Evaluation of canola cultivars for resistance to Helicoverpa armigera (Lepidoptera: Noctuidae) using demographic parameters.

The cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is one of the most important pests on a wide range of crops worldwide. The antibiotic resistance of 10 canola cultivars ('Sarigol', 'Hayula420', 'Opera', 'Okapi', 'Modena', 'RGS003', 'Zarfam', 'Licord', 'Talaye', and 'SLM046') to H. arimgera was evaluated using demographic parameters including life table, reproduction, development, and adult longevity. Larval period ranged from 18.8 to 16.1 d on Hayula420 and RGS003, respectively. The longest development time of immature stages was on Sarigol and Hayula420 (36.8 d) and the shortest one was on Zarfam (34.8 d). The highest daily and total fecundity (1,082.4 and 254.8 eggs, respectively) was on RGS003 and the lowest was on Talaye (517.0 and 41.4 eggs, respectively). The r(m) values varied from 0.153 on Sarigol to 0.179 on Opera. The net reproductive rate (R0) was calculated to be lowest on Talaye (157.4) and highest on RGS003 (331.5). The comparison of demographic parameters of H. armigera on different cultivars of canola and the cluster analysis revealed that Hayula420, Talaye, Sarigol, and SLM046 were the most resistant cultivars to this insect. Such results could be useful to develop an integrated pest management strategy of H. armigera on canola cultivars.

Alginate-magnetic short nanofibers 3D composite hydrogel enhances the encapsulated human olfactory mucosa stem cells bioactivity for potential nerve regeneration application.

The design of 3D hydrogel constructs to elicit highly controlled cell response is a major field of interest in developing tissue engineering. The bioactivity of encapsulated cells inside pure alginate hydrogel is limited by its relatively inertness. Combining short nanofibers within a hydrogel serves as a promising method to develop a cell friendly environment mimicking the extracellular matrix. In this paper, we fabricated alginate hydrogels incorporating different magnetic short nanofibers (M.SNFs) content for olfactory ecto-mesenchymal stem cells (OE-MSCs) encapsulation. Wet-electrospun gelatin and superparamagnetic iron oxide nanoparticles (SPIONs) nanocomposite nanofibers were chopped using sonication under optimized conditions and subsequently embedded in alginate hydrogels. The storage modulus of hydrogel without M.SNFs as well as with 1 and 5 mg/mL of M.SNFs were in the range of nerve tissue. For cell encapsulation, OE-MSCs were used as a new hope for neuronal regeneration due to their neural crest origin. Resazurin analyses and LIVE/DEAD staining confirmed that the composite hydrogels containing M.SNFs can preserve the cell viability after 7 days. Moreover, the proliferation rate was enhanced in M.SNF/hydrogels compared to alginate hydrogel. The presence of SPIONs in the short nanofibers can accelerate neural-like differentiation of OE-MSCs rather than the sample without SPIONs.

Effect of Arsenophonus Endosymbiont Elimination on Fitness of the Date Palm Hopper, Ommatissus lybicus (Hemiptera: Tropiduchidae).

The date palm hopper, Ommatissus lybicus de Bergevin, is one of the most important pests of the date palm in the Middle East and North Africa. This insect uses its needle-like sucking mouthparts to feed on phloem, which is devoid of most essential amino acids and many vitamins. The absence of essential nutrient in its diet is suggested to be ameliorated by endosymbionts in O. lybicus. Arsenophonus is one of the main bacterial endosymbionts widely prevalent in O. lybicus. In this study, we used antibiotics to eliminate Arsenophonus from O. lybicus originating from three populations (Fin, Qale'e Qazi, and Roodan) and studied the effects on the fitness of the pest. Our results revealed that the removal of Arsenophonus increased the developmental time of the immature stages and reduced the values of different life-history parameters including nymphal survival rate and adult longevity in the host. Furthermore, elimination of Arsenophonus completely obliterated offspring production in all O. lybicus populations investigated. These results confirm the dependency of O. lybicus on Arsenophonus for fitness and give a new insight regarding the possibility of symbiotic control of O. lybicus.