Quantitative and quality losses caused by rodents in on-farm stored maize: a case study in the low land tropical zone of Kenya

Rodents are one of the major storage pests in on-farm maize storage in the tropics. However, information on actual magnitude of weight and quality losses caused by rodents in maize stores and species of rodent associated with the losses is scarce and if available would help to improve maize postharvest management. Maize stores of small-scale farmers in the lowland tropical zone of Kenya were monitored for actual weight losses caused by rodents and rodent trapping was conducted to determine species and estimate population of the rodents associated with the losses. Moulds and total aflatoxin contamination and nutritional value of rodent-damaged grain and non-damaged grain samples were also compared to evaluate the impact of rodent infestation on grain quality. In a sample of 20 farmers, we found that cumulative weight losses due to rodents ranged from 2.2 to 6.9% in shelled maize grain and from 5.2 to 18.3% in dehusked cobs after storage for 3 months. Rattus rattus was the only rodent species captured over the whole trapping period with a trap success rate of 0.6–10.0%. Total mould count, Fusarium spp. incidence and total aflatoxin contamination were significantly higher in rodent-damaged grains than in the non-damaged ones whereas no significant differences were observed for the incidence of Aspergillus spp. There were also significant decreases in dry-matter, fat, crude protein and fatty acid content in rodent-damaged grain compared to non-damaged grain. These findings show that rodents are a significant cause of postharvest losses in on-farm maize storage and impact negatively on food nutrition and safety. Mitigation strategies for postharvest losses should therefore include rodent control.     

Low permeability triple-layer plastic bags prevent losses of maize caused by insects in rural on-farm stores

Participatory on-farm trials were conducted to assess effectiveness of Purdue Improved Crop Storage (PICS?) bags for storage of maize in small-scale farmers’ stores in rural villages in eastern Kenya. A PICS bag is a three-layered hermetic bag-system that forms a barrier against the influx of oxygen and the escape of carbon dioxide. Jute, woven polypropylene or PICS bags were filled with shelled maize grain, purchased from the participating farmers, and the three sets of bags kept in the farmers’ own stores for 35 weeks. Oxygen and carbon dioxide levels in the PICS bags were monitored, as well as the temperature and relative humidity in all the bags. Grain moisture, live insect population, grain damage and weight loss were examined at intervals of seven weeks. Oxygen and carbon dioxide composition demonstrated that PICS bags are capable of sustaining good air-barrier properties under farmer storage conditions. Moreover, moisture content of maize stored in PICS bags did not change throughout the storage period whereas the moisture content of maize stored in polypropylene and jute bags decreased significantly in the final 14 weeks. Maize stored in PICS bags remained free from insect infestation and the weight loss due to insect damage was below 1 %. On the contrary, polypropylene and jute bags permitted profuse build-up of insect populations. At 35 weeks, grain damage reached 77.6 % and 82.3 % corresponding to 41.2 % and 48.5 % weight loss in the polypropylene and jute bags respectively. These findings demonstrate that PICS bags are effective in controlling losses caused by storage pests under farmer storage conditions.     

An assessment of the magnitudes and factors associated with postharvest losses in off-farm grain stores in Kenya

Off-farm grain storage is an important postharvest undertaking by government, traders and processors in Kenya. A survey was conducted in 2014/2015 to assess the kinds and magnitudes of perceived losses experienced in off-farm stores, and the factors associated with them. Store supervisors or key personnel charged with grain storage in 39 public and 74 private stores, spread across the six maize growing agro-ecological zones, were interviewed using a structured questionnaire. Total perceived losses averaged 17.6± 2.3%, and were attributed to insects (7.2± 1.0%), molds (5.7± 2.1%), moisture loss (3.4± 0.5%), rodents (2.0± 0.5%), spillage (0.50 ± 0.0%) and birds (0.10± 0.0%). Total losses experienced in public and privately owned stores were not significantly different. The losses attributed to insect and the vertebrate pests, moisture loss and spillage, were also not significantly different in the two storage systems. However, losses due to molds were significantly higher in the private stores. From regression analysis, higher losses were associated with the use of residual insecticides, purchasing low quality maize for storage, reuse of storage bags, untimely control of storage pests, and the agro-climatic conditions of the moist transitional, moist mid-altitude and dry mid-altitude zones. Relying on infestation reports to initiate pest control had the highest marginal effect (21.7%). Lower loss magnitudes were associated with cleaning and drying grain before storage, early pest control and storage periods shorter than two months. These findings provide important reasons for appraising current off-farm storage techniques with a view to taking possible actions for improvements. It is recommended that innovations to mitigate maize postharvest losses should also target off-farm storage, as the losses incurred are significant.     

