Movements and habitat choice of resident and translocated adult female Grass Snakes (Natrix natrix) during the egg-laying period

2019 ◽  
Vol 29 (4) ◽  
pp. 245-251
Author(s):  
Johan Elmberg
2019 ◽  
pp. 245-251
Author(s):  
Johan Elmberg

We used externally applied transmitters to study movements of female grass snakes (Natrix natrix) during the egg-laying period in a near-urban landscape in Sweden. Half of the studied snakes were residents while the other half were translocated individuals with no previous experience of the area. As predicted, resident females moved more goal-oriented and shorter distances than did translocated individuals. Habitat use did not differ between resident and translocated snakes; they were typically found in bushes, reeds, and tall vegetation. Habitat preference (use in relation to availability) showed that bushy habitats, tall grassy vegetation and reedbeds were over-used in proportion to availability, whereas forest and open grass lawns were used less than expected based on availability. Our study highlights the importance of preserving and restoring linear habitat components providing shelter and connectivity in conservation of grass snakes. We suggest that externally applied transmitters are a better option than surgically implanted ones in movement studies of grass snakes, and that translocation as a conservation method for snakes has drawbacks.


2021 ◽  
Author(s):  
Kathryn Bartley ◽  
Wan Chen ◽  
Richard Lloyd Mills ◽  
Francesca Nunn ◽  
Daniel Price ◽  
...  

Abstract Background: The blood feeding poultry red mite (PRM), Dermanyssus gallinae, causes substantial economic damage to the egg laying industry worldwide, and is serious welfare concern for laying hens and poultry house workers. In this study we have investigated the temporal gene expression across the 6 stages/sexes (egg, larvae, protonymph and deutonymph, adult male and adult female) of this neglected parasite in order to understand the temporal expression associated with development, parasitic lifestyle, reproduction and allergen expression. Results: RNA-seq transcript data for the 6 stages was mapped to the PRM genome creating a publicly available gene expression atlas (on the OrcAE platform in conjunction with the PRM genome). Network analysis and clustering of stage-enriched gene expression in PRM resulted in 17 superclusters with stage-specific or multi-stage expression profiles. The 6 stage specific superclusters were clearly demarked from each other and the adult female supercluster contained the most stage specific transcripts (2,725), whilst the protonymph supercluster the fewest (165). Fifteen pairwise comparisons performed between the different stages resulting in a total of 6025 Differentially Expressed Genes (DEGs) (P>0.99). These data were evaluated alongside a Venn/Euler analysis of the top 100 most abundant genes in each stage. An expanded set of cuticle proteins and enzymes (chitinase and metallacarboxypeptidases) were identified in larvae and underpin cuticle formation and ecdysis to the protonymph stage. Two mucin/peritrophic-A salivary proteins (DEGAL6771g00070, DEGAL6824g00220) were highly expressed in the blood-feeding stages, indicating peritrophic membrane formation during feeding. Reproduction-associated vitellogenins were the most abundant transcripts in adult females, whilst in adult males, an expanded set of serine and cysteine proteinases and an epididymal protein (DEGAL6668g00010) were highly abundant. Assessment of the expression patterns of putative homologues of 32 allergen groups described for the house dust mites indicated a bias in expression towards the non-feeding larval stage.Conclusions: This study is the first evaluation of temporal gene expression across all stages of PRM and has provided insight into developmental, feeding, reproduction and survival strategies employed by this mite. The publicly available PRM resource on OrcAE offers an invaluable tool for researchers investigating the biology and novel interventions of this parasite.


