (e.g., Mascheroni and Calvelo, 1982;Flinn et al., 2015). inclusum occurred (black bar) and the first time interval that produced no adult emergence of the exposed life stage (grey bar). ...
... However, there are no recent studies published in the scientific literature evaluating susceptibility of psocids to cold temperature. Therefore, the objective of this study was to determine susceptibility of psocids to À18 C, a common industry standard for commercial freezers in the US (Johnson and Valero, 2003;Flinn et al., 2015). ...
Article
Full-text available
A series of studies was conducted by exposing young and old eggs, nymphs, and adults of the psocids Liposcelis bostrychophila (Badonnel), L. paeta (Pearman), L. decolor (Pearman), and L. entomophila (Enderlein) to −18 °C for various time intervals. Survival was assessed as initial and final, at different times depending on the life stage. Young eggs of L. bostrychophila were the most tolerant life stage of any of the species, with scattered survival out to 120 h of exposure to −18 °C. Eggs were the most tolerant life stage for each species, requiring 24, 12, and 2 h of exposure for complete kill of L. paeta, L. decolor, and L. entomophila, respectively. Nymphs and adults of all species were far more susceptible than eggs, with no final survival after two hours of exposure. Results show the extreme variation between different psocid life stages and species to cold temperatures, and provide guidelines for using cold as a control strategy for psocids. Our results show that 24 h at −18 °C is sufficient to kill all life stages of the psocid species tested, except for young L. bostrychophila eggs which will require at least 128 h of exposure at −18 °C for complete mortality.
... Hence, this management option can be used against C. chinensis. However, some of the factors such as the insulating effects of stacked bags of commodities, and time required for penetrating the cold temperature through stacked bags must be considered when employing cold temperature as a management option for food storage facilities (Flinn et al., 2015). Further, the cold susceptible of stored product insects can be enhanced by integrating mechanical process such as grain cleaning with the synergists like poisonous food baits, chemicals with inhibition characteristics etc. Table 4 Developmental time (day, mean ± SE), adult longevity (day, mean ± SE), adult weight (mg, mean ± SE), and sex ratio of adult Callosobruchus chinensis emerged from larva exposed to different temperatures and storage durations. ...
Article
Full-text available
Azuki bean weevil, Callosobruchus chinensis L. is a cosmopolitan pest of stored grain legumes. Larvae cause huge losses of energy and seeds in the storage. This study assessed the effects of short-term exposure to low-temperatures (4, 0, and − 4 °C) under seven durations of storage (1, 5, 10, 15, 20, 25, and 30 days) on the survival, development, and adult performance of C. chinensis in laboratory. The effects were studied on three life stages (egg, larva [2–3 instar], and pupa) of C. chinensis. The results showed that low-temperature treatments have significant effects on the life variables of C. chinensis. Among the stages, egg and pupa stages were most sensitive to low-temperature. The very low survival rates of eggs at − 4 °C, no pupa stages of C. chinensis survived after 10 days storage. Cold exposure at − 4 °C for < 10 days not only increased egg and pupa mortality, but the negative effects also transmitted to the larvae and pupa developed from those eggs (64.3 days) and least adults were emerged with minimum longevity. Increasing the duration of cold exposure further reduced survival rates, e.g. about 20% of the eggs survived after 15 days exposure at − 4 °C, but < 30% of them survived after 25 days treatment at 4 and 0 °C. Low-temperature treatments have also affected on the adult performances such as adult weight. However, there were not any negative effects of low-temperatures on the seed germination. The life variables of C. chinensis are discussed in terms of targeting particular susceptibilities to low-temperatures in different durations of storage as an alternative to chemical treatments.
... In this context, Johnson and Valero [24] conducted studies in a commercial freezer set at −18°C to examine the effects of freezing on the disinfestation of different life stages of the cowpea weevil, Callosobruchus maculatus (F.) present in bulk-stored garbanzo beans and reported that egg mortality was estimated to be >98% after just 7 d of exposure, and complete mortality of eggs occurred after 14 d of frozen storage, with the egg stage being the most tolerant to −18°C and the adults being most susceptible at this temperature. Similar results were obtained by Flinn et al. [25] reporting that treating flour pallets in commercial freezers for 5.5 days at −17.8°C was a feasible method for achieving 100% mortality of T. castaneum eggs. Other techniques such as hot water treatment (50°C for 10 min, 55°C for 5 min and 60°C for 3 min) [19] and hot air (at 55°C for 30 min, 60°C for 20 min and 60°C for 15 min) have also obtained 100% mortality E. ceratoniae larvae [26]. ...
