scholarly journals Winter is coming: cold hardiness attributes of a field population of the potato tuberworm Phthorimaea operculella

2015 ◽  
Author(s):  
Stefanos S Andreadis ◽  
Yianna Poulia ◽  
Sofia Noukari ◽  
Barbara Aslanidou ◽  
Matilda Savopoulou-Soultani
Keyword(s):  
Cold Hardiness ◽  
Developmental Stages ◽  
Phthorimaea Operculella ◽  
Field Population ◽  
Freezing Injury ◽  
Winter Mortality ◽  
Supercooling Point ◽  
Short Term ◽  
Significant Difference ◽  
Potato Tuberworm

The potato tuberworm, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), is a worldwide pest of solanaceous crops especially devastating to potatoes. In the present study we investigated the cold hardiness profile of short-term acclimated and non-acclimated immature and adult stages of a field population of P. operculella. Late instars displayed the lowest mean supercooling point, for both short-term acclimated and non-acclimated individuals, however, no significant differences were observed among developmental stages. Unlike supercooling capacity, acclimation at 5 oC for 5 days enhanced the ability to survive at subzero temperatures after a 2 h exposure. Mean lethal temperature (LTemp50) of all developmental stages (egg, late instar, pupa and adult) decreased after short-term acclimation, however only adults displayed a significant difference among acclimated and non-acclimated individuals concerning their LTemp50 (-11.1 and -8.3 oC, respectively). Generally, pupae were the most cold tolerant developmental stage followed in decreasing order by the eggs and adults, while interestingly late instars were the least ones. Non-freezing injury above the supercooling point was well documented for all developmental stages indicating a pre-freeze mortality and suggesting that P. operculella is considered to be chill tolerant rather than freeze intolerant. Nevertheless, given its high degree of cold hardiness, winter mortality of P. operculella due to low temperatures is not likely to occur and potential pest outbreak can take place following a mild winter.

scholarly journals Winter is coming: cold hardiness attributes of a field population of the potato tuberworm Phthorimaea operculella

2015 ◽  
Author(s):  
Stefanos S Andreadis ◽  
Yianna Poulia ◽  
Sofia Noukari ◽  
Barbara Aslanidou ◽  
Matilda Savopoulou-Soultani
Keyword(s):  
Cold Hardiness ◽  
Developmental Stages ◽  
Phthorimaea Operculella ◽  
Field Population ◽  
Freezing Injury ◽  
Winter Mortality ◽  
Supercooling Point ◽  
Short Term ◽  
Significant Difference ◽  
Potato Tuberworm

The potato tuberworm, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), is a worldwide pest of solanaceous crops especially devastating to potatoes. In the present study we investigated the cold hardiness profile of short-term acclimated and non-acclimated immature and adult stages of a field population of P. operculella. Late instars displayed the lowest mean supercooling point, for both short-term acclimated and non-acclimated individuals, however, no significant differences were observed among developmental stages. Unlike supercooling capacity, acclimation at 5 oC for 5 days enhanced the ability to survive at subzero temperatures after a 2 h exposure. Mean lethal temperature (LTemp50) of all developmental stages (egg, late instar, pupa and adult) decreased after short-term acclimation, however only adults displayed a significant difference among acclimated and non-acclimated individuals concerning their LTemp50 (-11.1 and -8.3 oC, respectively). Generally, pupae were the most cold tolerant developmental stage followed in decreasing order by the eggs and adults, while interestingly late instars were the least ones. Non-freezing injury above the supercooling point was well documented for all developmental stages indicating a pre-freeze mortality and suggesting that P. operculella is considered to be chill tolerant rather than freeze intolerant. Nevertheless, given its high degree of cold hardiness, winter mortality of P. operculella due to low temperatures is not likely to occur and potential pest outbreak can take place following a mild winter.

