scholarly journals Alternative Nesting Strategies of Polistine Wasps in a Subtropical Locale

Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 53
Author(s):  
Scott Nacko ◽  
Mark A. Hall ◽  
Gregg Henderson
Keyword(s):  
Warm Season ◽  
Social Wasp ◽  
Paper Wasps ◽  
Early Season ◽  
Late Season ◽  
Colony Cycle ◽  
Phylogenetic Studies ◽  
Mischocyttarus Mexicanus ◽  
Study Sites ◽  
Nest Searching

Phylogenetic studies suggest that historically all paper wasps (Vespidae: Polistinae) in North America have tropical origins, but some species have adapted to survive temperate conditions. Subtropical climates, which are intermediate between temperate and tropical, allow a unique opportunity to study ancestral traits which can be retained or lost within populations, and ultimately elucidate the process of social wasp evolution. We investigated the phenology of paper wasps at study sites in subtropical Baton Rouge, USA, through nest searching and monitoring of nest parameters throughout the warm season (March–October). Across the year, two periods of nest initiation occurred: from March–May (early season nests, i.e., before the summer solstice), and from July–September (late season nests, after the solstice). We observed 240 Polistes nests from six species, of which 50.8% were initiated in early season and 49.2% in late season. In contrast, Mischocyttarus mexicanus rarely built late season nests and had longer early season colony duration than Polistes bellicosus and P. dorsalis, which built more nests in the late season than early. Across all species, late season nests had significantly shorter colony duration (~87.6 days) than early season nests (~166 days), and only P. bellicosus had fewer adults at peak population in late season nests than in early season nests. Results indicate both a bivoltine colony cycle in Polistes of subtropical climates, as well as differences in nesting strategies between genera.

The disappearance of subordinate foundresses in paper wasps: eviction by nestmates or reproductive strategy?

1999 ◽  
Vol 77 (12) ◽  
pp. 1928-1933 ◽  
Author(s):  
George J Gamboa ◽  
Janet L Savoyard ◽  
Laura M Panek
Keyword(s):  
Reproductive Strategy ◽  
Indirect Evidence ◽  
Social Wasp ◽  
Time Interval ◽  
Paper Wasps ◽  
Polistes Fuscatus ◽  
Colony Cycle ◽  
The Social ◽  
Behavioural Evidence ◽  
Related Mortality

Videotaped observations (371.3 h) were conducted in 1995, 1996, and 1997 on 50 multiple-foundress colonies of the social wasp Polistes fuscatus. Observations were made during the mid-preworker, late-preworker, and early-postworker stages of the colony cycle. The vast majority of lost subordinate cofoundresses (62 of 77) disappeared during the time interval from 2 weeks before to 4 weeks after the emergence of the first workers. The loss of subordinates did not appear to be the result of senescence or foraging-related mortality. Lost subordinates were from productive and presumably healthy colonies. In colonies containing two or more subordinates, lost subordinates had significantly greater dominance ranks than expected. There was no behavioural evidence that lost subordinates were evicted from their colony by queens, other subordinate foundresses, or workers. Lost subordinates were not observed to renest, join sister colonies, or adopt orphaned nests. Our results indicate that lost subordinates leave colonies of their own volition. Indirect evidence from other studies suggests that subordinates may disperse and usurp colonies from other sites.

The timing of conflict and cooperation among cofoundresses of the social wasp Polistes fuscatus (Hymenoptera: Vespidae)

1996 ◽  
Vol 74 (1) ◽  
pp. 70-74 ◽  
Author(s):  
George J. Gamboa ◽  
Katherine A. Stump
Keyword(s):  
Social Wasp ◽  
Adaptive Significance ◽  
Field Observations ◽  
Polistes Fuscatus ◽  
Conflict And Cooperation ◽  
Colony Cycle ◽  
The Social ◽  
Theoretical Predictions ◽  
Ecological Pressure ◽  
Temporal Overlap

Field observations were made on 37 preworker, multiple-foundress colonies of the social wasp Polistes fuscatus. In total, 401.9 h of behavioural observations of cofoundresses were conducted at three different periods prior to the emergence of workers. Cofoundresses displayed a marked, significant increase in aggression at about the time in the colony cycle when reproductive-destined eggs began to be laid. Both queens and their subordinates became increasingly aggressive at this time. These empirical results support theoretical predictions that conflict among cofoundresses would intensify over the production of reproductive-destined (but not worker-destined) eggs. Cooperation in foraging to minimize nest inattendance as well as synchronicity (temporal overlap) in activity also increased significantly at the onset of the production of reproductive-destined eggs. Thus, conflict and cooperation are not necessarily antagonistic in P. fuscatus. Foundresses minimized the time that nests are unattended at a time in the colony cycle when most conspecific usurpations occur. This suggests that the ecological pressure of conspecific usurpation has favoured increased coordination in foraging to minimize the time nests are unattended. The adaptive significance, if any, of an increase in synchronicity of activity among cofoundresses at the onset of the production of reproductives is not obvious.

