Differences in pupal cold hardiness and larval food consumption between overwintering and non-overwintering generations of the common yellow swallowtail,Papilio machaon(Lepidoptera: Papilionidae), from the Osaka population

2016 ◽  
Vol 19 (3) ◽  
pp. 180-187
Author(s):  
Norio Hirai ◽  
Yuka Hirai ◽  
Minoru Ishii
Keyword(s):  
Food Consumption ◽  
Cold Hardiness ◽  
Larval Food ◽  
The Common

Mechanism of freezing resistance in eco-dormant birch buds under winter subzero temperatures

2019 ◽  
Author(s):  
Keita Endoh ◽  
Seizo Fujikawa
Keyword(s):  
Cold Hardiness ◽  
Common Property ◽  
Leaf Primordia ◽  
Intercellular Spaces ◽  
Freezing Resistance ◽  
Cooling Rates ◽  
Dormant State ◽  
Sem Observation ◽  
Subzero Temperatures ◽  
The Common

Abstract Maximum freezing resistance is a component of winter survival and is associated with the eco-dormant state. Differential thermal analysis (DTA) has shown that changes of the freezing response of the dormant buds depend not only on species and bud type, but also on cooling rates. In order to clarify the freezing adaptation at the cellular level of eco-dormant buds in Japanese white birch, birch buds cooled at a rate of 0.2 °C min−1 and 5 °C day−1 were precisely examined by cryo-scanning electron microscopy (cryo-SEM). Freezing responses of floral dormant buds having female inflorescent primordia and leaf primordia with high-cold hardiness were assessed for extracellular freezing patterns by DTA. Cryo-SEM observation showed freezing of viscous solution filling intercellular spaces within buds and formation of extracellular ice in a random distribution within certain tissues, including green scales, leaf primordia and peduncles. The tissues producing extracellular ice had the common property that distinct intercellular spaces were present among cells having comparatively thick primary walls. In contrast, extracellular ice was not formed within flower primordium and parts of leaf primordium. These tissues had also the common property that no detectable intercellular spaces existed around the cells having thin primary walls. Cryo-SEM observation confirmed that all cells in tissues, regardless of whether extracellular ice was formed within tissues, and also regardless of differences in cooling rates, showed distinct cellular shrinkage by freezing. Recrystallization experiments by cryo-SEM confirmed that all freezable water in cells was eliminated by cooling at 0.2 °C min−1 at least to −30 °C. These results confirmed that all cells in birch buds responded to subzero temperatures through rapid equilibrium dehydration. In contrast to deep supercooling associated with extraorgan freezing of other freezing resistant buds of trees in an eco-dormant state, the mechanism of freezing resistance in eco-dormant birch buds is freezing adaptations by extracellular freezing.

ECONOMIC INJURY LEVELS OF THE ALFALFA WEEVIL (COLEOPTERA: CURCULIONIDAE)

1973 ◽  
Vol 105 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Philip G. Koehler ◽  
David Pimentel
Keyword(s):  
Food Consumption ◽  
Larval Density ◽  
New York State ◽  
Live Weight ◽  
Dry Weight ◽  
Larval Feeding ◽  
Larval Food ◽  
Alfalfa Weevil ◽  
Second Growth ◽  
Economic Injury

