scholarly journals Effects of Hypoxia on Acoustic Activity of Two Stored-Product Pests, Adult Emergence, and Grain Quality

2019 ◽  
Vol 112 (4) ◽  
pp. 1989-1996 ◽  
Author(s):  
Anastasia W Njoroge ◽  
Richard W Mankin ◽  
Bradley Smith ◽  
Dieudonne Baributsa
Keyword(s):  
Emerging Adults ◽  
Grain Quality ◽  
Callosobruchus Maculatus ◽  
Sitophilus Oryzae ◽  
Adult Emergence ◽  
Stored Grain ◽  
Acoustic Activity ◽  
Oxygen Levels ◽  
Post Exposure ◽  
Grain Damage

Abstract Modified atmospheres such as hermetic storage are widely used for the control of stored grain insect pests. To improve their effectiveness, there is need to better understand insect responses to low-oxygen environments. Adult Callosobruchus maculatus F. (Coleoptera: Chrysomelidae: Bruchinae) on cowpea and Sitophilus oryzae L. (Coleoptera: Curculionidae) on wheat were exposed to hypoxia treatments consisting of 1, 3, and 5% oxygen levels for 14 d. Acoustic activity was monitored during the experiment, and insect mortality and grain quality were examined immediately after the hypoxia treatments. Adult emergence was assessed 45 d post-treatment. All three hypoxia treatments eliminated acoustic activity of both species within 4 d. There was neither insect survival for both species nor significant grain damage immediately after 14-d exposure to hypoxia treatments. No adult insects emerged 45 d post-exposure on grains maintained at 1% oxygen level for 14 d. However, at 3 and 5% oxygen levels, there were eggs on cowpea, holes in wheat, and emerging adults for both insect species 45 d post-exposure. Although insect activity ceased within 4 d when hypoxia was maintained below 5%, there is need to explore exposure beyond 14 d for 3 and 5% oxygen levels, to ensure to avoid potential adult emergence from eggs and other insect life stages post-treatments. Maintaining 3–5% hypoxia conditions for a longer duration would ensure insufficient oxygen is available for progeny development.

Mortality of Different Life Stages of Rhagoletis indifferens (Diptera: Tephritidae) Exposed to the Entomopathogenic Fungus Metarhizium anisopliae

2005 ◽  
Vol 40 (2) ◽  
pp. 167-177 ◽  
Author(s):  
Wee L. Yee ◽  
Lawrence A. Lacey
Keyword(s):  
Emerging Adults ◽  
Metarhizium Anisopliae ◽  
Entomopathogenic Fungus ◽  
Laboratory Tests ◽  
Fungal Spores ◽  
Adult Emergence ◽  
Fruit Fly ◽  
Life Stages ◽  
Post Exposure ◽  
Rhagoletis Indifferens

Effects of the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin on the mortality of different life stages of the western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), were determined in laboratory tests. When teneral adults were exposed to fungal spores mixed in soil (7.63 × 105 and 1.61 × 106 spores/g) or applied to the surface of soil (1.14 × 106 and 2.28 × 106 spores/cm2) with 13 to 30% moisture, adult emergence was not reduced, but 14.9 to 68.0% of emerging adults were infected at death. When adult flies were exposed to various concentrations of dry spores inside vials, 15 mg (4.59 × 108 spores/10 flies) was the lowest needed for 100% mortality at 7 d post exposure, and resulted in 5.96 × 106 spores adhering to each fly. Females exposed to 1.80 mg (5.51 × 107 spores/10 flies) laid as many eggs as control females between 0 and 3 d post exposure, but due to mortality infected flies laid fewer eggs between 3 and 7 d. Third-instar larvae exposed to treated soil (9.63 × 104 to 4.81 × 106 spores/cm2) with 20% moisture were not infected.

scholarly journals Evaluation of Purdue Improved Crop Storage Triple Layer Hermetic Storage Bag against Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) and Sitophilus zeamais (Motsch.) (Coleoptera: Curculionidae)

Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 204 ◽  
Author(s):  
Kimondo Mutambuki ◽  
Hippolyte Affognon ◽  
Paddy Likhayo ◽  
Dieudonne Baributsa
Keyword(s):  
Weight Loss ◽  
Insect Pests ◽  
Prostephanus Truncatus ◽  
Stored Grain ◽  
Maize Weevil ◽  
Oxygen Levels ◽  
Triple Layer ◽  
Grain Damage ◽  
Maize Grain ◽  
Jute Bags

