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.

DEVELOPMENT AND BIONOMICS OF CHRYSOMELOBIA LABIDOMERAE (ACARI: TARSONEMINA; PODAPOLIPIDAE), A PARASITE OF THE MILKWEED LEAF BEETLE (COLEOPTERA: CHRYSOMELIDAE)

1975 ◽  
Vol 107 (6) ◽  
pp. 627-638 ◽  
Author(s):  
Thomas C. Baker ◽  
George C. Eickwort
Keyword(s):  
Leaf Beetle ◽  
High Population ◽  
Immature Stages ◽  
Adult Males ◽  
Nymphal Instar ◽  
Male And Female ◽  
Adult Females ◽  
Original Length ◽  
Chrysomelobia Labidomerae ◽  
Pharate Adult

AbstractAdult females of Chrysomelobia labidomerae Eickwort lay eggs on the upper surfaces of the hind wings of Labidomera clivicollis (Kirby). The eggs hatch in approximately 7 days and male and female larvae feed at the base of the wings and in the meso–metathoracic crevice and swell to about twice their original length. For about the second half of the approximately 7-day larval stadium, the larvae are inactive (pharate adults) and are usually cemented to the undersurfaces of the elytra. Inactive female larvae are accompanied by adult males that apparently copulate with the newly emerged adult females. The pharate adult is enclosed in a cuticular sac that may represent a calyptostatic nymphal instar. Adult females feed on the beetle’s abdominal terga and sometimes also occur on its venter where they do not feed. Females disperse from host to host when the beetles copulate. The species is arrhenotokous. Mites overwinter on the diapausing adult beetles and do not infest the immature stages of their host. Even at high population levels, the mites do not noticeably affect the longevity or fecundity of their hosts.

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 Metagenomic Survey of the Highly Polyphagous Anastrepha ludens Developing in Ancestral and Exotic Hosts Reveals the Lack of a Stable Microbiota in Larvae and the Strong Influence of Metamorphosis on Adult Gut Microbiota

2021 ◽  
Vol 12 ◽  
Author(s):  
Martín Aluja ◽  
Jesús Alejandro Zamora-Briseño ◽  
Vicente Pérez-Brocal ◽  
Alma Altúzar-Molina ◽  
Larissa Guillén ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Host Plant ◽  
Prunus Persica ◽  
Mangifera Indica ◽  
Anastrepha Ludens ◽  
Adult Males ◽  
Larval Food ◽  
Microbial Composition ◽  
Host Fruit ◽  
Casimiroa Edulis

We studied the microbiota of a highly polyphagous insect, Anastrepha ludens (Diptera: Tephritidae), developing in six of its hosts, including two ancestral (Casimiroa edulis and C. greggii), three exotic (Mangifera indica cv. Ataulfo, Prunus persica cv. Criollo, and Citrus x aurantium) and one occasional host (Capsicum pubescens cv. Manzano), that is only used when extreme drought conditions limit fruiting by the common hosts. One of the exotic hosts (“criollo” peach) is rife with polyphenols and the occasional host with capsaicinoids exerting high fitness costs on the larvae. We pursued the following questions: (1) How is the microbial composition of the larval food related to the composition of the larval and adult microbiota, and what does this tell us about transience and stability of this species’ gut microbiota? (2) How does metamorphosis affect the adult microbiota? We surveyed the microbiota of the pulp of each host fruit, as well as the gut microbiota of larvae and adult flies and found that the gut of A. ludens larvae lacks a stable microbiota, since it was invariably associated with the composition of the pulp microbiota of the host plant species studied and was also different from the microbiota of adult flies indicating that metamorphosis filters out much of the microbiota present in larvae. The microbiota of adult males and females was similar between them, independent of host plant and was dominated by bacteria within the Enterobacteriaceae. We found that in the case of the “toxic” occasional host C. pubescens the microbiota is enriched in potentially deleterious genera that were much less abundant in the other hosts. In contrast, the pulp of the ancestral host C. edulis is enriched in several bacterial groups that can be beneficial for larval development. We also report for the first time the presence of bacteria within the Arcobacteraceae family in the gut microbiota of A. ludens stemming from C. edulis. Based on our findings, we conclude that changes in the food-associated microbiota dictate major changes in the larval microbiota, suggesting that most larval gut microbiota is originated from the food.

scholarly journals Sources of sodium in the Finnish diet

1981 ◽  
Vol 53 (5) ◽  
pp. 275-284 ◽  
Author(s):  
Pirjo Pietinen
Keyword(s):  
Food Consumption ◽  
Food Industry ◽  
Sodium Intake ◽  
Adult Population ◽  
Daily Intake ◽  
Mobile Clinic ◽  
Food Items ◽  
Naturally Occurring ◽  
Total Sodium ◽  
Added Salt

The purpose of this report was to study all available information for estimating the sources of naturally occurring sodium and added salt in the Finnish diet. The calculations were based on food consumption statistics, sales figures of salt, salt use in the Finnish food industry and catering, and on the food consumption data provided by the mobile clinic dietary survey of 1973—1976. The average daily per capita intake of added salt is 10—11 g and that of the naturally occurring sodium in foodstuffs is 0.6 g which is equivalent to 1.5g of NaCl, the total intake being 11—12 g. In the adult population the mean daily intake of sodium expressed as NaCl is 12—15 g in men and 10—12 g in women. The average salt concentration in the diet is 4.3 g/1 000 kcal (10.3 g/10 MJ) and that of adults 4.5 g/1 000 kcal (10.6 g/10 MJ). Of the total sodium intake 50 % is derived from the salt used by the food industry and in catering, 38 % from salt added by the consumer at home, and 12 % from the naturally occurring sodium in the foodstuffs. Of the added salt, 57 %is used by the food industry and catering and 43 % by the consumer. Of the different food items, baked products (bread, buns and pastries) arc the most important sources of sodium, constituting 22 % of the total sodium intake. The share of bread alone is 16% and that of sausages and other meat products is 14%. The share of other food items is less than 10 %.