Article
Full-text available
Background . Insect infestation caused by Ectomyelois ceratoniae or carob moth is one of the main postharvest problems that can lead to a decrease of the marketable quality of dates. The control of carob moth is a mandatory process for exported fruits, and the main chemical method used to prevent pest diseases of palm date is treatment with methyl bromide. However, its use is being restricted due to direct harmful effects on the environment and indirect effects on humans. Freezing treatments could be physical alternatives to methyl bromide and other chemicals. Three freezing treatments at −18°C (50 h, 77 h, and 125 h) were studied for E. ceratoniae mortality in Deglet Noor date fruits. Results . The results showed that freezing at −18°C led to 100% mortality of all the stages of E. ceratoniae found in naturally infested dates. Fruit quality was examined under a selected sanitizing freezing treatment (50 hours at −18°C). This freezing treatment induced an increase of monosaccharides and a reduction in antioxidant activity (40 to 45%, measured with FRAP and DPPH assays). However, other parameters such as color, amino acids, total phenolic content, and microbial and sensorial quality were not affected by that treatment. All samples remained above the limit of marketability as there was no chilling injury. Conclusion . This treatment can be recommended as a green alternative to chemical treatments to control carob moth while yielding optimum-quality Deglet Noor date fruits that could be exported to developed countries.
... Combinations of 0, 5, 10, 25, or 50 S. oryzae were added to grain treatment bags and likewise, T. castaneum to flour. In all cases, the wheat and flour had been purchased and stored in a freezer at −17.8°C for at least 6 mo to ensure no other live insects were present when testing began (Flinn et al. 2015). To reduce interference from background noise, the bags were placed on the Plexiglas base connected to the PDS inside a sound-and vibration-shielded room described previously by Vick et al. (1988a). ...
Article
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Reduction of postharvest losses is gaining increased priority in warm regions where insect infestation may cause rapid deterioration of staple commodities. Acoustic detection can be used to assess the likelihood of insect infestations in bags of grain, flour, and other commodities that are stored in small holdings in developing countries, enabling rapid targeting of treatments. A portable postharvest insect detection system was developed with the goal to provide low-cost capability to acoustically assess infestations in small-scale storage facilities. Electret microphones input pest insect sounds to a 32-bit microcontroller platform that digitized and stored the signals on a digital memory card transferable to a portable laptop computer. The insect sounds then were analyzed by custom-written software that matched their spectra to those of known pests. Infestations of Sitophilus oryzae (L) in 2.6-kg bags could be detected down to densities of 1.9 adults/kg in grain and Tribolium castaneum (Herbst) down to 3.8 adults/kg in flour in laboratory settings. Also, differences in the rates of sounds per insect in treatments with different numbers ranging from 5 to 50 insects suggested that the sound rates of adults of different species at different population densities may be noticeably affected by aggregation pheromones or other behaviorally active semiochemicals. Further testing is needed but previous experience with acoustic detection systems suggests that the prototype has potential for use in small storage facilities where early detection of infestations is difficult to provide.
... In addition, bagged grain is a microclimate that encourages insect growth (Omodara et al., 2020), at least when hermetic packaging is not used. The microclimates of bagged products change at a slower rate than the outside temperatures (Flinn et al., 2015). As climates continue to change, these rates inside packaged goods can become more variable and a reduction in the period of cool temperatures that suppress insect growth may result in earlier insect population growth and larger population sizes throughout the post-harvest supply chain (Plarre and Burkholder, 2009;Omodara et al., 2020). ...
Article
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Climate change is a danger to the agricultural system and will impact the availability of food to feed the world. While much attention has focused on the effects of climate change on pest management prior to harvest, much less attention and time has been devoted to determining the effects of climate change on pest management in the postharvest supply chain from farm to fork. Climate change may percolate to pest management at a macro level through compositional changes in which species attack commodities through distributional changes or what commodities are grown in a region (and thus processed in that area). However, climate change may also result in altered microclimates at food facilities, which can be tied to increased generation times, elevated damage and contamination potential, greater abundance of species, and greater need for external inputs. A variety of integrated pest management (IPM) strategies may help increase the resiliency and adaptation of management to climate change. Tactics susceptible to warming temperature changes in climate showing decreased efficacy include semiochemical-based, behaviorally-based tactics, a subset of insecticides (e.g., pyrethrins and pyrethroids), and those that rely on low temperature (e.g., grain aeration, grain chilling). Tactics at food facilities showing resilience to warming temperature changes in climate include packaging, other groups of insecticides, and likely sanitation. Data gaps include predicting changing distributions for stored product insects under climate change, translating macro climate changes into microclimate changes at food facilities, and rigorously investigating how IPM tactic efficacy varies under changing climate. Increased scrutiny of how climate change will affect pest management in the postharvest supply chain will deliver improved outcomes for the entire agricultural system.
