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

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.

EFFECT OF THE HELIOTHIS NUCLEAR POLYHEDROSIS VIRUS INFECTION ON FOOD CONSUMPTION BY HELIOTHIS ZEA1,2

1986 ◽  
Vol 21 (2) ◽  
pp. 118-126 ◽  
Author(s):  
N. E. Flusche ◽  
W. C. Yearian ◽  
A. J. Mueller ◽  
S. Y. Young
Keyword(s):  
Food Consumption ◽  
Nuclear Polyhedrosis Virus ◽  
Developmental Stages ◽  
Heliothis Zea ◽  
Field Tests ◽  
Mortality Level ◽  
Larval Food ◽  
Consumption Reduction ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis

Frass production by Heliothis zea (Boddie) larvae infected at varying mortality levels with Heliothis nuclear polyhedrosis virus (NPV) was determined and used to estimate the effect of the virus on larval food consumption. Treatment in the early stages was essential to substantially reduce food consumption. Reduction in food consumption was also directly related to NPV dosage. Food consumption by larvae surviving NPV treatment was not significantly different from the untreated larvae. Field tests indicated that NPV applications must be timed against 1st- or 2nd-stage larvae to achieve an appreciable mortality level and prevent infected larvae from reaching the damaging late developmental stages. Preliminary maximum treatment levels for use of Heliothis NPV for suppression of H. zea on soybean are presented.

Influence of Maternal Education on Food Consumption and Energy and Nutrient Intake in a Group of Pre-School Children from Madrid

2003 ◽  
Vol 73 (6) ◽  
pp. 439-445 ◽  
Author(s):  
Navia ◽  
Ortega ◽  
Requejo ◽  
Perea ◽  
López-Sobaler ◽  
...  
Keyword(s):  
Food Consumption ◽  
School Children ◽  
Food Habits ◽  
Nutrient Intake ◽  
Maternal Education ◽  
Statistical Significance ◽  
Dietary Adequacy ◽  
Consumption Energy ◽  
Maternal Educational Level ◽  
Energy And Nutrient Intake

A study was conducted on the influence of maternal education level on food consumption, energy and nutrient intake, and dietary adequacy in 110 pre-school children from Madrid, Spain. With increasing maternal education, children consumed more sugar (p < 0.05), fruit (p < 0.05), and fish (p < 0.05). Snacking was more frequent with decreasing maternal education (p < 0.05). Though statistical significance was not reached, the consumption of pre-cooked foods was greater among children of mothers educated to a higher level, a phenomenon probably related to the work situation of these women. With respect to dietary composition, no significant differences were found between groups for macronutrient, fiber and energy intakes, except for energy supplied by polyunsaturated fatty acids (PUFA), which was greater in the children of less educated women (p < 0.01). This is probably due to their greater consumption of sunflower seed oil. The diets of children belonging to well-educated mothers came closer to meeting the recommended intakes for folate, vitamin C, and iodine. It would seem that maternal educational level influences the food habits of children. Mothers with less education may require special advice in this area.

Men’s Hunger, Food Consumption, and Preferences for Female Body Types

2014 ◽  
Vol 45 (6) ◽  
pp. 495-497 ◽  
Author(s):  
Nicolas Guéguen
Keyword(s):  
Food Consumption ◽  
Female Body ◽  
The Body ◽  
Slender Body ◽  
Mediation Effect ◽  
Point Scale ◽  
Body Type ◽  
Experimental Conditions

Nelson and Morrison (2005 , study 3) reported that men who feel hungry preferred heavier women. The present study replicates these results by using real photographs of women and examines the mediation effect of hunger scores. Men were solicited while entering or leaving a restaurant and asked to report their hunger on a 10-point scale. Afterwards, they were presented with three photographs of a woman in a bikini: One with a slim body type, one with a slender body type, and one with a slightly chubby body. The participants were asked to indicate their preference. Results showed that the participants entering the restaurant preferred the chubby body type more while satiated men preferred the thinner or slender body types. It was also found that the relation between experimental conditions and the choices of the body type was mediated by men’s hunger scores.

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