Field effectiveness of improved hermetic storage technologies on maize grain quality in Central Mexico

Maize is the main crop cultivated by small scale farmers (SSF) in Mexico, and its production represents an important goal for local food security. However, SSF very often face severe post-harvest losses in maize, mainly because of insect pests and the lack of suitable storage technology. This study was conducted to compare the field effectiveness in terms of maize quality under on-field conditions of SSF of two improved hermetic storage technologies with the traditional storage. The field experiment was performed on-farm in the highlands of Central Mexico. Maize grains were stored in three storage devices: hermetic plastic bag (sBag), hermetic plastic silo (Bioxilo), or traditional polypropylene sacks. The study considered the quantitative evaluation of storage, physical, nutritional, and industrial qualities of maize after 4, 8 and 12 months of storage. Environmental conditions of storage such as oxygen levels, temperature and humidity were monitored. After 1 year of field storage, compared with traditional sacks, sBag and Bioxilo showed a significant lower losses in storage due to insects. When controlled infested maize by artificial insect infestation methods was used, the improved technologies were also effective in reducing grain losses. Furthermore, both sBag and Bioxilo prevented grain quality detriment in terms of physical, nutritional and industrial (for tortilla and seed) properties (p < 0.01). Additionally, compared with traditional storage, sBag and Bioxilo showed efficient control of the hermetic conditions in terms of oxygen, temperature and humidity, but no significant differences were detected between the two improved technologies. In summary, under on-farm conditions, the successful preservation of maize grain quality was achieved by the improved sBag and Bioxilo in the highlands of Mexico. In the future, positive effects of this storage system will need to be validated under tropical conditions.     

Mapping of maize storage losses due to insect pests in central Mexico

Postharvest grain storage are a major problem in Mexico, influencing the economy, livelihoods, and food security of most farmers. At present, very limited information is available on postharvest maize losses and the associated insect pests in Mexico. Therefore, the objective of this study was to quantify and map maize storage losses in Central Mexico (State of Mexico) to analyze the effects of major pests in the different regions and to provide useful data to policymakers and local stakeholders. The study was conducted with 120 farmers dispersed across all regions of maize production in the State of Mexico. Storage losses were quantified using standardized maize samples that harvest, stored for a year, and sampled periodically. These data, together with geographic coordinates, were integrated into a geographic information system (GIS) to generate maps of maize storage damage and weight losses. The resulting maps show that in the southern region of the State of Mexico the standardized samples exhibited the highest maize losses after a one-year storage period, with an average of 76% loss and 100% grain damage, followed by the northern region, with an average of 18% loss and 52% damage. The eastern region reported 10% loss and 16% damage, whereas the Central region showed 5% loss and 14% damage. The main storage pests identified displayed localized geographic distributions, with the maize weevil, Sitophilus zeamais, being mainly localized in the South, the larger grain borer, Prostephanus truncatu, in the East and North, and the angoumois grain moth, Sitotroga cerealella, in the Northeast and Central regions. Thus, these maps are robust tools that will help towards improving storage facilities and increasing food security for small-scale farmers.     

Assessing drivers of maize storage losses in south west Benin using a fractional response model

An assessment of drivers of maize storage losses was undertaken in south west Benin applying the Fractional Response Model on information collected from 400 smallholder maize farmers. The mean loss of maize during the storage period reported by farmers was estimated at 10.25 percent of the total harvest. The average marginal effect obtained from the fitted Fractional Response Model revealed that storage technologies, farmers’ post-harvest attitudes, insect damage, weather conditions and infrastructures play a significant role in storage losses maize farmers experience in south west Benin. The findings revealed that farmers who used bags and plastic containers respectively reduced storage losses by 6.7 and 7.8 percentage points compared to farmers who used woven granary baskets. The results also indicated that applying ash, neem leaves, pepper or lemon increased the storage loss by 4.11 percentage points compared to storing without protectant. Drying after harvesting decreased the storage loss by 1.9 percentage point. In contrast, the storage loss increased by 5.1 percentage points for respondents who reported insects as predators of their stored maize, and by 2.1 percentage points when it rains at the time of maize harvest. A one-degree increase in temperature was associated with an increase in storage losses of 4.4 percentage points and farmers who live at less than 26.09 km to market reduced storage losses by 0.17 percentage point. Effective policies for a sustainable reduction of storage losses among maize farmers in the area should consider the need to raise awareness about the loss issue that represents the use of woven granary basket, ash, neem leaves, pepper and lemon as storage technologies. Farmers should be informed to avoid harvesting during times of rain, encouraged to properly dry their produce after harvesting and sustainable hermetic equipment robust against insect growth during storage should be promoted.     

