scholarly journals Reproductive ecology and behavior of Thoropa miliaris (Spix, 1824) (Anura, Leptodactylidae, Telmatobiinae)

2004 ◽  
Vol 4 (2) ◽  
pp. 1-10 ◽  
Author(s):  
Ariovaldo Antonio Giaretta ◽  
Kátia Gomes Facure
Keyword(s):  
Paternal Care ◽  
Single Layer ◽  
Southeastern Brazil ◽  
Rock Surface ◽  
Limiting Factor ◽  
Egg Mass ◽  
Short Supply ◽  
Egg Masses ◽  
Valid Taxon ◽  
And Behavior

Thoropa species are distributed in southern and southeastern Brazil and have semiterrestrial tadpoles on rocky environments. Herein, we provide further data on reproduction, paternal care and tadpole cannibalism in T. miliaris. Guarding males were tested for disturbances in their egg masses. Egg masses were laid in stripes of wet rock; eggs were in a single layer and were adhered to the rock surface, roots, and to one another. The tadpoles hatched between four and six days. The egg number in two egg masses was 750 and 1190; eggs were gray and the yolk were about 1.7 mm in diameter; 2.3 mm with the jelly capsule. Aggressive interactions were observed between males. Males remained with their egg masses during the night and reacted aggressively to the experimental disturbances. Late stage tadpoles were found cannibalizing eggs. An egg mass in a recently formed wet stripe died from drought. The strips of wet rock are the only places where eggs and tadpoles can develop and represent a limiting factor for reproduction because they occur in short supply. For the females, the selection of newly formed wet strips may represent a trade-off between the advantages of using places free of cannibalistic and/or competitive tadpoles and the risks of losing offspring by drought. Our results do not support Cycloramphinae as a valid taxon, indicating that the morphological and behavioral similarities between Thoropa and Cycloramphus species should be interpreted as convergence.

scholarly journals Efficacy of the parasitoid, Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) on the cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) egg masses

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Hend O. Mohamed
Keyword(s):  
Spodoptera Littoralis ◽  
Insect Pests ◽  
Single Layer ◽  
Control Agent ◽  
Physical Characteristics ◽  
Great Ability ◽  
Egg Masses ◽  
Cotton Leafworm ◽  
Lepidoptera Noctuidae ◽  
Trichogrammatoidea Bactrae

Abstract Background The Egyptian cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) is one of the major insect pests, causing a significant damage on different cultivated agricultural crops. Developing an alternative non-chemical tool, an effective and environmentally friendly method to suppress pest's infestation is essentially needed. Therefore, biological control by releasing the egg parasitoids could be the most promising tool for integrated pest management. Results This study was designed to evaluate the efficacy of the egg parasitoid, Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) as a bio-control agent against S. littoralis egg masses with different physical characteristics (number of egg layer and degree of scale density) in a no-choice and choice tests, under laboratory conditions. Also, the parasitoids’ fitness in terms of parasitism percentage, developmental period, adults’ emergence percentage, female offspring percentage, and longevity were investigated. The results revealed that T. bactrae wasps had a great ability to parasitize S. littoralis egg masses, but with different rates, related to their layers and scales’ thickness in both tests. The highest parasitism percentage was observed on one-layer eggs, followed by two layers. However, 3-layer eggs were the least preferable one. High numbers of adult emergencies (> 80%) were observed in all tested egg masses, except in the case of 3 layers with high scales. Furthermore, female-biased sex ratios were noticed at all examined eggs, with only the exception of high-scaly eggs with a single layer that recorded the lowest rate (≤ 45%). Besides, the survival of adult female parasitoids was not significantly affected in both tests. Conclusions T. bactrae could be used as a bio-control agent against S. littoralis egg masses with different physical characteristics based on the achieved results.

scholarly journals New terpenoid metabolites from the skin extracts, an egg mass, and dietary sponges of the Northeastern Pacific dorid nudibranch Cadlinaluteomarginata

1997 ◽  
Vol 75 (6) ◽  
pp. 773-789 ◽  
Author(s):  
Eric J. Dumdei ◽  
Julia Kubanek ◽  
John E. Coleman ◽  
Jana Pika ◽  
Raymond J. Andersen ◽  
...  
Keyword(s):  
Structure Elucidation ◽  
Egg Mass ◽  
The Novel ◽  
Egg Masses ◽  
Northeastern Pacific ◽  
First Time