Hermetic technologies are being promoted in Africa as safer and more effective methods of grain storage on smallholder farms. However, farmers and policy makers lack knowledge of their efficacy in controlling major stored grain pests. An on-station study was conducted to evaluate the triple layer Purdue Improved Crop Storage (PICS) airtight bags against two major storage insect pests. Two sets each of PICS, jute and polypropylene bags were filled with 50 kg maize grain per bag. Each set was replicated four times. One set of PICS bags was each infested with 50 insects each of the larger grain borer P. truncatus and the maize weevil S. zeamais; while the other set was not. One set of jute and polypropylene woven bags was treated with a cocktail of 1.6% Pirimiphos methyl and 0.3% Permethrin, serving as positive controls; while the remaining sets with untreated maize grain formed negative controls. Gas analysis in the PICS bags followed the expected trend with oxygen levels falling sharply below 10% and carbon dioxide increasing to almost 10% after 12 weeks hence resulting in insect death. After 16 weeks, increase in oxygen levels may be attributed to perforation of the bags from outside by the P. truncatus. Results showed that PICS bags were significantly (P < 0.05) superior to treated and untreated controls of polypropylene and jute bags in suppressing insect development, maize grain damage and weight loss during storage. Weight loss in polypropylene and jute bags reached 40% and 41%, respectively, at 24 weeks after storage compared to PICS (2.4–2.9%). These results demonstrate that PICS bags can be used to store maize against P. truncatus and S. zeamais attack.

scholarly journals Are variations in kernel-related morphometric and chemical parameters correlated with differences in Sitophilus oryzae attack in maize?

2021 ◽  
Author(s):  
Chiara Lanzanova ◽  
Cristina Agape ◽  
Giulia Castorina ◽  
Carlotta Balconi ◽  
Michela Alfieri ◽  
...  
Keyword(s):  
Emerging Adults ◽  
Sitophilus Oryzae ◽  
Seed Storage ◽  
Adult Emergence ◽  
Maize Breeding ◽  
Research Activities ◽  
Maize Genotypes ◽  
Males And Females ◽  
Moderately Resistant ◽  
Maize Kernels

Insect infestation during seed storage affects cereal productivity. Sitophilus oryzae, which is present in various climates, is one of the primary pests for maize (Zea mays ) seeds. In this study, kernels of a set of eight inbred lines of importance for both maize breeding and research activities were characterised for morphological and biochemical parameters as well as for their susceptibility to S. oryzae. S. oryzae was reared in laboratory-controlled conditions and the susceptibility index (SI, range: 0-11), which depends on both number of emerging adults and their median developmental period, was measured. Maize kernels of each of the eight maize lines were put in contact with less than 3-day old males and females of S. oryzae for 13 days. Infested kernels were checked daily for new adult emergence. Four maize lines were susceptible to S. oryzae attack (SI = 7.5 to 9.7) while the others appeared to be moderately resistant (SI = 4.6-6.9). Our results highlighted the occurrence of variability for insect susceptibility among different maize genotypes, however, variations in the kernel traits analysed do not allow us to make predictions about the response to insect attack.

scholarly journals Testing the Insecticidal Activity of Nanostructured Alumina on Sitophilus oryzae (L.) (Coleoptera: Curculionidae) Under Laboratory Conditions Using Galvanized Steel Containers

Insects ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 87 ◽  
Author(s):  
Guillermo López-García ◽  
Micaela Buteler ◽  
Teodoro Stadler
Keyword(s):  
Sitophilus Oryzae ◽  
Galvanized Steel ◽  
Stored Grain ◽  
Treatment Rate ◽  
Laboratory Conditions ◽  
Grain Damage ◽  
Pest Insects ◽  
Stored Grain Pest ◽  
Short Time ◽  
First Time