scholarly journals Impacts of compound hot–dry extremes on US soybean yields

2021 ◽  
Vol 12 (4) ◽  
pp. 1371-1391
Author(s):  
Raed Hamed ◽  
Anne F. Van Loon ◽  
Jeroen Aerts ◽  
Dim Coumou
Keyword(s):  
Soil Moisture ◽  
Synergistic Effects ◽  
Weather Data ◽  
Yield Variability ◽  
Critical Element ◽  
Early Season ◽  
Soybean Yield ◽  
Late Season ◽  
The Us ◽  
Dry Conditions

Abstract. The US agriculture system supplies more than one-third of globally traded soybean, and with 90 % of US soybean produced under rainfed agriculture, soybean trade is particularly sensitive to weather and climate variability. Average growing season climate conditions can explain about one-third of US soybean yield variability. Additionally, crops can be sensitive to specific short-term weather extremes, occurring in isolation or compounding at key moments throughout crop development. Here, we identify the dominant within-season climate drivers that can explain soybean yield variability in the US, and we explore the synergistic effects between drivers that can lead to severe impacts. The study combines weather data from reanalysis and satellite-informed root zone soil moisture fields with subnational crop yields using statistical methods that account for interaction effects. On average, our models can explain about two-thirds of the year-to-year yield variability (70 % for all years and 60 % for out-of-sample predictions). The largest negative influence on soybean yields is driven by high temperature and low soil moisture during the summer crop reproductive period. Moreover, due to synergistic effects, heat is considerably more damaging to soybean crops during dry conditions and is less problematic during wet conditions. Compounding and interacting hot and dry (hot–dry) summer conditions (defined by the 95th and 5th percentiles of temperature and soil moisture respectively) reduce yields by 2 standard deviations. This sensitivity is 4 and 3 times larger than the sensitivity to hot or dry conditions alone respectively. Other relevant drivers of negative yield responses are lower temperatures early and late in the season, excessive precipitation in the early season, and dry conditions in the late season. We note that the sensitivity to the identified drivers varies across the spatial domain. Higher latitudes, and thus colder regions, are positively affected by high temperatures during the summer period. On the other hand, warmer southeastern regions are positively affected by low temperatures during the late season. Historic trends in identified drivers indicate that US soybean production has generally benefited from recent shifts in weather except for increasing rainfall in the early season. Overall, warming conditions have reduced the risk of frost in the early and late seasons and have potentially allowed for earlier sowing dates. More importantly, summers have been getting cooler and wetter over the eastern US. Nevertheless, despite these positive changes, we show that the frequency of compound hot–dry summer events has remained unchanged over the 1946–2016 period. In the longer term, climate models project substantially warmer summers for the continental US, although uncertainty remains as to whether this will be accompanied by drier conditions. This highlights a critical element to explore in future studies focused on US agricultural production risk under climate change.

Availability of existing early-season rice cultivars as resources for selecting high-yielding short-duration cultivars of machine-transplanted late-season rice

2019 ◽  
Vol 56 (2) ◽  
pp. 218-226
Author(s):  
Jiana Chen ◽  
Min Huang ◽  
Fangbo Cao ◽  
Xiaohong Yin ◽  
Yingbin Zou
Keyword(s):  
Grain Yield ◽  
Short Duration ◽  
Good Yield ◽  
Rice Production ◽  
Hunan Province ◽  
Rice Cultivars ◽  
Growth Duration ◽  
Yield Performance ◽  
Early Season ◽  
Late Season

AbstractHigh-yielding short-duration cultivars are required due to the development of mechanized large-scale double-season rice (i.e. early- and late-season rice) production in China. The objective of this study was to identify whether existing early-season rice cultivars can be used as resources to select high-yielding, short-duration (less than 115 days) cultivars of machine-transplanted late-season rice. Field experiments were conducted in Yongan, Hunan Province, China in the early and late rice-growing seasons in 2015 and 2016. Eight early-season rice cultivars (Liangyou 6, Lingliangyou 211, Lingliangyou 268, Xiangzaoxian 32, Xiangzaoxian 42, Zhongjiazao 17, Zhongzao 39, and Zhuliangyou 819) with growth durations of less than 115 days were used in 2015, and four cultivars (Lingliangyou 268, Zhongjiazao 17, Zhongzao 39, and Zhuliangyou 819) with good yield performance in the late season in 2015 were grown in 2016. All cultivars had a growth duration of less than 110 days when grown in the late season in both years. Zhongjiazao 17 produced the maximum grain yield of 9.61 Mg ha−1 with a daily grain yield of 108 kg ha−1 d−1 in the late season in 2015. Averaged across both years, Lingliangyou 268 had the highest grain yield of 8.57 Mg ha−1 with a daily grain yield of 95 kg ha−1 d−1 in the late season. The good yield performance of the early-season rice cultivars grown in the late season was mainly attributable to higher apparent radiation use efficiency. Growth duration and grain yield of early-season rice cultivars grown in the late season were not significantly related to those grown in the early season. Our study suggests that it is feasible to select high-yielding short-duration cultivars from existing early-season rice cultivars for machine-transplanted late-season rice production. Special tests by growing alternative early-season rice cultivars in the late season should be done to determine their growth duration and grain yield for such selection.

