scholarly journals Effect of exposure to short-day photoperiods on the host-feeding activity of Ixodes persulcatus Schulze nymphs (Acari : Ixodidae) reared in a long-day photoperiod before and after molting

2002 ◽  
Vol 53 (3) ◽  
pp. 187-189 ◽  
Author(s):  
Kazuyoshi FUJIMOTO
Keyword(s):  
Feeding Activity ◽  
Ixodes Persulcatus ◽  
Host Feeding ◽  
Short Day ◽  
Long Day ◽  
Before And After

Thermoregulation, growth, and reproduction in Alaskan collared lemmings: role of short day and cold

1991 ◽  
Vol 261 (3) ◽  
pp. R522-R530 ◽  
Author(s):  
H. A. Maier ◽  
D. D. Feist
Keyword(s):  
Food Intake ◽  
Thermal Conductance ◽  
Reproductive Condition ◽  
Reproductive Morphology ◽  
Short Day ◽  
Long Day ◽  
Dicrostonyx Groenlandicus ◽  
Before And After ◽  
Growth And Reproduction

To assess factors controlling seasonal thermoregulatory and reproductive changes, collared lemmings (Dicrostonyx groenlandicus) were exposed for 16 wk to long day (LD, 22 h light: 2 h dark) and warm (15 +/- 3 degrees C), LD and cold (1 +/- 0.5 degrees C), short day (SD, 4 h light: 20 h dark) and warm, SD and cold or acclimatized to outdoor winter conditions (OUT). Hair length and color, body mass, and food intake were monitored weekly. Resting metabolic rates (RMR) and nonshivering thermogenesis (NST) were estimated several times by measuring oxygen consumption before and after norepinephrine injections. Body composition and reproductive condition were determined at the end of the experiment. SD and OUT groups had a 15.8% lower (P less than 0.01) RMR at 7 degrees C than the LD groups. Lower thermal conductance in SD and OUT animals appears due to molt to white winter pelage, which occurred by week 3 in SD but not in LD groups. Neither SD, cold, nor OUT altered NST or reproductive morphology. SD-exposed lemmings showed 19.2% greater growth than those in LD, resulting primarily from a 29.2 and 15.0% increase in lean and ash components, respectively. Cold exposure increased food intake by 34.7%. Results suggest that the pineal gland, which mediates SD effects, may influence molt and growth but not NST or reproductive morphology.

scholarly journals Anthonomus rubi on Strawberry Fruit: Its Biology, Ecology, Damage, and Control from an IPM Perspective

Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 701
Author(s):  
Lorenzo Tonina ◽  
Giulia Zanettin ◽  
Paolo Miorelli ◽  
Simone Puppato ◽  
Andrew G. S. Cuthbertson ◽  
...  
Keyword(s):  
Feeding Activity ◽  
Host Feeding ◽  
Mass Trapping ◽  
Natural Habitats ◽  
Potential Control ◽  
North East ◽  
Monitoring Tools ◽  
Anthonomus Rubi ◽  
And Control

The strawberry blossom weevil (SBW), Anthonomus rubi, is a well-documented pest of strawberry. Recently, in strawberry fields of Trento Province (north-east Italy), new noteworthy damage on fruit linked to SBW adults was observed, combined with a prolonged adult activity until the autumn. In this new scenario, we re-investigated SBW biology, ecology, monitoring tools, and potential control methods to develop Integrated Pest Management (IPM) strategies. Several trials were conducted on strawberry in the laboratory, field and semi-natural habitats. The feeding activity of adult SBW results in small deep holes on berries at different stages, causing yield losses of up to 60%. We observed a prolonged survival of newly emerged adults (>240 days) along with their ability to sever flower buds without laying eggs inside them in the same year (one generation per year). SBW adults were present in the strawberry field year-round, with movement between crop and no crop habitats, underlying a potential role of other host/feeding plants to support its populations. Yellow sticky traps combined with synthetic attractants proved promising for both adult monitoring and mass trapping. Regarding control, adhesive tapes and mass trapping using green bucket pheromone traps gave unsatisfactory results, while the high temperatures provided by the black fabric, the periodic removal of severed buds or adults and Chlorpyrifos-methyl application constrained population build-up. The findings are important for the development of an IPM strategy.