Maize storage insects (Sitophilus zeamais and Prostephanus truncatus) prefer to feed on smaller maize grains and grains with color,especially green

Maize is the major food staple in Eastern and Southern Africa, and since production is seasonal, on-farm storage is practiced by farmers. Because stored maize is susceptible to pests, improved storage methods are being developed which need to be evaluated for their effectiveness in reducing losses. The standard count and weigh method (CWM) assumes storage insects attack grains of different sizes in equal measure, although this has not been tested. This study therefore analyzed storage insects’ feeding preferences for maize grains of different sizes. Maize grain was sieved and split into four size categories, colored with food dyes, remixed, and distributed into 48 jars, each with about 300 g of grain, artificially infested with maize weevils (Sitophilus zeamais) or larger grain borers (Prostephanus truncatus), 40 insects per jar. After two months, the grains were separated into their size categories (visually, by color), and grain damage and weight loss was estimated with the CWM. Results show that storage insects have a preference for feeding on smaller, rather than larger grains; and on colored rather than uncolored grains. Small-sized and colored grains were more likely to be perforated by insects and suffered more weight loss. This preference, observed for both species, is more pronounced in S. zeamais, who also distinguish between different colors, and prefer green. The size effect is, however, comparatively small and the average weight loss calculated by a size-adjusted formula is not significantly different from that calculated by the standard CWM. However, the resulting differences in weight losses between grains of different sizes are small. Weight loss calculated by weighted CWM, while in principle more accurate, does not in practice lead to significantly different estimates. Therefore, the results do not warrant a change in the conventional CWM for weight loss in stored grain.     

Moisture content,insect pests and mycotoxin levels of maize on farms in Tamale environs in the northern region of Ghana

Maize production in Ghana has been increasing steadily but increases in yield are being undermined by post-harvest losses. This study is part of a larger project to characterize post-harvest losses in Ghana at different points in distribution channels. Here we determined factors contributing to losses during on-farm storage in the Northern Region of Ghana. This study was conducted in six communities: Adubiyili, Diari, Pong-Tamale, Savelugu, Toroyili and Zamnayili. Losses were determined for maize on cobs stored in thatched granary structures, shelled maize in polypropylene (PP) bags stored on the floor in farmers’ homes or small storehouses, and shelled maize in PP bags stored in warehouses. Maize moisture content, temperature, percent weight loss, percent insect damaged kernels on numerical basis (IDK_nb), insect pest abundance, and mycotoxin (aflatoxin and fumonisin) levels were determined. Moisture content values of maize at pre-harvest and heaping stages in all six communities were below 15% wb. There were no insect pests on maize at the pre-harvest stage and only a few larvae were found in the heaping stage, but Sitophilus spp., Tribolium castaneum and Cryptolestes ferrugineus infested maize during storage, with significantly more found in granary structures than maize in PP bags in homes or storehouses. Warehouses had significantly fewer insects than granaries and homes or storehouses. Percent IDK_nb values in all six communities were <2% per 250 g in the field. Aflatoxin levels were significantly lower at the pre-harvest stage, with average concentration below action limits established in Ghana, compared to the heaping stage, where average level exceeded the threshold. Fumonisin levels were low and similar for both stages. Data from the present study show that heaping maize on-farm prior to primary processing can increase aflatoxin beyond the acceptable level and should not be practiced.     

Distribution of mycotoxins and risk assessment of maize consumers in five agro-ecological zones of Nigeria

Many individuals are not only food insecure but chronically exposed to high levels of mycotoxins through their diets in many developing countries. Seventy composite samples of stored maize grains were collected from farmers’ storage structures in five agro-ecological zones (AEZs) of Nigeria where maize is predominantly produced between August 2011 and February 2012. The grains were analysed for mycotoxin contamination with the liquid chromatography tandem mass spectrometry method and mycotoxin occurrence maps constructed from the database of the distribution of the toxins. A risk assessment was also carried out in order to provide information on the extent of human exposure to the toxins. Twelve regulated mycotoxins with negative economic and public health consequences were detected in the maize grains across the AEZs at concentrations exceeding the maximum allowable limits including AFM₁ that was detected for the first time in Nigerian maize. There is a high risk of contamination of the stored grains by Nigerian consumers especially in the Derived and Southern Guinea Savannas, resulting in a national burden of between 126.85 and 38,682.29 DALYs. Intervention strategies are therefore needed across the AEZs to ensure that safe and wholesome foods are made available to the populace.     

