Egg Hatching and Survival of Immature Stages ofAedes aegypti(Diptera: Culicidae) Under Natural Temperature Conditions During the Cold Season in Buenos Aires, Argentina

2016 ◽  
Vol 54 (1) ◽  
pp. 106-113 ◽  
Author(s):  
María Sol De Majo ◽  
Pedro Montini ◽  
Sylvia Fischer
Keyword(s):  
Buenos Aires ◽  
Cold Season ◽  
Immature Stages ◽  
Egg Hatching ◽  
Temperature Conditions ◽  
Natural Temperature

Effect of Temperature on the Predator, (Reuter) (Hemiptera: Anthocordiae) Feeding on Cryptolestes pusillus (Schon.) (Coleoptera: Cucujidae)

1970 ◽  
Vol 15 ◽  
pp. 41-46 ◽  
Author(s):  
MM Rahman ◽  
W Islam ◽  
KN Ahmed
Keyword(s):  
Life History ◽  
Insect Pest ◽  
Developmental Time ◽  
Effect Of Temperature ◽  
Hatching Rate ◽  
Immature Stages ◽  
Egg Hatching ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Cryptolestes Pusillus

Xylocoris flavipes (Reuter) is one of the dominant predators of many stored product insect pest including Cryptolestes pusillus. The influence of temperature on predator development, survival and some selected life history parameters was determined. Eggs laid/female (27.27±2.52) and egg hatching rate (%) (88.25±2.19) were highest at 30°C and lowest at 20°C (5.43±1.19 and 30.79±4.63%) respectively but no eggs laid at 15°C. Mortality among immature stages (%) was highest (51.71±1.48) at 35°C and lowest (24.25c±1.14) at 25°C. Developmental times decreasing with the increasing of temperature. Maximum numbers of progeny/female/day (3.55±0.76) were produced at 25°C and minimum (0.83±0.04) were at 20°C.The sex ratios (% female) of X. flavipes were 47.04, 56.68, 51.66 and 50.07 for 20, 25, 30 and 35°C respectively. Survivorship of ovipositing females was highest at 25°C but lowest at 35°C respectively. Key words: Xylocoris flavipes, Cryptolestes pusillus, life history, temperature, developmental time   doi: 10.3329/jbs.v15i0.2201 J. bio-sci. 15: 41-46, 2007

scholarly journals Spatio-temporal variation of predatory hoverflies (Diptera: Syrphidae) and their relationship with aphids in organic horticultural crops in La Plata, Buenos Aires

2020 ◽  
Vol 79 (4) ◽  
pp. 15-22
Author(s):  
María F. Diaz Lucas ◽  
Lilián M. Passareli ◽  
Noelia Maza ◽  
Daniel A. Aquino ◽  
Nancy M. Greco ◽  
...  
Keyword(s):  
Buenos Aires ◽  
Wild Plants ◽  
Immature Stages ◽  
Matricaria Chamomilla ◽  
Horticultural Crops ◽  
Direct Observations ◽  
Parasitism Rates ◽  
Diplazon Laetatorius ◽  
Wild Vegetation ◽  
Spatio Temporal

Population variations of predatory hoverflies in agroecosystems depend mainly on the resources that crops and wild vegetation provides them as well as death caused by natural enemies. We identified I) aphidophagous hoverfly species in lettuce and broccoli crops in Buenos Aires, II) the seasonal variations of the immature stages and their larval parasitism, and III) the wild plants, surrounding the crops, visited by adults. Fortnightly, 30 leaves were randomly selected in both crops during 2018-2019 and immature stages of syrphids and aphids per leaf were recorded. Adults were manually collected in patches of the wild plants (during 10 min of direct observations), and plants visited by adults were determined. The hoverflies were Allograpta exotica Wiedemann and Toxomerus duplicatus Wiedemann. Only A. exotica was recorded in crops. The dominant aphids were Myzus persicae (Sulzer) in lettuce and Brevycorine brassicae (L.) in broccoli. Parasitism rates ranged between 8 and 100% and the species were Diplazon laetatorius (Fabricius), in both crops, and Pachyneuron aff. nelsoni only in broccoli. Galinsoga parviflora Cav. and Matricaria chamomilla L. were the wild plants most often visited by hoverflies. This work provides basic information for the control of aphids by hoverflies in the framework of conservation biological control

Effects of Constant and Fluctuating Low Temperatures on the Development of Aedes aegypti (Diptera: Culicidae) from a Temperate Region

