Storage Insect Research Articles

Feasibility of polylactic acid and essential oil composite with insecticidal properties for prevention of Sitophilus oryzae and Oryzophilus surinamensis in Sorghum and Pearl millet

Current study provides insight on the feasibility of polylactic acid (PLA) integrated with (1:1 ratio) of essential oils belonging to Ocimum gratissimum (OG) and Mentha spicata (MS) for prevention of major stored insect pests (Sitophilus oryzae and Oryzophilus surinamensis) in Sorghum and Pearl millet. A combination of OG and MS essential oils (1:1) was incorporated into the PLA polymer matrix. Further, SPME analysis of synthesized PLA showed the presence of volatiles corresponding to carvone (6.44 %) and thymol (6.22 %). Synthesized PLA composites were tested against S. oryzae and O. surinamensis using Sorghum and Pearl millets, and insect mortality was equivalent to commercial super bags (CSB). The head space oxygen decreased significantly in CSB and slightly in PLA bags. Thickness of EO blended PLA composite was increased (99 μm), tensile strength (23.94 MPa), WVTR (1.42 g/m2.hr) analysis, significant folding ability, and swelling capacity (0.24 %) showed slight reduction in composite film. TGA showed good thermal stability (334˚C) and XRD displayed the increased crystallinity (38.35 %) in PLAOM films, SEM and FTIR analysis of the synthesized composite films revealed complete homogenization of EO and PLA matrix. In addition, SEM analysis of insects (control & treated) revealed less topology changes in the elytra. Biodegradability study confirmed the weight loss in PLA films. Hence, current approach of using composite EO's with PLA offers sustainable solution for prevention of infestation during storage of millets.

Mapping of quantitative trait loci associated with resistance to bruchids (Callosobruchus maculatus) in cowpea (Vigna unguiculata)

AbstractCowpea bruchid (Callosobruchus maculatus) is a major storage insect pest that reduces cowpea (Vigna unguiculata) yield and seed quality, making it unsafe for consumption. This study seeks to identify and map quantitative trait loci (QTLs) associated with resistance to cowpea bruchids. A total of 120 F2 lines from a cross between MU9 (susceptible) and WC42 (resistant) were genotyped with 2753 single nucleotide polymorphism markers. The F2:3 seeds were screened for resistance to cowpea bruchids using a no‐choice experiment. Significant differences were observed among the F2:3 lines for bruchid‐resistance traits, except on oviposition. The Dobie susceptibility index scale grouped the F2:3 lines from moderately resistant to highly susceptible, hence no highly resistant line was identified in this study. Ten QTL for resistance to bruchids were identified on chromosomes Vu02, Vu03, Vu04, Vu06, Vu08, Vu09, and Vu11. Two major QTLs were identified and mapped: on Vu06 for median development period (MDP6.1MW, R2 = 25.9%) and a co‐localized QTL region on Vu09 for number of adult bruchid emergence (NEI9.1MW, R2 = 28.6%), number of eggs per 10 seeds (NE9.1MW, R2 = 18.8%), average number of exit holes on seeds (ANH9.1MW, R2 = 19.6%), and seed weight (R2 = 15.6%–16.3%), respectively. Therefore, markers linked to the QTL identified in this study including MDP6.1MW, NEI9.1MW, and ANH9.1MW can be validated for marker‐assisted selection to fasten breeding for resistance to bruchid in cowpea.

Detection Limits of Insect Fragments in Spiked Whole Wheat Flour Using Multiplex Polymerase Chain Reaction (PCR)

The need for a sensitive molecular method to detect specific species of insect contaminants in food products remains a significant challenge in the food industry. This study evaluated the detection limit of a multiplex end-point PCR assay for detecting insects in food. The assay amplifies two fragments of the cytochrome oxidase subunit I gene (COI-Fa and COI-Fb) and one fragment of the protein-coding wingless (wg) gene found in insects. Five insect species, comprising three vectors of foodborne pathogens (the housefly, Musca domestica, the American cockroach, Periplaneta americana, and the pharaoh ant, Monomorium pharaonis) and two storage insect pests (the red flour beetle, Tribolium castaneum and the Indian meal moth, Plodia interpunctella), were spiked separately and in combination at levels of 1, 0.1, 0.01, and 0.001% in whole wheat flour. At spike levels greater than 0.01%, amplicon bands of expected sizes were seen in 100% of samples containing fragments from distinct insect species. At least 25% of spiked samples at the lowest spike level had amplicon bands, except for samples spiked with M. domestica. Results showed an 18.9% probability (with 11.3% and 30% lower and upper confidence limits, respectively) of detecting insect fragments at the lowest spike level (0.001%, corresponding to 3–22 fragments), which is far below the FDA’s regulatory level of less than 75 fragments per 50 g of wheat flour. The intensity of amplicon bands in the gel images was higher at higher spike levels. However, this method is not quantitative enough to extrapolate the intensity of the amplicon bands to the number of insect fragments present in a sample. This multiplex assay was also evaluated in a variety of market food samples derived from plants and animals, showing its potential use in various food types. Overall, the sensitivity and specificity of this molecular approach suggest that it could be used in the future as a screening tool for detecting insect contaminants in food.