Most stored-grain pest insects increase their population within a relatively short time, causing serious damage to stored products. Sitophilus oryzae (L.) is one of the world’s major stored-grain pest insects and was chosen as the model insect for our studies. This study compared the efficacy of three different dusts under laboratory conditions: aluminum dust (nanostructured alumina), DiatomiD®, and Protect-It® (commercial diatomaceous earth). Parental survival, grain damage, and progeny production were measured at 250 and 500 ppm in treated wheat. The tests were conducted in 400 mL galvanized steel jars, an experimental model used for the first time to measure the effectiveness of nanostructured alumina, since most studies have been typically performed in small petri dishes. Parental survival obtained was highest in the untreated controls, followed in decreasing order by DiatomiD®, Protect-It®, and nanostructured alumina (NSA). NSA caused the greatest mortality. All treatments significantly reduced grain weight loss and frass production in wheat infested by S. oryzae. The degree of progeny (F1) suppression was directly related to the product and treatment rate, progeny being significantly suppressed by NSA in wheat followed by Protect-It® and DiatomiD®. Therefore, NSA had a greater impact on insect population dynamics.

Toxic and repellent action of sugarcane bagasse-based lignin against some stored grain insect pests

1970 ◽  
Vol 25 ◽  
pp. 27-30 ◽  
Author(s):  
LA Muslima Khanam ◽  
D Talukder ◽  
MA Hye
Keyword(s):  
Tribolium Castaneum ◽  
Sugarcane Bagasse ◽  
Laboratory Experiments ◽  
Callosobruchus Maculatus ◽  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Repellent Activity ◽  
Stored Grain ◽  
Time Intervals ◽  
Class V

Laboratory experiments were carried out to investigate the efficacy of sugarcane bagasse-based lignin against four stored grain insect pests viz., Tribolium castaneum, Tribolium confusum, Sitophilus oryzae and Callosobruchus maculatus. Mortality was assessed after 24, 48 and 72 h of treatment and LD50 values were calculated at the respective time intervals. It was observed that T. castaneum is more susceptible to the lignin than the other test insects. Repellent activity of the product was conducted for T. castaneum and T. confusum. All the concentrations of the product were found to be repellent to both the insect species. Strong repellent activity was observed at concentrations of 471.57 and 628.76 µg.cm-2 to T. confusum showing the repellency of class V activity. Key words: Bagasse-based lignin, toxicity, repellency, Tribolium castaneum, T. confusum, Sitophilus oryzae, Callosobruchus maculatus Univ. j. zool. Rajshahi Univ. Vol.25 2006 p.27-30

scholarly journals Effect of Hypoxia on the Lethal Mortality Time of Adult Sitophilus oryzae L

Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 952
Author(s):  
Pragya Kandel ◽  
Michael E. Scharf ◽  
Linda J. Mason ◽  
Dieudonne Baributsa
Keyword(s):  
Value Chain ◽  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Adult Emergence ◽  
Storage Conditions ◽  
Hermetic Storage ◽  
Oxygen Levels ◽  
Modified Atmospheres ◽  
Time Required ◽  
Income Insecurity

Sitophilus oryzae is one of the most destructive pests of stored grains. It leads to significant quantitative and qualitative losses, resulting in food and income insecurity among farmers. Chemical pesticides are the most common methods used by farmers and other grain value chain actors to manage this pest. However, pesticides are increasingly becoming unattractive for pest control due to health hazards posed to applicators, consumers, the environment, and insect resistance. Modified atmospheres have the potential to manage stored insect pests as an alternative to pesticides. There is limited understanding of when insect pests die when grain is stored in airtight containers. This experiment was conducted to assess the time required to reach mortality of adult S. oryzae when exposed to 1, 3, and 5% oxygen levels. Results revealed that the LT50 for 1, 3, and 5% of oxygen were reached after 69.7 h, 187.8 h, and 386.6 h of exposure, respectively. No adult emergence was observed on infested grains following exposure to 1 and 3% oxygen levels. This result provides vital rationale for storing grain in hermetic storage conditions for at least 39 days to achieve adult S. oryzae mortality and minimize grain reinfestation.

