scholarly journals Life history and population dynamics of Aspidiotus nerii (Bouche, 1833), Homoptera: Diaspididae, Saissetia oleae (Olivier, 1751), Homoptera: Lecanidae and Pollinia pollini (Costa, 1857), Homoptera: Asterolecanidae on olive trees in the Blida Region (Algeria)

2020 ◽  
Vol 10 (5) ◽  
pp. 62-68
Author(s):  
Guessab Asmaa ◽  
M. Biche ◽  
M. Biche
Keyword(s):  
Developmental Stages ◽  
Climatic Factors ◽  
Abundant Species ◽  
High Rate ◽  
Two Generations ◽  
Aspidiotus Nerii ◽  
Saissetia Oleae ◽  
Olive Trees ◽  
Cycle Monitoring ◽  
Population Counts

The work consists of a study on the level of infestation of the 3 species of olive-infused mealybugs at the two stations (Soumaa and Guerrouaou) in the Blida région, with particular attention to the évolution of Pollinia pollini (Asterolecanidae), Octaspidiotus nerii (Diaspididae) and Saissetia oleae (Lecanidae). Unlike the Soumaa station, there is a large infestation in the Guerrouaou station by the three (most abundant) species with a high rate. The life cycle monitoring and the bio-ecology of these three pests were carried out through periodic population counts on the leaves and twigs of the tree from 08 August 2016 to 29 May 2017 in the wilaya of Blida. It appears that the study of the biology of P.pollini evolves in 2 annual generations (the first is the spring generation; the second is through the summer. The larval stage remains the most abandoned compared to other developmental stages. The South orientation seems the most affectionate by P.pollini. We can conclude that O .nerii has two generations « spring and automne » depending on climatic factors. The East and West exposure represent the places most sought after by this scale where we found a relative abundance between larvae and adult females. S. oleae develops only one generation per year (automnal génération). Females are the most abundant in Soumaa station and larvae in Guerrouaou station. The eastern orientation and the automne season are the most favourable for the development of the mealybug.

scholarly journals Population dynamics, seasonal fluctuations and spatial distribution of the olive psyllid Euphyllura olivina Costa (Homoptera, Psyllidae) in Algeria

2021 ◽  
pp. 183-196
Author(s):  
A. Guessab ◽  
M. Elouissi ◽  
F. Lazreg ◽  
A. Elouissi
Keyword(s):  
Climatic Factors ◽  
Larval Instar ◽  
Life Stages ◽  
Seasonal Fluctuations ◽  
Euphyllura Olivina ◽  
Two Generations ◽  
Olive Groves ◽  
The Difference ◽  
Population Counts ◽  
Considerable Damage

The olive psyllid Euphyllura olivina Costa (Homoptera, Psyllidae) causes considerable damage in olive groves in the Mediterranean basin, there by affecting production. To assess the rate of infestation and provide elements of integrated pest management, we monitored the life cycle and bio–ecology of this pest through population counts on the leaves and twigs of the tree from 29 March 2019 to 27 March 2020 at two relatively distant olive farms (Ain fares and Oued taria) in the wilaya of Mascara, Algeria. Our results showed that infestation was high on trees in the Oued taria farm. We found that E. olivina developed two generations per year, in spring, influenced by the climatic factors. The difference between the relative abundance of the different life stages (eggs, larval instar 1, 2, 3, 4 and 5, female and male) in the cardinals orientations was significant. Infestation was highest on the southern and central orientations of the tree. Populations fluctuations were significantly affected by season at both farms.

scholarly journals A survey of scale insects (Hemiptera: Coccoidea) occurring on olives in Tunisia

2011 ◽  
Vol 43 (3) ◽  
pp. 315 ◽  
Author(s):  
Rramzi Mansour ◽  
Rim Mkaouar ◽  
Kaouthar Grissa Lebdi ◽  
Pompeo Suma ◽  
Agatino Russo
Keyword(s):  
Abundant Species ◽  
Scale Insect ◽  
Scale Insects ◽  
Insect Fauna ◽  
Aspidiotus Nerii ◽  
Hymenopteran Species ◽  
Olive Groves ◽  
Saissetia Oleae ◽  
Northeastern Tunisia ◽  
Northwest Region