Exploring chemical composition and insecticidal activities of Alpinia calcarata rhizome essential oil against three major storage insects

Alpinia calcarata (Roscoe), generally recognized as snap ginger or lesser galangal of the Zingiberaceae family, undergoes widespread cultivation in tropical nations. It is characterized by its noteworthy pharmacological attributes, such as anti-inflammatory, analgesic, antinociceptive, reproductive, anti-cancer, and gastro-protective effects. Many storage pests now resist traditional chemical pesticides. Transitioning to organic alternatives is a preferable and sustainable solution. This research investigates the insecticidal activity of essential oil from A. calcarata rhizomes, obtained via hydro-distillation. Chemical analysis was conducted, and the study assessed its toxicity and repellent effects on Tribolium castaneum (Herbst), Lasioderma serricorne (F.), and Callosobruchus chinensis (L). A yield of 0.44 ± 0.02 % essential oil was obtained from dry rhizomes. Gas chromatography-mass spectrometry (GC-MS) characterization revealed the major chemical constituents as 1,8-cineole (25.71 %), ethyl iso-allocholate (16.01 %), and fenchyl acetate (15.15 %). The findings from the investigation into the pesticidal characteristics of essential oils derived from the rhizome of A. calcarata unveiled significant contact (LC50 at 24 h was 10.9 mg/cm2 for T. castaneum, 1.0 mg/cm2 for L. serricorne and 0.5 mg/cm2 for C. chinensis) and fumigant toxicity (LC50 at 24 h was 4.05 mg/L air for T. castaneum, 1.75 mg/L air for L. serricorne, and 1.03 mg/L air for C. chinensis). The repellent efficacy was evaluated through an area preference test, revealing robust repellent activity at various concentrations. Undoubtedly, the essential oil extracted from the rhizome of A. calcarata is valuable and has the potential to be a safe, organic pesticide for controlling storage pests.

Artemisia fragrans Willd. Essential Oil: Chemical Profile and Insecticidal Potential against the Confused Flour Beetle, Tribolium confusum du Val.

The confused flour beetle, Tribolium confusum du Val, is one of the cosmopolitan and polyphagous storage insect pests. The frequent application of chemical insecticides has resulted in several side effects, including threats to human health and non-target organisms and the resistance of insect pests. In the current study, the fumigant toxicity and feeding deterrence potential of Artemisia fragrans Willd. essential oil on T. confusum adults were investigated. The essential oil was rich in terpenic compounds, in which α-thujone (27.8%) and 1,8-cineole (22.8%) were dominant. The essential oil displayed significant fumigant toxicity on T. confusum, where a concentration of 35.3 μL/L caused 100% mortality of the treated adults after 48 h. The LC30 and LC40 values (lethal concentrations to kill 30% and 40% of tested insects: 15.1 and 18.4 μL/L, respectively) significantly decreased the nutritional indices of the pest, including the consumption index, relative consumption rate, and relative growth rate. The feeding deterrence index of the essential oil were calculated as being 62.29 and 48.66% for the concentrations of 15.1 and 18.4 μL/L after 5 days, respectively. Accordingly, A. fragrans essential oil can be considered an efficient, available, and natural alternative to detrimental chemical pesticides in the management of T. confusum.

