Factors Affecting Stem Borer Parasitoid Species Diversity and Parasitism in Cultivated and Natural Habitats

2010 ◽  
Vol 39 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Duna Madu Mailafiya ◽  
Bruno Pierre Le Ru ◽  
Eunice Waitherero Kairu ◽  
Paul-André Calatayud ◽  
Stéphane Dupas
2009 ◽  
Vol 133 (6) ◽  
pp. 416-429 ◽  
Author(s):  
D. M. Mailafiya ◽  
B. P. Le Ru ◽  
E. W. Kairu ◽  
P.-A. Calatayud ◽  
S. Dupas

2021 ◽  
Vol 9 (1) ◽  
pp. 72 ◽  
Author(s):  
Giorgio Anfuso ◽  
Matteo Postacchini ◽  
Diana Di Luccio ◽  
Guido Benassai

Coastal area constitutes a vulnerable environment and requires special attention to preserve ecosystems and human activities therein. To this aim, many studies have been devoted both in past and recent years to analyzing the main factors affecting coastal vulnerability and susceptibility. Among the most used approaches, the Coastal Vulnerability Index (CVI) accounts for all relevant variables that characterize the coastal environment dealing with: (i) forcing actions (waves, tidal range, sea-level rise, etc.), (ii) morphological characteristics (geomorphology, foreshore slope, dune features, etc.), (iii) socio-economic, ecological and cultural aspects (tourism activities, natural habitats, etc.). Each variable is evaluated at each portion of the investigated coast, and associated with a vulnerability level which usually ranges from 1 (very low vulnerability), to 5 (very high vulnerability). Following a susceptibility/vulnerability analysis of a coastal stretch, specific strategies must be chosen and implemented to favor coastal resilience and adaptation, spanning from hard solutions (e.g., groins, breakwaters, etc.) to soft solutions (e.g., beach and dune nourishment projects), to the relocation option and the establishment of accommodation strategies (e.g., emergency preparedness).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel K. N’Woueni ◽  
Orou G. Gaoue

AbstractThe conversion of natural systems into farms and agroecosystems is the main cause of biodiversity loss. In human-dominated landscapes, understanding the interactions between agroforestry systems and adjacent natural vegetation is fundamental to developing sustainable agricultural systems. Species can move between these two systems with natural systems providing the regional pool of species that shape the agricultural values and conservation value of the agroforestry systems. We investigated the influence of neighboring natural habitats on traditional agroforestry systems in the buffer zone of Pendjari Biosphere Reserve in Benin to understand the contribution of regional processes on the quality of agroforestry systems. We expected that agroforestry parklands adjacent to natural vegetation with high species diversity will also have higher plant species diversity. We found no similarity in plant species composition between agroforestry systems and adjacent natural habitats. A small proportion of species in adjacent natural habitats were found in agroforestry systems. The proportion of shared species was not significantly influenced by plant diversity in adjacent natural habitats or the distance from the agroforestry systems to the natural adjacent habitat. However, plant diversity in agroforestry systems was strongly associated with site ethnobotanical values indicating that farmers act as a supplemental but severe environmental filter of the regional species pool. Our study suggests that promoting the plantation of plants with high ethnobotanical use-value is a potentially viable strategy for sustainable agriculture and ecological restoration in Biosphere reserves.


2021 ◽  
Author(s):  
Fatemeh Nezhadi ◽  
farzad fayaz ◽  
Hooshmand Safari ◽  
Ezzat Karami ◽  
Abdol Rahman Rahimi

Abstract We conducted the present study on seven important medicinal species of Achillea (4 replications per species) (in a total of 28 samples) in their natural habitats in two consecutive years (2018, 2019) in terms of morphological, cytogenetic, and ecological aspects. This study aimed to examine the environmental variables affecting the morphology, cytogenetics, and evolution of the plant. The results indicated that the populations had a Ploidy base number (x= 9) and the diploid, tetraploid, and hexaploid levels were observed. In addition to the inter-species diversity, there was the intra-species genetic diversity as (4x, 6x) Ac. millefolium (2x, 4x), Ac.vermicularis (2x, 4x), Ac. tenuifolia (2x, 4x), Ac. Alppica(2x) , Ac.talagonica(2x),Ac. biebersteinii, and Ac.wilhelmsii (4x). Further studies also indicated that 11 out of 28 populations had 1A symmetry, 15 populations had 2B symmetry, a population had 2A, and another population had 2B. Principal component analysis (PCA) of cytogenetic variables could not differentiate the species well probably due to the superiority of intra-species diversity of populations to inter-species diversity. Therefore, it seems that the evolution and speciation of this genus are mostly due to the increase or decrease in the amount of chromatin and chromosome length. The examination of principal component analysis in environmental indices also showed that Ac. millefolium hexaploid species was more adapted to the environment with higher percentages of clay and silt while the Ac.tenuifolia tetraploid species preferred a sandy habitat over other environmental factors. Furthermore, Ac.vermicularis tetraploid species indicated the greatest sensitivity to altitude. However, the Ac.biebersteinii tetraploid species reacted to meteorological parameters, such as perception rate and minimum temperature.