Control of torpor and body weight patterns by a seasonal timer in Siberian hamsters

1989 ◽  
Vol 257 (1) ◽  
pp. R142-R149 ◽  
Author(s):  
T. J. Bartness ◽  
J. A. Elliott ◽  
B. D. Goldman
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Implant Removal ◽  
Daily Torpor ◽  
Short Day ◽  
Siberian Hamsters ◽  
Long Day ◽  
Preparatory Phase ◽  
Pelage Color ◽  
Seasonal Responses

Two experiments were designed to assess whether the short-day-induced patterns of shallow daily torpor, body weight, and other seasonal responses (food intake and pelage pigmentation) exhibited by Siberian hamsters (Phodopus sungorus sungorus) are under the control of a "seasonal timekeeping mechanism" that is independent of reproductive status [testosterone, (T)]. We examined whether the patterning and expression of these seasonal responses were altered by decreases in serum T that accompany gonadal regression during the first 8 wk of short-day exposure (i.e., the "preparatory phase" of the torpor season) or by experimental increases in serum T after this phase. Short-day-housed, castrated hamsters bearing T implants had long-day levels of the hormone and did not exhibit torpor. Appropriate seasonal patterns and levels of torpor, body weight, pelage color stage, and food intake were exhibited after T implant removal although serum T was clamped to long-day levels during the preparatory phase. In animals that were gonad intact during the preparatory phase and were subsequently castrated and given T implants, torpor did not occur as long as the implants were in place. However, the patterns and levels of daily torpor, food intake, and body weight rapidly returned to appropriate seasonal values compared with the castrated, blank-implanted controls on T implant removal; these effects occurred whether the T implants were removed when torpor frequency was increasing, at its peak, or decreasing across the torpor season. T did not affect pelage color stage under any condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Cessation of Long Day Melatonin Rhythms Time Puberty in a Short Day Breeder*

Endocrinology ◽  
1988 ◽  
Vol 123 (3) ◽  
pp. 1636-1641 ◽  
Author(s):  
DOUGLAS L. FOSTER ◽  
FRANCIS J. P. EBLING ◽  
LEE E. CLAYPOOL ◽  
CELIA J. I. WOODFILL
Keyword(s):  
Short Day ◽  
Long Day

Transcriptomic analysis of Allium sativum uncovers putative genes involved in photoperiodic pathway and hormone signaling under long day and short day conditions

Plant Science ◽  
2021 ◽  
pp. 111095
Author(s):  
Muhammad Jawaad Atif ◽  
Bakht Amin ◽  
Muhammad Imran Ghani ◽  
Muhammad Ali ◽  
Somia Khursheed ◽  
...  
Keyword(s):  
Allium Sativum ◽  
Transcriptomic Analysis ◽  
Hormone Signaling ◽  
Short Day ◽  
Long Day

scholarly journals Agronomic Performance and Flowering Behavior in Response to Photoperiod and Vernalization in Barley (Hordeum vulgare L.) Genotypes with Contrasting Drought Tolerance Behavior

2021 ◽  
Author(s):  
Jamal Abu-Elenein ◽  
Rabea Al-Sayaydeh ◽  
Zahera Akkeh ◽  
Zakaria Al-Ajlouni ◽  
AbdRaheem A. Al-Bawalize ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Agronomic Performance ◽  
Short Day ◽  
Drought Tolerant ◽  
Long Day ◽  
Meristem Development ◽  
Rainfed Conditions ◽  
Barley Genotypes