... Levels of mortality during development due to predation, disease, or mechanical damage under conditions found in mills is unknown. Research has previously established the feasibility of cold temperatures as a disinfestation strategy, which would be useful for organic pest management (Flinn et al., 2015). Although the lower limit of development for most stored product insects is around 15 C (Howe, 1965;Fields, 1992), it may be possible to limit development on extraneous rice by-products using slightly higher temperatures than the lower developmental threshold, where insects may be present and accumulate in areas where finished products are stored before shipment at warmer temperatures. ...
Conference Paper
The red flour beetle (Tribolium castaneum Herbst) is a globally distributed secondary pest of stored grains and is the primary pest in rice mills. During the process of milling rice, many different rice fractions are produced as the hulls and bran layers are removed to produce white rice. The objective of this study was to determine how red flour beetles develop on various rice fractions and temperatures. Beetles were exposed to brown rice, rice bran, milled whole rice, milled broken rice, and rice flour at 22, 27, 32, and 37°C. The developmental times, survival and elytra lengths were measured. For all temperatures and fractions, there was over 50% adult development from the neonate stage. As temperature increased for all fractions, development time decreased; however, there was no significant difference between 32 and 37°C. The beetles grew larger on rice bran. The results of this study will provide information on where red flour beetles are most likely to colonize in mills based on the preferred milling fractions and will identify where to target monitoring and control efforts.
Article
Laboratory tests on acclimated and nonacclimated life stages of Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) (adults, pupae, larvae, and eggs) and Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) (adults, larvae, and eggs) were conducted at 0, -5, -10, and -15°C to evaluate effects of acclimation on susceptibility to cold treatment. Acclimation of all tested life stages for 7 d at 15°C affected susceptibility of both species to the cold temperatures. After 1 d exposures for ≥2 h, acclimated adults had a noticeable increase in cold tolerance compared with nonacclimated adults for both tested species. Nonacclimated pupae of T. confusum were equally susceptible to cold compared with acclimated pupae at short exposures to low temperatures. Exposure of nonacclimated life stages of T. confusum, at -10°C for 1 d gave 0% survival. Similarly, almost all (99.6%) nonacclimated individuals of O. surinamensis died at -10°C. At 0°C, nonacclimated larvae were more cold tolerant than acclimated larvae, but this trend was reversed when larvae were exposed to -5°C. Mixed results were obtained for larvae of O. surinamensis because in some of the combinations tested, nonacclimated larvae were more tolerant, even at temperatures that were lower than 0°C. In contrast to O. surinamensis, eggs of T. confusum that had not been exposed to cold were not affected by acclimation, while exposure to cold showed increased cold hardiness in acclimated eggs. Results show that individual stored-product insect species may have mixed susceptibility to cold temperatures, which must be taken into account when using cold treatment as a management strategy.
Chapter
Stored product insects can infest products all along the supply chain, from raw grains stored in bins, through the milling and production process, and in final packaged goods in retail stores and homes. Traditionally they have been referred to as “stored grain insects,” which is misleading because of their prevalence in packaged food products and in more traditional urban settings in addition to rural grain storage. There are a variety of management strategies that can be used for control of these insect pests, which can differ depending on the points in the supply chain where they can be found. Topics discussed in this chapter include the various components of the supply chain, the associated insect pests, and the management strategies. Emphasis will be placed on reviewing recent research since the fourth edition of this book. References are provided, but the references are not an exhaustive list on any of the subjects, and inclusion or noninclusion of a reference does not constitute priority, recommendations, or an endorsement.
