Reproduction in an Introduced Population of Elaphe schrenckii (Strauch, 1873) in Eelde, the Netherlands

2020 ◽  
Vol 27 (6) ◽  
pp. 325-333
Author(s):  
Richard R. J. H. Struijk ◽  
Rémon Ter Harmsel ◽  
Daesik Park
Keyword(s):  
The Netherlands ◽  
Release Site ◽  
Mean Value ◽  
Limiting Factor ◽  
Hatching Rate ◽  
Egg Hatching ◽  
Field Surveys ◽  
Initial Release ◽  
Continuous Presence ◽  
Oviposition Sites

In 1994 an unknown number of captive bred Russian rat snakes, Elaphe schrenckii (Strauch, 1873) were introduced near Groningen Airport Eelde (Drenthe Province), the Netherlands. Research in 2016/2017 confirmed that the species has become established and is expanding slowly, as recent sightings are known at distances up to 5.3 km from the initial release site. Although the continuous presence over two decades and sightings of different life stages of E. schrenckii specimens indicate successful reproduction, no reproductive data existed. To gain more insight, we conducted field surveys between 2014 and 2016 to collect data on oviposition sites and reproduction. Eggs of E. schrenckii were encountered in three compost heaps. Twenty-two clutches were found in these heaps in total, comprising a total of 332 eggs. Additionally, 42 loose eggs were found, totaling the number of retrieved eggs to 374. Minimum clutch sizes range from 10 – 21 eggs and average 15.1 ± 3.2 eggs (N = 22). Total individual egg hatching rate is 87.8% (N = 271). Clutch hatching rate varied between 46.2% and 100% with a mean value of 86.7 ± 18.8% (N = 16). Our findings indicate the importance of compost heaps for this species regarding reproduction as suitable sites for oviposition within this non-native range. Also, fecundity does not seem to be negatively affected by conditions in its invasive range; clutch size is on the high side. Because hatching rates can be high, its reproduction does not seem to be a limiting factor for further expansion within Eelde and surroundings.

scholarly journals The predatory bug Orius strigicollis shows a preference for egg-laying sites based on plant topography

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11818
Author(s):  
Chendi Yu ◽  
Jun Huang ◽  
Xiaoyun Ren ◽  
G Mandela Fernández-Grandon ◽  
Xiaowei Li ◽  
...  
Keyword(s):  
Insect Pests ◽  
Southern China ◽  
Oviposition Behavior ◽  
Egg Laying ◽  
Oviposition Site ◽  
Hatching Rate ◽  
Egg Hatching ◽  
Wide Range ◽  
Orius Strigicollis ◽  
Oviposition Sites

Background Oviposition site selection is an important factor in determining the success of insect populations. Orius spp. are widely used in the biological control of a wide range of soft-bodied insect pests such as thrips, aphids, and mites. Orius strigicollis (Heteroptera: Anthocoridae) is the dominant Orius species in southern China; however, what factor drives its selection of an oviposition site after mating currently remains unknown. Methods Here, kidney bean pods (KBPs) were chosen as the oviposition substrate, and choice and nonchoice experiments were conducted to determine the preferences concerning oviposition sites on the KBPs of O. strigicollis. The mechanism of oviposition behavior was revealed through observation and measurement of oviposition action, the egg hatching rate, and the oviposition time. Results We found that O. strigicollis preferred the seams of the pods for oviposition, especially the seams at the tips of the KBPs. Choice and nonchoice experiments showed that females did not lay eggs when the KBP tail parts were unavailable. The rates of egg hatching on different KBP parts were not significantly different, but the time required for females to lay eggs on the tip seam was significantly lower. Decreased oviposition time is achieved on the tip seam because the insect can exploit support points found there and gain leverage for insertion of the ovipositor. Discussion The preferences for oviposition sites of O. strigicollis are significantly influenced by the topography of the KBP surface. Revealing such behavior and mechanisms will provide an important scientific basis for the mass rearing of predatory bugs.

scholarly journals Toxicity and Sublethal Effect of Farnesyl Acetate on Diamondback Moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 109
Author(s):  
Norazila Yusoff ◽  
Idris Abd Ghani ◽  
Nurul Wahida Othman ◽  
Wan Mohd Aizat ◽  
Maizom Hassan
Keyword(s):  
Plutella Xylostella ◽  
Sublethal Effects ◽  
Diamondback Moth ◽  
Sublethal Effect ◽  
Sublethal Concentration ◽  
Pupal Weight ◽  
Control Group ◽  
Hatching Rate ◽  
Egg Hatching ◽  
Female Ratio