Socioeconomic Determinants of Insect Pest Control Methods’ Utilization for Storage in North Central Nigeria

The impetus for this study is the need to understand factors influencing the use of insect pest control methods in North Central Nigeria. Specifically, the study described the socioeconomic characteristics of respondents, assessed awareness and use of insect pest control methods, examined farmers’ considerations and investigated factors influencing insect pest control decisions. Using a structured interview schedule to elicit information, data was collected by means of multi-stage sampling technique to select a total of 384 cowpea farmers for this study. A purposive selection of Kwara and Niger States paved way for the purposive choice of two agricultural zones in Kwara state and one agricultural zone in Niger state. Percentages, frequency counts, ranks, mean, and ordinary least square regression was used to analyze the data. The study revealed that the intended time of sale, time required to apply method, and time of application were the factors most considered for store insect pest control. Ordinary Least Square regression estimates demonstrate positive significant relationship between farm size (t=4.681), group membership (t=4.688), and quantity stored in tons (t=2.312) and intensity of use. Conversely, years of education (t=-2.196), years of cowpea farming experience (t=-3.419), and frequency of extension contact (t=-.534) had significant negative relationship with intensity of use. In conclusion, it is recommended that policy makers and extension staff put into consideration farm size, group membership, quantity stored, years of education, years of cowpea farming experience and frequency of extension contact in optimizing extension strategy for promotion of indigenous and alternative insect pest control methods.

Efficacy of Eucheuma denticulatum Extract and Azadirachta indica Powder against Maize Weevil (Sitophilus zeamais) Infesting Stored Maize Grains

Storage insect pests destroy food grains in storage. In the present study, the insecticidal activity of red seaweed extract (Eucheuma denticulatum) and neem (Azadirachta indica) was examined against maize weevils (Sitophilus zeamais) and the quality of the stored maize was assessed for a three months storage period. Three rates (0.0, 1.6 and 4.8% w/w) of neem powder and seaweed extract were used as treatments. The collected data were subjected to analysis of variance (ANOVA) using General Linear Model in SPSS computer software packages (version 25) and mean comparisons were conducted using Turkey’s (HSD) test at the 5% level of significance. Sitophilus zeamais, mortality, grain weight loss, and rate of germination were recorded for each treatment. The 4.8%w/w mixture of seaweed extract and neem seed powder was more toxic, followed by the mixture of the extract and neem leaf powder (84.5% and 73.3% mortality rates, respectively), while in the control, mortality was 20%. In all treatments, Sitophilus zeamais mortality increased with increasing doses. Grain weight loss was high in the control (5.6%), followed by grains treated with 1.6% extracts of Eucheuma denticulatum alone (2.8%). The percentage of damaged maize grains was high in the control (14%) and low in grains treated with 4.8% seaweed extract and neem leaf powder (3.3%). Percentage germination was high in grains treated with 4.8% and 1.6% seaweed extracts alone (96% and 87% respectively) and in control (91%). Additionally, sensory evaluation results in terms of color, odor and overall acceptability showed that maize grains treated with both botanicals could be accepted by the general public for consumption. The results indicate promising potential for seaweed extract and neem powder in controlling maize weevils, offering sustainable and environmentally friendly solutions for stored grain protection.

Quality and Price of Beans at the Market Node in Five Districts of Uganda.

We investigated the varieties of beans traded in five districts of Uganda and the factors affecting the quality and price of the beans at the market node. A semi-linear hedonic price model with 12 variables categorized as product and trader attributes was used to determine the factors influencing prices. Traders were found to be unmindful of the names of new bean varieties released by NARO. They used various names for both the new and local varieties. Brokers were identified as the leading suppliers of poor-quality beans. The respondents cited variations in the quality of beans received from different suppliers. Beans that were owned by traders exhibited slightly higher moisture content (17%) than is recommended. Storage insect infestation was identified as the primary cause of quality decline. Product attributes were associated with changes in the prices of beans. However, their effect was comparatively lower than the traders’ characteristics. We recommend targeted sensitization about new bean varieties, emphasizing their benefits, post-harvest handling, and quality requirements at all value chain nodes. Monitoring trader traits and societal factors associated with price fluctuations is also crucial to price stability.

