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 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.

scholarly journals Analytical assessment of maize kernels for Fe, Zn, and β-carotene dense cultivars with low phytate contents

2020 ◽  
Vol 49 (1) ◽  
pp. 40-48
Author(s):  
A. Sharma ◽  
S. Prasad ◽  
R. Arun Kumar ◽  
S. Jaiswal ◽  
P.K. Agrawal ◽  
...  
Keyword(s):  
Molar Ratio ◽  
Lower Amount ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Maize Cultivars ◽  
Maize Genotypes ◽  
Analytical Assessment ◽  
Maize Kernels ◽  
Hill Agriculture ◽  
Β Carotene

The present paper reports that significant genetic variability was evident in Fe, Zn, β-carotene, and phytic acid (phytate, PA) contents in a set of 39 diverse maize genotypes collected from maize breeding programme of hill agriculture, India. The Fe, Zn, β-carotene, and PA concentrations were found to be in the range 19.31–50.64 mg kg−1, 12.60–37.18 mg kg−1, 0.17–8.27 µg g−1, and 6.59–7.13 g kg−1, respectively. The genotypes V335, V420, V393, V416, V414, V372, and V351 were identified to have higher concentration of β-carotene, Fe, and Zn but lower amount of PA. Possible availability of the minerals Fe and Zn was determined using molar ratio between PA as inhibitor and β-carotene as promoter for their absorption. The micronutrient molar ratio showed that Fe and Zn traits could be dependent of each other. Low R2 value revealed relation between β-carotene and kernel colour. The selected genotypes could be considered as potential sources of favourable genes for further breeding programs to develop micronutrient enriched maize cultivars.

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.

scholarly journals Susceptibility of six varieties of rice to the infestation of rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae)

2012 ◽  
Vol 21 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Humayun Reza Khan ◽  
Polash Kanti Halder
Keyword(s):  
Oryza Sativa ◽  
Emerging Adults ◽  
Sitophilus Oryzae ◽  
Ambient Condition ◽  
Rice Weevil ◽  
Rice Varieties ◽  
Moisture Contents ◽  
The Mean

The susceptibility of six varieties of rice, Oryza sativa, viz. Lata, Minicate, Nazersail, Parija, Kalijira and Kataribhog, to the infestation of the rice weevil, Sitophilus oryzae (L.), was studied on the basis of population build up under an ambient condition (28 ± 4ºC and 70 ± 4 % RH) of the laboratory. The mean weights of each grain of the above six rice varieties were 16.9, 16.1, 11.43, 13.87, 6.23 and 9.77 mg, respectively; mean lengths were 6.47, 6.56, 5.37, 5.38, 4.22 and 4.92 mm, respectively; mean widths were 2.45, 2.03, 2.05, 2.17, 1.6 and 1.9 mm, respectively; and moisture contents were 11.55, 10.75, 11.6, 12.71, 11.85, and 12.1 per cents, respectively. As far as the number of emerging adults is concerned, the weevil showed the highest number (695) in Nazersail on the 16th week, Lata (755) on the 18th week, Minicate (654) on the 16th week, Parija (482) on the 20th week, Kalijira (402) on the 20th week, and Kataribhog (456) on the 20th week. The mean numbers of the adult weevils in the above six varieties after 22 weeks of rearing were 425, 410, 351, 387, 357 and 400, respectively and was statistically significant at 5% level. The degree of susceptibility of the rice varieties to the rice weevils from the highest to lowest susceptibility was ? Lata > Nazersail > Minicate > Pariza > Kataribhog > Kalijira.DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11514 Dhaka Univ. J. Biol. Sci. 21(2): 163-168, 2012 (July)

Laboratory and field trials to determine the modes of action of malathion and diesel oil against Culicoides furens (Poey) (Dipt., Ceratopogonidae)

1971 ◽  
Vol 60 (3) ◽  
pp. 399-407
Author(s):  
John B. Davies
Keyword(s):  
Emerging Adults ◽  
Larval Mortality ◽  
Adult Emergence ◽  
Field Trials ◽  
Diesel Oil ◽  
Modes Of Action ◽  
Marine Diesel ◽  
Pupal Mortality