A survey performed in 2009 within 52 Tunisian olive groves, located in 17 different olive-growing sites, revealed the occurrence of six scale insects on olives. The identified species were: the armoured scales Aspidiotus nerii Bouché, Lepidosaphes ulmi (L.), and Parlatoria oleae (Colvée), the soft scales Saissetia oleae (Olivier) and Filippia follicularis (Targioni Tozzetti) and the mealybug species Peliococcus cycliger (Leonardi). The soft scale F. follicularis is a new record for the Tunisian insect fauna. A mong these species, S. oleae was the predominant scale insect occurring throughout olive groves of northeastern Tunisia, whereas the mealybug P. cycliger was by far the most abundant species within olives groves of the Northwest region of Tunisia. However, P. oleae was the least abundant species, being present in only one olive-growing site in northeastern Tunisia. L arvae of the noctuid moth Eublemma scitula (Rambur) were reported feeding on S. oleae and the coccinellid Chilocorus bipustulatus L . was found feeding on both S. oleae and A. nerii. The two hymenopteran species Scutellista cyanea Motschulsky and Metaphycus spp. were recorded as the main parasitoids of S. oleae.

scholarly journals Development and Interrogation of a Transcriptomic Resource for the Giant Triton Snail (Charonia tritonis)

2021 ◽  
Author(s):  
AH Klein ◽  
CA Motti ◽  
AK Hillberg ◽  
T Ventura ◽  
P Thomas-Hall ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Cell Signalling ◽  
Natural Populations ◽  
Olfactory Receptors ◽  
Gill Tissue ◽  
Abundant Species ◽  
Population Outbreaks ◽  
Coral Reef Ecosystems ◽  
Specialist Predators ◽  
G Protein Coupled

AbstractGastropod molluscs are among the most abundant species that inhabit coral reef ecosystems. Many are specialist predators, along with the giant triton snail Charonia tritonis (Linnaeus, 1758) whose diet consists of Acanthaster planci (crown-of-thorns starfish), a corallivore known to consume enormous quantities of reef-building coral. C. tritonis are considered vulnerable due to overexploitation, and a decline in their populations is believed to have contributed to recurring A. planci population outbreaks. Aquaculture is considered one approach that could help restore natural populations of C. tritonis and mitigate coral loss; however, numerous questions remain unanswered regarding their life cycle, including the molecular factors that regulate their reproduction and development. In this study, we have established a reference C. tritonis transcriptome derived from developmental stages (embryo and veliger) and adult tissues. This was used to identify genes associated with cell signalling, such as neuropeptides and G protein-coupled receptors (GPCRs), involved in endocrine and olfactory signalling. A comparison of developmental stages showed that several neuropeptide precursors are exclusively expressed in post-hatch veligers and functional analysis found that FFamide stimulated a significant (20.3%) increase in larval heart rate. GPCRs unique to veligers, and a diversity of rhodopsin-like GPCRs located within adult cephalic tentacles, all represent candidate olfactory receptors. In addition, the cytochrome P450 superfamily, which participates in the biosynthesis and degradation of steroid hormones and lipids, was also found to be expanded with at least 91 genes annotated, mostly in gill tissue. These findings further progress our understanding of C. tritonis with possible application in developing aquaculture methods.

scholarly journals Capture efficiency for small dominant mesozooplankters (Copepoda, Appendicularia) off Buenos Aires Province (34ºS-41ºS), Argentine Sea, using two plankton mesh sizes

2009 ◽  
Vol 57 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Rosana Di Mauro ◽  
Fabiana Capitanio ◽  
María Delia Viñas
Keyword(s):  
Buenos Aires ◽  
Developmental Stages ◽  
Fish Larvae ◽  
Abundant Species ◽  
Accurate Estimation ◽  
Buenos Aires Province ◽  
Oikopleura Dioica ◽  
Great Loss ◽  
Argentine Sea ◽  
Significant Difference

Two plankton mesh sizes of 67 µm and 220 µm were compared to evaluate their efficiency in the capture of the smallest copepods and appendicularians present in the Buenos Aires coastal area (Argentine Sea). A total of 12 copepod species and one appendicularian species were recorded in this study. The copepods were separated into 4 groups: harpacticoids, cyclopoids, small calanoids and large calanoids and their developmental stages. Among the cyclopoids, Oithona nana was the most abundant species, being 96.29 % underestimated by the 220 µm mesh, whereas Microsetella norvegica dominated the harpacticoids and was captured exclusively by the smaller mesh. Similar results were found for copepodites I-III of small calanoids, whose net sampled underestimation reached 99.70%. On the other hand, no significant difference between meshes was found for adults and copepodites IV-V of small calanoids or any of the developmental stages of large calanoids. A great loss of biomass was observed for O. nana when applying the larger mesh. In regards to the appendicularian Oikopleura dioica, all size ranges below 1,000 µm length were better estimated by the 67 µm mesh in terms of abundance and biomass. Our results clearly show that the 67 µm mesh was more efficient in the capture of early stages of small copepods thus providing a more accurate estimation of the fish larvae prey field.