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is the most important pest of cruciferous vegetables worldwide. In this study, we evaluated the properties of selected farnesyl derivative compounds against P. xylostella. The toxicity and sublethal concentration (LC50) of farnesyl acetate, farnesyl acetone, farnesyl bromide, farnesyl chloride, and hexahydrofarnesyl acetone were investigated for 96 h. The leaf-dip bioassays showed that farnesyl acetate had a high level of toxicity against P. xylostella compared to other tested farnesyl derivatives. The LC50 value was 56.41 mg/L on the second-instar larvae of P. xylostella. Then, the sublethal effects of farnesyl acetate on biological parameters of P. xylostella were assessed. Compared to the control group, the sublethal concentration of farnesyl acetate decreased pupation and emergence rates, pupal weight, fecundity, egg hatching rate, female ratio, and oviposition period. Furthermore, the developmental time of P. xylostella was extended after being exposed to farnesyl acetate. Moreover, the application of farnesyl acetate on P. xylostella induced morphogenetic abnormalities in larval–pupal intermediates, adults that emerged with twisted wings, or complete adults that could not emerge from the cocoon. These results suggested that farnesyl acetate was highly effective against P. xylostella. The sublethal concentration of farnesyl acetate could reduce the population of P. xylostella by increasing abnormal pupal and adults, and by delaying its development period.

scholarly journals APPLICATION OF THE BENFORD LAW IN ASSESSMENT OF WILDFIRE DATA ACCURACY

2018 ◽  
Vol 8 (1) ◽  
pp. 30-36
Author(s):  
Роман Котельников ◽  
Roman Kotelnikov ◽  
Алескандр Мартынюк ◽  
Aleskandr Martynyuk
Keyword(s):  
Key Management ◽  
Mean Value ◽  
Data Accuracy ◽  
Forest Protection ◽  
Field Surveys ◽  
Outsourced Data ◽  
The Russian Federation ◽  
Mean Time ◽  
Benford Law ◽  
Area Data

Timely availability of accurate burned out area data is a key management aspect in forest protection arrange-ments. Special operation multilevel net-work including field surveys of burned out areas has been established now to verify appropriate data accuracy. In the mean time extensive levels of information from various sources accumulated in wildfire databases enable statistical assessment of the data accuracy drastically reducing time and financial costs of verification operations. Mathematically proven that amount of numbers that specify real natural facilities may grow exponentially due to the Benford law. The paper proves applicability of the Benford law provisions in assessment of wildfire area data accuracy through analysis of first figure occurrence in numbers specifying forest covered burned out area in the Russian Federation territory in 2016 and assessed a minimum set of values needed for an adequate result. In addition the paper highlights an opportunity of variously outsourced data accuracy comparative analysis. Taking into consideration that variation of individual figure occurrence frequency in analyzed value packages may have a different sign for various figures it is offered to apply an indicator representing a mean value of appropriate figure occurrence probability variation modules. The offered procedure based on the Benford law application may be a part of a risk-targeted approach to plan control supervisory operations in forest relations.

scholarly journals Nanocomposite coatings for hatching eggs and table eggs

2021 ◽  
Vol 6 (1) ◽  
pp. 573-586
Author(s):  
Oleksandr Chekh ◽  
Olga Bordunova ◽  
Vadym Chivanov ◽  
Evgenia Yadgorova ◽  
Larisa Bondarchuk
Keyword(s):  
Pathogenic Bacteria ◽  
Protective Coatings ◽  
Storage Conditions ◽  
Hatching Rate ◽  
Green Technologies ◽  
Egg Hatching ◽  
Poultry Products ◽  
Hatching Eggs ◽  
And Storage

Abstract Theoretical and applied aspects of the concept of using biomimetic protective coatings GREEN ARTICLE (ARTIficial cutiCLE) in the poultry industry, namely in the production of table and hatching eggs, are developed. The basic matrix component of the protective coatings GREEN ARTICLE is chitosan, an environmentally friendly, inexpensive, and harmless material. It is experimentally proved that electrochemical and ultrasonic technologies for modifying a solution of chitosan in peroxide compounds (peracetic acid and hydrogen peroxide) with nanoparticles of oxides like titanium, iron, zinc, and metals, such as titanium, copper, and calcite, allow to create protective coatings of double action in accordance with the technologies: (a) extending the shelf life of table eggs, food green article (FGA) and (b) preventing contamination of hatching eggs with pathogenic microflora, increasing the hatchability of eggs, and the quality of chicken, hatching green article (HGA). In the technology of storing table eggs, artificial cuticles based on chitosan FGA are characterized by the following characteristics: increased thickness of 6–10 µm, low gas and moisture permeability, and high biocidal activity against pathogenic bacteria and viruses. It is shown that the use of FGA technology in the production of table eggs can extend the period of transportation and storage of products by 33–35 days at a temperature of 24°C and maintained a grade A (Haugh unit = 71–60) through the entire 35 days period. The technology HGA reduces the rate of contamination of hatching eggs with pathogenic microflora by 99.29–99.7%, while increasing the egg hatching rate by 2.3–11.6% compared to the control, depending on the cross of the poultry and the storage conditions of the hatching eggs. It is important that these technologies have a great prospect for application in countries that develop green technologies for the production of poultry products.