One field and four laboratory trials were run to determine the reason for the success of 1–8% malathion in diesel oil in controlling Culicoides furens (Poey) in swamp mud in Jamaica. In the laboratory malathion and marine diesel oil (1:4000) was an effective larvicide for up to two days after application to the mud, but diesel oil alone gave only slight mortality even after six days. Judged by the emergence of adults, diesel oil gave 100% pupal mortality for five days and still showed some effect after four weeks; this effect was not improved by the addition of malathion. In the field, counts of emerging adults showed that diesel oil at 106–5 gal/acre gave 97–8% control of C. furens for up to eight weeks after application. It is concluded that, because of the possibility of pupicidal action, insecticides should be assessed on adult emergence rather than larval mortality.

scholarly journals Racial and Sex Differences in 24 Hour Urinary Hydration Markers among Male and Female Emerging Adults: A Pilot Study

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1068 ◽  
Author(s):  
William M. Adams ◽  
Derek J. Hevel ◽  
Jaclyn P. Maher ◽  
Jared T. McGuirt
Keyword(s):  
College Students ◽  
Emerging Adults ◽  
Fluid Intake ◽  
Urine Volume ◽  
Urine Osmolality ◽  
Urine Specific Gravity ◽  
Urine Color ◽  
Males And Females ◽  
Race Ethnicity ◽  
Hispanic White

The purpose of this study was to examine 24 h urinary hydration markers in non-Hispanic White (WH) and non-Hispanic Black (BL) males and females. Thirteen males (BL, n = 6; WH, n = 7) and nineteen females (BL, n = 16, WH, n = 3) (mean ± SD; age, 20 ± 4 y; height, 169.2 ± 12.2 cm; body mass, 71.3 ± 12.2 kg; body fat, 20.8 ± 9.7%) provided a 24 h urine sample across 7 (n = 13) or 3 (n = 19) consecutive days (148 d total) for assessment of urine volume (UVOL), urine osmolality (UOSM), urine specific gravity (USG), and urine color (UCOL). UVOL was significantly lower in BL (0.85 ± 0.43 L) compared to WH college students (2.03 ± 0.70 L) (p < 0.001). Measures of UOSM, USG, and UCOL, were significantly greater in BL (716 ± 263 mOsm∙kg−1, 1.020 ± 0.007, and 4.2 ± 1.4, respectively) compared to WH college students (473 ± 194 mOsm∙kg−1, 1.013 ± 0.006, 3.0 ± 1.2, and respectively) (p < 0.05). Differences in 24 h urinary hydration measures were not significantly different between males and females (p > 0.05) or between the interaction of sex and race/ethnicity (p > 0.05). Non-Hispanic Black men and women were inadequately hydrated compared to their non-Hispanic White counterparts. Our findings suggest that development of targeted strategies to improve habitual fluid intake and potentially overall health are needed.

Oviposition Preference and Larval Performance of Drosophila suzukii (Diptera: Drosophilidae), Spotted-Wing Drosophila: Effects of Fruit Identity and Composition

2019 ◽  
Vol 48 (4) ◽  
pp. 867-881 ◽  
Author(s):  
Laure Olazcuaga ◽  
Nicolas O Rode ◽  
Julien Foucaud ◽  
Benoit Facon ◽  
Virginie Ravigné ◽  
...  
Keyword(s):  
Emerging Adults ◽  
Oviposition Behavior ◽  
Oviposition Preference ◽  
Adult Emergence ◽  
Spotted Wing Drosophila ◽  
Larval Performance ◽  
Drosophila Suzukii ◽  
Management Tools ◽  
Factors Affecting ◽  
And Performance

Abstract A better understanding of the factors affecting host plant use by spotted-wing drosophila (Drosophila suzukii) could aid in the development of efficient management tools and practices to control this pest. Here, proxies of both preference (maternal oviposition behavior) and performance (adult emergence) were evaluated for 12 different fruits in the form of purees. The effect of the chemical composition of the fruits on preference and performance traits was then estimated. We synthesized the literature to interpret our findings in the light of previous studies that measured oviposition preference and larval performance of D. suzukii. We show that fruit identity influences different parts of the life cycle, including oviposition preference under both choice and no-choice conditions, emergence rate, development time, and number of emerging adults. Blackcurrant was always among the most preferred fruit we used, while grape and tomato were the least preferred fruits. Larvae performed better in cranberry, raspberry, strawberry, and cherry than in the other fruits tested. We found that fruit chemical compounds can explain part of the effect of fruit on D. suzukii traits. In particular, oviposition preference under choice conditions was strongly influenced by fruit phosphorus content. In general, the consensus across studies is that raspberry, blackberry, and strawberry are among the best hosts while blackcurrant, grape and rose hips are poor hosts. Our results generally confirm this view but also suggest that oviposition preferences do not necessarily match larval performances. We discuss opportunities to use our results to develop new approaches for pest management.