Synthesis and Biological Evaluation of Thymol Functionalized Oxadiazole thiol, Triazole thione and β-lactam Derivatives

2020 ◽  
Vol 17 ◽  
Author(s):  
Jyoti Gaba ◽  
Sunita Sharma ◽  
Pardeep Kaur ◽  
Sukesha Joshi
Keyword(s):  
Adult Emergence ◽  
Biological Evaluation ◽  
Phytopathogenic Fungi ◽  
Egg Laying ◽  
Callosobruchus Chinensis ◽  
Spectroscopic Techniques ◽  
Stored Grain ◽  
Thymol Derivatives ◽  
Grain Damage ◽  
Ir Spectroscopic

Abstract:: In the present study, different derivatives of thymol (1) viz. hydrazide (2), oxadiazole thiol (3), triazole thione (4), hydrazones (5-7) and β-lactams (8-10) were synthesized. All synthesized compounds were identified and characterized using elemental analysis, UV-Visible, 1H NMR, 13C NMR, IR spectroscopic techniques. Synthesized thymol derivatives were evaluated for antifungal potential against phytopathogenic fungi Fusarium moniliforme, Rhizoctonia solani, Dreschlera madis of maize in comparison to recommended standards in terms of percent inhibition and ED50 values. Thymol was more effective as compared to its derivatives against all three tested fungi. Hydrazones (5-7) and β-lactams (8-10) having m-NO2 substituted phenyl ring (6, 9) were less effective as compared to o-NO2 and p-NO2 analogues against F. moniliforme and R. solani, however reverse trend was observed against D. maydis. Thymol and its derivatives were also tested for insecticidal activity against stored grain (chickpea) insect Callosobruchus chinensis and various parameters viz. egg laying, adult emergence and grain damage were recorded and compared. Compounds having oxadiazole thiol (3) and triazole thione (4) moiety showed promising effects against insect C. chinensis.

scholarly journals Comparative toxicity of botanical powders, diatomaceous earth, pirimiphos methyl, rice husk (powder and ash) against Callosobruchus maculatus (Fab.)

2018 ◽  
Vol 5 (11) ◽  
pp. 709-724
Author(s):  
M. O. Ashamo ◽  
A. I. Babalola ◽  
O. C. Ogungbite
Keyword(s):  
Weight Loss ◽  
Rice Husk ◽  
Diatomaceous Earth ◽  
Callosobruchus Maculatus ◽  
Rice Husk Ash ◽  
Adult Emergence ◽  
Small Scale ◽  
Comparative Toxicity ◽  
Grain Damage ◽  
Pirimiphos Methyl

This study was carried out to investigate the comparative toxicity of seeds of Piper guineense Schum & Thonn, Capsicum annum L., diatomaceous earth, pirimiphos-methyl dust, rice husk (powder and ash) against Callosobruchus maculatus (F.) in stored cowpea seeds. Toxicity test was carried out by exposing five pairs each of freshly emerged beetles to the substrate materials at the rates of 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 g/20 g of grains. The experiment conducted at ambient temperature of 28 oC + 2 oC and 75% + 5% relative humidity was replicated three times and arranged in a completely randomized design. Adult mortality was observed for four days. The following phytochemicals were observed in the materials: alkaloids, saponins, tannin, flavonoid and glycosides. Results of the toxicity assay revealed that rice husk ash was the most toxic to adult C. maculatus with 100% mortality (p < 0.05) within 72 h of exposure at a concentration of 0.1 g/20 g grains. Pirimiphos methyl gave a significantly high mortality of 76.67% at a concentration of 0.2 g/20 g of grains in cowpea after 72 h of application. The least efficacy was observed with rice husk powder evoking 3.33% at a dosage of 0.3 g/20 g in cowpea. The treated grains significantly reduced the oviposition and adult emergence of C. maculatus and were significantly different from the control in all the different dosages. Oviposition and adult emergence were lowest in rice husk ash with 8 eggs and 24.62% adult emergence in C. maculatus, at 0.5 g/20 g dosage. The percentage adult emergence in the untreated grains was significantly different (higher) (p > 0.05) from the emergence in the treated cowpea grains across the dosages. At all levels of dosages, the powders and ash significantly reduced weight loss, damage and weevil perforation index caused by the beetle. Rice husk ash at 0.5 g dosage recorded the lowest weight loss, grain damage and weevil perforation index of 0.40%, 1.95% and 5.80%, respectively. The findings from this research showed that rice husk ash was most potent/toxic to C. maculatus and its use could be encouraged especially in small scale storage.

