Seasonal responses and their geographic variation in Chrysopa downesi: ecophysiological and evolutionary considerations

1981 ◽  
Vol 59 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Maurice J. Tauber ◽  
Catherine A. Tauber
Keyword(s):  
New York ◽  
Geographic Variation ◽  
Thermal Thresholds ◽  
Preoviposition Period ◽  
Geographic Populations ◽  
Dark Green ◽  
Diapause Incidence ◽  
T Values ◽  
Two Populations ◽  
Seasonal Responses

A comparison of Chrysopa downesi strains from Montana and from New York indicates that they share several characteristics in their seasonal cycles: (1) a short-day – long-day requirement for diapause prevention, (2) dark green adult coloration all year round, (3) relatively high t values (lower thermal thresholds for development), and (4) sensitivity to photoperiod during the nondiapause preoviposition period.Responsiveness to prey differs between the two strains. Prey presence very slightly reduces diapause incidence and greatly shortens the nondiapause preoviposition period in the strain from Montana, whereas prey presence has little or no influence on the strain from the northeastern United States. The strains also differ in their ability to terminate diapause spontaneously; unlike the northeastern strain, a proportion of the northwestern strain ends diapause without an overt, external stimulus.The two populations of C. downesi thus share the two characteristics that are basic to the model of C. downesi's sympatric speciation from an ancestor like C. carnea. In contrast, the differences between the two populations in their responsiveness to prey presence parallels the geographic variation in C. carnea. We propose two alternate pathways (polyphyletic and monophyletic) for the evolution of the seasonal responses of the two geographic populations.

Density-dependent polyphenism and geographic variation in size among two populations of lubber grasshoppers (Romalea microptera)

2009 ◽  
Vol 34 (5) ◽  
pp. 644-651 ◽  
Author(s):  
JASON E. JANNOT ◽  
ALEXANDER E. KO ◽  
DUSTIN L. HERRMANN ◽  
LAURA SKINNER ◽  
EMILY BUTZEN ◽  
...  
Keyword(s):  
Geographic Variation ◽  
Density Dependent ◽  
Two Populations

GEOGRAPHIC VARIATION IN DIAPAUSE INCIDENCE, LIFE-HISTORY TRAITS, AND CLIMATIC ADAPTATION IN DROSOPHILA MELANOGASTER

Evolution ◽  
2005 ◽  
Vol 59 (8) ◽  
pp. 1721 ◽  
Author(s):  
Paul S. Schmidt ◽  
Luciano Matzkin ◽  
Michael Ippolito ◽  
Walter F. Eanes
Keyword(s):  
Drosophila Melanogaster ◽  
Life History ◽  
Geographic Variation ◽  
Life History Traits ◽  
Climatic Adaptation ◽  
Diapause Incidence

LIFE HISTORY PARAMETERS IN MELANOPLUS SANGUINIPES (F.) IN TWO CRESTED WHEATGRASS PASTURES

1988 ◽  
Vol 120 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Norma E. Sanchez ◽  
Jerome A. Onsager
Keyword(s):  
Life History ◽  
Survival Rates ◽  
Adult Longevity ◽  
Melanoplus Sanguinipes ◽  
Crested Wheatgrass ◽  
Life History Parameters ◽  
Preoviposition Period ◽  
Point Estimates ◽  
Two Populations ◽  
Net Replacement

AbstractA combination of published techniques provided point estimates of life history parameters for two natural field populations of Melanoplus sanguinipes (F.) in crested wheatgrass pastures. Stage-specific survival rates averaged 0.4798, 0.2261, 0.7628, and 0.6903 for egg, instars I–III combined, instar IV, and instar V, respectively. Daily survival rates of adults averaged 0.9702, but were slightly lower for females than for males. Estimated duration of nymphal instars averaged 8.4 days, the adult preoviposition period averaged 13.3 days, and adult longevity averaged 26.7 and 36.3 days in the two populations. Oviposition rates were estimated for up to four successive ovipositions, and net replacement rates of populations also were estimated. Neither population replaced itself, indicating that potential capacities for increase were not approached under conditions of these studies.

scholarly journals Geographic variation in the morphology of the sand-dwelling lizard Nothobachia ablephara (Squamata: Gymnophthalmidae)

2019 ◽  
Vol 18 (2) ◽  
pp. 195-207
Author(s):  
Carolina Nisa Ramiro ◽  
Renato Sousa Recoder ◽  
Miguel Trefaut Rodrigues
Keyword(s):  
Geographic Variation ◽  
Morphological Traits ◽  
Geographical Variation ◽  
Multivariate Analyses ◽  
Molecular Study ◽  
Northeastern Brazil ◽  
Sexually Dimorphic ◽  
Morphometric Variation ◽  
The One ◽  
Two Populations

Geographic variation in the morphology of the sand-dwelling lizard Nothobachia ablephara (Squamata: Gymnophthalmidae). Nothobachia ablephara is a small microteiid lizard with an elongated body and reduced limbs; it occurs in isolated dune felds in the state of Bahia (Xique-Xique and Alagoado) and small sandy patches in northeastern Brazil. A previous molecular study found a marked mtDNA divergence between populations of N. ablephara from Alagoado and Xique-Xique dunes, suggesting that the two populations diverged from one another between 3 and 4 million years ago. Given this isolation, it is interesting to explore whether morphological traits of the lizards refect the reported genetic divergence of the populations. Scale counts of the sexes and the populations differ signifcantly, but there is considerable overlap of values. Univariate and multivariate analyses revealed signifcant morphometric variation between sexes and populations; however, this is mostly explained by size differences. Females are larger than males in all characters that are sexually dimorphic, and individuals from Xique-Xique are larger than those from Alagoado in all characters that vary geographically. The sample from Alagoado has more sexually dimorphic characters than the one from Xique-Xique. Although N. ablephara displays some geographical variation, the two populations could not be unequivocally distinguished by scale counts and morphometric data.