Article
Development of Tribolium castaneum (Herbst), the red flour beetle, was assessed on different rice components and their various by-products (i.e., diets) commonly found in rice mills, in two separate experiments. In the first experiment, eggs did not develop through to the adult stage on rough rice hulls, paddy rice dust, and milled rice dust, while eggs developed to the adult stage to some extent on rice flour, milled whole kernels, brown rice, milled broken kernels, and bran. For the diets where development occurred, the lowest percentage was on brown rice, and adults that emerged on brown rice had smaller elytra compared to adults emerging on the other diets. In the second experiment, 1–2-day old neonates were exposed on the diets listed above and held at 22, 27, 32, and 37 °C. At all temperatures, development to the pupal and adult stages was slowest on rice flour. At 22 °C, development to those stages took about twice as long compared to development at 27 °C. As temperature increased developmental times were reduced. Even though neonates developed slowest on rice flour adult emergence rates were not affected. Predictive models were used to estimate potential population development on the diets. At 22 and 27 °C, adult size as measured by elytra length was greatest when they developed on bran, while body weight was generally lowest for adults that developed on brown rice. Results show that T. castaneum can utilize rice components and by-products produced during the rice milling process, although not all components or by-products were optimal for development, and emphasis should be placed on cleaning and sanitation to remove food sources to limit infestations. Mill managers can use these results to show the importance of sanitation, and potentially improve overall pest management programs inside the mill.
Article
Extreme temperature has been used as an alternative to chemical treatments for stored product pests for years. Resistance to heat or cold treatments has not been documented in stored product insects, but repeated use of ineffective treatments could lead to adaptive tolerance. Trogoderma variabile (Dermestidae) is a common pest of stored products, and the larval stage is highly resistant to cold and destructive. We artificially selected populations by inducing chill coma at four different cold temperature treatments: 3 and 5 h at -10°C and 3 and 5 h at 0°C. Recovery time was highly heritable after selection for seven generations for decreased recovery time (cold tolerance) and increased recovery time (cold susceptibility) at all time and temperature combinations. Three replicate populations for each time and temperature combination varied substantially, suggesting different mutations in each population were probably responsible for selected phenotypes. Body size decreased in populations selected for cold susceptibility compared with those selected for cold tolerance and survivorship to long-term cold stress increased in the cold-tolerant populations compared with the susceptible populations. After the cessation of the selection experiment, cold tolerance dissipated within four generations from the populations at -10°C, but was maintained in populations exposed to 0°C. Our results suggest that warehouse beetles can adapt to cold stress quickly, but in the absence of cold stress, the proportion of cold-tolerant/susceptible individuals is quickly reduced, suggesting that some of the mutations responsible for these phenotypes may be associated with fitness costs under normal conditions.
Chapter
Once cereal grain is harvested and put into storage, it provides a resource for a range of insect pests of stored grain. With few exceptions, these insects rarely attack grain in the field before harvest, but once the grain is in storage there is a degree of inevitability that insect infestation will occur. This means that methods are needed to either disinfest grain or to protect it from infestation during storage. The aim of this chapter is to review recent advances in insect pest management in stored grain, ranging from methods that are well established to those that are still being evaluated. This topic has been the subject of considerable laboratory and field research as evidenced by the large and growing body of published studies. Resistance to phosphine resistance and various insecticides, as well as the phase-out of methyl bromide as an ozone-depleting substance, continue to be major drivers for research on management of insects in stored products. Other research has focussed on improving the basic understanding of various methods or ways of improving methods currently in use. Despite extensive research on a wide variety of chemical and non-chemical treatments, very few have been commercialised. Two examples are spinosad, which has been registered as a grain protectant, and sulfuryl fluoride, which is now available as a grain fumigant. The interest in non-chemical treatments, especially aeration cooling, is encouraging. In general, integrated pest management is seen as the goal of entomologists, requiring the strategic integration of multiple methods to provide maximum effect with minimal health and environmental risks. Some of the chemical and non-chemical treatments reviewed in this chapter have great potential to be used as part of an integrated approach.
Chapter
Stored product insects represent a diverse group of species that can infest raw grains but also can infest structures associated with the milling, processing, storage, and distribution of finished grains and grain-based products. One of the recent developments in managing these insects is documenting the extensive presence of these insects in and around milling, processing, and warehouse facilities (Semaeo et al. 2013), which represents a new awareness of the infestation potential.
Article
Laboratory tests were carried out to examine the efficacy of different exposure intervals (2 h, 4 h, 8 h, 1 d, 2 d, 3 d, and 7 d) on different life stages (adults, pupae, larvae, and eggs) of Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), the confused flour beetle, and Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), the saw-toothed grain beetle (adults, larvae, and eggs) to 0, -5, -10, and -15°C. Larvae and pupae of T. confusum were more cold-tolerant than eggs or adults. Exposure to temperatures of -10°C for 1 d will kill nearly 100% of all life stages of T. confusum. O. surinamensis was more cold-tolerant than T. confusum. Adults of O. surinamensis were not killed when exposed for 1 d at -5°C, but egg hatch was drastically reduced after 2 h of exposure at the same temperature. Eggs and adults of O. surinamensis were more cold-tolerant than larvae. Our study indicates that target insect species and life stage, temperature, and exposure interval should all be considered when cold treatment is selected as a control strategy against T. confusum and O. surinamensis. Facility managers can use these data in planning cold treatments.
