Added: Ervin Hudgens - Date: 14.07.2021 21:15 - Views: 42129 - Clicks: 9772
The leaf beetle, Ophraella communa, has been introduced to control the spread of the common ragweed, Ambrosia artemisiifolia, in China. We hypothesized that the beetle, to be able to track host-range expansion into colder climates, can phenotypically adapt to cold temperatures across generations. Therefore, we questioned whether parental experience of colder temperatures increases cold tolerance of the progeny. Specifically, we studied the demography, including development, fecundity, and survival, as well as physiological traits, including supercooling point SCPwater content, and glycerol content Girls having sex in Bettles county O.
Overall, the entire immature stage decreased survival of about 0. Glycerol contents of both female and male in progeny was ificantly higher when maternal and paternal adults were cold acclimated as compared to other treatments. This resulted in the supercooling point of the progeny adults being ificantly lower compared to beetles emerging from parents that experienced room temperatures. These suggest that cold hardiness of O.
This is an open-access article distributed under the terms of the Creative Commons Attributionwhich permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The funders had no role in study de, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist. In a changing environment, such as during range expansion, organismal rapid adaptation to novel environmental conditions is needed for assuring survival . Such maternal effects have been reported in both animals and plants .
For example, repeated exposition to cold temperatures in female flies resulted in a change in sex ratio and of offspring Girls having sex in Bettles county. Insects may be ificantly impacted if temperature deviates from the optimum range however, the amplitude of the impact depends on the rate, Girls having sex in Bettles county, and duration of temperature change . Resistance to cold temperatures, or cold hardiness of insects, is reflected by four variables relating to insect physiology including; water content, accumulation of glycerol or other low molecular weight polyols and sugars cryoprotectantssupercooling point SCPand survival capacity under low temperature .
studies revealed that better cold hardiness is typically associated with lower SCP, lower water content, and higher glycerol content in the insect . We can thus posit that temperature-driven maternal effects are an excellent strategy for insect herbivores to be able to track range expansion of the host plant into colder climates.
We tested this hypothesis using Ophraella communa Coleoptera: Chrysomelidae. Adults and larvae of the beetle feed on leaves of the common ragweed Ambrosia artemisiifolia . Due to the insect potential to drastically reduce plant fecundity O. However, insects may be disfavored when common ragweed populations are expanding into colder regions of China . Indeed, study revealed that the development and female fecundity of O.
However, during the gradual temperature decrease from summer to Girls having sex in Bettles county, cold hardiness of O. Adults overwinters in soil and can even survive severe subzero temperatures during winter . Therefore, if maternal effects are adaptive we should expect cold hardiness of the progeny being enhanced by maternal and paternal cold experience.
We measured fitness parameters survival rate, longevity, fecundity, and life table analyses and cold hardiness indices SCP, water and glycerol contents of O. The common ragweed, Ambrosia artemisiifolia is the most widespread plant of the genus Ambrosia in North America and has become invasive in most European as well as Asian countries such as Japan and China . Plants were used for experiments when they reached a height of about 50 cm.
Ophraella communa pupae were collected from A. Both A. studies have shown that minimum threshold temperatures of egg, larva, pupa and entire immature stage of O. Based on these findings, the present experiment was deed as follows: 30 females and 30 males kept separated were put in similar plastic boxes as above, and transferred randomly in three environmental chambers PRYD, Ningbo Haishu Aifu Experimental Equipment Co.
Larvae were maintained on A. Pupae were then detached from leaves, placed in an unsealed cuvette individually, and monitored daily until adult emergence. Survival rates and developmental period of the different developmental stages egg, larval, pupae, and entire immature stage were recorded. Newly emerging adults were randomly sampled and paired by sex, and provided daily with fresh A.
All eggs laid on twigs were counted until the female died. Longevity of adult beetles was finally recorded. For measuring SCP, an additional 30 F 1 adult beetles from each treatment were removed from ragweed plants and then starved for 12 h. Each adult beetle abdomen was fixed to a thermocouple that was attached to an automatic data recorder uR, ModelYokogawa Electric Co. The SCP was taken to be the temperature recorded by the thermocouple just before the sudden increase in temperature caused by the emission of the latent heat of crystallization .