Cold hardiness attributes of a field population of the potato tuberworm, Phthorimaea operculella

2016 ◽  
Vol 160 (2) ◽  
pp. 109-116 ◽  
Author(s):  
Stefanos S. Andreadis ◽  
Yianna Poulia ◽  
Sofia Noukari ◽  
Barbara Aslanidou ◽  
Matilda Savopoulou-Soultani
Keyword(s):  
Cold Hardiness ◽  
Phthorimaea Operculella ◽  
Field Population ◽  
Potato Tuberworm

Comparing the freezing susceptibility of third-instar larvae of Gnorimus variabilis (Cetoniidae: Trichiinae) from three distant geographical regions

2004 ◽  
Vol 82 (6) ◽  
pp. 873-879 ◽  
Author(s):  
D Renault ◽  
P Vernon ◽  
G Vannier
Keyword(s):  
Cold Hardiness ◽  
Geographical Location ◽  
Supercooling Point ◽  
Freezing Resistance ◽  
Experimental Conditions ◽  
Local Climate ◽  
The Third ◽  
Geographical Regions ◽  
Significant Difference ◽  
Third Instar Larvae

We compared the freezing susceptibility of three populations of Gnorimus variabilis (L., 1758) (Coleoptera: Cetoniidae) sampled from three distant locations in France. To separate the effects of habitat quality from those of genetics, we reared imagos from all field populations in a common garden experiment until the emergence of the third-instar larvae. The local climate appeared to determine the cold hardiness of the third-instar larvae, which live exclusively in cold seasons. The geographical location had an effect on the frost resistance (supercooling point) of the third-instar larvae of G. variabilis. We found no significant differences between the supercooling points of the populations originating from separate latitudes but from the same longitude, Sare (–10.9 ± 4.1 °C) and Husson (–11.5 ± 3.8 °C). Nonetheless, significant differences occurred between the larvae originating from the same northern latitude but from separate longitudes, Husson and La Robertsau (–17.8 ± 2.9 °C). It is the first time that a highly significant difference in the supercooling point of one stage within a single species has been observed along geographical gradients. Moreover, 19 of the 24 larvae originating from La Robertsau were alive after they were kept for 22 h at –10 °C compared with only 7 of the 24 larvae originating from Sare. When the three populations were reared in the laboratory under the same experimental conditions, the differential cryoresistance was preserved. It is likely that the greater freezing resistance found in the third-instar larvae of G. variabilis from La Robertsau could have a genetic component.

scholarly journals Enzyme Activity, Cold Hardiness, and Supercooling Point in Developmental Stages of Acrosternum arabicum (Hemiptera: Pentatomidae)

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Mozhgan Mohammadzadeh ◽  
Hamzeh Izadi
Keyword(s):  
Cold Hardiness ◽  
Developmental Stages ◽  
Instar Nymph ◽  
Amylolytic Activity ◽  
Supercooling Point ◽  
Optimal Activity ◽  
Adult Females ◽  
First Instar ◽  
The Mean ◽  
Optimal Ph

Abstract Several species of pentatomid bugs feed on pistachio fruits in Iran. Acrosternum arabicum Wagner (Hemiptera: Pentatomidae) is one of the most important pests of pistachio in Rafsanjan, Iran. This study was carried out to investigate the carbohydrase activities, supercooling points, and cold hardiness profiles of different developmental stages of A. arabicum under laboratory conditions. The midgut amylolytic of A. arabicum showed an optimal pH at 7.0. The highest amylolytic activity was found in the female adults (35.41 ± 0.90 nmol/min/gut). The mean amylolytic activity measured in first instar nymph was 6.75 ± 0.54 nmol/min/gut. Midgut α- and β-glucosidase showed an optimal activity at pH 5 and 7, respectively. These activities increased from first (83 ± 5 and 54 ± 5 nmol/min, respectively) to fifth (881 ± 17 and 237 ± 14 nmol/min, respectively) instar nymphs. The enzyme activities increased in the adults. Midgut α- and β-galactosidase showed an optimal activity at pH 5. α- and β-galactosidase activities were low in the first instar nymphs (73 ± 5 and 21 ± 3 nmol/min, respectively). The level of α- and β-galactosidase activities in the female adults (533 ± 18 and 246 ± 6 nmol/min, respectively) was higher than the nymphs. The lowest super cooling points (−19 and −18.2 °C, respectively) and the highest cold hardiness (22 and 18% following 24 h exposure at − 20 °C, respectively) were recorded for the eggs and adult females.