AbstractEconomic injury levels of the alfalfa weevil on alfalfa were investigated in New York State. The dry weight food consumption for the larval stage of the alfalfa weevil averaged 7.34 mg/larva. For every gram (dry weight) of alfalfa consumed, 1.59 g (live weight) in insect tissue was produced. In the laboratory, it was found that insect food consumption could account for only about 50% of the total weight loss in alfalfa plants after 10 days of larval feeding. Therefore, alfalfa weevil damage to alfalfa was more than the larval food consumption, and this was believed to be due to the loss of the plant’s photosynthetic potential. In the field on first growth alfalfa, the economic injury level was calculated to be 56 larvae/stem. First growth alfalfa was less severely injured by alfalfa weevil larvae than our second growth alfalfa infested with equal populations of alfalfa weevils. It was shown that first growth alfalfa was able to compensate for 87% of the insect feeding while second growth alfalfa could compensate for only 50%. Since the alfalfa plant’s capacity to compensate for alfalfa weevil feeding can vary due to environmental conditions and plant characteristics, economic injury levels must be adjustable. To provide more reliability to economic injury levels, we propose that in alfalfa the following seven measurements be made: (1) alfalfa weevil larval density; (2 and 3) parasites and predators of the weevil; (4) rainfall and moisture level; (5) plant nutrients; (6) alfalfa variety; and (7) stage and previous management of alfalfa stand.

scholarly journals Gregarines modulate insect responses to sublethal insecticide residues

Oecologia ◽  
2021 ◽  
Author(s):  
Marina Wolz ◽  
Alia Schrader ◽  
Eileen Whitelaw ◽  
Caroline Müller
Keyword(s):  
Food Consumption ◽  
Anthropogenic Pollution ◽  
Leaf Beetle ◽  
Additional Stress ◽  
Adult Males ◽  
Larval Food ◽  
Insecticide Exposure ◽  
Naturally Occurring ◽  
Parasite Infections ◽  
Sublethal Concentrations

AbstractThroughout their lifetime, insects face multiple environmental challenges that influence their performance. Gregarines are prevalent endoparasites in most invertebrates that affect the fitness of their hosts, but are often overlooked in ecological studies. Next to such biotic factors, a current common challenge is anthropogenic pollution with pesticides, which causes a major threat to non-target organisms that are readily exposed to lethal or sublethal concentrations. In a laboratory study, we investigated whether the presence of gregarines modulates the food consumption and life history traits of a (non-target) leaf beetle species, Phaedon cochleariae, in response to sublethal insecticide exposure. We show that the larval food consumption of the herbivore was neither affected by gregarine infection nor sublethal insecticide exposure. Nevertheless, infection with gregarines led to a delayed development, while insecticide exposure resulted in a lower body mass of adult males and a reduced reproduction of females. Individuals exposed to both challenges suffered most, as they had the lowest survival probability. This indicates detrimental effects on the population dynamics of non-target insects infected with naturally occurring gregarines that face additional stress from agrochemical pollution. Moreover, we found that the infection load with gregarines was higher in individuals exposed to sublethal insecticide concentrations compared to unexposed individuals. To counteract the global decline of insects, the potential of natural parasite infections in modulating insect responses to anthropogenic and non-anthropogenic environmental factors should be considered in ecological risk assessment.

A comparison of the peroxidase isozymes of wheat plants grown at 6 °C and 20 °C

1969 ◽  
Vol 47 (2) ◽  
pp. 263-265 ◽  
Author(s):  
D. W. A. Roberts
Keyword(s):  
Gel Electrophoresis ◽  
Cold Hardiness ◽  
Isozyme Pattern ◽  
Agar Gel ◽  
Peroxidase Isozymes ◽  
Controlled Conditions ◽  
The Common ◽  
Agar Gel Electrophoresis ◽  
Different Levels

The peroxidase isozymes from the first leaf of seven varieties of wheat of different levels of cold hardiness have been studied by agar gel electrophoresis. The plants were grown under controlled conditions at 6 °C or 20 °C. The isozyme pattern changes during ontogeny. The intensity of staining of the fastest moving "anionic" band is much greater in the leaves of the common wheats grown at 6 °C than in similar leaves from plants grown at 20 °C. This increase in peroxidase is apparently not associated with cold hardiness.

Influence of larval food consumption on the fecundity of the lacewing Chrysoperla carnea

1993 ◽  
Vol 67 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Y. Zheng ◽  
K. M. Daane ◽  
K. S. Hagen ◽  
T. E. Mittler
Keyword(s):  
Food Consumption ◽  
Chrysoperla Carnea ◽  
Larval Food
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