Evaluation of the performance of maize storage facilities for control of storage insect pests in Ethiopia

Maize plays a vital role in Ethiopia's food security, supporting the lives of millions of people. However, postharvest grain deterioration due to insect infestation is a significant issue. To address this and improve food availability, reducing storage losses is essential. The experiments were carried out in both indoor and outdoor settings, where the indoor experiment evaluated the effectiveness of different storage facilities (jute sack, PICS bag, fertilizer bag, AgroZ® bag, and polypropylene bag) over varying durations (0, 2, 4, 6, and 8 months) in three replications. In the outdoor experiment, traditional and modified gombisa constructed in an open field at the Jimma University Research Site (Eladale), along with different storage duration (initial loading, 2, 4, 6, and 8 months after storage), were evaluated in three replications. The data collected included grain damage percentage, weight loss, seed germination, and proximate analysis. Statistical analysis revealed significant differences in grain damage, weight loss, and seed germination of grains stored in different storage types. Jute sacks showed the most severe damage to grains and weight loss, while PICS and AgroZ® bags had the lowest values. The PICS and AgroZ® bags exhibited the highest seed germination, while the Jute bags had the lowest. In particular, traditional gombisa storage resulted in more significant grain damage, weight loss, and reduced germination than modified gombisa. As storage duration increased, grain damage and weight loss increased significantly in Jute sacks, Polyethylene bags, and traditional gombisa. Furthermore, the proximate analysis showed that storage periods and facilities significantly affected the characteristics of the quality of the maize grain. The moisture content, the crude protein, and the crude fat decreased with longer storage durations in all storage types, while the crude fiber and the ash content increased. The results confirmed the effectiveness of PICS, AgroZ® bags, and modified gombisa in reducing the qualitative and quantitative losses caused by the infestation of storage insect pests. These storage methods can be recommended to protect maize grain for eight months.

Identifying archived insect bulk samples using DNA metabarcoding: A case study using the long‐term Rothamsted Insect Survey

AbstractInsect populations are declining in many parts of the world, but a lack of long‐term monitoring data is impeding our ability to understand and mitigate the causes of insect biodiversity loss. Whilst high‐throughput sequencing (HTS) approaches, such as DNA metabarcoding, have the potential to revolutionize insect biomonitoring through rapid scalable identification, it is unclear to what extent HTS can be applied to long‐term stored insect samples. Archived insect samples could inform forecasting and provide valuable information regarding past changes to biodiversity. Here, we assess the efficacy of DNA metabarcoding to identify archived samples from the longest passive monitoring scheme in the United Kingdom: the Rothamsted Insect Survey (RIS). With a focus on aphids as the target taxa of a national network of suction‐traps, we analyze a 16‐year time‐series of stored samples (2003–2018) using DNA metabarcoding from one of the RIS suction traps as an exemplar. We achieved this by using a non‐destructive DNA extraction protocol, ensuring the integrity of archival samples for further studies. We compared the identities of aphids determined by both metabarcoding (as inferred amplicon sequence variants [ASVs]) and morphological identification and found that metabarcoding detected most genera with varying success (mean > 76%). When comparing the two methods objectively (i.e., including taxa not detected morphologically), however, congruence decreased (51%). We show that minimum sequence copy thresholds can minimize metabarcoding false positives, but at the expense of introducing false negatives, highlighting the need for careful data curation. Detectability of taxa identified morphologically and similarity between the two methods did not significantly vary over time, demonstrating the viability of metabarcoding for screening archival samples. We discuss the advantages and challenges of metabarcoding for insect biomonitoring, particularly from archival samples, including improvements to sample handling, processing, and archiving. We highlight the wider potential of HTS approaches for stored samples from insect monitoring schemes, unlocking the immense potential of global historical time series.

Postharvest practices and loss determinants for interventions among smallholder potato farmers in Tiyo district, Arsi zone, Ethiopia

