Population-Growth Potential of Epiphyas-Postvittana, the Lightbrown Apple Moth (Lepidoptera, Tortricidae) in Relation to Diet, Temperature and Climate

1995 ◽  
Vol 43 (4) ◽  
pp. 381 ◽  
Author(s):  
W Danthanarayana ◽  
H Gu ◽  
S Ashley

Life-history parameters and developmental rates of Epiphyas postvittana were determined for four natural food plants and Shorey's diet at each of six temperatures. The rate of development of larvae and the life-history parameters were influenced by both temperature and diet. The highest r(m) value was given by populations feeding on Plantago lanceolata, followed by those on Shorey's diet and Rumex crispus, all at 25 . 2 degrees C, then by Malus pumila at 19 . 9 degrees C and Trifolium repense at 25 . 2 degrees C. Zero population growth occurred at 7 . 1 and 30 . 7 degrees C. A life-table study of five geographical strains of the moth under non-variable conditions (constant temperature and artificial diet) showed that finite rate of increase (lambda) was significantly correlated with climatic features of habitats, viz. mean annual Values of temperature, rainfall and relative humidity. Peak values of lambda occurred at cooler temperatures, moderate levels of habitat moisture and high altitudes (500-1000 m); the Canberra population gave the highest value (lambda = 1 . 157), followed by Armidale (lambda = 1 . 152), Melbourne (lambda = 1 . 141), Mildura (lambda = 1 . 135) and Auckland (lambda = 1 . 118). Higher performance of E. postvittana on herbaceous plants than on woody plants suggests that it primarily evolved as a feeder on herbaceous plants.

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 108 ◽  
Author(s):  
Byju N. Govindan ◽  
William D. Hutchison

Temperature is a critical single factor influencing insect population dynamics, and is foundational for improving our understanding of the phenology of invasive species adapting to new agroecosystems or in the process of range expansion. An age-stage, two-sex life table was therefore developed to analyze fundamental demographic features such as development, survival, and reproduction of a Minnesota-acclimated population of the invasive brown marmorated stink bug (Halyomorpha halys), in the north central USA. All salient life history parameters were estimated to better understand the population growth potential of H. halys at the current limit of its northern range in North America. We examined the effect of selected constant temperatures on immature development and survival (15–39 °C), adult reproduction and longevity (17–36 °C) of H. halys in the laboratory. The Minnesota population developed faster and survived at higher rates relative to a population that had previously established in Pennsylvania, USA. Mean generation time for the Minnesota population was minimized at 30 °C, while survival and fecundity were maximized at 27 and 23 °C, respectively. Given these findings, we assessed the effect of temperature on the intrinsic rate of increase ( r m ), the life table parameter that integrates the effects of temperature on development, survival, and reproduction. A Ratkowsky model predicted r m was maximized (0.0899) at 27.5 °C. We discuss the implications of our findings for understanding population growth rates for H. halys in the context of a warming climate, and potential to emerge as a serious crop pest in the Midwest U.S. region.


2007 ◽  
Vol 13 ◽  
pp. 333-336
Author(s):  
S.A. Härri ◽  
J. Krauss ◽  
C.B. Müller

Plant-endophyte associations can have major impacts on the dynamics of consumer interaction-webs but long-term effects of mycotoxins and the ability of herbivores to adapt to these toxins have not been studied. To understand the potential of aphids to cope with mycotoxins, we compared the life-history parameters for aphids conditioned for several generations on endophyte-infected plants with those of endophyte-naïve aphids on both endophyteinfected and endophyte-free grasses. Aphids conditioned on endophyte-infected plants produced more offspring during the first days of adulthood than endophyte-naïve aphids independent of the endophyte infection of the test environment. However, the endophyte-conditioned aphids tended to have a shorter lifespan, which resulted in similar numbers of total offspring produced for endophyte-conditioned and endophyte-naïve aphids. The difference in life-history parameters caused by the conditioning environment suggests that the effects of endophytes on herbivore life-history traits may represent an adaptive change that should be considered in future studies of endophyte-herbivore interactions. Keywords: Rhopalosiphum padi, Neotyphodium lolii, Lolium perenne, common strain, adaptation, long-term effects, microbes, endosymbionts, reproductive strategy, life-history traits


2018 ◽  
Vol 109 (2) ◽  
pp. 212-220 ◽  
Author(s):  
Z.-Z. Chen ◽  
L.-X. Xu ◽  
L.-L. Li ◽  
H.-B. Wu ◽  
Y.-Y. Xu

AbstractThe oriental fruit moth, Grapholita molesta, is an important pest in many commercial orchards including apple, pear and peach orchards, and responsible for substantial economic losses every year. To help in attaining a comprehensive and thorough understanding of the ecological tolerances of G. molesta, we collected life history data of individuals reared on apples under different constant temperature regimes and compared the data with moths reared under a variable outdoor temperature environment. Because G. molesta individuals reared at a constant 25°C had the heaviest pupal weight, the highest survival rate from egg to adult, highest finite rate of increase, and greatest fecundity, 25°C was considered as the optimum developmental temperature. The G. molesta population reared at a constant 31°C had the shortest development time, lowest survival rate and fecundity, resulting in population parameters of r < 0, λ < 1, lead to negative population growth. The population parameters r and λ reared under fluctuating temperature were higher than that reared under constant temperatures, the mean generation time (T) was shorter than it was in all of the constant temperatures treatments. This would imply that the outdoor G. molesta population would have a higher population growth potential and faster growth rate than indoor populations raised at constant temperatures. G. molesta moths reared under fluctuating temperature also had a higher fertility than moths reared under constant temperatures (except at 25°C). Our findings indicated that the population raised under outdoor fluctuating temperature conditions had strong environment adaptiveness.