scholarly journals Daya Tetas Telur dan Sintasan Larva Dari Hasil Penambahan Madu pada Bahan Pengencer Sperma Ikan Nila (Oreochromis niloticus)

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Yunus Ayer ◽  
Joppy Mudeng ◽  
Hengky Sinjal
Keyword(s):  
Experimental Design ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Larval Survival ◽  
Hatching Rate ◽  
Dilution Ratio ◽  
Egg Hatching ◽  
Research Results ◽  
Spermatozoa Motility ◽  
Randomized Design

The objective of research was to determine the concentration of honey in sperm dilution  for improving hatching rate of egg and survival of nile tilapia larvae (Oreochromis niloticus).The number of fish used was five pairs broodstock. Dilution substance was NaCl and honey.  Observations were conducted on spermatozoa motility, fertility and egg hatching rate. Experimental design used was complete randomized design. Sperm dilution substance was prepare by disolving honey  (0 mL; 0,60 mL; 0,65 mL dan 0,70 mL) in 100 mL; 99,40 mL; 99,35 mL and  99,30 mL NaCl respectively.  Each dilution was homogenized using aerator for 15 minutes. Fertilization was done 12 hours after ovulation.  Egg hatching rate was observed after ovulation. Research results showed the use of honey had significant effet on egg hatching rate, but not on larval survival.  Treatment D (0,70 mL honey in 99,30 mL NaCl) had the highest hatching rate (77.33%). Dilution ratio 1:60 was the best indicated by spermatozoa motility 96.66%, fertility 71.65, hatching rate 70% and larval survival 81.67%   Keywords : honey, egg hatching rate, larval survival, Oroechromnis niloticus

scholarly journals In Vitro Anthelmintic Activity of Crude Extracts of Artemisia herba-alba and Punica granatum against Haemonchus contortus

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Aliyi Hassen Ahmed ◽  
Mebrat Ejo ◽  
Teka Feyera ◽  
Dereje Regassa ◽  
Bahar Mummed ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Anthelmintic Activity ◽  
Punica Granatum ◽  
Limiting Factor ◽  
Egg Hatching ◽  
Traditional Use ◽  
Egg Hatch ◽  
Inhibition Effect ◽  
Crude Extracts

Gastrointestinal nematodes (GINs) are the major limiting factor for the successfulness of livestock production throughout the world. Emergence of resistance strains as well as scarcity and high cost of the currently available drugs has led to the evaluation of other alternative helminth control options, mainly from plants. The current study is aimed at investigating the in vitro anthelmintic efficacy of crude methanolic extracts of two traditionally important medicinal plants, Artemisia herba-alba and Punica granatum, against Haemonchus contortus using adult motility assay (AMA) and egg hatch inhibition assay (EHIA). Four graded concentrations of the extracts were tested for both the AMA (10, 5, 2.5, and 1.25 mg/mg) and EHIA (0.1, 0.25, 0.5, and 1 mg/mL) in replicates. Albendazole and phosphate-buffered saline (AMA) or distilled water (EHIA) were used as the positive and negative controls, respectively. The crude extracts of A. herba-alba and P. granatum exhibited a potential anthelmintic activity at all dose levels in a concentration- and time-dependent fashion. The highest concentration (10 mg/mL) of all the extracts caused a significantly (p<0.05) superior nematocidal activity compared to the negative control. Moreover, significant and concentration-dependent egg hatching inhibition effect was observed from both plant extracts. Maximal (98.67%) egg hatching inhibition effect was exhibited by the flower extract of A. herba-alba at 1 mg/mL concentration. The relative egg hatch inhibition efficacy indicated that both plants caused a significantly (p<0.05) greater egg hatch inhibition within 48 hr of exposure. The current study validated the traditional use of both plants as a natural anthelmintic against H. contortus justifying a need to undertake detail pharmacological and toxicological investigation on both plants.

Evidence of Migration and Homing of Lobsters (Homarus americanus) on the Scotian Shelf

1986 ◽  
Vol 43 (11) ◽  
pp. 2206-2211 ◽  
Author(s):  
D. S. Pezzack ◽  
D. R. Duggan
Keyword(s):  
Return Migration ◽  
Release Site ◽  
Homarus Americanus ◽  
Winter Period ◽  
Scotian Shelf ◽  
Long Distance ◽  
Initial Release

In the Browns Bank region of the Scotian Shelf between June 1982 and December 1983, 6285 tagged lobsters (Homarus americanus) were released. Of the 2486 lobsters recaptured, 361 were recaptured more than once. Eight lobsters released in late May to mid-July were recaptured the following spring and summer, with at least one intervening recapture in the fall–winter period. Five of the eight lobsters showed homing tendencies. Two lobsters made long-distance (> 200 km) return migrations, three made short (50–100 km) return migrations, and three moved long distances but did not return. One lobster at large 6 mo and four at large 22–34 mo made long-distance return migrations, moving over 200 km and returning to within 9–42 km of the initial release site. The data indicate that some lobsters undertake long-distance return migration, which returns the lobsters to specific sections of the Shelf.

