scholarly journals Global Habitat Suitability of Spodoptera frugiperda (JE Smith) (Lepidoptera, Noctuidae): Key Parasitoids Considered for Its Biological Control

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 273
Author(s):  
Ghislain T. Tepa-Yotto ◽  
Henri E. Z. Tonnang ◽  
Georg Goergen ◽  
Sevgan Subramanian ◽  
Emily Kimathi ◽  
...  

The present study is the first modeling effort at a global scale to predict habitat suitability of fall armyworm (FAW), Spodoptera frugiperda and its key parasitoids, namely Chelonus insularis, Cotesia marginiventris,Eiphosoma laphygmae,Telenomus remus and Trichogramma pretiosum, to be considered for biological control. An adjusted procedure of a machine-learning algorithm, the maximum entropy (Maxent), was applied for the modeling experiments. Model predictions showed particularly high establishment potential of the five hymenopteran parasitoids in areas that are heavily affected by FAW (like the coastal belt of West Africa from Côte d’Ivoire (Ivory Coast) to Nigeria, the Congo basin to Eastern Africa, Eastern, Southern and Southeastern Asia and some portions of Eastern Australia) and those of potential invasion risks (western & southern Europe). These habitats can be priority sites for scaling FAW biocontrol efforts. In the context of global warming and the event of accidental FAW introduction, warmer parts of Europe are at high risk. The effect of winter on the survival and life cycle of the pest in Europe and other temperate regions of the world are discussed in this paper. Overall, the models provide pioneering information to guide decision making for biological-based medium and long-term management of FAW across the globe.

2021 ◽  
Author(s):  
Ingrid Zanella-Saenz ◽  
Elisabeth A. Herniou ◽  
Jorge E. Ibarra ◽  
Ma.Cristina Del Rincón-Castro ◽  
Ilse Alejandra Huerta-Arredondo

Abstract Fall armyworm (FAW), Spodoptera frugiperda (Smith, 1797), is a polyphagous, voracious, and economically important agricultural pest. Biological control of FAW is a strategy that must be further explored. This study evaluated six baculovirus strains isolated from infected FAW larvae from Mexico, Argentina, Honduras, and the United States. Five alphabaculoviruses (SfNPV-An2, SfNPV-Arg, SfNPV-Fx, SfNPV-Ho and SfNPV-Sin) and one betabaculovirus (SfGV-RV), were tested against FAW larvae, showing a wide diversity of virulence levels among strains when their estimated LC50s were compared, being SfNPVArg, SfNPV-Ho and SfNPV-Fx more virulent than SfNPV-An 2 , SfNPV-Sin and SfGV-RV. To determine any virulence difference in vitro studies of these isolates, Sf9 cell cultures were used. Interestingly, only ODVs from four of the test SfNPV strains showed infectivity on Sf9 cell cultures, and some differences in virulence were observed. Genomic restriction analyses and partial sequences of lef-8, lef-9 , and polh/granulin genes showed little variability among alphabaculoviruses, both, among them and with previously reported sequences. However, sequences from SfGV-RV were closer to previously reported sequences from the SfGVVG008 strain than the SfGV-Arg and SfGV-VG014 strains. The great difference in the in vivo virulence was not correlated with great similarity among the isolates. The characterization of these six baculoviruses isolates offers the basis for exploring their potential as biological control agents against S. frugiperda, as well the initial studies on their specific infection mechanisms, evolution, and ecology.


Author(s):  
Birce Dikici ◽  
Matthew J. Lehman

Surface tension and solution evaporation of aqueous solutions of sodium lauryl sulfate (SLS), ECOSURF™ EH-14, and ECOSURF™ SA-9 under natural convection is examined through experimental methods. SLS is an anionic surfactant while EH-14 and SA-9 are environmentally-friendly nonionic surfactants. Surfactants are known to affect evaporation performance of solutions and are studied in relation to water loss prevention and heat dissipation. Surfactants could be useful under drought conditions which present challenges to water management on a yearly basis in arid areas of the world. Recent water scarcity in the greater Los Angeles area, south eastern Africa nations, eastern Australia and eastern Mediterranean countries has high cost of water loss by evaporation. Surfactants are studied as a potential method of suppressing evaporation in water reservoirs. Surfactants are also studied as performance enhancers for the working fluid of heat dissipation devices, such as pulsating heat pipes used for electronics cooling. Some surfactants have been shown to lower thermal resistances and friction pressure in such devices and thereby increase their efficiency. The static surface tensions of the aqueous-surfactant solutions are measured with surface tensiometer using Wilhelmy plate method. The surfactants are shown to lower surface tension significantly from pure water. The surface tension values found at the Critical Micelle Concentration are 33.8 mN/m for SLS, 30.3 mN/m for EH-14, and 30.0 mN/m for SA-9. All three surfactants reduced natural convection water loss over 5 days with SLS showing the greatest effect on evaporation rates. The maximum evaporation reduction by each surfactant from distilled water with no surfactants after 5 days is 26.1% for SLS, 20.8% for EH-14, and 18.4% for SA-9.