Postharvest loss reduction, which will contribute to several sustainable development goals (SDGs) including SDG 1, 2, 3, 9, 12 and 13, is an important strategy for food and nutrition security. It requires interventions designed based on timely and reliable statistical data. However, lack of produce-specific loss data and associated factors along the postharvest value chain stages remains a challenge to implement appropriate interventions. Therefore, a survey was conducted on socio-demographic characteristics, postharvest practices, extent and causes of losses, and factors influencing postharvest loss of potato crops in Tiyo district of Arsi Zone, Ethiopia in 2022. A multistage sampling method was used to select a total of 209 smallholder potato farming household heads through a combination of purposive and simple random sampling techniques. Quantitative data collection was carried out online using computer-assisted personal interviewing (CAPI) by programming a semi-structured questionnaire in KoboCollect software for tablets. Descriptive statistics and ordinal probit regression model were used to analyze the collected data and determinant factors influencing postharvest loss of potatoes at various farm-level stages, respectively. An aggregate of 15-46% loss exists between harvesting and marketing. Losses during harvesting, sorting, cleaning, packaging, field-to-storage transport, storage, and storage-to-market transport were 58.9%, 6.2%, 2.9%, 2.4%, 3.8%, 20.1%, and 5.7%, respectively. Elevated loss during harvesting and storage in the area is likely to reflect poor handling and storage practices. The primary causes of losses were poor harvesting and handling techniques, poor storage facility, and insects and worms. Moreover, regression model estimations of categorical losses, as perceived by farmers, reveal that socio-demographic variables and postharvest factors influenced potato loss. During the harvest stage, working family members significantly (p<0.01) increased loss while years of schooling (p<0.05) significantly reduced loss. In addition, harvesting using leaf color change observation as a criterion had significantly (p<0.01) mitigated potato loss. In storage, female respondents (p<0.05), land size (p<0.05), and lack of training (p<0.1) had accentuated loss. During transport, the age of household reduced (p<0.1) loss whereas farming experience promoted (p<0.1) it. To reduce the existing losses, farmers’ awareness should be increased concerning each stage. The study recommends the need for stakeholders’ intervention focusing on postharvest knowledge and skill capacity building, demonstration of simple innovative ventilated storage construction using locally available materials, appropriate packaging (such as reusable plastic crates) and transport methods, and simple value addition methods (such as potato drying using indirect solar dryers and potato flour processing for fortifying local cereals). Key words: CAPI, Ethiopia, ordinal probit regression, postharvest practices, potato loss determinants

Effect of Moringa oleifera Leaf Powder and Seed Oil on Insect Pests of Stored Maize and Cowpea

The leaf powder of Moringa oleifera was applied as direct admixture at 5g, 10g and 15g while the seed oil was applied at 5ml and 10ml to 100g each of Maize and Cowpea grains respectively, while the control was without insecticide application to test for insect mortality., progeny development and damage caused on stored maize and cowpea (Sitophilus zeamais and Callosobruchus maculatus). The experiment was laid out in a Completely Randomized Design (CRD) and results obtained were subjected to analysis of variance (ANOVA) while means were separated using the Least Significant Difference (LSD). The result showed significantly (P<0.05) progeny reduction of adult Sitophilus zeamais and Callosobruchus maculatus using Moringa oleifera leaf powder at different concentration 0, 5g (23.90, 28.62), 10g and 15g respectively. Control (0) recorded the highest number 68.51 in Callosobruchus maculatus, and 56.85 in Sitophilus zeamais. Mortality test result showed that moringa leaf powder significantly(P<0.05) increased the mortality of adult S. zeamais and C. maculatus with increase in concentration after 96 hours of exposure while moringa seed oil offered 100% mortality after 24 hours of exposure. Germination of maize and cowpea was not affected after treatment with moringa leaf powder and seed oil. Contact toxicity result showed significant adult mortality of S. zeamais and C. maculatus on filter paper with 15% mortality in C. maculatus and 10% in S. zeamais. Damage was significantly reduced in treated grains compared with the untreated control. Moringa seed oil was more toxic to S. zeamais and C. maculatus compared to moringa leaf powder and the untreated control. The protective effect of moringa seed oil against S. zeamais and C. maculatus comes principally through oviposition suppression and reduced or complete inhibition of adult emergence, consequently reducing or eradicating infestation risk, damage and loss of maize and cowpea grains in storage. While the use of plant essential oils against storage insect pest is being advocated, the availability, affordability and the tendency of tainting protected grains should be considered.

Particle Size Effect of Piper guineense in the Control of the ‘Sitophilus zeamais Motchulski’ on Maize

Sitophilus zeamais is perhaps the most important storage insect pest of maize. The negative health implication of synthetic pesticides necessitates research into botanicals. We investigated the efficacy of ground Piper guineense (particles sizes 150, 300, 600, 1180, and 2360 µm) in controlling S. zeamais. The botanicals were compared with pirimorphos methyl and control (untreated seeds). Completely Randomized Design was used with three replications. Each treatment was infested with 20 adult weevils. Weevils were withdrawn after 14 days and the experiment was observed for another 38 days to count emerged adult weevils, numbers of damaged grains and exit holes on seeds, and determine loss in seed weight. Progressive efficacy and significant differences were observed among the botanicals and Pirimorphos methyl from four days after treatment application (DAT) to 14 DAT (90%, 100%, 100%, and 46.67%for Pirimorphos methyl, 150, 300, and 2360 µm of Piper respectively) as the particle size decreases. Piper of 150 and 300 µm particle sizes produced no new adult weevil and no seed weight loss at 52 DAW compared to others. The efficacy of piper at different particle sizes from 4 DAT showed that graduating piper particle size has significant effects on its insecticidal activity. It was concluded that ground piper of particle size 150µm is the most effective and is therefore recommended for effective control of maize weevils in storage.