Metabolism during normal, fragmented, and recovery sleep

1991 ◽  
Vol 71 (3) ◽  
pp. 1112-1118 ◽  
Author(s):  
M. H. Bonnet ◽  
R. B. Berry ◽  
D. L. Arand
Keyword(s):  
Time Course ◽  
Total Sleep Time ◽  
Sleep Time ◽  
Adult Males ◽  
O2 Uptake ◽  
Recovery Sleep ◽  
Nonrestorative Sleep ◽  
Naturally Occurring ◽  
Co2 Output ◽  
Metabolic Variables

Average metabolic data (O2 uptake and CO2 output) were obtained for each 3-min period during consecutive nights of normal, experimentally fragmented, and recovery sleep in a group of 12 normal young adult males. Naturally occurring arousals and awakenings resulted in a characteristic increase in metabolism on the baseline night. The placement of brief frequent experimental arousals on the following night resulted in significantly increased metabolism throughout the night and significantly decreased sleep restoration as measured by morning performance, mood, and alertness tests, even though total sleep time was minimally reduced. Metabolic variables were significantly decreased compared with baseline on the nondisturbed recovery night that followed the sleep fragmentation night. The data cannot be used to infer that increased metabolism during sleep causes nonrestorative sleep, but the direction and time course of metabolic change accompanying arousal are consistent with that hypothesis.

scholarly journals Feeding and Ovipositional Responses of Adult Elm Leaf Beetle (Coleoptera: Chrysomelidae) to Simple and Complex Asian Elm Hybrid Selections

2001 ◽  
Vol 19 (3) ◽  
pp. 128-131
Author(s):  
Fredric Miller ◽  
George Ware
Keyword(s):  
Leaf Tissue ◽  
Leaf Beetle ◽  
Adult Longevity ◽  
Adult Males ◽  
Breeding Programs ◽  
Leaf Beetles ◽  
Elm Leaf Beetle ◽  
The Mean ◽  
Ulmus Davidiana ◽  
Preovipositional Period

Abstract Nine recently developed simple and complex Asian hybrids with Ulmus davidiana, U. japonica, U. parvifolia, U. pumila, U. szechuanica and/or U. wilsoniana parentage were evaluated in no-choice laboratory bioassays for their suitability for the adult elm leaf beetle, Xanthogaleruca luteola (Müller). Suitability of each biotype was defined by the mean percentage of leaf tissue removed, the mean percentage of females ovipositing, and the mean number of eggs laid per female. Adult female beetles laid significantly more eggs on U. pumila (control) and the complex hybrid U. ‘Morton Red Tip’-Danada Charm™ indicating their greater suitability for ELB. The least suitable single and complex hybrids for adult elm leaf beetles as indicated by feeding and reproduction were U. davidiana x U. ‘ Morton’ -Accolade™ and U. szechuanica x U. japonica. Females feeding on more suitable elms oviposited 3 days earlier than females feeding on less suitable elms. Adult beetle fecundity was correlated with the length of the preovipositional period but mean percentage of females ovipositing was not correlated with length of the preovipositional period. Adult males and females lived approximately 4 days longer on the more suitable elms than on less suitable elms but adult longevity was not correlated with suitability. The percentage of leaf tissue removed by adult beetles on the different biotypes was correlated with beetle fecundity. Less suitable selections of U. davidiana x U. ‘ Morton’ -Accolade™ and U. szechuanica x U. japonica seem promising for future elm breeding programs.

Latent Oxidative Stress Responses of Ozone-Fumigated Cucumber Plants Are Enhanced by Simultaneous Cold Exposures

1996 ◽  
Vol 51 (5-6) ◽  
pp. 355-362
Author(s):  
Peter Streb ◽  
Hermann Schaub ◽  
Jürgen Feierabend
Keyword(s):  
Oxidative Stress ◽  
Glutathione Reductase ◽  
Stress Responses ◽  
Additional Stress ◽  
Cucumis Sativus L ◽  
Naturally Occurring ◽  
Car Exhaust ◽  
Long Time ◽  
Defence Responses ◽  
Oxidative Stress Responses

Abstract Cucumber plants (Cucumis sativus L.) were grown under controlled conditions and fumigated with either O3, diluted automobile exhaust or a combination of both. The ratio of variable to maximum chlorophyll fluorescence (Fv/Fm) was estimated as a measure of PSII activity Activities of the enzymes catalase, glutathione reductase and guaiacol-dependent peroxidase and contents of the antioxidants ascorbate and glutathione were assayed as potential indicators of oxidative stress. The behavior of catalase and of PSII are of particular diagnostic interest because they require continuous repair in light. Exposures of up to 13 days to moderate concentrations of the pollutant gases alone did not induce striking changes in any of the activities that were assayed. A lso when the plants were subjected to an additional stress treatment by exposing them to 4 short cold treatments (2h each at 0 - 4 °C in light on days 12-15 after sowing) which induced marked declines of the Fv/Fm ratio, the chlorophyll content and the catalase activity, these cold-induced symptoms of photodamage were not significantly enhanced by the fumigation treatments. However, increases of the activities of glutathione reductase and peroxidase observed during a period of recovery following the cold-exposures were markedly higher in O3-fumigated plants, as compared to plants grown in filtered air or fumigated with car exhaust alone. The results emphasize that effects of moderate pollutant exposures may be latent or delayed over long time periods and that defence responses can be enhanced when plants are exposed to additional, naturally occurring stress situations.

Sign in / Sign up

Export Citation Format

Share Document