Finally, glycerol was measured from 5 male and 5 female F1 adult beetles from each treatment. The whole-body glycerol content of beetles was determined using an enzymatic assay A, Sigma Chemical Company, St. Briefly, twelve hours-starved individual adults were homogenized in 25 mM sodium phosphate buffer pH 7. The supernatant was then neutralized with 5 M potassium carbonate to pH 7. Glycerol levels were determined spectrophotometrically by measuring sample absorbance at nm . Overall, if stage differentiation was ignored, a single age-specific survival rate l x curve of progeny Girls having sex in Bettles county.
Two-way ANOVAs were conducted for testing the interactive effects of temperature, and gender on the survival rates, longevities and cold hardiness physiological parameters of O. Overall, temperature experienced by parents did not affect development time of immature stages in the next generation Table 1. However, temperature treatment strongly affected survival Table 1Fig.
We also found temperature variation effect of parent beetles on the next generation female fecundity Fig. Water content in progeny adult beetles was similar independent of cold treatments experienced by the parents Table 3. Insects that experienced colder temperatures had the lowest supercooling point i. With the present study we show that generation cold experience impact survival, longevity, fecundity and physiological parameters in the progeny beetles. Insects living in temperate regions have to cope with low winter temperatures, which may strongly influence the establishment and persistence of perennial populations in the field .
In general, survival rates of insects decrease with decreasing temperatures and this phenomenon has been also observed in O. Many insect species are thus able to increase their over-wintering survival through increased cold hardiness during the pre-winter months . Whether low temperature experience of insects can stimulate increased tolerance to cold in the next generation remained until now an open question. Additionally, at low temperatures, resources of the insect are diverted into high-quality egg production, which, due to physiological trade-offs, result in overall reduced fecundity .
Subsequently, because high quality eggs impose an increase in the metabolic rates, females may additionally experience reduced longevity . Because studies explored only the effects of low temperatures on one generation, positive physiological adaptation transmitted to the next generation remained hidden. Indeed, as we report here, higher longevity and increased cold hardiness may be seen as counterbalancing adaptations against reduced survival in the next generation.
Insects in nature have evolved various physiological mechanisms to improve their cold-hardiness, and hence their survival under cold environments . Indeed, cold acclimation often in insects accumulating reserves of glycogen that are subsequently broken down into glycerol during cold temperatures in order to improve their cold-hardiness .
Additionally, in insects, glycerol accumulation is often associated with both lower SCP and reduced water content .
Thus, insects can often improve their cold hardiness via physiological changes meditated by cold acclimation . Our experiments showed that higher levels of glycerol content point in the progeny is mediated by maternal and paternal cold environment, in which, the coldest temperatures trigger females to allocate higher levels of glycerol in the progeny. This in bettles to have lower supercooling points when parents experienced colder temperatures. It has been demonstrated that cold hardiness, via changes in the relative composition of their body fluids and fats, is a plastic trait that can be influenced by fluctuations in abiotic factors e.
The present experiment is in line with the idea that O. Future work will need to assess whether increase in cold hardiness as shown here finally in increased survival when next generation beetles are placed at low temperatures. For example, in Drosophila melanogastercold exposure Girls having sex in Bettles county with variation in feeding regimes resulted in fewer, smaller offspring, and resulted in a male-biased sex ratio . Similarly, A different nutritional experience resulted in modified offspring survival and fecundity in the gypsy moth, Lymantria dispar .
In our study, although cold temperatures have a little effect on progeny O. In plants, it has recently been shown that small interfering RNAs and phytohormones are needed to mediated transgenerational priming for increased resistance against biotic and abiotic stresses . Future work is thus necessary for measuring iRNAs-mediated transgenerational effects in beetles . Independently of the mechanisms behind the observedwe believe that generation environmentally-induced cold hardiness in O. This implies that the descendants of O.
Such studies are thus not only needed to improve knowledge of fundamental physiological processes, but are also needed to further improve biological control practices of noxious and biodiversity-threatening weeds worldwide. We are very Girls having sex in Bettles county to the anonymous reviewers whose appropriate commentary strengthened the manuscript. We are also very grateful to Prof. We thank Mr. Min Luo, Ms.
Wei Guo and Dr. Xing-Wen Zheng, Mr. Yong-Xiang Fang and Ms. Browse Subject Areas?
Click through the PLOS taxonomy to find articles in your field. Abstract The leaf beetle, Ophraella communa, has been introduced to control the spread of the common ragweed, Ambrosia artemisiifolia, in China.
Introduction In a changing environment, such as during range expansion, organismal rapid adaptation to novel environmental conditions is needed for assuring survival .Girls having sex in Bettles county
email: [email protected] - phone:(228) 552-6389 x 5406
Cite This Item