2021 ◽  

Abstract Within Hymenoptera, the superfamily Chalcidoidea (chalcidoid wasps) is the second largest superfamily after Ichneumonoidea. Because of the preponderance of parasitoid species, Chalcidoidea is one of the most important groups in applied biological control. This book provides a comprehensive, accurate checklists for the chalcidoid fauna of Iran. The species listed in each family chapter include all the species recorded in the literature from Iran through 2019, with one exception as noted in Chapter 10 (Eurytomidae). Each family chapter includes differential characters to distinguish the family, hypothesized phylogenetic relationships with other families, and general biological attributes of the family. Previous cataloguing efforts of the Iranian fauna for the family are summarized, as well as the information included in the checklist of species for the family. This summary information includes the number of species recorded from Iran, any newly recorded species, a comparison of the Iranian fauna with those of adjacent countries, and major host attributes of the family in Iran. Also included for each species record are host records and plant associates in Iran, when known, and additional comments as necessary. The final chapter tabulates the species diversity of Iranian Chalcidoidea by family, the species newly exclude from Iran, the species presently considered as endemic to Iran and the number of species of each family that are known from each of the 31 provinces that comprise Iran. Because of the importance of chalcidoids for biological control of pests in Iran, host information for parasitoid species that is provided throughout the chapters is synthesized in an Appendix at the end of the book.


Author(s):  
M. Rajkumar ◽  
Jun Sun ◽  
I. R. Jenkinson ◽  
M.M. Rahman

A twelve-month investigation was undertaken on how copepod community structure varied in relation to environmental factors in the Coleroon estuary, south-east India. Sampling was monthly, from Station 1 in the sea to Station 4 in the Vettar backwaters. Canonical correspondence analysis (CCA) was applied to elucidate the environmental factors affecting the copepod community. A total of 104 copepod species in 38 genera and 26 families were recorded, with the Calanoids, Acartia erythraea and Oithona brevicornis being the most dominant. At all four stations, both these species loaded near the intercept of CCA axes 1 and 2, perhaps reflecting that they were autochthonous. Most species occurred in distinct seasonal patterns. Abundances ranged from 13 × 103 to 215 × 103 (ind. m−3). Coleroon waters showed high diversity (bits/ind.), from 5.29 at Station 3 to 4.97 at Station 4. Abundance correlated positively with temperature and salinity and negatively with rainfall, dissolved oxygen concentration (DO) and pH. Species diversity correlated strongly with abundance (P < 0.01). Abundance and diversity were highest during the summer, and both correlated positively with salinity. Temperatures (air and water), salinity, pH and DO varied in the ranges 26–36°C, 25–34.2°C, 9–38, 7.0–8.7 and 3.0–6.8 ml l-1, respectively. Nitrate, nitrite, phosphate and silicate (µM) varied in the ranges: 4.7–64.5, 0.4–14.1, 0.2–12.9 and 9.3–148, respectively.


2020 ◽  
Vol 8 ◽  
Author(s):  
Alyona Tretyakova ◽  
Nickolay Grudanov ◽  
Pavel Kondratkov ◽  
Olga Baranova ◽  
Natalya Luneva ◽  
...  

Weeds are plants that, although not specially cultivated, grow and often adapt to growing in arable lands. They form an ecological variant of flora, as a historically-formed set of species growing on cultivated soils. For the rational use of the chemical and biological crop protection products and to produce safe and high-quality food, up-to-date data on the floristic diversity of weeds and the patterns of its geographical change are required. The need for a weeds' database arises that allows many specialists to work together independently. However, the great value of any database lies not in its existence, but in the accumulation of data that can be used to analyse the factors affecting the species diversity of weeds. A dataset of weed species diversity and their distribution in the European part of Russia, based on the results of the authors' own research from 1999 to 2019, has been created. The dataset includes 24,284 observations of occurrences of weed plants, which were obtained on the basis of 2,049 relevés of segetal plant communities in seven regions of the European part of Russia. In total, the dataset includes information about 329 species of vascular plants growing in 65 farmlands: cereals, spring and winter crops, industrial crops, row crops and perennial grasses (Tretyakova et al. 2020).


2016 ◽  
Vol 25 (1) ◽  
pp. 99
Author(s):  
Ni Made Delly Resiani ◽  
I Wayan Sunanjaya

Rice is the staple food of Indonesia's population. Various problems occur in an effort to increase production and productivity. One problem is the attack of yellow rice stem borer (PBPK) which may result in yield losses up to 90%. Utilization of parasitoid is an alternative to suppress the attack of Yellow Rice Stem Borer. The study was conducted in Tabanan, covering three locations with the altitudes of 50, 300, and 550 meters above sea leve, and at the Plant Pests and Diseases laboratory of the Faculty of Agriculture, University of Udayana. The study aimed to determine the effectiveness of parasitization of the best Yellow Rice Stem Borer as a natural control agent at different altitudes. The method used was survey by taking a sample group of Yellow Rice Stem Borer eggs with a purposive random sampling in the area of 2.5 hectares (one block in each location was an area of 0.5 hectares) at each location. Observations on parasitoid found in Yellow Rice Stem Borer eggs were done on parasitoid species diversity, equality, abundance, parasitation level, sex ratio, and the pattern of parasitoid invasion. The results showed three species of parasitoid eggs PBPK as biological control agents. Parasitation level of T. rowani and T. japonicum was the highest at the altitude of 50 meters above sea level, while T. schoenobii at the altitude of 300 and 500 meters above sea level.


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