Article
Tribolium castaneum (Herbst), the red flour beetle, is a cosmopolitan stored product insect that infests a variety of raw grains and processed grain products. Although this pest is prevalent in rice mills, there is a comparative lack of data on growth and development on rice by-products and fractions compared to other grains. In this study, ten mixed-sex adults were exposed on 200 g of either rice flour or brown rice, and populations were assessed after 2, 4, 6, 8, and 10 months at 22, 27, or 32 °C. At 22 °C, the number of adults, pupae and larvae on rice flour and brown rice remained low throughout the 12-month storage period. At 27 °C, the number of adults on rice flour increased to a maximum at 8 months, while adult populations on brown rice remained relatively constant from 2 to 10 months, with few pupae or larvae in the samples. At 32 °C, adult populations on rice flour and brown rice were constant after month 2, with low numbers of pupae and larvae. Adult predation could have accounted for low numbers of pupae and larvae. Using the original 10-month data, populations were projected for an additional 14 months to predict population patterns. Adult numbers showed an increase over time at all temperatures on rice flour and brown rice at 22 °C but numbers seemed to stabilize at 27 and 32 °C. For both diets at 27 and 32 °C, projected pupae and larvae numbers remained steady but low compared to adults. However, populations would not be expected to increase indefinitely because at some point the resources would become limited and populations would crash or decline. Results show T. castaneum can deplete fixed resources such as bags of rice flour or brown rice when temperatures equal or exceed 27 °C.
Article
Estimated direct and indirect losses of grains and grain-based products caused by stored-product insects range from about 10% in temperate regions to almost 50% in humid tropical areas. Pest management strategies in bulk grains include the use of fumigants such as phosphine and sulfuryl fluoride, and grain protectants, which are sprayed directly on commodities as they are loaded into storage. Fumigants, aerosols, and contact sprays are also used as structural treatments in mills, processing plants, and food warehouses. Some older organophosphate protectants and contact sprays have been phased out worldwide and have been replaced by safer insecticides, including pyrethroids and insect growth regulators (IGRs). These IGRs include juvenile hormone analogues (JHAs), ecdysteroids and chitin synthesis inhibitors, and are considered safe due to their insect specificity. Methoprene is the JHA that has been used most extensively in stored-product pest management. The formulations of methoprene originally introduced into the stored-product market in the 1980s contained the racemic mixture with both R- and S- forms, but now only the purified S-methoprene isomer is used. Methoprene has received broad attention and has been tested over decades for its direct lethal effects, but many recent studies focus more on sub-lethal effects. Although methoprene has been used for more than four decades, there has not been a recent and comprehensive synopsis or review of this IGR on stored-product insects. This review addresses the history and present use of methoprene with special emphasis on stored-product protection.
Article
Temperature and nutrition are two prominent environmental variables influencing insect life from development to reproduction. Here, we assessed various components of fitness (developmental times, survival rates, egg production, and weight gain) of Tribolium confusum fed on wheat, barley or corn flour at 15, 27 and 35°C with a view of understanding its level of susceptibility. The shortest developmental times, the highest survival percentage, egg production, and weight gain were achieved by feeding larvae on wheat flour at 35°C, while the opposite results were attained by feeding larvae on barley or corn flour at 15°C. Interaction of temperature × diet significantly affected the above-mentioned biological features. The correlation between the alterations in the biological features and the main nutrients of the flours tested (total protein, carbohydrate, and lipid contents) is discussed. The results of this study suggest the value of a strategy for managing T. confusum by exposure to low temperatures.
Article
Full-text available
Aerosol insecticides can be important components of insect management plans for mills, food warehouses, and processing plants. In the United States, synergized pyrethrin is used alone or combined with an insect growth regulator (IGR), either methoprene or hydroprene. The presence of food material can result in increased survival of adult Tribolium castaneum (Herbst) or Tribolium confusum Jacquelin du Val exposed to synergized pyrethrins, but larvae appear to be more susceptible than adults. Results of field trials involving methoprene and pyriproxyfen indicate residual persistence of the IGRs. Tribolium castaneum is more susceptible than T. confusum to IGRs, but combination of pyrethrin with the IGR may produce an additive effect on T. confusum.