The incidence and distribution of the armyworms Mythimna convecta (walker) and Persectania spp. (Lepidoptera: Noctuidae) and their parasitoids in major agricultural districts of Victoria, south-eastern australia

1986 ◽  
Vol 76 (2) ◽  
pp. 199-210 ◽  
Author(s):  
G. McDonald ◽  
A. M. Smith
Keyword(s):  
Light Trapping ◽  
Light Trap ◽  
Field Studies ◽  
Abundant Species ◽  
Crop Damage ◽  
Eastern Australia ◽  
Two Generations ◽  
Regular Sampling ◽  
Trap Catches ◽  
Lepidoptera Noctuidae

AbstractField studies of Mythimna convecta (Walker), Persectania ewingii (Westwood) and P. dyscrita Common, and their associated parasitoids, were conducted in cereals and pastures in Victoria, Australia, in 1980–83. The study included a survey of the armyworm fauna in the major agricultural districts, detailed phenological studies within five oat crops, and ultraviolet-light trapping of adults. M. convecta was the most abundant species in cereals and was found more commonly in the warmer months of spring and summer in all districts. Larval development in oat crops during spring was preceded by little moth activity in light traps. P. ewingii was common in the southern districts and in the cooler months from May to September. It was the most prevalent armyworm species in pastures and rarely occurred in barley. P. dyscrita was the least abundant species and occurred mostly in the drier inland areas, particularly in the west. Light-trap catches of P. ewingii and P. dyscrita suggested there were two generations, one in spring and one in the autumn. Regular sampling in oat crops showed that M. convecta developed faster and was usually more abundant than P. ewingii during seed development and ripening, and hence had the potential to inflict more crop damage. Of the 17 species of parasitoids reared from field-collected larvae, the wasp Campoletis sp. was the most abundant. In 1980–82, average parasitism ranged from 13 to 16% but fell to 2% after the drought of 1982.

scholarly journals A uterus-inspired 3D niche drives embryo development beyond implantation

2020 ◽  
Author(s):  
Zhen Gu ◽  
Jia Guo ◽  
Jinglei Zhai ◽  
Guihai Feng ◽  
Xianning Wang ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Developmental Process ◽  
High Rate ◽  
Mammalian Embryo ◽  
Uterine Endometrium ◽  
Experimental Systems ◽  
In Vitro Systems ◽  
Development In Vitro

Abstract The mammalian embryo must undergo dramatic morphogenetic changes to invade the uterine endometrium and achieve implantation. Thus, recapitulation of implantation using in vitro systems is crucial for revealing the mechanisms controlling early development and the main problems compromising human fertility. Experimental systems based on two-dimensional (2D) platforms cannot fully recapitulate the in vivo 3D microenvironments of the embryo. Therefore, here we use collagen grafted onto polydimethylsiloxane (PDMS) based on the uterine mechanics and microstructure to establish a uterus-inspired 3D niche (U3N). Our U3N enables mouse embryos to form egg cylinders at high rate and reach the developmental stages of heartbeat. Moreover, a unique interface forms between the embryo and collagen, showing the invasion of trophoblasts into collagen fires, which simulate the developmental process of implantation. Our findings highlight embryo-substrate interaction as a key characteristic of post-implantation development in vitro and as an important design parameter of 3D conditions for embryo culture.

Molecular characterization and incidence of new tospovirus: Soybean Vein Necrosis Virus (SVNV) in Egypt

2024 ◽  
Vol 84 ◽  
Author(s):  
A. S. Abd El-Wahab
Keyword(s):  
Plant Species ◽  
Abundant Species ◽  
High Rate ◽  
Survey Study ◽  
Mechanical Transmission ◽  
Necrosis Virus ◽  
Thrips Species ◽  
Vein Necrosis ◽  
Soybean Plants ◽  
Natural Incidence