2019 ◽  
Vol 56 (6) ◽  
pp. 1661-1668 ◽  
Author(s):  
María Sol De Majo ◽  
Gabriela Zanotti ◽  
Raúl E Campos ◽  
Sylvia Fischer
Keyword(s):  
Aedes Aegypti ◽  
Low Temperatures ◽  
Buenos Aires ◽  
High Survival ◽  
Immature Stages ◽  
Temperate Region ◽  
Development Times ◽  
Average Survival ◽  
Geographical Regions ◽  
Aegypti Population

Abstract Most studies of the effects of low temperature on the development of immature stages of Aedes aegypti (L.) have been performed at constant temperatures in the laboratory, which may not accurately reflect the variable environmental conditions in the field. Thus, the aim of this study was to assess the effect of constant temperatures (CT) and fluctuating low temperatures (FT) on the fitness of Ae. aegypti of Buenos Aires, Argentina. Three CT treatments (12, 14, and 16°C) and three FT treatments (12, 14, and 16°C ± 4°C) were performed and then survival, development time, and size of adults analyzed for each treatment. The immature stages completed development in all the treatments, with an average survival of 88% at 16°C, 85% at 14°C, and 22% at 12°C, and showed no differences between the CT and FT treatments. Development times were similar between the CT and FT treatments at 16°C (average ± SD: 22.7 ± 2.0 d) and at 14°C (average ± SD: 30.5 ± 2.5 d), whereas at 12°C, they lasted longer under CT (average ± SD: 46.6 ± 5.1 d) than under FT (average ± SD: 37 ± 6.5 d). The sizes of the adults at 12 and 14°C were similar but larger than those at 16°C, and showed no differences between the CT and FT treatments. Compared to populations of other geographical regions assessed in previous studies, the shorter development times and the high survival at 14 and 16°C, and the ability to complete development at 12°C, a fact not previously reported, suggest that the Ae. aegypti population of Buenos Aires city has a higher tolerance to these conditions.

scholarly journals Cold season mortality and hatching behavior of Aedes aegypti L. (Diptera: Culicidae) eggs in Buenos Aires City, Argentina

2011 ◽  
Vol 36 (1) ◽  
pp. 94-99 ◽  
Author(s):  
Sylvia Fischer ◽  
Iris Soledad Alem ◽  
María Sol De Majo ◽  
Raúl Ernesto Campos ◽  
Nicolás Schweigmann
Keyword(s):  
Aedes Aegypti ◽  
Buenos Aires ◽  
Cold Season ◽  
Buenos Aires City

Description of a new Corythucha Stål from Argentina (Hemiptera: Heteroptera: Tingidae), with a description of its life cycle

Zootaxa ◽  
2009 ◽  
Vol 2170 (1) ◽  
pp. 61-68 ◽  
Author(s):  
SARA I. MONTEMAYOR
Keyword(s):  
Life History ◽  
New Species ◽  
Quercus Robur ◽  
Buenos Aires ◽  
The Other ◽  
South American ◽  
Immature Stages ◽  
South American Species ◽  
History Of ◽  
A New Species

A new species of the genus Corythucha, C. bonaerensis n. sp., is described along with its egg and all immature stages. It was found in the province of Buenos Aires (Argentina) feeding on Quercus robur, its host plant. Comments on the life history of C. bonaerensis are provided together with photographs, and illustrations. The main differences with the other South American species, and other Corythucha species that feed on Quercus worldwide, are also discussed.

Differential inhibition of egg hatching in Aedes aegypti populations from localities with different winter conditions

2020 ◽  
pp. 1-8
Author(s):  
Raúl E. Campos ◽  
Gabriela Zanotti ◽  
Cristian M. Di Battista ◽  
Javier O. Gimenez ◽  
Sylvia Fischer
Keyword(s):  
Aedes Aegypti ◽  
Low Temperatures ◽  
Buenos Aires ◽  
Geographical Origin ◽  
Larval Mortality ◽  
Acclimation Temperature ◽  
Subtropical Region ◽  
Egg Hatching ◽  
Winter Conditions ◽  
Winter Temperatures