Postharvest insect resistance in maize

One of the main challenges for the 21st century is ensuring global food security. Today, maize is the largest staple crop produced worldwide. Postharvest primary insect pests, especially the maize weevil (Sitophilus zeamais) and the large grain borer (Prostephanus truncatus) cause food-grain losses during storage up to 40% of total production, mainly in developing countries. Alternatives for pest management have been explored, including the implementation of hermetic storage structures and the application of chemical insecticides. Nevertheless, in low-income regions, both strategies are rarely accessible to smallholders. Modern breeding programs have endeavored to develop insect-resistant varieties, which diminish postharvest pest losses. In this review, we report the current status and advances in maize kernel-pest interactions, the bases and mechanisms of kernel resistance and their biotechnological perspectives. We demonstrate that the comprehension of resistance mechanisms has been fundamental for the development of new productive and resistant varieties, representing a sustainable alternative for developing countries. Finally, we analyse the biotechnological perspectives of natural kernel resistance in global food security.     

The use and profitability of hermetic technologies for grain storage among smallholder farmers in eastern Kenya

Hermetic storage technologies (HSTs) have been disseminated in Sub-Saharan Africa (including Kenya) to reduce grain storage losses among farmers. We carried out a study in three counties in eastern Kenya to assess the use and profitability of HSTs among farmers. Data were collected from 613 farmers using a semi-structured questionnaire and Kobo Toolbox via android tablets. Results showed an increase in use of HSTs among farmers from 53.7% in 2015 to 91.2% in 2017. PICS was the most used hermetic bags by farmers (84%) in 2017. Majority of farmers (73.5%) received training in the use of HSTs from extension agents and agro-dealers. About 40% of respondents purchased additional (one to five) bags after their first experience using them. The quantity of grain produced made up about half of the farmer’s decision to store. The primary reason (87%) farmers used hermetic bags was the need to manage insect pests. Maize and beans were the most produced and most stored crops; but maize was the most stored in HST. Grain price seasonality showed a near doubling effect between the lean and harvest seasons. Estimates of the return on investments (ROI) ranged between 13 and 80% for all crops and maize stored in hermetic bags had the highest ROI. Awareness and trainings are key in increasing adoption and proper use of HSTs.     

Traditional maize post-harvest management practices amongst smallholder farmers in Guatemala

Much of the maize that is produced in Guatemala is planted, harvested and handled via subsistence-oriented agricultural practices, strongly connected to Mayan heritage. This post-harvest assessment study was done to characterize the current practices used in the region of Huehuetenango, Guatemala, in order to identify the different grain handling practices in the region as well as possible factors contributing to post-harvest losses of maize. A total of 280 families representing 14 rural communities were surveyed through interviews. Survey revealed that most (88%) of interviewed farmers prefer to dry the maize cobs after harvest by laying them in stacks exposed to direct sunlight. After drying, harvested maize is stored until consumption along with purchased maize kernels from the market. Among storage practices, 62% of surveyed families store the maize as shelled kernels; while 38% store it on cobs. When storing shelled maize, bags are the preferred containers among 81% of farmers, while only 14% use metal silos. Among farmers who stored maize on cobs, 74% use the tapanco as the preferred storage structure. Forty-one percent of farmers indicated storing the maize for at least 4 months. During the storage time, 61% of farmers perform grain quality checks once a week. Moreover, 65% perform pest control during storage; however, in most cases, the control is not preventive but corrective. For 49% of farmers, the main cause of loss between harvest and consumption is the mishandling of grain moisture, leading to insect and fungal infestation. With this data, it was possible to identify diverse maize harvesting, drying, storage and consumption practices within the studied communities. Understanding the traditional post-harvest practices will help better design intervention steps to improve these practices and to increase food security and food safety for smallholder farmers in the Guatemalan Highlands.     