Uji Repelensi Minyak Atsiri Serai Wangi dan Ekstrak Daun Mimba Terhadap Hama Gudang Corcyra cephalonica

Corcyra cephalonica is storage insect pest that are polyphagous. (Cymbopogon nardus L.) is a plant from the Gramineae group that produces essential oils. Useful as an insect repellent. In addition to the use of citronella, the pest attack of Corcyra cephalonica can be overcome with neem leaf extract. Neem is a plant that contains ingredients that can overcome pests on plants. This research was conducted to find out the test of repellency of citronella essential oil and neem leaf extract on repellent of Corcyra cephalonica by knowing the right concentration in biological pest management applications. The study used the basic pattern of non-factorial RAL. Used a dual-choice method. Treatment, (A1) : 10% citronella oil (A2) : 15% citronella oil (B1) : 10% neem extract (B2) : 15% neem extract. the results of the research that have been obtained, it can be concluded that the response of citronella essential oil and neem leaf extract to the rejection of Corcyra cephalonica at the larval stage were significantly different. The repellent of citronella essential oil and neem leaf extract of the imago stage were very significantly different. The highest percentage of imago repellency was in the 15% neem leaf extract treatment.

Phytochemical Analysis of Some Selected Indigenous Plants in Eastern Region of Sri Lanka used for Minimizing Insect Damage on Stored Grains during Storage

Grains are precious food in developing countries but are tragically susceptible to attack by several stored insects. Thus, grain productions often fall below demand. As the resistance of pests against synthetic chemical pesticides and residues in foods increased, consumers‘ awareness turned toward food and environmental safety. The studies conducted in Sri Lanka revealed that the botanical pesticides are being used to minimize these problems and have the potential to battle against pests on stored grains during storage. Further the reference in Sri Lanka evidenced that the botanical pesticides are readily available, inexpensive, easily biodegradable and low toxic to non-target organisms. With this concept the present study has been undertaken to analyze the secondary metabolites, known as phytochemicals that possess antioxidant or anti insecticidal properties, which are much safe, eco-friendly and can combat with the man-made chemicals in controlling the storage pests. The study was carried out to find the presence of phytochemicals namely, alkaloid, flavonoid, phenol, tannin, steroids, cardiac glycosides, terpenoid, saponine and reducing sugars in an aqueous extract of some selected indigenous plants, which are available in Eastern Region of Sri Lanka namely; Capsicum annuum (Chilli), Citrus aurantiifolia (Lime) Piper nigrum (Pepper), Azadiracta indica (Neem), Moringa oleifera (Moringa) Eucalyptus globules (Eucalyptus), Justicia adhatoda (Adhathodai) Annona reticulate (Annona), Cymbopogan citratus (Lemon grass) Vitex trifolia (Nochchi), Ocimum tenuiflorium (Thulsi), Lantenna camera(Nayunni), Eichhornia crassipes (Water hayasinth), Tagetes erecta (Marigold) piper longum (Thipilli) and Achyranthes aspera (Nayuruvi), that have pesticidal properties. The leaves of selected crops were dried at room temperature for a period of one week and grounded in to fine powder to take 10 g of powder from each to prepare 200 ml of water extract using electro thermal soxhlet for 36 hours and analyses qualitatively by the standard scientific procedures. The results showed that the water extract of Neem, Moringa and Thulsi contained all the above tested phytochemicals. The flavonoid was observed in all tested crops except Thipilil, which contained only phenol and tannin. Further Pepper, Eucalyptus, Lemon grass, Annona, and Chilli did not show alkaloids where Annona had only flavonoid, phenol and tannin. Nochchi showed all the phytochemicals except cardiac glycosides and terpenoid. The study confirmed the strength of tested crops in utilizing them in the pest management programme at storage because of the presence of one or more groups of the major insecticidal components like, alkaloids and flavonoids. The study also exposes the way for further studies related to the impact of individual plant insecticidal components against storage pests. 
 Keywords: Aalkaloids, Aqueous, Extract, Grains and phytochemical