Article
Full-text available
A spatial model of Cryptolestes ferrugineus (Stephens) population dynamics and bin temperature was used to simulate effects of time of aeration, bin size, and latitude on C. ferrugineus density in stored wheat. In unaerated grain, densities of C. ferrugineus were predicted to be much greater in wheat stored in Oklahoma than in Kansas or South Dakota and reach greater densities in 272.2-T (10,000 bu) than in 81.6-T (3,000 bu) bins. Automatic aeration controllers (fans turned on when outside air was 10ºC lower than grain temperature) suppressed C. ferrugineus population growth better than manual aeration starting in November. Automatic aeration also worked better when started at grain harvest rather than waiting until 1 September. In Oklahoma, automatic aeration starting at harvest was the only aeration strategy that prevented C. ferrugineus from exceeding 2/kg. Average fan hours to cool the grain to 10ºC using automatic control starting at harvest was 270 h for 272.2-T bins and 220 h for 81.6-T bins. Starting automatic aeration at harvest added an additional 30 h. This small increase in fan hours resulted in much greater C. ferrugineus suppression, especially in latitudes similar to those of Oklahoma and Kansas. In temperate climates, automatic aeration controllers should greatly reduce the need for chemical control.
Article
Full-text available
One California processor of organic garbanzo beans (Cicer arietinum L.), unable to use chemical fumigants, relies on 30-d storage at -18 degrees C to disinfest product of the cowpea weevil, Callosobruchus maculatus (F). To determine whether the storage period may be shortened, the most cold-tolerant life stage of the cowpea weevil was identified. Laboratory studies showed that the egg stage was most tolerant to -18 degrees C and that adults were most susceptible. To examine the efficacy of cold storage disinfestation, bags of black-eyed peas, Vigna unguiculata (L.) Walp., infested with cowpea weevil eggs were buried within garbanzo bean bins placed in a commercial cold storage facility kept at approximately -18 degrees C and removed after 7, 14, and 21 d. Survival was highest in eggs located at the center of the bins and coincided with the slowest cooling rate. Although temperatures within the bins did not reach -18 degrees C until after 14-19 d, egg mortality was estimated to be >98% after just 7 d of exposure. Complete mortality of eggs occurred after 14 d of cold storage. A 2-wk treatment regimen may be sufficient for control of cowpea weevil in organic legumes.
Article
Purpose of review: Tactics to manage infestations of stored-product insects in grain-processing facilities historically included the use of heat treatments and the fumigant methyl bromide. The phase out of methyl bromide in the USA in 2005, because of its adverse effects on stratospheric ozone, has renewed interest in using heat treatments. In this review, a brief history regarding the use of heat treatments in grain-processing facilities, such as flour mills, is described along with recent research developments and future research needs. Findings: Scientific literature published during the last decade shed new light on the following areas: identification of a heat-tolerant stage of a species based on stage-specific susceptibility at different constant elevated temperatures; differences in susceptibility among stored-product insect species to elevated temperatures; confusion in determining a heat-tolerant stage during commercial heat treatments of grain-processing facilities; impact of sanitation on insect responses; degree and duration of insect suppression obtained following a heat treatment intervention; development and validation of a thermal death kinetic model to predict survival of heat-tolerant insect life stages as a function of time-dependent temperature data; and development of software programs to estimate the heat energy required including costs of a heat treatment based on fuel used and predicting survival of heat-tolerant insect stages in "real time" during heat treatments. Directions for future research: Temperature-time mortality relationships have been developed for a few economically important insect species and additional species should be evaluated in both laboratory and field conditions. Very little is understood about the impact of the lethal and sub-lethal elevated temperatures used during heat treatments on insect behaviour and reproduction. The costeffectiveness of combining elevated temperatures with other chemical or nonchemical methods in grain-processing facilities also should be explored.
Article
The fumigant methyl bromide (MB) is being phased out of production and usage to control stored-product insects in flour and rice mills, as well as feed and food production plants, in the United States and other developed countries throughout the world. A phase-out schedule has also been established for undeveloped counties under a delayed timeline compared to the one established for developed countries. Whole-plant alternatives to MB treatment, such as the fumigant sulfuryl fluoride and heat, can be used in place of MB, but they have some limitations as well, which will be briefly discussed in this review. Hence, residual surface treatments with contact insecticides and insect growth regulators and aerosol applications are receiving increased attention for incorporation into management programs that historically relied on MB fumigations. This review will focus on recent research with contact insecticides and aerosols for controlling stored-product insects in structures and how they can be viewed as options for control to alleviate concerns regarding the phase-out and reduced availability of MB for structural fumigations. A brief discussion of emerging pest species or groups, and how they can be controlled with surface treatments and aerosols, is also included in the review.