Hermetic storage technologies reduce maize pest damage in smallholder farming systems in Mexico

In Mexico, smallholder farmers use a variety of technologies to store their maize grain for several months, which may result in high losses in quantity and quality of grain. This work compared the effectiveness of different storage technologies for minimizing losses in smallholder conditions in 109 different locations from 21 to 2816 m above sea level (asl) across different agroecological zones of Mexico, under “controlled” (i.e. managed by researchers), and “non-controlled” conditions (i.e. on-farm managed by extension agents). Depending on the common practice at each site, conventional storage technologies (polypropylene bag with and/or without insecticide) were compared to alternative storage technologies (selected from hermetic metal silos, hermetic bags, recycled plastic containers, silage plastic bags, and inert dusts-micronized and standard lime) during one to 12 months. Data on grain damages were collected at the beginning and end of the storage period. Climatic variables and initial grain infestation with pests influenced the ability of a technology to minimize losses, particularly under tropical conditions. After six months of storage, percentages of insect-damaged grain with polypropylene bags, the most common farmers’ practice, were 39.4% and 4.1%, respectively, in lowlands (<500 m asl) and highlands (>2000 m asl). With hermetic metal silos, percentages of insect-damaged grain after six months of storage were 3.8% on average in the highlands and similar in lowlands, with 2.9%. Hermetic technologies, which prevent the introduction of oxygen, were effective in reducing losses under farmers’ conditions across agroecological areas, regardless of storage time. Recycled hermetic containers had similar results and were a viable low-cost alternative to more expensive options like hermetic metal silos. With adequate technical support for their appropriate use, hermetic technologies have the potential to reduce grain losses during storage and strengthen food security in Mexico and Latin American countries with similar conditions.     

Local post-harvest practices associated with aflatoxin and fumonisin contamination of maize in three agro ecological zones of Tanzania

A survey was undertaken of a total of 120 farmers, 40 from each of the three studied agro-ecological zones of Tanzania, to determine local post-harvest management practices associated with aflatoxin (AF) and fumonisin (FB) contamination of maize. Data on practices (collected using a structured questionnaire) and maize samples were obtained from each of the 120 farmers. FB and AF contamination in the samples were analysed by HPLC. A total of 45% and 85% of maize samples were positive for AF and FB respectively, with levels ranging from 0.1 to 269 μg kg^?1 for AF and from 49 to 18 273 μg kg^?1 for FBs. Significant differences in contamination level were observed among the three agro-ecological zones. Farmers in the three agro-ecological zones practised similar practices in varying degrees. Drying, sorting and protecting maize against insect infestation are practices that showed significant association with AF or FB contamination of maize. Drying maize on mat/raised platform, sorting (damaged, discoloured and moulded grains) and application of synthetic insecticides during storage are practices that were associated with less contamination of maize with AF and FB. The results can be used to advise on effective post-harvest strategies for prevention of AF and FB contamination of maize in rural Tanzania.     

Food security through increasing technical efficiency and reducing postharvest losses of rice production systems in Bangladesh

Rice accounts for nearly 70 % of calories consumed in Bangladesh. Therefore, any effort to improve food security in the country must find ways to increase availability of rice. This paper investigates two of these ways: increasing technical efficiency of rice production and reducing post-harvest losses. Technical efficiency was measured from Cobb-Douglas and translog production functions for the rice production seasons Aus (spring), Aman (summer) and Boro (winter). Efficiency estimates ranged from 73 to 83 %, suggesting that the potential exists for substantial increases in rice production while continuing to use current technologies and inputs. Variables influencing technical efficiency were farm size, level of famers’ education, farmers’ experience in production, microcredit, training and extension. Post-harvest losses between farmer and retailer were estimated at 10–12 %, suggesting potentially an additional source of rice without changes in production. Reduction of postharvest losses were significantly related to the availability of extension services.     

Factors associated with fumonisin contamination of maize in Uganda

BACKGROUND: During production and handling, maize is attacked by many Fusarium species, some of which are prolific producers of fumonisins. Contamination of maize with fumonisins is influenced by climate, agronomic and postharvest practices. This study investigated the factors associated with the occurrence of fumonisins in maize produced in three agroecological zones of Uganda. RESULTS: All the maize samples were positive for fumonisins with levels ranging from 0.27 to 10 mg kg^?1. A positive and significant correlation (P < 0.01) was observed between fumonisin levels and agroecological zone. Maize from high altitude zone had significantly higher (P < 0.05) mean total fumonisin content (4.93 mg kg^?1) than maize from the mid altitude‐moist (4.53 mg kg^?1) and mid altitude‐dry (4.50 mg kg^?1) zones. Five farmer practices, namely intercropping, crop rotation, delayed harvesting, drying maize on bare ground and planting treated seeds were significantly associated with fumonisin production in maize. Intercropping, delayed harvesting and drying maize on bare ground increased fumonisin contamination whereas crop rotation and planting treated seeds reduced the contamination. CONCLUSION: All maize samples obtained from the three agroecological zones were contaminated with fumonisins. The study showed that some of the farmers' practices predispose maize to fumonisin contamination. The findings are important for future studies aimed at designing strategies to control and prevent contamination of maize with fumonisins. Copyright © 2009 Society of Chemical Industry     