Chemical investigations of Cadlinaluteomarginata skin extracts, egg masses, and dietary sponges have led to the identification of the novel terpenoids cadlinaldehyde (30), spongian 32, seco-spongian 35, 20-acetoxy-12-marginatone (38), and lutenolide (39) from the nudibranch skin extracts, the new drimane sesquiterpenoid 1α,2α-diacetoxyalbicanyl acetate (40) from the nudibranch's egg mass, and the new sesquiterpenoids O-methyl-9-oxofurodysininlactone (47), 2-oxomicro-cionin-2-lactone (48), and O-methyl-2-oxomicrocionin-2-lactone (49), from the dietary sponge Pleraplysilla sp. The known terpenoids furodysinin (1), furodysin (16), marginatafuran (21), and 9,11-dihydrogracillin A (37), which have been frequently isolated from C. luteomarginata skin extracts, were found for the first time in extracts of the dietary sponges Pleraplysilla sp. and Aplysilla sp. One of the new terpenoids, cadlinaldehyde (30), has an unprecedented degraded sesterterpenoid skeleton. Keywords: nudibranch, sponge, terpenoids, structure elucidation.

GROUND RELEASES OF TRICHOGRAMMA MINUTUM RILEY (HYMENOPTERA: TRICHOGRAMMATIDAE) AGAINST THE SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE)

1987 ◽  
Vol 119 (3) ◽  
pp. 251-263 ◽  
Author(s):  
S.M. Smith ◽  
M. Hubbes ◽  
J.R. Carrow
Keyword(s):  
Optimal Strategy ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Egg Mass ◽  
Northern Ontario ◽  
Inundative Release ◽  
Egg Masses ◽  
Trichogramma Minutum ◽  
Spruce Stands ◽  
Natural Parasitism

AbstractDuring 1982 and 1984, ground releases of Trichogramma minutum Riley were assessed for control of the spruce budworm, Choristoneura fumiferana (Clemens), on 12- to 20-year-old, white spruce stands in northern Ontario. Maximum parasitism of susceptible egg masses was 16 and 87% following the release of 480 000 and 12 million female T. minutum per hectare, respectively. Releases at intervals of 1 week maintained parasitism of susceptible egg masses at constant levels throughout the oviposition period of spruce budworm. When parasitism of susceptible egg masses was maintained above 78.2% during the ovipositional period, total egg mass parasitism averaged 58.0% and resulted in an 80.3% reduction of overwintering 2nd-instar larvae. The optimal strategy for reducing spruce budworm was two releases of T. minutum at an interval of 1 week in the ovipositional period. This allowed a second generation of parasitoids to emerge from the spruce budworm eggs that were more efficient in maintaining high levels of parasitism than those emerging from the standard rearing host. Natural parasitism of spruce budworm egg masses was less than 4% and there was no carryover of parasitism in the years following inundative release. The rate of T. minutum release necessary to achieve effective mortality of spruce budworm during outbreak populations is discussed briefly.

Sexual reproduction and larval development of Rhaphidrilus nemasoma Monticelli, 1910 (Polychaeta: Ctenodrilidae)

1989 ◽  
Vol 67 (10) ◽  
pp. 2345-2351 ◽  
Author(s):  
Pei-Yuan Qian ◽  
Fu-Shiang Chia
Keyword(s):  
British Columbia ◽  
Sexual Reproduction ◽  
Larval Development ◽  
Intertidal Zone ◽  
Vancouver Island ◽  
Benthic Diatoms ◽  
Egg Mass ◽  
High Fecundity ◽  
Egg Masses ◽  
Trochophore Stage

Adult specimens and egg masses of Rhaphidrilus nemasoma were collected in the low intertidal zone from Execution Rock, Bamfield, Vancouver Island, British Columbia, in June of 1986. Each egg mass contained about 1000 eggs. The eggs were green, spherical, and measured 125–145 μm in diameter. Larval development took place within the egg mass until the three-or four-setiger stage, at which time they emerged from the egg mass. Newly emerged larvae crawled on the bottom of the culture beakers and fed on benthic diatoms. Metamorphosis took place soon after emergence and was completed within 2 weeks. Paddle cilia were observed at the early trochophore stage, and their possible function, and the extremely high fecundity of this polychaete, are discussed.

scholarly journals Intertidal life: field observations on the clingfish Gobiesox barbatulus in southeastern Brazil

2011 ◽  
Vol 9 (1) ◽  
pp. 233-240 ◽  
Author(s):  
Tiago H. S Pires ◽  
Fernando Z Gibran
Keyword(s):  
Developmental Stages ◽  
Feeding Activity ◽  
Single Layer ◽  
Egg Laying ◽  
Reproductive Season ◽  
Feeding Habit ◽  
Southeastern Brazil ◽  
Field Observations ◽  
Nocturnal Feeding ◽  
Particulate Feeding