MODES OF SEASONAL ADAPTATION IN THE INSECTS: I. WINTER SURVIVAL

1978 ◽  
Vol 110 (11) ◽  
pp. 1167-1205 ◽  
Author(s):  
H. V. Danks
Keyword(s):  
Life Cycle ◽  
Cold Hardiness ◽  
Winter Survival ◽  
Freezing Injury ◽  
Winter Mortality ◽  
Ecological Data ◽  
Seasonal Adaptation ◽  
Warm Up ◽  
Factors Affecting ◽  
Cold Hardy

AbstractFactors affecting the winter survival of temperate-zone insects are reviewed. Certain species suffer high winter mortality especially in cold years, or in years with below normal amounts of insulating snow.Survival depends on the choice of winter microhabitat and on cold-hardiness, but also on biological features that have not previously been emphasized. These include behaviour that results in placement of overwintering eggs in less severe sites and manufacture of cocoons or other structures that retard inoculation by ice, or desiccation. The possible role of habitat heterogeneity in facilitating population survival is stressed.Microhabitats are characterized mainly with respect to temperature. They differ markedly among geographic areas and not only in midwinter conditions (including the extent of variation), but also in the time at which entry to the microhabitat in fall is necessary to avoid the risk of frost. The cues that govern entry into these microhabitats include negative phototaxis in many species but have not been subjected to quantitative analysis. Deeper layers are warmer in winter but warm up more slowly in spring and therefore some species, especially in arctic habitats where rapid vernal development is advantageous because the season is short, overwinter in superficial or insolated sites.Supposed mechanisms of cold- and freezing-injury and its avoidance are reviewed. There are several theories of freezing-injury: many modem theories focus on damage to the cell membrane, apparently caused by changes in cell volume induced during freezing. Injury is avoided by suppression of haemolymph nucleators (enhancing supercooling); or by a variety of methods, especially those involving solutes, minimising damage to frozen tissues. Among these solutes, the prevalence of glycerol in overwintering insects is not unexpected since glycerol is a normal metabolite in animals and can play several possible roles in cryoprotection.Cold-hardiness is metabolically costly because of these solute adjustments. The cold-hardiness of a taxon depends partly on climatic history during its evolution. Faunal composition at the highest latitudes reflects this dependence.The winter survival of many high-latitude insects varies rather widely from year to year; but the many detailed studies on cold-hardiness that have been made in the laboratory have seldom been related to natural mortality.The overwintering stage depends partly on the taxon. It is often fixed within a genus, but less closely within higher taxa. Proportionately more species overwinter as larvae at higher latitudes, especially when the life cycle lasts more than one year. Habitat also influences the overwintering stage: aquatic species generally overwinter as larvae, although species of temporary pools frequently overwinter as eggs. Overwintering in more than one stage is not common.This review suggests that winter survival of a group depends on latitude (or its climatic equivalent), habitat, and evolutionary history. It might therefore be especially useful to compare cold-hardiness, developmental rates, control of the life cycle and other features among species at the same latitude from each extreme of a series, that contrasts cold-hardy groups in stable habitats (such as Chironomidae) with aerial or vegetation dwelling groups that are not cold-hardy (such as Orthoptera). Future study of winter survival also demands more ecological data (overwintering stage, microhabitat, and conditions experienced there) for a larger sample of the fauna, and the simultaneous measurement of cold-hardiness.

Extrakorporális és intrakorporális anasztomózis rövid távú eredményeinek összehasonlítása malignus daganat miatt végzett laparoszkópos jobb oldali hemikolektómia esetén

2020 ◽  
Vol 73 (4) ◽  
pp. 148-152
Author(s):  
Kornél Vajda ◽  
László Sikorszki
Keyword(s):  
Length Of Stay ◽  
Gold Standard ◽  
Average Length ◽  
Colon Surgery ◽  
Right Hemicolectomy ◽  
Malignant Tumours ◽  
Short Term ◽  
Significant Difference ◽  
Laparoscopic Assisted ◽  
Laparoscopic Hemicolectomy