Abstract Field survey study was conducted season (2017). Soybeans and weeds were weekly sampled randomly. Thrips adults were identified and counted. Detection of the virus isolate and the natural incidence was determined using; Mechanical transmission, host range, DAS-ELISA, RT-PCR. The natural incidence thrips individuals was detected depending on the SVNV% in thrips individuals and weeds hosts. Ten thrips species were associated with soybean plants in the field. The most abundant species was T. tabaci, average 256.5 average no.of individuals, followed by F. occidentalis (142.5 average no. of individuals), then N. variabilis (86.6/ average no. of individuals). Fourteen thrips species occurred on 5 legumes field crops and 41 weed plant species within soybean field. The highest average number 40.6.of individuals were recorded on Ammi majus. While the lowest one 3.3 average no. of individuals were on Urtica urens. Only 21diagnostic plant species were susceptible to infection with SVNV. G. max and Vigna radiate, were the highest percentage of infection 80% followed by V. unguilata & N. benthamiana, 75%. Egyptian isolate of Soybean vein necrosis virus (SVNV) in this study showed a high degree of similarity and it is closely related to TSWV from Egypt (DQ479968) and TCSV from USA (KY820965) with nucleotide sequence identity of 78%. Four thrips species transmitted SVNV (F. fusca 4.0%, F. schultzei 4.3%, F. tritici 3.3% and N. variabilis 68.0% transmission). Both C. phaseoli and M. sjostedti can acquire the virus but unable to transmit it. The following species; T. tabaci, F. occidentalis, S. dorsallis and T. palmi cannot acquire or transmit SVNV. The incidence of SVNV in the field started by the end of July then increased gradualy from 12.7 to 71.3% by the end of the season. In conclusion, few thrips individuals invaded soybean crops are enough to transmit high rate of SVNV within the crop. Furthermore, several vector species are also abundant on weeds, which are the major sources of soybean viruses transmitted to the crops. This information might be important for control and reduce the incidence of SVNV infection.

The Painted Leafhopper, Endria inimica (Say), a Vector of Wheat Striate Mosaic Virus in Manitoba

1966 ◽  
Vol 98 (9) ◽  
pp. 922-931 ◽  
Author(s):  
P. H. Westdal ◽  
H. P. Richardson
Keyword(s):  
Life Cycle ◽  
North America ◽  
Mosaic Virus ◽  
Lower Limit ◽  
Virus Transmission ◽  
Low Frequency ◽  
High Rate ◽  
Life Stages ◽  
Rate Of Development ◽  
Two Generations

AbstractThe painted leafhopper, Endria inimica (Say), occurs in grasslands in southern Canada and the northern states of the U.S.A. It is the only known vector of wheat striate mosaic virus (WSMV) in North America. In Manitoba the insect is not abundant. It does not migrate into the province, and overwinters in the egg stage only. There are two generations per year, the first completing development on grasses about 1 July and the second developing mainly on cereals in summer. E. inimica has a high rate of development at 90° F.; the lower limit is near 60° F. At 80 ± 5° F. the life cycle was completed in 45.8 days. In the field, in summer, the life cycle was completed in 42 days. A description of the life stages of the insect is presented.WSMV has occurred only in trace amounts in Manitoba. Leafhoppers collected in the field showed a low frequency of virus transmission and the source of overwintered virus appeared to be small. The disease does not appear to constitute a serious problem in Manitoba.

Nutrient Removal by High Rate Pond System in a Mediterranean Climate (France)

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1535-1541 ◽  
Author(s):  
B. Picot ◽  
H. El Halouani ◽  
C. Casellas ◽  
S. Moersidik ◽  
J. Bontoux
Keyword(s):  
Mediterranean Climate ◽  
Climatic Factors ◽  
Climatic Conditions ◽  
High Rate ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Low Light ◽  
Treatment Conditions ◽  
Photosynthetic Assimilation ◽  
P Removal

The objective of the present study vas to ascertain the mechanisms involved in nitrogen and phosphorus removal from wastewater and to determine the most effective treatment conditions for removing these nutrients by high rate ponding in a Mediterranean climate. Tests carried out in Mèze (France) showed that variations of climatic factors (light and temperature), can be compensated by changes in detention times. The following strategy was adopted: the pond was operated with long detention times (8 days) in winter, which is characterized by low light intensity and low temperatures, and with short detention times (4 days) in summer, when the climatic conditions are more favorable. The results obtained show that the rates of HH4-N and PO4-P removal were high and stable (94 and 71%, respectively) during the study period February to September, 1988. The phenomena responsible for nutrient elimination in the high rate pond are the following: photosynthetic assimilation, volatilization of ammonia and precipitation of calcium phosphate due to the high pH obtained by intense algal photosynthetic activity. Wastewater treatment by high rate ponding appears to be an attractive technique for preventing eutrophication in receiving water.

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