Article
Tests were carried out on carefully aged eggs of the Mediterranean flour moth at 15 and 25°C at various concentration levels of sulfuryl fluoride and over various exposure times. Eggs aged 1–2 days were more tolerant than other age groups, followed by 2–3 day-old, 0–1 day-old and 3–4 day-old eggs. At 15°C 1–2 day-old eggs needed a ct (concentration×time) product of about 4000 mg.h/l to prevent hatch and 3000 to prevent emergence. Other age groups were controlled by about 3000 and 2000 mg.h/l respectively. Increasing the temperature from 15°C greatly increased the efficacy of the fumigant. At 25°C 1–2 day eggs needed a ct product of about 1000 mg.h/l to prevent hatch and 800 to prevent adult emergence. Other age groups required about 800 and 650 mg.h/l respectively. Considerable variation among age groups was apparent in the slopes of regression lines for the toxicity tests, whether time or concentration was fixed in the tests. There was evidence of line curvature, data sets based on different mortality ranges giving different results for calculated LD values. For example, those based on low or medial responses would sometimes grossly exaggerate the dosages required for high levels of mortality. At both 15°C and 25°C, fixing concentration or time of exposure in the analyses resulted in comparable results for calculated mortality levels provided that the data points included the full range of mortality response up to 100%.
Article
Temperatures and moisture contents inside a metal silo filled with 20t of wheat were monitored from August 2003 to October 2004 in Western Canada. In the summer and then repeated in the autumn of 2005, grain moisture contents inside small columns, inserted in the top of the grain bulk in the same metal silo, were measured after 4 and 8 weeks. The columns had the following configurations: 1) both the top and bottom of the column were open; 2) the top of the column was open and the bottom was sealed; and 3) the top of the column was sealed and the bottom was open.During the 15-month period, headspace temperature averaged 2.9±0.2°C higher than that of the ambient air with a maximum of 18.3°C and a minimum of 0°C. There was larger temperature fluctuation in the headspace than inside the grain mass. The average temperature gradient was 5.09±1.24°C/m inside the grain mass. The highest temperature gradient was 32.4°C/m and it was located at the center of the bin at 1.6m high. “Inside” grain had a lower moisture change than the surface grain.Grain in the top section of the column with the column configuration of Top End Open had the largest change of its moisture content, and grain in the middle section of the column with any of the configurations did not change. Grain inside the small columns at different locations in the silo had different moisture movement trends. These trends were consistent with the measured moisture migration in the entire silo. These results confirm that even in a small silo there were temperature gradients large enough to drive air movement and the induced convection currents could cause moisture migration.
Article
A table is presented giving the minimum temperature and humidity at which 43 species of beetle, 9 species of moth and one mite can multiply sufficiently to become pests, and the range of temperature most favourable for each. An estimate of the maximum rate of increase for each species is also given.
Article
Heating or cooling is used extensively to control stored-product insect and mite pests. For most stored-product insects 25–33°C is optimal for growth and reproduction, at 13–25 or at 33–35°C insects are able to complete their development and produce offspring, but <13 or >35°C insects eventually die. The more extreme the temperature the more quickly insects die, with death occurring in a few minutes at −20 or 55°C. Lethal temperatures vary considerably and depend on species, stage of development, acclimation, and relative humidity. Extensive tables listing the survival of the major stored-product insects and mites at extreme temperatures from over 50 papers is presented. There are many ways to cool the commodity: turning, aeration or refrigerated aeration, or to heat the commodity: infrared, microwaves, high frequency irradiation, or hot air in fluidized-bed. Some of these processes are available commercially, while others have been tested only in the laboratory.The proposed behavioral, physiological, and biochemical mechanisms that enable stored-product insects to survive extreme temperatures are reviewed. Possible synergists that might make stored-product insects more susceptible to extreme temperatures are suggested. One example is the use of ice-nucleating active bacteria to increase the supercooling points of insects, thereby making them less cold-hardy. The supercooling points of four beetles has been measured and compared to published data for other stored-product insects. A standard protocol for examining the survival of stored-product insects at extreme temperatures is outlined.