The influence of population density on the number of eggs laid by females of Cardiaspina albitextura (Psyllidae)

1963 ◽  
Vol 11 (2) ◽  
pp. 190 ◽  
Author(s):  
LR Clark
Keyword(s):  
Egg Production ◽  
Adult Stage ◽  
Limiting Factor ◽  
Severe Damage ◽  
Population Densities ◽  
Experimental Conditions ◽  
Nymphal Development ◽  
The Mean ◽  
Peak Abundance ◽  
Oviposition Sites

Field observations and experiments suggest that crowding during the period of nymphal development does not greatly affect the mean number of eggs laid by Cardiaspina albitextura females. Under experimental conditions, crowding in the adult stage on foliage undamaged by nymphs resulted in reduction of the mean number of eggs laid, the supply of favourable food being probably the limiting factor. In association with increase in the number of adults per shoot, mean egg production declined at a progressively decreasing rate. At the highest population densities tested, the mean number of eggs laid per female was approximately one-third to one-fifth of the number laid by uncrowded females. Both at low and high population densities, the mean number of eggs laid per female on previously unoccupied foliage was about twice as high as on foliage which had been occupied previously by numerous other adults of the same psyllid generation. At times of peak abundance in areas of outbreak, the foliage damage caused during the period of nymphal development greatly limits both the quantity of favourable food and the number of oviposition sites available when C. albitextura reaches the adult stage. The experimental results suggest that the crowding of adults which occurs on the small amount of foliage that escapes very severe damage by nymphs contributes towards the observed limitation of egg production. However, the scattered distribution of such foliage and the poor dispersal powers of C. albitextura females probably play a more important part in determining the very low mean number of eggs laid per female reaching the adult stage. It appears that many females fail to find favourable foliage and consequently lay scarcely any eggs.

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 Cyclo(l-Pro–l-Leu) of Pseudomonas putida MCCC 1A00316 Isolated from Antarctic Soil: Identification and Characterization of Activity against Meloidogyne incognita

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 768 ◽  
Author(s):  
Yile Zhai ◽  
Zongze Shao ◽  
Minmin Cai ◽  
Longyu Zheng ◽  
Guangyu Li ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Pseudomonas Putida ◽  
Meloidogyne Incognita ◽  
High Performance ◽  
Larval Mortality ◽  
Control Treatment ◽  
Hatching Rate ◽  
Antarctic Soil ◽  
Egg Hatching ◽  
Flight Mass Spectrometry

Pseudomonas putida MCCC 1A00316 was originally isolated from an Antarctic soil and has demonstrated potential nematicidal activity. Thus, it has promising applications for the biological control of Meloidogyne incognita. The larval mortality and egg-hatching inhibition rates of M. incognita will increase with the rising concentration of culture filtrates of P. putida MCCC 1A00316 and the duration of exposure. Thus, this study aimed to separate, purify, and identify nematicidal compounds from P. putida MCCC 1A00316 and to validate their anti-M. incognita activities. Compounds were purified through silica gel column chromatography and thin-layer chromatography combined with high-performance liquid chromatography (HPLC). Structural identification was conducted through liquid chromatography time-of-flight mass spectrometry, 1H nuclear magnetic resonance (NMR) spectroscopy, 13C-NMR, and Marfey’s method. The isolated compounds were identified as cyclo(l-Pro–l-Leu) on the basis of the results of the above analyses and previously reported data. The effects of various concentrations of cyclo(l-Pro–l-Leu) on the mortality rates of second-stage juveniles (J2) of M. incognita were investigated. Results showed that HPLC-purified cyclo(l-Pro–l-Leu) displayed nematicidal activities. The mortality rate of M. incognita J2 reached 84.3% after 72 h of exposure to 67.5 mg/L cyclo(l-Pro–l-Leu). The lowest egg-hatching rate (9.74%) was observed after 8 days of incubation with 2000 mg/L cyclo(l-Pro–l-Leu). An egg-hatching rate of 53.11% was obtained under the control treatment (sterile distilled water). However, cyclo(l-Pro–l-Leu) did not elicit chemotaxis activity to M. incognita. This is the first work to investigate the anti-M. incognita characteristics of cyclo(l-Pro–l-Leu).

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