The clingfish Gobiesox barbatulus shows nocturnal feeding activity, spending most part of the day stationary and adhered to the inferior part of stones. To feed, this species uses the sit-and-wait and particulate feeding tactics. It shows a carnivorous feeding habit mostly consuming small benthic crustaceans. It can move in two ways: (1) "stone-by-stone", sliding its ventral sucker disc across each stone and (2) "surf", when it takes advantage of the energy of the ebbing tide to quickly cross a distance up to four times its body length. Its reproductive season occurs between the end of spring and the beginning of summer, during which time it lays about 2,000 adhesive eggs of 1 mm each in a single layer under stones. It has more than one egg-laying session per reproductive season, therefore showing several different developmental stages. It performs fanning, mouthing and guarding of the eggs as forms of parental care. Data shown here also indicates that G. barbatulus has some shelter fidelity, being probably territorial.

scholarly journals Implementing Mass Rearing of Trissolcus japonicus (Hymenoptera: Scelionidae) on Cold-Stored Host Eggs

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 840
Author(s):  
Barbara Bittau ◽  
Maria Luisa Dindo ◽  
Giovanni Burgio ◽  
Giuseppino Sabbatini-Peverieri ◽  
Kim Alan Hoelmer ◽  
...  
Keyword(s):  
Mass Rearing ◽  
Classical Biological Control ◽  
Egg Parasitoid ◽  
Egg Mass ◽  
Severe Damage ◽  
Progeny Production ◽  
Asian Origin ◽  
Egg Masses ◽  
Trissolcus Japonicus ◽  
Promising Solution

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), a pest of Asian origin, has been causing severe damage to Italian agriculture. The application of classical biological control by the release of Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), an exotic egg parasitoid, appears to be one promising solution. In Italy, releases of T. japonicus in the field were authorized in 2020. In this study, some parameters that could influence the rearing of T. japonicus in insectaries were investigated. A significantly higher production of progeny was observed on host eggs stored at 6 °C (86.5%) compared to −24 °C (48.8%) for up to two months prior to exposure to parasitism. There were no significant differences in progeny production from single females in a vial provided with only one egg mass (83.2%) or 10 females inside a cage with 6 egg masses (83.9%). The exposure of parasitoids to refrigerated (6 °C) egg masses of H. halys for 72 h led to a significantly higher production of progeny (62.1%) compared to shorter exposures for 48 (44.0%) or 24 h (37.1%). A decline in production of progeny by the same female was detected between the first (62.1%) and the second parasitization (41.3%). Adult parasitoids stored at 16 °C for up to 90 days had an 87.1% survival rate, but a significant decrease in progeny production was detected. These parameters could be adjusted when rearing T. japonicus for specific aims such as the production of individuals for field release or colony maintenance.

Microflora of Meloidogyne egg masses: species composition, population density and effect on the biocontrol agent Verticillium chlamydosporium (Goddard)

Nematology ◽  
2001 ◽  
Vol 3 (8) ◽  
pp. 729-734 ◽  
Author(s):  
C.J.(Hans) Kok ◽  
Artemis Papert ◽  
C.B.(Chula) Bok-A-Bin
Keyword(s):  
Bacterial Population ◽  
Biocontrol Agent ◽  
Bacterial Species ◽  
Antagonistic Activity ◽  
Parasitic Fungus ◽  
Egg Mass ◽  
Egg Masses ◽  
Soil Suppressiveness ◽  
Verticillium Chlamydosporium

AbstractEgg masses of Meloidogyne fallax from tomato and potato growing in soil from a nematode suppressive and a nonsuppressive field sustained bacterial population densities two to three orders of magnitude higher than those of the rhizosphere soil. BIOLOG metabolic profiling identified 16 bacterial species from egg masses. Results further indicated 20 species not listed in the BIOLOG database. 122 isolates of bacteria and 19 isolates of fungi from M. fallax or M. hapla were tested for in vitro antagonism against the nematode egg parasitic fungus Verticillium chlamydosporium: 23% of the bacteria and 74% of the fungi showed antagonistic activity. Pseudomonads showed an overall stronger antagonistic activity than the other bacteria. Our conclusions are that Meloidogyne egg masses are a densely populated microbial niche and that their microflora may well be an important factor in determining the success of nematode antagonists. However, we could not find a relationship between the egg mass microflora and differences in soil suppressiveness between the sample sites.