1968 ◽  
Vol 19 (2) ◽  
pp. 323 ◽  
Author(s):  
RW Hewetson ◽  
JV Nolan

The development of a resistance by cattle to artificial infestations with Boophilus microplus ticks is reported and the sequence of development discussed. There was a regression of adult female ticks becoming replete with infestation (regression y = 2399.41 – 574x ± 54) up to the fourth infestation. The weight of replete female ticks dropped from resistant cattle increased with infestation but this effect is confounded with the effects of climate. The day of modal drop of replete females increased with infestation, which indicated an effect of resistance on modal drop. Egg-laying was not affected by a developing resistance, but the fertility of eggs from female egg-laying ticks was. There was an increase in fertility of eggs laid after the second infestation.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Francesca Nunn ◽  
Jessica Baganz ◽  
Kathryn Bartley ◽  
Sarah Hall ◽  
Stewart Burgess ◽  
...  

Abstract Background Dermanyssus gallinae, or poultry red mite (PRM), is an important ectoparasite in laying hen, having a significant effect on animal welfare and potentially causing economic loss. Testing novel control compounds typically involves in vitro methodologies before in vivo assessments. Historically, in vitro methods have involved PRM feeding on hen blood through a membrane. The use of hen blood requires multiple procedures (bleeds) to provide sufficient material, and the use of a larger species (e.g. goose) could serve as a refinement in the use of animals in research. Methods The in vitro feeding device used was that which currently employs a Parafilm™ M membrane (Bartley et al.: Int J Parasitol. 45:819–830, 2015). Adult female PMR were used to investigate any differences in mite feeding, egg laying and mortality when fed goose or hen blood. Effects on these parameters when PRM were fed through either the Parafilm™ M membrane or the Baudruche membrane alone or through a combination of the membrane with an overlaid polyester mesh were tested using goose blood. Results Poultry red mites fed equally well on goose or hen blood through the Parafilm™ M membrane, and there were no significant differences in mortality of PRM fed with either blood type. A significant increase (t test: t = 3.467, df = 4, P = 0.03) in the number of eggs laid per fed mite was observed when goose blood was used. A 70% increase in PRM feeding was observed when the mites were fed on goose blood through a Baudruche membrane compared to when they were fed goose blood through the Parafilm™ M membrane. The addition of an overlaid polyester mesh did not improve feeding rates. A significant increase (analysis of variance: F(3, 20) = 3.193, P = 0.04) in PRM egg laying was observed in mites fed on goose blood through the Baudruche membrane compared to those fed goose blood through the Parafilm™ M membrane. A mean of 1.22 (standard error of the mean ± 0.04) eggs per fed mite was obtained using the Baudruche feeding device compared to only 0.87 (SEM ± 0.3) eggs per fed mite using the Parafilm™ M device when neither was combined with a polyester mesh overlay. Conclusion The in vitro feeding of adult female PRM can be readily facilitated through the use of goose blood in feeding devices with the Baudruche membrane.


1968 ◽  
Vol 100 (7) ◽  
pp. 777-781 ◽  
Author(s):  
R. W. Fisher ◽  
N. G. Morgan

AbstractDicofol was applied to bean leaf discs in various ways. The number of drops per disc, the concentration of dicofol in each drop, and the size of the drops were related to egg laying and mortality of adult female mites placed on the discs. Under the conditions of the experiment, an increase in concentration above normal field strength (0.046% active ingredient) had little effect, even though the deposits were discontinuous and similar to those expected from low-volume spraying. Repellency of dicofol to mites was reaffirmed and toxicity effects were significant when about one-quarter of the leaf surface was covered by deposit.


2016 ◽  
Vol 69 ◽  
pp. 305-309
Author(s):  
C.A. Rowe ◽  
D.P. Logan ◽  
P.G. Connolly

Chorus cicada Amphipsalta zelandica (Biosduval) is an endemic species of cicada that is a pest of kiwifruit Adult female cicadas cause damage to kiwifruit canes when egg laying The oviposition wound often stimulates the local formation of callus tissue in kiwifruit canes The effect of eggnest callusing on the proportion of eggs to hatch successfully was investigated as a potential plant resistance trait for selection The proportion of callus tissue covering the eggnest and the number of eggs hatched were measured from eggnests in canes of two kiwifruit cultivars Hayward and Zesy002 and stems of Hass avocado Eggnests with more callus tissue had reduced egg hatch in both cultivars of kiwifruit and avocado The host plant also affected egg hatch with significantly different hatch rates between the two kiwifruit cultivars and avocado at zero percent callusing