Article
A spreadsheet model was developed to evaluate the economic costs of new post-harvest integrated pest management technologies, such as grain chilling, against traditional pest control methods, such as phosphine fumigation. The model considers 34 factors including electrical power consumption, capital investment cost, chemical costs, and less quantifiable factors such as worker safety, environmental issues, and changes in end-product value. When applied to the storage of popcorn, a high value speciality crop, and wheat, the annual operating costs of chilled aeration compared to phosphine fumigation with ambient aeration were up to 128 and 300% lower, respectively. The effect of high capital investment with low variable costs, as with chilled aeration, was compared to the low capital investment and high variable costs of phosphine fumigation using a multi-year Net Present Cost (NPC) model. For the case studies evaluated, the NPC of chilled aeration ranged from −122 to 197% of that for in-house fumigation with ambient aeration. Chilling of popcorn became economically feasible if a premium of less than one cent per retail bag could be obtained for popcorn labeled post-harvest pesticide-free. Chiller unit prices of US$ 80,000–90,000 were found to be a reasonable capital expenditure for this alternative integrated pest management technology.
Article
Field trials were conducted in metal wheat storage bins to determine whether pressure aeration, pushing ambient air from the bottom, or suction aeration, pulling air down from the top, would be more efficient at cooling the wheat mass and thereby limiting insect population growth. Aeration was accomplished at an approximate airflow rate of 0.22 to 0.31 m 3 /min/t and was done by adjusting thermostatic controllers to operate the aeration fans when ambient temperatures fell below specified thresholds. Summer and autumn cooling cycles using suction aeration cooled the warmest part of the bin, the top of the grain mass first, which resulted in lower overall wheat mass temperatures compared to pressure aeration, where the top of the grain mass always remained warmer than with suction aeration. This cooling effect was most pronounced in the upper surface of the grain mass, and insect pest populations as measured by pitfall traps were consistently less in bins with suction versus pressure aeration. Results seem to indicate that suction aeration would be more beneficial than pressure aeration for controlling insect pests in wheat stored in the southern plains of the United States.
Article
Information necessary for controlling insect eggs in packaged commodities by means of lethal low temperatures is presented. Time-temperature-mortality relationships for the eggs of 5 species of stored-product insects were investigated. Exposures of 7, 8, and 9 h, respectively, at −10°C were sufficient to kill 95% of the eggs of Oryzaephilus surinamensis (L.), Tribolium castaneum (Herbst), and Ephestia cautella (Walker); exposures of 28 and 62 h, respectively, were required to achieve LD95 for the eggs of Callosobruchus maculates (F.) and Lasioderma serricorne (F.). The times required for selected packaged commodities to become chilled throughout were determined.
Article
Methyl bromide is used to control insects as a space fumigant in flour and feed mills and ship holds, as a product fumigant for some fruit and cereals, and for general quarantine purposes. Methyl bromide acts rapidly, controlling insects in less than 48 h in space fumigations, and it has a wide spectrum of activity, controlling not only insects but also nematodes and plant-pathogenic microbes. This chemical will be banned in 2005 in developed countries, except for exceptional quarantine purposes, because it depletes ozone in the atmosphere. Many alternatives have been tested as replacements for methyl bromide, from physical control methods such as heat, cold, and sanitation to fumigant replacements such as phosphine, sulfuryl fluoride, and carbonyl sulfide, among others. Individual situations will require their own type of pest control techniques, but the most promising include integrated pest management tactics and combinations of treatments such as phosphine, carbon dioxide, and heat.
Temperature monitoring
  • F Jian
  • D S Jayas
Jian, F., Jayas, D.S., 2012. Temperature monitoring. In: Hagstrum, D.W., Phillips, T.W., Cuperus, G. (Eds.), Stored Product Protection. Kansas State University, Manhattan, KS., USA, pp. 271e282.
Freeze-outs for Insect Control. Bulletin 4903-4904. Association of Operative Millers
  • G C Worden
Worden, G.C., 1987. Freeze-outs for Insect Control. Bulletin 4903-4904. Association of Operative Millers, Minneapolis, MN.
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P.W. Flinn et al. / Journal of Stored Products Research 63 (2015) 42e46
Stored grain ecosystem and heat and moisture transfer in grain bulks The Mechanics and Physics of Modern Grain Aeration Management
  • S Navarro
  • R T Noyes
  • D S Jayas
Navarro, S., Noyes, R.T., Jayas, D.S., 2002. Stored grain ecosystem and heat and moisture transfer in grain bulks. In: Navarro, S., Noyes, R.T., Jayas, D.S. (Eds.), The Mechanics and Physics of Modern Grain Aeration Management. CRC Press, Boca Raton, FL, pp. 35e78.
Bulletin 4903-4904. Association of Operative Millers
  • G C Worden
Worden, G.C., 1987. Freeze-outs for Insect Control. Bulletin 4903-4904. Association of Operative Millers, Minneapolis, MN.