Assessments of some animal bones biochar as paddy protectants against rice weevil, Sitophilus oryzae L. [Coleoptera: Curculionidae]

The main insect pest of stored paddy is Sitophilus oryzae (rice weevil). Huge amounts of rice are produced by peasant farmers each year, but the bulk of it is wasted due to insufficient storage facilities and insect pest attacks brought on by careless handling. In this study, the insecticidal effects of biochar on S. oryzae were assessed in femurs from Sus scrofa (pig), Gallus gallus (chicken), and Bos taurus (cattle). Adult mortality, adult emergence, weight loss, seed damage, and weevil perforation index are among the indicators evaluated. To apply the biochar, different dosages were used: 0.2, 0.4, 0.6, 0.8, and 1.0 g/20 g of paddy rice. In this work, the population of adult S. oryzae on paddy rice was dramatically reduced by all animal bones biochar tested for insecticidal activity (p < 0.05). The animal bone biochar became more effective with increasing dosage. After 24 h of treatment, pig biochar induced a 36.67 % mortality rate of adult S. oryzae, followed by cow biochar's 20 % mortality rate of rice weevils. The fatal dose of cattle, pig, and chicken biochar at which 50 % (LD50) of the population of adult S. oryzae responded after 24 h of treatment were 0.83g, 0.43g, and 0.90g, respectively. It should be encouraged to utilize biochar made from animal bones to combat the S. oryzae in stored paddy. They could be utilized as a green control measure to lessen the risk brought on by the usage of synthetic chemical insecticides in the environment.

Phytochemical Characterization of Callistemon lanceolatus Leaf Essential Oils and Their Application as Sustainable Stored Grain Protectants against Major Storage Insect Pests

Food storage has been important since the dawn of agriculture and human settlement. Insect pests cause major losses to food grains during storage and production. Essential oils are good alternatives for chemical insecticides for the management of storage pests. Red bottlebrush, Callistemon lanceolatus, is a flowering plant of the Myrtaceae family. This research work aimed to extract the oil from bottlebrush leaves, and chemically characterize and assess their repellent and insecticidal properties against the cowpea seed beetle, Callasobruchus maculatus (F.) (Coleoptera: Chrysomelidae), cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Ptinidae), and red flour beetle, Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae), for the first time. The essential oil yielded by hydro-distillation of bottlebrush leaves was 1.02 ± 0.01%. GC-MS analysis determined the chemical composition of the volatile oil comprised 1,8-cineole (19.17%), α-terpineol (11.51%), α-pinene (10.28%), and α-Phellandrene (9.55%). The C. lanceolatus leaf oil showed potent repellence, contact toxicity, and fumigation toxic effects. In the contact toxicity assay, at 24 h, the LC50 values were 1.35, 0.52, and 0.58 mg/cm2 for the red flour beetle, cigarette beetle, and cowpea seed beetle, respectively. Likewise, in the fumigation assay observed after 24 h, LC50 values of 22.60, 5.48, and 1.43 µL/L air were demonstrated for the red flour beetle, cigarette beetle, and cowpea seed beetle, respectively. Additionally, there was no significance found by a phytotoxicity assay when the paddy seeds were exposed to C. lanceolatus oil. The results show that the volatile oils from red bottlebrush leaves have the potential to be applied as a biopesticide. Therefore, C. lanceolatus leaf oil can be utilized as a bio-insecticide to control stored product insects.

The distribution of insect pests and the associated loss of stored sorghum in the Kena district of Konso Zone, South-Western Ethiopia.

Sorghum is a staple crop grown in the poorest and most food-insecure regions of Ethiopia. But storage insect pests are its key constraints that have been causing considerable loss. Accordingly, an assessment of the prevalence of insect pests and the associated loss of sorghum stored under farmers' traditional storages was done in randomly selected major sorghum-growing kebeles of Kena District using a nested design between November 1, 2019 and December 30, 2020. It was conducted through the sampling of one kg of grain from a total of 360 randomly selected farmers' storages. Pests' abundance was determined by dividing the total number of individual species by the total number of samples. A count and weight method was used to estimate percent grain damage and weight loss by pests. Sitophilus zeamais, Sitophilus oryzae, Sitotroga cereallella, Tribolium castaneum, Tribolium confusum, Cryptolestes ferrugineus, Cryptolestes pusillus, Rhyzopertha dominica, and Plodia interpunctella were the pests identified from grain samples. When compared to mid-latitude, where they were found in the range between 2.36± 0.21 and 17.50±0.98 mean number of species, all of these pests had a considerably (p < 0.05) larger distribution in low-land kebeles, where they predominated in the range between 5.44±2.00 and 23.61±1.75 amean number. During the nine-month storage period, the degree of pest infestation, percentage of grain damage, and weight loss were significantly (p < 0.05) higher in the bamboo bins when no management measures were implemented in the mid-land and low-land kebeles, respectively, than in the barn. Consequently, bamboo bin storage was considered ineffective for sufficient sorghum grain protection against pests and the associated loss over a longer storage period. But barn storage and the use of cultural pest management practices performed better in protecting stored sorghum from pests. Therefore, improving the bamboo bin storage method is needed to improve its grain protection efficacy.