1971 ◽  
Vol 26 (4) ◽  
pp. 485-489 ◽  
Author(s):  
P. A. Berberian ◽  
M. Rockstein ◽  
F. H. Gray

2021 ◽  
Vol 15 (4) ◽  
pp. 22-28
Author(s):  
A. M. Atayev ◽  
M. M. Zubairova ◽  
N. T. Karsakov

The purpose of the research is study of some reproductive characteristics of the biology of ticks of the family Ixodidae which are widespread in the southeast of the North Caucasus.Materials and methods. In 2000–2010, 9 series of experiments were carried out in the conditions of the plain belt in Dagestan. The first, second, and third series of experiments were intended to find out the duration of the tick searching for a place to fix on the animal, the duration of the skin incised and the proboscis inserted into the wound, and the engorgement duration; and the fourth series was intended to clarify the tick wintering on the animal. Such experiments were performed on two-year-old calf bulls on the Educational and Experimental Farm of the Dagestan State Agrarian University with Boophilus annulatus, Rhipicephalus bursa, Hyalomma detritum, H. scupense, and H. anatolicum in 2000. Five hungry adult female ticks were placed onto all 5 calf bulls in the middle third of the neck. We conducted experiments on searching for a place for egg-laying, egg-laying duration in the environment, number of eggs in a clutch, duration of the larva formed and the hatching rate, distance of the larvae from the hatching place, and larvae death rate in five specially equipped sites of pastures of 1 m2 . Five adult female ticks of B. annulatus, R. bursa, H. detritum, H. scupense, and H. anatolicum were placed after engorgement in each biological site.Results and discussion. Ixodid ticks perform their natural physiological functions associated with feeding and reproduction with significant time fluctuations. The search for a place to fix on the animal took 4–8 hours; the skin incised and proboscis inserted in the wound took 2–5 hours; the engorgement took 4–6 hours; the search for an egg-laying place took 10– 22 hours; the egg-laying duration in the environment was 18–23 hours; the number of eggs in a clutch was 4–13K; the duration of the larva formed and the hatching rate was 10–15 days and 58.0–75% respectively; the distance of the larva from the hatching place was 0.5–1.5 m; death rate of the larva in captivity was 100%; and the tick wintering on the animal was near the neck, ears, in the dewlap, the flank and the udder. These features are typical for the analyzed tick species in the southeast of the North Caucasus and, probably, for other taxa of these genera.


1983 ◽  
Vol 115 (7) ◽  
pp. 807-813 ◽  
Author(s):  
Helmut Riedl ◽  
S. A. Hoying

AbstractFenvalerate applied at field rates (3.4–13.7 g AI/100 L) to pear foliage in early season remained highly active to the predatory mite Typhlodromus occidentalis Nesbitt for several months until leaf drop. According to leaf disc assays, fresh deposits of fenvalerate caused considerable direct mortality but most of the later mortality was apparently caused by repellency of the residue and subsequent mite departures. Fenvalerate applied to the bark lost its contact activity more quickly than on foliage. In contrast, adult female Tetranychus urticae Koch suffered no mortality when exposed to leaf deposits, but at high dosages of fenvalerate egg laying was temporarily reduced. In slide-dip tests fenvalerate was about 5 times more toxic to T. occidentalis than to T. urticae (LC50's of 1.21 and 6.74 g AI/100 L, respectively). Our data suggest that because of the persistence of fenvalerate and the high sensitivity of T. occidentalis to this compound this predatory mite would not be able to reestablish after foliar fenvalerate applications and provide biological control of phytophagous mites.


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