Geographic variation in the advertisement call of Crinia signifera (Anura:Myobatrachidae) on Kangaroo Island and across southern south-eastern Australia

2008 ◽  
Vol 56 (4) ◽  
pp. 223 ◽  
Author(s):  
Murray J. Littlejohn
Keyword(s):  
Geographic Variation ◽  
Pulse Number ◽  
Advertisement Call ◽  
Regional Study ◽  
South Eastern ◽  
Island Sample ◽  
Eastern Australia ◽  
Continental Islands ◽  
Two Populations ◽  
South Eastern Australia

The male advertisement call of anuran amphibians has a major role in mate choice, and regional variation in this attribute can act as an indicator of speciation and a marker for genetic differentiation. As part of a regional study of geographic variation in the male advertisement call of Crinia signifera across south-eastern Australia and adjacent larger continental islands, samples of advertisement calls from two populations on Kangaroo Island and two populations on the adjacent Fleurieu Peninsula were compared. Four call attributes were considered: pulse number, call duration, pulse rate and dominant frequency. Pulse number is considered the most reliable for comparative purposes because it is not influenced by effective temperature or audio recording and analysis. The two island populations (central and eastern, ~24 km apart) differ significantly in pulse number, with contact but no overlap of interquartile ranges. The eastern sample differs markedly from those on the nearby Fleurieu Peninsula – which are both similar to the more distant central island sample. Geographic variation in pulse number in these four samples and 11 others from two recent publications is then interpreted in the light of land bridges and lower temperatures of the late Pleistocene and early Holocene.

Hog's Back Formation: a new (Middle Ordovician) stratigraphic unit, Ottawa Embayment, eastern Ontario, Canada

1997 ◽  
Vol 34 (5) ◽  
pp. 588-597 ◽  
Author(s):  
Osman Salad Hersi ◽  
George R. Dix
Keyword(s):  
New York ◽  
Carbonate Facies ◽  
Lake Champlain ◽  
Middle Ordovician ◽  
Stratigraphic Unit ◽  
Type Section ◽  
Eastern Ontario ◽  
Dark Green

The Hog's Back Formation, exposed in Ottawa, Ontario, is a new stratigraphic unit that disconformably overlies the Rockcliffe Formation and underlies, with apparent conformity, the Pamelia Formation of the Ottawa Group. The Hog's Back Formation is 14.3 m thick at its type section (Prince of Wales Falls, Ottawa) and thickens eastward to 27 m in Russell County, about 40 km southeast of Ottawa. It consists of lower, dark green shales with thin lime-mudstone and sandstone interbeds, and upper thin to thick beds of fine crystalline greenish grey sandy and calcareous dolostones with thin to medium (10–30 cm) pinkish grey, bioclastic packstone and grainstone interbeds. The latter thicken eastward and correlate with the "St. Martin calcarenites" of the Beaconsfield Member, Laval Formation, in the Montréal area. Together, these beds correlate with the Valcour Formation, Chazy Group, in the Lake Champlain area of New York. Conodonts and macrofossils indicate a Chazyan (Llandeilian) age for the Hog's Back Formation. The lower sandstone–shale–carbonate assemblage of the formation indicates sedimentation in peritidal environments, and documents initial regional flooding of nearshore sandy facies of the Rockcliffe Formation. The overlying carbonate facies represent sabkha environments punctuated by storm deposition. The gross shallowing-upward succession of the formation was terminated by renewed flooding associated with another regional transgressive event heralding deposition of the Ottawa Group.

PHEROMONES OF IPS PINI (COLEOPTERA: SCOLYTIDAE): VARIATION IN RESPONSE AMONG THREE POPULATIONS

1972 ◽  
Vol 104 (12) ◽  
pp. 1917-1923 ◽  
Author(s):  
Gerald N. Lanier ◽  
Martin C. Birch ◽  
Richard F. Schmitz ◽  
Malcolm M. Furniss
Keyword(s):  
New York ◽  
Geographic Variation ◽  
Local Population ◽  
Field Tests ◽  
Ips Pini ◽  
Pheromone Production ◽  
Opposite Trend ◽  
Enoclerus Lecontei ◽  
Tomicobia Tibialis ◽  
And Control

AbstractReciprocal field tests of attraction between populations of Ips pini (Say) from California, Idaho, and New York disclosed geographic variation in pheromone systems. These differences reside both in pheromone production and reception. However, it is unknown whether variation in the pheromone bouquets is qualitative, quantitative, or both.In New York, both sexes responded in higher numbers to their own pheromone than that produced by California or Idaho males. In California, beetles of both sexes discriminated against New York, but in Idaho only females made this distinction. In both California and Idaho, the local population showed a slight preference for the pheromone produced by Idaho males over that produced by California males.The predator Enoclerus lecontei (Wolc.) demonstrated a four-fold preference for attractants produced by males from New York over those produced by beetles from California and Idaho. The parasitoid Tomicobia tibialis Ashmead showed the opposite trend.There is no evidence that geographic variation in the pheromones produced by I. pini is sufficient to enforce breeding isolation between adjacent populations. However, these results dramatize the necessity of considering pheromonal variability in programs applying pheromones for the survey and control of widely distributed pests.

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