Observations on the life-history traits of the North American parasitoid Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae) attacking Agrilus planipennis (Coleoptera: Buprestidae) in Ontario, Canada

2016 ◽  
Vol 148 (3) ◽  
pp. 294-306 ◽  
Author(s):  
Lucas E. Roscoe ◽  
D. Barry Lyons ◽  
Sandy M. Smith
Keyword(s):  
Emerging Adults ◽  
Tree Height ◽  
Adult Emergence ◽  
Mass Rearing ◽  
Agrilus Planipennis ◽  
Potential Fecundity ◽  
The North ◽  
Parasitism Rates ◽  
Ash Trees ◽  
History Of

AbstractUnder laboratory and field conditions in Ontario, Canada, we explored the natural history of Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae), an indigenous solitary endoparasitoid of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in North America. Adult P. sulcata emergence was ~20.2–23.9 days after host emergence at 21°C, with P. sulcata females emerging an ~5.4–5.8 days before males. Females also represented 61.8 and 67.0% of emerging adults in the two years sampled. Mean adult longevities for males and females of P. sulcata were 23.8±1.10 and 28.9±1.11 days at 21°C, respectively. Mean potential fecundity of P. sulcata at emergence was 55.7±2.9 eggs per female. Based on adult emergence, parasitism at two sites varied from 11.7% to 34.4%. Adult parasitoids were first observed in the field in early June, with peak capture occurring in late June. Parasitism rates in A. planipennis-infested ash trees was not affected by tree height below 360 cm, whereas parasitism was not observed at heights>360 cm. Our results suggest that although mass rearing will be challenging, observed parasitism rates in conjunction with temporal and spatial synchrony indicate that indigenous P. sulcata may be an important source of mortality for A. planipennis populations.

Resistance levels of selected rice genotypes to Sitophilus oryzae L. and Rhyzopertha dominica F. infestations

2020 ◽  
Vol 17 ◽  
pp. 39-46
Author(s):  
S.K. Ajao ◽  
K.O. Popoola ◽  
S Mande ◽  
A Togola
Keyword(s):  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Rhyzopertha Dominica ◽  
International Institute ◽  
Rice Varieties ◽  
Resistance Level ◽  
Susceptibility Index ◽  
Grain Damage ◽  
Rice Genotypes ◽  
Moderately Resistant

The need to screen new rice genotypes for resistance to stored product insect pests is important to boost production and availability of rice for food security. Therefore, thirteen rice genotypes and varieties included ten interspecific rice genotypes from two crossed parents Oryza sativa (WAB 56-104) and Oryza barthii (IRGC 106107), the two parents and NERICA8 variety were collected from Africa Rice Center, International Institute of Tropical Agriculture (IITA) Ibadan, to examine their resistance level to infestation by Sitophilus oryzae L. and Rhyzopertha dominica F. The resistance of the varieties were assessed by artificial infestation with 12 unsexed adults each in 10 g of the rice varieties in four replicates under laboratory conditions of 26 ± 2oC temperature and 75 ± 5% relative humidity in a completely randomized design. Number of adult insect emergent, per cent grain damage, percent weight loss of infested samples and index of susceptibility were determined. Correlation analysis between nutritional contents of the varieties and infestation variables were also obtained. Results indicate differential responses of the two insects on the rice genotypes/varieties. The O. barthii parent was resistant, while the O. sativa parent was moderately resistant using the susceptibility index. Of the ten rice genotypes, G4, G3, G1, G7, G2, G10 and G9 were resistant in descending order, while G5 and G6 were moderately resistant, whereas only G8 was susceptible. NERICA8 was also found to be susceptible to infestation. In addition, the resistant grains had lower ash content. Modification in genetic variations and nutritional contents of new rice varieties may be a critical factor in insect resistant genotype pro-grammes to reduce post-harvest losses incurred by farmers. Keywords: Rice resistant genotypes; Rhyzopertha dominica; Oryzae sativa; Oryzae barthii; Sitophilus oryzae; susceptibility index

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.

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