Abstract Background In barley, flowering behavior is a highly regulated and complex process where the appropriate matching of reproductive development with seasonal variation in water availability confer barley adaptation to different environments. In this study, the role of variation in flowering time and drought tolerance in four selected barley genotypes was studied under field and controlled conditions. For this purpose, field trials were conducted for two consecutive seasons at three diverse environments where the studied genotypes were subjected to either rainfed conditions or rainfed plus supplementary irrigation under two different sowing dates. Furthermore, reproductive meristem development in two selected barley genotypes, Rum (drought tolerant) and Steptoe (drought-sensitive) was also assessed in response to both vernalization and water stress under two different photoperiod conditions.Results Variation in the number of days to heading was more pronounced under rainfed conditions than under well water conditions. For agronomic performance, Rum was superior under all tested environments, which assure its general adaptability to multiple environments, while Steptoe was the poorest. The transition to reproductive meristem was faster under vernalized long-day conditions as compared to vernalized short-day conditions. The progress of shoot apical meristem development and heading under long-day conditions was significantly faster in Rum than that of Steptoe. A clear effect of drought stress was observed on shoot apical meristem development in Steptoe. Under short-day conditions, vernalized Rum plants subjected to water deficit showed an advanced meristem development stage a significant earlier HD when compared with non-stressed plants. This early flowering behavior in stressed Rum plants under short-day conditions was accompanied by higher gene expression of the Vrn-H1 gene. Conclusion In conclusion, the integration of vernalization and photoperiod signals in drought-tolerant barley genotypes is associated with early flowering behavior and higher productivity in dry environments.

scholarly journals Photocontrol of Flowering and Extension Growth in the Long-day Plant Pansy

2003 ◽  
Vol 128 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Erik S. Runkle ◽  
Royal D. Heins
Keyword(s):  
Flower Development ◽  
Red Light ◽  
Reproductive Development ◽  
Extension Growth ◽  
Separate Experiment ◽  
Flower Initiation ◽  
Minimal Extension ◽  
Short Day ◽  
Long Day ◽  
Light Duration

Plastics that selectively reduce the transmission of far-red light (FR, 700 to 800 nm) reduce extension growth of many floricultural crops. However, FR-deficient (FRd) environments delay flowering in some long-day plants (LDPs), including `Crystal Bowl Yellow' pansy (Viola ×wittrockiana Gams). Our objective was to determine if FR light could be added to an otherwise FRd environment to facilitate flowering with minimal extension growth. In one experiment, plants were grown under a 16-hour FRd photoperiod, and FR-rich light was added during portions of the day or night. For comparison, plants were also grown with a 9-hour photoperiod [short-day (SD) control] or under a neutral (N) filter with a 16-hour photoperiod (long day control). Flowering was promoted most (i.e., percent of plants that flowered increased and time to flower decreased) when FR-rich light was added during the entire 16-hour photoperiod, during the last 4 hours of the photoperiod, or during the first or second 4 hours after the end of the photoperiod. In a separate experiment, pansy was grown under an FRd or N filter with a 9-hour photoperiod plus 0, 0.5, 1, 2, or 4 hours of night interruption (NI) lighting that delivered a red (R, 600 to 700 nm) to FR ratio of 0.56 (low), 1.28 (moderate), or 7.29 (high). Under the N filter, the minimum NI duration that increased percent flowering was 2 hours with a moderate or low R:FR and 4 hours with a high R:FR. Under the FRd filter, 2 or 4 hours of NI lighting with a moderate or low R:FR, respectively, was required to increase percent flowering, but a 4-hour NI with a high R:FR failed to promote flowering. Pansy appears to be day-neutral with respect to flower initiation and a quantitative LDP with respect to flower development. The promotion of reproductive development was related linearly to the promotion of extension growth. Therefore, it appears that in LDPs such as pansy, light duration and quality concomitantly promote extension growth and flowering, and cannot readily be separated with lighting strategies.

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