Maize and bean storage and their use by rural farmers in a Central state of Mexico

A study was carried out in the rural areas of the state of Guanajuato in Central Mexico to identify the way in which two different types of farmer store and use their maize and bean production. One of these groups of farmers utilizes a communal type of land named ejido, whereas the others own their property. It was found that the ejido farmers store between 1–2 tons of these basic products, to be used for seed (0.1–0.3 tons), home consumption (<1 ton), and possibly subsequent sale (<1 ton). However, the private property farmers have the option of storing more than the ejido farmers, and although they also cover the above mentioned needs, they usually have a surplus of these commodities for market (1–5 tons). The data indicate that both types of farmer (56%) lack adequate storage facilities, and store their maize and beans in rooms, which are also used for storing other commodities. The study shows that both types of farmer need information on appropriate technologies that would assist them in preventing the deterioration of these crops due to insect and rodent infestation. The interviewed farmers reported these pests are the main causes of damage to stored maize and beans.     

Determinants and income effect of yam postharvest loss management: evidence from the Zabzugu District of Northern Ghana

Globally, postharvest loss reduction has been emphasized as an effective option for improving food security and environmental sustainability. Yam production in the Zabzugu district of Northern Ghana suffers from high postharvest losses, with varying degrees of economic, social and environmental implications. Improving the welfare of farmers through postharvest loss reduction requires farmers’ effective management of the losses. The purpose of this study is to examine how effectively farmers manage postharvest losses and the rewards derived from such efforts. Using a cross-section of 201 randomly selected yam farmers from major production communities in the Zabzugu district of Northern Ghana, we applied a simultaneous equation modelling approach to examine the contemporaneous correlation between postharvest loss management and income. Results provided evidence that good postharvest loss management improves welfare of yam farmers through increased income earnings and vice versa, especially for those who produce for commercial purposes. On the other hand, subsistence farmers were better at managing postharvest losses, though with lower monetary rewards. The policy implications are that interventions should target farmer education and training to improve the skills of farmers in managing postharvest losses.     

Comparative performance of five hermetic bag brands during on-farm smallholder cowpea (Vigna unguiculata L.Walp) storage

Cowpea (Vigna unguiculata L. Walp) grain is an important source of protein for smallholder farmers in developing countries. However, cowpea grain is highly susceptible to bruchid attack, resulting in high quantitative and qualitative postharvest losses (PHLs). We evaluated the performance of five different hermetic bag brands for cowpea grain storage in two contrasting agro-ecological zones of Zimbabwe (Guruve and Mbire districts) for an 8-month storage period during the 2017/18 and 2018/19 storage seasons. The hermetic bag treatments evaluated included: GrainPro Super Grain bags (SGB) IVR™; PICS bags; AgroZ® Ordinary bags; AgroZ® Plus bags; ZeroFly® hermetic bags. These were compared to untreated grain in a polypropylene bag (negative control) and Actellic Gold Dust® (positive chemical control). All treatments were housed in farmers’ stores and were subjected to natural insect infestation. Hermetic bag treatments were significantly superior (p < 0.001) to non-hermetic storage in limiting grain damage, weight loss and insect population development during storage. However, rodent control is recommended, as rodent attack rendered some hermetic bags less effective. Actellic Gold Dust® was as effective as the hermetic bags. Callosobruchus rhodesianus (Pic.) populations increased within eight weeks of storage commencement, causing high damage and losses in both quality and quantity, with highest losses recorded in the untreated control. Cowpea grain stored in Mbire district sustained significantly higher insect population and damage than Guruve district which is ascribed to differences in environmental conditions. The parasitic wasp, Dinarmus basalis (Rondani) was suppressed by Actellic Gold Dust® and all hermetic treatments. All the hermetic bag brands tested are recommended for smallholder farmer use in reducing PHLs while enhancing environmental and worker safety, and food and nutrition security.