INSECT BIODIVERSITY AND ASSESSMENT OF POST-HARVEST GRAIN LOSSES IN STORED COWPEA (Vigna aunguiculata L.)

Insect pests cause huge economic losses to stored grain cereals and pulses in tropical and subtropical areas around the globe. The level of damage and losses caused by different insect pests varies depending upon the infesting species, type of food materials, duration of storage and structures. The information about the diversity of infesting species, their dispersal and abundance are key for devising effective pest management techniques against storage insect pests. The present study aimed to collect information on the distribution, relative abundance and biodiversity of major insect pests of stored cowpeas in Dera Ismail Khan (Khyber Pakhtunkhwa) and its adjoining Punjab province areas of Pakistan. The areas selected for biodiversity studies were Paniala, Mankera, Bhakkar, Paharpur, Kulachi, Ramak, Dera Ismail Khan, Darya Khan, Notak and Behal. A vast survey of godowns was conducted to find out the population dynamics of insect pests of stored cowpeas and to explore the % grains damage and weight losses in the mentioned areas. For the collection of samples, a spear sampler was used to collect 500-gram samples from the top, middle and bottom portions of the bags. Samples were preserved in plastic containers and after 30 days, were sieved out with the help of a 2mm mesh sieve to remove different types of dead and alive insects. A total of five species representing two distinct orders i.e., Coleoptera and Lepidoptera. Coleopterans are Callosobruchus maculatus, Tribolium castaneum, Oryzaephilus surinamensis, Trogoderma granarium belonged to four families including Chrysomelidae, Tenebrionidae, Silvanidae, Dermestidae and Lepidopteron are Sitotroga cerealella belonging to family Gelechidae. The most abundant species among all the recorded insect pests of cowpea was C. maculatus (53.60%) followed by T. castaneum (18.60%), S. cerealella (16.97%), O. surinamensis (6.49%) and T. granarium (04.34%). The maximum infestation (26.98%) and weight loss (28.91%) of cowpea was recorded in Darya Khan followed by Dera Ismail Khan (22.70% and 26.33%), whereas; minimum % infestation and weight losses were recorded in Bhakkar (16.91% and 17.14%) area showing significant differences between the surveyed areas. The C. maculatus is the most abundant specie of the stored cowpea grains in the surveyed areas and needs management tactics to minimize the post-harvest grains losses. The population of C. maculatus starts to build up during the month of March (23.30⁰C and 56.25% RH) and reaches at peak in May (35.32⁰C and 68.88% RH). Special measures should be taken during these months to minimize the infestation and losses caused by C. maculatus.

Hermetic storage for eco-friendly management of insect pests infesting stored sesame (Sesamum indicum L.)

Sesame provides excellent food, nutrition, health care, edible oil, and biomedicine. Insect pest infestations in stored sesame have been a problem of major concern in recent years. Two hermetic storage bags, viz., high density polyethylene (HDPE) bag and double layered polythene (DLP) bag, were evaluated alone and in combination with botanical treatment (sweet flag rhizome powder @ 10 g/kg seed) against rice moth and red flour beetle under storage condition in comparison with conventional farmers’ storage bags (jute gunny bag and cloth bag). Among the treatments, sesame seeds stored in HDPE bag with sweet flag rhizome powder and HDPE bag recorded significantly low seed damage due to the pests as compared to sesame seed stored in cloth and jute gunny bags at 6 months after treatment. The study revealed that HDPE bag alone or in combination with sweet flag rhizomepowder could be employed as an eco-friendly method for preventing storage insect pests infesting sesame under storage conditions.