Összefoglaló. Bevezetés: A laparoszkópia térhódítása a jobb oldali colon műtéteknél is nyilvánvaló. Ma legtöbb helyen a laparoszkóposan asszisztált jobb oldali hemikolektómia extrakorporális anasztomózissal a gold standard. A morbiditás randomizált vizsgálatok alapján még 30% körüli. A technikai fejlődés lehetővé tette az intrakorporális anasztomózist. Célkitűzés: Retrospektív módon elemezni rosszindulatú jobb oldali vastagbéldaganat miatt végzett laparoszkópos hemikolektómiák rövid távú eredményeit a két módszer összehasonlításával. Eredmények: 2018. 01. 01. – 2019. 12. 31. között 184 jobb oldali hemikolektómiát végeztünk, ezek közül 122 történt malignus betegség miatt. 51 esetben nyitott és 71 esetben laparoszkópos műtét történt. 37 férfi (átlagéletkor: 70,59 év) és 34 nő (átlagéletkor: 72,14 év) volt. 50 esetben extrakorporális (EA) és 21 esetben pedig intrakorporális anasztomózist (IA) végeztünk. Az EA csoportban 18, míg az IA csoportban 3 szövődmény alakult ki 30 napon belül (p = 0,067). Az EA csoportból 3, az IA csoportból 1 beteget veszítettünk el 30 napon belül (p = 0,66). Az átlagos ápolási idő az EA csoportban 9,48 (5–32) nap, míg az IA csoportban 6,52 (4–19) nap volt (p = 0,001) a szövődményes esetekkel együtt. A szövődményes esetek nélkül az EA csoportban 6,35 (5–10) nap, az IA csoportban pedig 5,55 (4–8) napnak bizonyult (p = 0,09). A műtéti idő pedig az EA csoportban 147 (90–240) perc, az IA csoportban pedig 146,47 (90–265) perc volt (p = 0,11). Konklúzió: Az irodalommal összhangban azt találtuk, hogy IA esetén kevesebb a szövődmény, ezzel is összefüggésben rövidebb az átlagos ápolási idő, és a műtéti időt tekintve nincs szignifikáns különbség. Ezeket figyelembe véve az intrakorporális anasztomózis javasolható jobb oldali laparoszkópos hemikolektómia esetén. Summary. Introduction: Laparoscopy became evident for right-sided colon surgery too. Today the laparoscopic-assisted right-hemicolectomy is the gold standard with extracorporeal anastomosis. Morbidity according to randomized trials is still approximately 30%. The development of the surgical technique resulted in the creation of intracorporeal anastomosis. Our aim was to compare the short-term results of the two methods. Aim: To analyse the short-term results of right-sided hemicolectomy that were performed due to malignant tumours with the comparison of the two methods. Results: A cohort of 184 right-sided hemicolectomy were performed from 01.01.2018 to 31.12.2019 from which 122 were operated on because of a malignant disease. 51 open and 71 laparoscopic operations were performed. The average age of 37 men and 34 women were 70.59 and 72.14 years, respectively. 50 patients underwent extracorporeal (EA) anastomosis and 21 intracorporeal (IA) anastomosis. Within 30 days the number of complications were 18 in the EA group and 3 in the IA group (p = 0.067). 3 from the EA group and 1 from IA group died within 30 days (p = 0.66). The average length of stay were 9.48 days in the EA group and 6.52 days in the IA group together with the complicated cases (p = 0.001) while 6.35 days and 5.55 days without the complicated cases (p = 0.09). The average duration of operation was 147 minutes in the EA and 146.47 minutes in the IA group (p = 0.11). Conclusion: We found concordance with the literature that there are fewer complications in case of IA which might be related to shorter length of stay. There is no significant difference between the surgical times. Bearing these facts in mind, IA might be suggested for right- sided laparoscopic hemicolectomy.

Effect of short-term use of oral contraceptive pills on intraocular pressure

2020 ◽  
Vol 35 (3) ◽  
Author(s):  
Tayyaba Gul Malik ◽  
Hina Nadeem ◽  
Eiman Ayesha ◽  
Rabail Alam
Keyword(s):  
Oral Contraceptive ◽  
Childbearing Age ◽  
Short Term ◽  
Oral Contraceptive Pills ◽  
Contraceptive Pills ◽  
Time Period ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Short Time

Objective: To study the effect of short-term use of oral contraceptive pills on intra-ocular pressures of women of childbearing age.   Methods: It was a comparative observational study, conducted at Arif memorial teaching hospital and Allied hospital Faisalabad for a period of six months. Hundred female subjects were divided into two groups of 50 each. Group A, included females, who had been taking oral contraceptive pills (OCP) for more than 6 months and less than 36 months. Group B, included 50 age-matched controls, who had never used OCP. Ophthalmic and systemic history was taken. Careful Slit lamp examination was performed and intraocular pressures (IOP) were measured using Goldman Applanation tonometer. Fundus examination was done to rule out any posterior segment disease. After collection of data, we analyzed and compared the intra ocular pressures between the two groups by using ANOVA in SPSS version 21.   Results: Average duration of using OCP was 14.9 months. There was no significant difference of Cup to Disc ratios between the two groups (p= 0.109). However, significant difference was noted between the IOP of OCP group and controls. (p=0.000). Conclusion: OCP significantly increase IOP even when used for short time period.