Geosciences ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 337 ◽  
Author(s):  
Charles M. Balagizi ◽  
Marcello Liotta

The processes of isotope fractionation in the hydrological cycle naturally occur during vapor formation, vapor condensation, and moisture transportation. These processes are therefore dependent on local and regional surface and atmospheric physical features such as temperature, pressure, wind speed, and land morphology, and hence on the climate. Because of the strong influence of climate on the isotope fractionation, latitudinal and altitudinal effects on the δ18O and δ2H values of precipitation at a global scale are observed. In this study, we present and compare the processes governing precipitation isotope fractionation from two contrasting climatic regions: Virunga in Central-Eastern Africa and the Central Mediterranean (Stromboli and Sicily, Italy). While Virunga is a forested rainy tropical region located between Central and Eastern Africa, the Mediterranean region is characterized by a rainy mild winter and a dry hot summer. The reported δ18O and δ2H dataset are from precipitation collected on rain gauges sampled either on a monthly or an approximately bimonthly basis and published in previous papers. Both regions show clearly defined temporal and altitudinal variations of δ18O and δ2H, depending on precipitation amounts. The Central Mediterranean shows a clear contribution of local vapor forming at the sea–air interface, and Virunga shows a contribution from both local and regional vapor. The vapor of Virunga is from two competing sources: the first is the continental recycled moisture from soil/plant evaporation that dominates during the rainy season, and the second is from the East African Great Lakes evaporation that dominates during the dry season.


1989 ◽  
Vol 3 (5) ◽  
pp. 523 ◽  
Author(s):  
JW Early ◽  
ID Naumann

Rostropria, gen. nov., comprising six new species (casta, garbo, gondola, inopicida, simplex and spiniventris) from eastern Australia, is most closely related to Neurogalesus Kieffer. The palpal formula is variable within Rostropria. R. inopicida is a parasite of the sugarcane soldier fly, Inopus rubriceps (Macquart) (Stratiomyidae), and a potential biological control agent for this pest of pastures and sugar cane. Euhoplopria Dodd is synonymised with Neurogalesus and the three described species (E. carinatifrons Dodd, E. lativentris Dodd, E. emargipennis Dodd) are transferred to Neurogalesus.


1987 ◽  
Vol 77 (1) ◽  
pp. 09-17 ◽  
Author(s):  
I. W. Forno

AbstractThe curculionid Cyrtobagous salviniae Calder & Sands and the pyralid Samea multiplicalis Guenée were released in north-eastern Australia for the biological control of the floating fern Salvinia molesta. C. salviniae destroyed large areas of weed and was successful at coastal and elevated sites. At equilibrium, there was less than 1 adult/20 plants and only a few, very small plants at each site. The rate at which the weed was controlled varied with mat density. The moth did not reduce plant growth permanently at any site and did not interfere with the performance of the weevil.


2003 ◽  
Vol 60 (2) ◽  
pp. 133-141 ◽  
Author(s):  
James Russell ◽  
Michael R. Talbot ◽  
Brian J. Haskell

AbstractLake Bosumtwi is one of the most widely studied palaeoclimate archives in West Africa. Results from numerous AMS 14C dates of samples from four piston cores from Lake Bosumtwi show that an abrupt sedimentary transition from a mid-Holocene sapropel to calcareous laminated muds occurred at about 3200 cal yr B.P. High-resolution analyses of the nitrogen isotopic composition of organic matter across this transition confirm its abrupt nature, and suggest that the change may signal a step toward increased aridity and intensified surface winds that affected western equatorial Africa from Ghana to the Congo basin. Northern and Eastern Africa experienced a similar abrupt shift toward aridity during the late Holocene, but at about 5000 cal yr B.P., a difference in timing that illustrates the regional nature of climate changes during the Holocene and the importance of feedback mechanisms in regulating Holocene climate variability. Furthermore, an abrupt change at about 3000 cal yr B.P. occurs at several sites adjacent to the tropical and subtropical Atlantic, which may hint at major changes in the surface temperatures of the tropical Atlantic and/or Pacific at this time.


1992 ◽  
Vol 40 (3) ◽  
pp. 303 ◽  
Author(s):  
M Tyndale-Biscoe ◽  
J Walker

Onthophagus australis (Guerin) is predominantly univoltine at two sites in south-eastern Australia, with Peaks Of activity in spring when most oviposition takes place, and in autumn when the new generation emerges. It overwinters mainly in the adult stage, and populations decline during summer droughts. The optimum temperature for oviposition is between 20 and 25-degrees-C, and the beetle produces food balls intermittently throughout life. The threshold temperature for development was estimated to be 5.2-degrees-C, and 1612 day-degrees (degrees-C) are required for development from egg to adult. In the laboratory, 100 beetles in a 1-L dung pad are able to reduce bush fly survival by 74%, and reduce the size of the fly puparia by 18%. In spring, when bush flies first build up their populations in the field, numbers of 0. australis did not often reach 100 per pad, thus limiting their usefulness for the biological control of the bush fly.


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