Energy metabolism of eggs during embryogenesis in Balanus balanoides

1987 ◽  
Vol 67 (1) ◽  
pp. 27-54 ◽  
Author(s):  
M. I. Lucas ◽  
D. J. Crisp†
Keyword(s):  
Oxygen Uptake ◽  
Neutral Lipid ◽  
Egg Mass ◽  
Diffusion Resistance ◽  
Energy Reserves ◽  
Egg Volume ◽  
Insoluble Protein ◽  
Egg Masses ◽  
Balanus Balanoides ◽  
Fertilized Egg

The partitioning and utilization of energy reserves during embryogenesis were followed in the cirripede Balanus balanoides and related to the described sequence of developmental stages. Egg volume and dry weights were measured. Between the recently fertilized egg and eggs containing well-developed embryos at the end of natural incubation there is a doubling of egg volume.The biochemical composition of the newly fertilized egg is dominated by TCA-insoluble protein (55 %). Neutral lipid accounts for 17 % of the dry weight, while phospholipid and polysaccharide contribute 3–5% and 5–7% respectively. About 36% of the TCA-insoluble protein is utilized during in vivo development, accounting for about three-quarters of the energy expenditure. During this time 40% of the carbohydrate and 20% of the neutral lipid reserves are also utilised. However, when starved adults retain their mature egg masses beyond the normal term, egg metabolism occurs largely at the expense of the remaining lipid reserves. These would be exhausted in a further 6–7 weeks and the embryos unable to survive. The ability of adults to postpone hatching may therefore have important implications for the energy reserves and viability of the newly hatched nauplii. Protein supplies most of the energy during embryogenesis, with neutral lipid assuming increased importance after development has been completed.Oxygen consumption of the egg masses measured in vitro was converted through aerobic oxycalorific equivalent into biochemical loss. This showed good agreement with direct measurement of summed energy losses of the biochemical components. It was apparent that oxygen uptake rate in the later stages was restricted by diffusion resistance due to egg packing, since eggs freed from the egg mass matrix showed a 30% increase in oxygen uptake and a reduction in development time.

scholarly journals Schooling behavior of Mugil curema (Perciformes: Mugilidae) in an estuary in southeastern Brazil

2007 ◽  
Vol 5 (1) ◽  
pp. 81-83 ◽  
Author(s):  
Carolina Delgado de Carvalho ◽  
Carolina Marocco Corneta ◽  
Virginia Sanches Uieda
Keyword(s):  
Food Intake ◽  
Southeastern Brazil ◽  
School Structure ◽  
Small Fish ◽  
Slow Movement ◽  
Marine Waters ◽  
Shallow Marine ◽  
Schooling Behavior ◽  
And Behavior ◽  
Number Of Individuals

Schools of mullets, Mugilidae, are abundant in estuaries and shallow marine waters. We report on the schooling behavior of juvenile white mullet, Mugil curema, in the estuary of the Canto da Paciência stream, in Ubatuba, southeastern Brazil. Schools of small fish (15 to 35 mm TL) were composed of a larger number of individuals (up to a hundred individuals), and were found feeding mainly in shallow nearshore waters, whereas schools of larger fish (40 to 100 mm TL) were observed only in deeper waters. Three patterns of swimming were observed for the schools: stationary feeding, slow movement while searching for food, and rapid displacement. The variations observed in school structure and behavior seem to be related to the balance between predation risk and increasing food intake.

scholarly journals Effect of Aerogel Particle Concentration on Mechanical Behavior of Impregnated RTV 655 Compound Material for Aerospace Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Firouzeh Sabri ◽  
Jeffrey G. Marchetta ◽  
K. M. Rifat Faysal ◽  
Andrew Brock ◽  
Esra Roan
Keyword(s):  
Mechanical Behavior ◽  
Room Temperature ◽  
Particle Concentration ◽  
Tensile Tests ◽  
Limiting Factor ◽  
Thermal And Mechanical Properties ◽  
Aerospace Applications ◽  
Elastomeric Matrix ◽  
Compound Material ◽  
And Behavior

Aerogels are a unique class of materials with superior thermal and mechanical properties particularly suitable for insulating and cryogenic storage applications. It is possible to overcome geometrical restrictions imposed by the rigidity of monolithic polyurea cross-linked silica aerogels by encapsulating micrometer-sized particles in a chemically resistant thermally insulating elastomeric “sleeve.” The ultimate limiting factor for the compound material’s performance is the effect of aerogel particles on the mechanical behavior of the compound material which needs to be fully characterized. The effect of size and concentration of aerogel microparticles on the tensile behavior of aerogel impregnated RTV655 samples was explored both at room temperature and at 77 K. Aerogel microparticles were created using a step-pulse pulverizing technique resulting in particle diameters between 425 μm and 90 μm and subsequently embedded in an RTV 655 elastomeric matrix. Aerogel particle concentrations of 25, 50, and 75 wt% were subjected to tensile tests and behavior of the compound material was investigated. Room temperature and cryogenic temperature studies revealed a compound material with rupture load values dependent on (1) microparticle size and (2) microparticle concentration. Results presented show how the stress elongation behavior depends on each parameter.

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