scholarly journals Field Evaluation of Yield and Yield Component Traits of Breeding Lines of Maize over Two Seasons in Derived Savannah Agro-Ecology

2018 ◽  
Vol 10 (4) ◽  
pp. 567-574
Author(s):  
Charles U. UBA ◽  
Christian U. AGBO ◽  
Uchechukwu P. CHUKWUDI ◽  
Andrew A. EFUSIE ◽  
Stella O. MUOJIAMA
Keyword(s):  
Grain Yield ◽  
Block Design ◽  
Field Evaluation ◽  
Yield Component ◽  
Seasonal Effects ◽  
International Institute ◽  
Early Season ◽  
Breeding Lines ◽  
Late Season ◽  
Positive Effects

The understanding of yield and the interaction with its components is very important for selection in early generations of crop breeding. Twelve maize genotypes were collected from International Institute for Tropical Agriculture (IITA) along with seven landraces in order to identify the contribution of different traits to yield improvement. The experiments were carried out in two different seasons (March/April-early and July/August- late) in a randomized complete block design with three replications. Early season planting had a higher grain yield than late season planting. The difference in grain yield between early and late season was 3.92 tons/ha. This represents a 27.8% increase in grain yield during the early season over the late season planting. Number of ears per plant and shelling percentage were not influenced by seasonal effects. Ear weight and days to tasselling showed the highest direct positive effects of 0.972 and 0.665, respectively on grain yield, during early season. Furthermore, ear weight, followed by shelling percentage, exerted the highest direct positive effect on grain yield in late season. Higher indirect positive effects were obtained for ear diameter, ear length, ear height and plant height via ear weight in both seasons. Ear weight, days to tasselling and ear length were identified as the major traits affecting yield of maize in both seasons in the derived Savannah agro-ecology.

scholarly journals Response of Sesame to Selected Herbicides Applied Early in the Growing Season

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
W. James Grichar ◽  
Jack J. Rose ◽  
Peter A. Dotray ◽  
Todd A. Baughman ◽  
D. Ray Langham ◽  
...  
Keyword(s):  
No Reduction ◽  
Field Studies ◽  
Yield Reduction ◽  
Early Season ◽  
Application Timing ◽  
Late Season ◽  
Growing Seasons ◽  
Leaf Chlorosis ◽  
Untreated Check ◽  
Dinitroaniline Herbicides

Growth chamber experiments were conducted to evaluate the response of sesame to PRE and POST applications of soil residual herbicides. PRE applications of acetochlor andS-metolachlor at 1.26 and 1.43 kg ai·ha−1showed little or no sesame injury (0 to 1%) 4 wks after herbicide treatments (WAT). POST treatments of acetochlor and trifluralin made 3 wks after planting (WAP) resulted in greater sesame injury (40%) compared to applications at bloom (18%). Field studies were conducted in Texas and Oklahoma during the 2014 and 2015 growing seasons to determine sesame response to clethodim, diuron, fluometuron, ethalfluralin, quizalofop-P, pendimethalin, pyroxasulfone, trifluralin, and trifloxysulfuron-sodium applied 2, 3, or 4 weeks after planting (WAP). Late-season sesame injury with the dinitroaniline herbicides consisted of a proliferation of primary branching at the upper nodes of the sesame plant (in the shape/form of a broom). Ethalfluralin and trifluralin caused more “brooming” effect than pendimethalin. Some yield reductions were noted with the dinitroaniline herbicides. Trifloxysulfuron-sodium caused the greatest injury (up to 97%) and resulted in yield reductions from the untreated check. Early-season diuron injury (leaf chlorosis and necrosis) decreased as application timing was delayed, and late-season injury was virtually nonexistent with only slight chlorosis (<4%) still apparent on the lower leaves. Sesame yield was not consistently affected by the diuron treatments. Fluometuron caused early-season injury (stunting/chlorosis), and a reduction of yield was observed at one location. Pyroxasulfone applied 2 WAP caused up to 25% sesame injury (stunting) but did not result in a yield reduction. Quizalofop-P caused slight injury (<5%) and no reduction in yield.