T1 Relaxation Time of Achilles Tendon at 3 Tesla with Special Reference to Relevant Clinical Score: A Preliminary Study

2020 ◽  
Vol 16 (2) ◽  
pp. 164-173
Author(s):  
Zeineb Tbini ◽  
Mokhtar Mars ◽  
Mouna Bouaziz
Keyword(s):  
Relaxation Time ◽  
Achilles Tendon ◽  
Clinical Score ◽  
3 Tesla ◽  
Acquisition Time ◽  
Short Term ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Spin Echo Sequence ◽  
Significant Difference

Purpose: The purpose of this study was to investigate T1 relaxation time of the human Achilles tendon, to test its short-term repeatability as well as the minimal detectable change, and to assess the extent that correlate with clinical symptoms. Methods: Twenty asymptomatic volunteers and eighteen patients with clinically and sonographically confirmed tendinopathy were scanned for ankle using a 3 Tesla (T) MR scanner. T1 maps were calculated from a variable flip angle gradient echo Ultra-short echo time sequence (VFA-GE UTE) and inversion recovery spin echo sequence (IR-SE) using a self-developed matlab algorithm in three regions of interest of Achilles Tendon (AT). Signal to Noise Ratio (SNR) between the two sequences was evaluated. INTRA-class Correlation Coefficient (ICC), Coefficient of Variation (CV) and the Least Significant Change (LSC) were calculated, to test short-term repeatability of T1. Subjects were assessed by the VISA-A clinical score. P values less than 0.005 were considered statistically significant. Results: Mean T1 values were 427.09 ± 53.37 ms and 528.70 ± 103.50 ms using IR-SE sequence and 575.43 ± 110.60 ms and 875.81 ± 425.77 ms with VFA-GE UTE sequence in the whole AT for volunteers and patients, respectively. : T1 values showed a significant difference between volunteers and patients (P=0.001). Regional variation of T1 in healthy and tendinopathic AT were greater for VFA-GE UTE sequence than for IR-SE sequence. VFA-GE UTE sequence showed clearly higher SNR compared to IR-SE sequence. Short-term repeatability of T1 values for volunteers showed an LSC of 22% and 14% for IR-SE sequence and VFA-GE UTE sequence, respectively. For patients, LSC was 14% and 5% for IR-SE sequence and VFA-GE UTE sequence, respectively. There was no correlation between T1 and VISA-A clinical score (p>0.005). Conclusion: VFA-GE UTE sequence used for T1 mapping calculation demonstrated short acquisition time and clearly high SNR. Results revealed that T1 relaxation time can be used as a biomarker to differentiate between healthy and pathologic Achilles tendon. However, T1 showed no correlation with the VISA-A clinical score.

Supercooling Points of Adult Dermacentor variabilis (Acari: Ixodidae) From a Population Near the Northern Distribution Limit

2020 ◽  
Author(s):  
Matthew E M Yunik ◽  
Neil B Chilton
Keyword(s):  
Cold Hardiness ◽  
Dermacentor Variabilis ◽  
Subzero Temperatures ◽  
Host Seeking ◽  
Short Period ◽  
Significant Difference ◽  
Northern Distribution ◽  
Dog Tick ◽  
Provincial Park ◽  
Established Population

Abstract The northern distributional limit of Dermacentor variabilis Say, the American dog tick, is expanding in Saskatchewan and Manitoba (western Canada). The ability of D. variabilis to continue to expand its range northwards will depend upon the ability of individuals within populations at the species distributional edge to withstand very low temperatures during winter. One component of cold hardiness is the supercooling point (SCP), the temperature below 0°C at which an individual freezes. In this study, the SCP was determined for 94 questing D. variabilis adults (44 females and 50 males) from an established population near Blackstrap Provincial Park in Saskatchewan. SCP values ranged from −18.2 to −6.7°C, with a median of −13.3°C. This suggests that host-seeking D. variabilis adults differ in their ability to survive exposure to subzero temperatures, for at least a short period of time, without freezing. The distribution of SCPs was bimodal, but there was no significant difference in SCP values between female and male ticks, and no relationship between SCP and tick body weight. It remains to be determined what factors contribute to the variation in SCP values among questing D. variabilis adults.

Sign in / Sign up

Export Citation Format

Share Document