Abstract In Argentina, the mosquito Aedes aegypti (L.) (Diptera: Culicidae) is distributed from subtropical to temperate climates. Here, we hypothesized that the expansion of Ae. aegypti into colder regions is favoured by high-phenotypic plasticity and an adaptive inhibition of egg hatching at low temperatures. Thus, we investigated the hatching response of eggs of three populations: one from a subtropical region (Resistencia) and two from temperate regions (Buenos Aires City and San Bernardo) of Argentina. Eggs collected in the field were raised in three experimental colonies. F1 eggs were acclimated for 7 days prior to immersion at 7.6 or 22°C (control eggs). Five immersion temperatures were tested: 7.6, 10.3, 11.8, 14.1 and 16°C (range of mean winter temperatures of the three localities). A second immersion at 22°C was performed 2 weeks later to assess the inhibition to hatch under favourable conditions. After the first immersion, we compared the proportions of hatched eggs and dead larvae among treatment levels, whereas after the second immersion we compared the hatching response among the three populations. The factors that most influenced the egg hatching response were the geographical origin of the populations and the immersion temperature, but not the acclimation temperature. The proportions of hatching and larval mortality at low temperatures were higher for Resistencia than for Buenos Aires and San Bernardo, whereas the hatching response at ambient temperature was lower for San Bernardo than for Buenos Aires and Resistencia. The results support the hypothesis that populations from colder regions show an adaptive inhibition of egg hatching.

Association between an ectoparasitic copepod (Caligus sp.) and the monogenean Udonella cf. caligorum Johnston 1835 on a catfish population

2017 ◽  
Vol 92 (2) ◽  
pp. 250-253
Author(s):  
D. Fogel ◽  
J.L. Fuentes ◽  
L.M. Soto ◽  
C. López
Keyword(s):  
Coastal Lagoon ◽  
Environmental Conditions ◽  
Time Scale ◽  
Hatching Success ◽  
Wild Population ◽  
Immature Stages ◽  
Egg Hatching ◽  
Egg Capsules ◽  
Genital Complex ◽  
North Eastern

AbstractWe analysed the association between a monogenean (Udonella cf. caligorum Johnston 1835) and its copepod host (Caligus sp.) living on a wild population of Arius herzbergii Bloch, 1794 in a north-eastern coastal lagoon from Venezuela. This study characterized infestation levels and analysed the effects of monogeneans on the fecundity and hatching success of the copepod host, as well as damage to its egg capsules and genital complex. A total of 218 Caligus specimens were analysed (94 males, 110 females and 14 immature stages) in which a total of 1017 monogeneans were found. These included 311 mature stages and 706 egg capsules. Monogenean stages were found attached to the cephalothorax, abdomen, genital complex and egg capsules of the copepods. No significant differences were found in fecundity and egg hatching when infested and non-infested ovigerous females were compared. No damage was observed on egg capsules or genital areas of infested ovigerous females. Our results suggest that this association, at the level of prevalence and intensity observed, is closer to commensalism than parasitism. The importance of considering that the nature of interaction is dynamic and changing with environmental conditions and time scale is highlighted.

Hatching of Heterodera filipjevi in controlled and natural temperature conditions in Turkey

Nematology ◽  
2010 ◽  
Vol 12 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Elif Sahin ◽  
Julie M. Nicol ◽  
I. Halil Elekcioglu ◽  
Roger Rivoal
Keyword(s):  
Initial Exposure ◽  
Second Stage ◽  
Temperature Conditions ◽  
Different Temperatures ◽  
Natural Temperature ◽  
Heterodera Filipjevi ◽  
Two Peaks ◽  
Hatching Rates

Abstract The effect of different temperatures under both in vitro and in vivo conditions on the hatching behaviour of second-stage juveniles (J2) of the cereal cyst nematode, Heterodera filipjevi, was studied. Cumulative percent hatching was affected significantly by temperature after 290 days of incubation. Hatching was significantly greater at lower temperatures (5, 10 and 15°C) compared with that at the higher temperatures of 20 and 25°C, ranging between 75 and 94% vs 19 and 22%, respectively. The highest cumulative hatch of 94% was obtained at a constant temperature of 15°C at 290 days. However, the lowest cumulative hatch of 33% was obtained after initial exposure to 5°C followed by transfer to 25°C at day 290. In general, incubating the cysts at lower initial temperatures of 10 or 15°C for 58 days gave the highest initial hatching rates 1 week after exposure to the final temperatures. Under natural temperature conditions in the field, J2 emergence started at 17°C in October and continued until the end of April in the temperature range of 2-17°C. A total hatch of 94% was recorded under field temperature conditions over the course of 1 year. Hatch of most J2 occurred in two peaks; the first in October and the second in February, and, accordingly, the greatest invasion by H. filipjevi is most likely to occur just after these two peaks. Heterodera filipjevi does not seem to have a diapause and could hatch anytime when wheat plants are available.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

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