Rhyzopertha dominica adult mortalities after exposure to indigenous Beauveria bassiana isolates from stored-grain pests: Effects of certain factors in sampling process

2018 ◽  
Vol 77 ◽  
pp. 205-210
Author(s):  
Mehmet Kubilay Er ◽  
Ali A. Işikber ◽  
Fadime Aydin ◽  
Ceyda Ücük ◽  
Hasan Tunaz
1980 ◽  
Vol 20 (103) ◽  
pp. 234 ◽  
Author(s):  
ER Sinclair ◽  
M Bengston

In a survey of 60 grain farms on the Darling Downs, Queensland, during 1977-78, the flat grain beetles Cryptolestes spp., which are germ feeders in stored grains, were found on 39 of the farms and in 15% of the 483 samples taken. Ninety percent of infestations involving Cryptolestes spp. were found in bag or bulk stores of seed and feed grain, where they were usually associated with heavy infestations of the three more common stored grain pests, the rice weevil Sitophilus oryzae (L.), the lesser grain borer Rhyzopertha dominica (F.), and the red flour beetle Tribolium castaneum (Herbest.). Three species of Cryptolestes were detected: C. pusillus (Schonherr) (45.6% of farms surveyed), C. ferrugineus (Steph.) (28.1 %), and C. pusilloides (Steel and Howe) (15.8%). During the farm survey, samples were also collected from 8 of the 11 central storages reported infested with Cryptolestes spp. C. ferrugineus was present in each of these samples, C. pusillus in only one, whilst C. pusilloides was not found. The three species were tested for resistance to malathion and fenitrothion, the most commonly used grain-protectant chemicals, by exposing adults to treated wheat. C. pusillus and C. pusilloides were susceptible to both malathion and fenitrothion (LC99.9 < 1 mg kg-1). C. ferrugineus, whilst susceptible to fenitrothion (LC99.9 < 1 mg kg-1) was resistant to malathion, with LC99.9 of 300-400 mg kg-1 compared with the recommended dose of 18 mg kg -1. Although C. pusillus was the most common species on farms, it was concluded that C. ferrugineus was the most important overall because it is biologically better suited to the grain in central storages, which is typically hot (>30�C) and of low moisture content (< 12% for wheat).


2018 ◽  
Vol 80 (3) ◽  
pp. 1005
Author(s):  
Surajit Kalita ◽  
Lakshmi Kanta Hazarika ◽  
Purnima Das ◽  
Karishma Das

Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 233
Author(s):  
Ali A. Badawy ◽  
Nilly A. H. Abdelfattah ◽  
Salem S. Salem ◽  
Mohamed F. Awad ◽  
Amr Fouda

Herein, CuO-NPs were fabricated by harnessing metabolites of Aspergillus niger strain (G3-1) and characterized using UV–vis spectroscopy, XRD, TEM, SEM-EDX, FT-IR, and XPS. Spherical, crystallographic CuO-NPs were synthesized in sizes ranging from 14.0 to 47.4 nm, as indicated by TEM and XRD. EDX and XPS confirmed the presence of Cu and O with weight percentages of 62.96% and 22.93%, respectively, at varied bending energies. FT-IR spectra identified functional groups of metabolites that could act as reducing, capping, and stabilizing agents to the CuO-NPs. The insecticidal activity of CuO-NPs against wheat grain insects Sitophilus granarius and Rhyzopertha dominica was dose- and time-dependent. The mortality percentages due to NP treatment were 55–94.4% (S. granarius) and 70–90% (R. dominica). A botanical experiment was done in a randomized block design. Low CuO-NP concentration (50 ppm) caused significant increases in growth characteristics (shoot and root length, fresh and dry weight of shoot and root, and leaves number), photosynthetic pigments (total chlorophylls and carotenoids), and antioxidant enzymes of wheat plants. There was no significant change in carbohydrate or protein content. The use of CuO-NPs is a promising tool to control grain insects and enhance wheat growth performance.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Tabassum Ara Khanum ◽  
Salma Javed

Abstract Background Stored grain products suffer a considerable economic loss due to insect infestations. The resistance of pests to insecticide, and residues on crops are produced by the application of insecticide. Nowadays, incremental necessity has been occurred to find out alternatives to chemicals. As biological control agents, entomopathogenic nematodes (EPNs) attract attention increasingly in the research area recently. Results The aim of the study was to evaluate the pathogenicity of Pakistani isolates Steinernema bifurcatum and S. affine against the stored grain pests, Tribolium castaneum and Lasioderma serricorne, under laboratory conditions. Suspensions of nematodes were applied at 4 different concentrations 0, 50, 100, and 200 IJs/ml and 3 variable temperatures 15, 30, and 45°C. Pathogenicity rate was recorded after 48 h of application. The larval stage is found more susceptible than the adult. At 200 IJs, S. bifurcatum showed high mortality of L. serricorne larva (92%) and T. castaneum larva (93%), whereas S. affine showed 90 and 95% mortality of L. serricorne and T. castaneum larva, respectively, at 200 IJs. The results revealed that both species of EPN were able to control and reproduce on L. serricorne and T. castaneum. Maximum mortality was recorded at 45 °C from S. bifurcatum whereas S. affine at 15 °C. Conclusions Therefore, S. bifurcatum and S. affine could be suggested as a biological control agent for hot and cold climatic zones, respectively.


2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Ahlam Ahmed Alfazairy ◽  
Yasien Mohamed Gamal Zedan El-Abed ◽  
Hanan Mohamed Ramadan ◽  
Hedaya Hamza Karam

AbstractAverage yields of Mattesia spores (spore productivity) had varied from a minimum yield (0.17 × 107 spores) for Laemophloeus turcicus adult to a maximum yield (7.46 × 107 spores) for Plodia interpunctella larva. Comparatively, the highest increase in Mattesia spore yield, recorded from P. interpunctella larva (7.46 × 107 spores) over the lowest one, estimated for L. turcicus adult (0.17 × 107 spores), was nearly 44-fold. The increase in Mattesia spore yields that calculated from the other hosts (P. interpunctella pupa or moth; Galleria mellonella larva; Rhyzopertha dominica adult; Sitophilus zeamais), over that estimated for L. turcicus adult, was less than 10-fold (6–9-fold). Based on the weight of 1 g of the insect host infected with Mattesia sp., small stored grain insect hosts (e.g. L. turcicus, S. zeamais, and R. dominica) seemed to achieve Mattesia spore yields more than the larger ones (e.g. P. interpunctella). The increase in spore yields over that used for the inoculum, based on an average of 25 P. interpunctella larvae per bioassay container, was ca. 2 to 31-fold. These results revealed that the Indianmeal moth, P. interpunctella, could serve as a potential host for mass propagating the isolated entomopathogenic protozoan, Mattesia sp. Besides Mattesia larval mortality, survivors of Mattesia infection suffered deformities and noticeable undersized pupae or adults than the control ones. Also, many copulated moths (ca.46%) were unable to become separated after copulation until they had died. Bioassay of siftings, obtained from L. turcicus-protozoan-infected stock cultures, was carried out in order to emphasize the suppressive potent role of such protozoan entomopathogens in long-term storage. With the highest tested concentration of the studied siftings (10%), mortality responses due to Mattesia infection ranged from 13 to 68% at 14–169 days post-treatment. The corresponding figures for Adelina infection were 7–42%.


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