scholarly journals Comparative Study of Cowpea Storage Technologies in the Sahel Region of Niger

Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 689
Author(s):  
Ousmane N. Bakoye ◽  
Baoua Ibrahim ◽  
Haoua Seyni ◽  
Laouali Amadou ◽  
Larry L. Murdock ◽  
...  
Keyword(s):  
Callosobruchus Maculatus ◽  
Insect Pests ◽  
Smallholder Farmers ◽  
Sub Saharan Africa ◽  
Stored Grain ◽  
Weight Losses ◽  
Grain Damage ◽  
Sub Saharan ◽  
Sahel Region ◽  
Storage Technologies

Cowpea stored on smallholders’ farms suffers serious losses to insect pests. A study conducted in Niger compared five postharvest technologies marketed in sub-Saharan Africa to protect stored grain. Naturally-infested cowpea stored for eight months showed adult Callosobruchus maculatus (F.) mortality of 97% to 100% in the hermetic bags (PICSTM, SuperGrainbagTM, AgroZ®, EVAL™, and ZeroFly® bags). There was no change in grain damage and weight loss of cowpea stored in hermetic bags. There was, however, a loss of up to 10 to 16% in germination when the grain was stored in hermetic bags. Results observed for grain stored in ZeroFly® bags impregnated with deltamethrin were substantial and similar to those in control woven bags. In both ZeroFly® and woven bags, (1) adult C. maculatus population augmented by 35.7% and 78.6%, (2) increased weight losses of 27.3% and 25.2%, and (3) reduced germination of 37.0% and 28.8%, respectively. After opening the bags, abrasions were noted on the liners of hermetic bags, potential damage that could limit their reuse if they only have a single liner. Smallholder farmers in the Sahel can safely store their cowpea in all the hermetic bags tested. However, further research is needed to mitigate insect damage on liners of hermetic bags to improve their performance and reusability.

scholarly journals Laboratory and microcosm experiments reveal contrasted adaptive responses to ammonia and water mineralisation in aquatic stages of the sibling species Anopheles gambiae (sensu stricto) and Anopheles coluzzii

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nwamaka Oluchukwu Akpodiete ◽  
Frédéric Tripet
Keyword(s):  
West Africa ◽  
Anopheles Gambiae ◽  
Emerging Adults ◽  
Sibling Species ◽  
Adult Emergence ◽  
Ecological Speciation ◽  
Sensu Stricto ◽  
Rice Fields ◽  
Anopheles Coluzzii ◽  
Phenotypic Quality

Abstract Background The sibling species of the malaria mosquito, Anopheles gambiae (sensu stricto) and Anopheles coluzzii co-exist in many parts of West Africa and are thought to have recently diverged through a process of ecological speciation with gene flow. Divergent larval ecological adaptations, resulting in Genotype-by-Environment (G × E) interactions, have been proposed as important drivers of speciation in these species. In West Africa, An. coluzzii tends to be associated with permanent man-made larval habitats such as irrigated rice fields, which are typically more eutrophic and mineral and ammonia-rich than the temporary rain pools exploited by An. gambiae (s.s.) Methods To highlight G × E interactions at the larval stage and their possible role in ecological speciation of these species, we first investigated the effect of exposure to ammonium hydroxide and water mineralisation on larval developmental success. Mosquito larvae were exposed to two water sources and increasing ammonia concentrations in small containers until adult emergence. In a second experiment, larval developmental success was compared across two contrasted microcosms to highlight G × E interactions under conditions such as those found in the natural environment. Results The first experiment revealed significant G × E interactions in developmental success and phenotypic quality for both species in response to increasing ammonia concentrations and water mineralisation. The An. coluzzii strain outperformed the An. gambiae (s.s.) strain under limited conditions that were closer to more eutrophic habitats. The second experiment revealed divergent crisscrossing reaction norms in the developmental success of the sibling species in the two contrasted larval environments. As expected, An. coluzzii had higher emergence rates in the rice paddy environment with emerging adults of superior phenotypic quality compared to An. gambiae (s.s.), and vice versa, in the rain puddle environment. Conclusions Evidence for such G × E interactions lends support to the hypothesis that divergent larval adaptations to the environmental conditions found in man-made habitats such as rice fields in An. coluzzii may have been an important driver of its ecological speciation.

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