Heterogeneity in fire severity within early season and late season prescribed burns in a mixed-conifer forest

2006 ◽  
Vol 15 (1) ◽  
pp. 37 ◽  
Author(s):  
Eric E. Knapp ◽  
Jon E. Keeley
Keyword(s):  
Sierra Nevada ◽  
Prescribed Burning ◽  
Fire Severity ◽  
Basal Area ◽  
Conifer Forest ◽  
Fuel Loading ◽  
Early Season ◽  
Late Season ◽  
Fuel Loads ◽  
In Fire

Structural heterogeneity in forests of the Sierra Nevada was historically produced through variation in fire regimes and local environmental factors. The amount of heterogeneity that prescription burning can achieve might now be more limited owing to high fuel loads and increased fuel continuity. Topography, woody fuel loading, and vegetative composition were quantified in plots within replicated early and late season burn units. Two indices of fire severity were evaluated in the same plots after the burns. Scorch height ranged from 2.8 to 25.4 m in early season plots and 3.1 to 38.5 m in late season plots, whereas percentage of ground surface burned ranged from 24 to 96% in early season plots and from 47 to 100% in late season plots. Scorch height was greatest in areas with steeper slopes, higher basal area of live trees, high percentage of basal area composed of pine, and more small woody fuel. Percentage of area burned was greatest in areas with less bare ground and rock cover (more fuel continuity), steeper slopes, and units burned in the fall (lower fuel moisture). Thus topographic and biotic factors still contribute to the abundant heterogeneity in fire severity with prescribed burning, even under the current high fuel loading conditions. Burning areas with high fuel loads in early season when fuels are moister may lead to patterns of heterogeneity in fire effects that more closely approximate the expected patchiness of historical fires.

Weed Control in Soybean (Glycine max) with Flumetsulam, Cloransulam, and Diclosulam

1999 ◽  
Vol 13 (4) ◽  
pp. 791-798 ◽  
Author(s):  
David R. Shaw ◽  
Andrew C. Bennett ◽  
Donald L. Grant
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Standard Treatment ◽  
The Other ◽  
Early Season ◽  
Late Season ◽  
Pitted Morningglory

Cloransulam postemergence (POST), diclosulam preemergence (PRE), and flumetsulam preplant incorporated (PPI) and POST were evaluated in six trials at two locations for control of sicklepod and pitted morningglory in soybean. Sicklepod control with cloransulam plus flumetsulam POST was equivalent to chlorimuron POST in seven of eight comparisons both 3 and 6 wk after treatment. Sicklepod control with cloransulam POST was equivalent to chlorimuron in only three of eight comparisons 3 wk after treatment, but late-season control was equivalent in five of six comparisons. Pitted morningglory control with cloransulam alone or in tank-mixture with flumetsulam POST was equivalent to chlorimuron in all comparisons. Control of sicklepod and pitted morningglory was greater in most comparisons when a POST application followed flumetsulam plus trifluralin PPI compared to only trifluralin PPI. In a total PRE stale seedbed system, where all treatments were tank-mixed with pendimethalin plus glyphosate, sicklepod control with all rates of flumetsulam and 26 or 35 g ai/ha diclosulam was equivalent to the standard treatment of imazaquin or metribuzin plus chlorimuron. None of the total PRE programs controlled sicklepod as well as when glyphosate was applied sequentially POST. Pitted morningglory was controlled 83 to 93% with 26 or 35 g/ha diclosulam, equivalent to imazaquin, metribuzin plus chlorimuron, or sequential glyphosate applications 8 wk after the PRE application. Increasing flumetsulam rate increased pitted morningglory control early season, but flumetsulam was not as effective as the other herbicides.

Weed Competition in Rice

Weed Science ◽  
1968 ◽  
Vol 16 (2) ◽  
pp. 252-255 ◽  
Author(s):  
Roy J. Smith
Keyword(s):  
Oryza Sativa ◽  
Weed Competition ◽  
Early Season ◽  
Echinochloa Crusgalli ◽  
Late Season ◽  
Sesbania Exaltata ◽  
Hemp Sesbania

Barnyardgrass [Echinochloa crusgalli (L.) Beauv.], duck-salad [Heteranthera limosa (Sw.) Willd.], hemp sesbania [Sesbania exaltata (Raf.) Cory], and northern jointvetch [Aeschynomene virginica (L.) B.S.P.] significantly reduced rice [Oryza sativa L.] yields. Damage to rice increased as populations of barnyardgrass, hemp sesbania, and northern jointvetch increased. Barnyardgrass and duck-salad lowered yields during early season, but hemp sesbania and northern jointvetch decreased yields in late season.

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