1985 ◽  
Vol 42 (5) ◽  
pp. 873-879 ◽  
Author(s):  
J. M. Berkson ◽  
D. P. DeMaster

A series of population simulations were used to test the accuracy of estimating the discrete rates of population change (RPC) from annual pup counts. The simulations indicate that pup counts can give a biased estimate of RPC, and that the magnitude and direction of bias depends on which life history parameters are density dependent and on the maximum rate of population change. In general, if pre-census pup survival is density dependent the estimated RPC using pup counts is too low. If post-census pup survival is density dependent, the estimated RPC is too high. If adult survival is density dependent, there is very little bias in the estimate. The results indicate that pup counts can be reliable indicators of population growth, but caution should be used in interpreting the results unless density feedback mechanisms have been identified.


2014 ◽  
Vol 1 (1) ◽  
pp. 18-29
Author(s):  
Saeid Javadi Khederi ◽  
Mohammad Khanjani

The demographic parameters of brown mite, Bryobia rubrioculus Scheuten were carried out in order to characterize the population growth potential at five constant temperatures: 20, 22.5, 25, 27.5 and 30ºC, 60 ± 5 % RH and 16: 8 (L: D) h. The highest intrinsic rate of natural increase (rm = 0.0243/day), net reproductive rate (R0 = 2.4 ♀/♀/T) and finite rate of increase (λ = 1.0245 day-1) values were determined at 22.5°C. The mean generation time (T) of the population ranged from 22.7 days at 30°C to 45.8 days at 20°C. The maximum and minimum survival rates (lx) were recorded at 22.5ºC and 30ºC. Survivorship data (lx) of adult females were summarized and compared using the shape and scale parameters of the Weibull frequency distribution model across. The age specific fecundity data (mx) was modeled as a function of time by using Polynomial model. The lower temperature threshold (t) and thermal constant (k) of the immature stages were estimated using Ikemoto and Takai linear model to be 12.85ºC and 279.7 degree days (DD), respectively. Of the non-linear models, the Analitis-1, Analitis-2, Analitis-3 and Analitis/Allahyari models were found to be the best for the modeling development rate of immature stages of B. rubrioculus. The optimal temperature for population growth of brown mite on apple was found at 22.5°C.


1974 ◽  
Vol 25 (3) ◽  
pp. 351 ◽  
Author(s):  
RJ Rippingale ◽  
EP Hodgkin

The intrinsic rate of increase of an animal population can be calculated from data on longevity, sex ratio, maturation rate and fecundity and can be expressed as r in the population growth equation Nt = N0ert. Laboratory and field data are used to calculate the value of r per day for the copepod Gladioferens imparipes Thomson. The r values obtained, 0.146 per day at 15� C and 0.293 per day at 25� C, are both high. This high population growth potential is interpreted as an adaptation to the estuarine habitat.


2020 ◽  
Vol 113 (2) ◽  
pp. 964-973
Author(s):  
Zahra Abedi ◽  
Ali Golizadeh ◽  
Mahmoud Soufbaf ◽  
Mahdi Hassanpour ◽  
Ali Jafari-Nodoushan ◽  
...  

Abstract Plant–herbivore interactions can be influenced by plant developmental stages. Effects of four different developmental stages of pomegranate fruit (Hazelnut size, Walnut size, Juicy, and Ripe) were investigated on life table parameters, nutritional yield, and energy contents (protein, glycogen, and lipid) of Ectomyelois ceratoniae (Zeller) under controlled conditions in two pomegranate cultivars, namely Shahvare-Danesefid and Esfahani-Daneghermez as susceptible and resistant cultivars, respectively. Biochemical characteristics of the four developmental stages were determined, and a correlation was made with life-history and nutritional responses of E. ceratoniae. Significant differences were observed in developmental time and adult fecundity of E. ceratoniae across various tested stages in both pomegranate cultivars. The highest value of intrinsic rate of increase (rm) was found in Juicy and lowest in Hazelnut-size stage of Shahvare-Danesefid. The highest rm value was on Walnut-size and Juicy stages, and the lower rate was obtained from the feeding of E. ceratoniae on Ripe and Hazelnut-size stages in Esfahani-Daneghermez. A higher relative growth rate (RGR) was observed in Juicy (in Shahvare-Danesefid) and Walnut-size stages (in Esfahani-Daneghermez) when compared with other developmental stages tested. Life-history parameters of E. ceratoniae were correlated with biochemical qualities of pomegranate stages. Results indicated Juicy (Shahvare-Danesefid) and Walnut-size stages (Esfahani-Daneghermez) were relatively susceptible pomegranate stages, and Hazelnut-size and Ripe stages were unsuitable for feeding of E. ceratoniae in Shahvare-Danesefid and Esfahani-Daneghermez, respectively. Findings of this research could aid in the development of integrated management programs of E. ceratoniae in pomegranate orchards.


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