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.

Feeding Ecology of the Nocturnal Gecko Hemidactylus brookii in Ghana

1980 ◽  
Vol 1 (3) ◽  
pp. 269-276 ◽  
Author(s):  
R.A. Avery
Keyword(s):  
Food Intake ◽  
Food Consumption ◽  
Feeding Ecology ◽  
Daily Intake ◽  
Live Weight ◽  
Dry Weight ◽  
Wet Season ◽  
Daily Food Intake ◽  
Daily Food ◽  
The Relationship

AbstractThe diet of Hemidactylus brookii captured at Legon, Ghana, during July was composed entirely of arthropods; Lepidoptera larvae and cockroaches formed 40% of the total weight of food. Daily food intake during the dry season estimated from production of excretory urates was equivalent to that of small diurnal lizards, and given by the relationship F = 20.9W0.51 where F = food consumption in mg dry weight per day and W = live weight in grams. Daily intake during the wet season was variable and often reduced.

Cereal Consumption, Production, and Prices in West Pakistan (Notes & Comments)

1968 ◽  
Vol 8 (2) ◽  
pp. 288-306 ◽  
Author(s):  
G. C. Hufbauer
Keyword(s):  
Food Consumption ◽  
Ad Hoc ◽  
Dry Weight ◽  
Small Sample ◽  
Tax Rates ◽  
Active Population ◽  
Early Settlement ◽  
Consumption Rates ◽  
Late Nineteenth ◽  
Better Than

In the late nineteenth and early twentieth centuries, several Punjab Settlement Officers attempted to estimate food consumption rates. These estimates, based on direct observation and ad hoc guesses, were made partly out of academic curiosity, but more urgently, as an aid in establishing the land revenue (i.e., tax) rates. The pre-1926 estimates are summarized in Table I, expressed in pounds of wheat and other foodgrain consumption per person per year1. Broadly speaking, the later, more systemtic observers (e.g., Sir Ganga Ram and C. B. Barry), found lower consumption levels than the earlier observers. It was generally accepted that the rural populace ate better than urban dwellers. Despite the ingenuity of the early Settlement Officers, their compiled estimates suffer from all the difficulties of haphazard small sample observation. Given the revenue purpose of the estimates, they may be biased towards the able-bodied, economically active, population. Further, the very early estimates may have confused dry weight with cooked weight, including water.

scholarly journals Plant Pathogen Invasion Modifies the Eco-Evolutionary Host Plant Interactions of an Endangered Checkerspot Butterfly

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 246
Author(s):  
Paul M. Severns ◽  
Melinda Guzman-Martinez
Keyword(s):  
Pacific Northwest ◽  
Plant Pathogen ◽  
Plantago Lanceolata ◽  
Larval Feeding ◽  
Plant Interactions ◽  
Larval Food ◽  
Disease Symptoms ◽  
Pathogen Invasion ◽  
The Pacific ◽  
Germination Timing

New plant pathogen invasions typified by cryptic disease symptoms or those appearing sporadically in time and patchily in space, might go largely unnoticed and not taken seriously by ecologists. We present evidence that the recent invasion of Pyrenopeziza plantaginis (Dermateaceae) into the Pacific Northwest USA, which causes foliar necrosis in the fall and winter on Plantago lanceolata (plantain), the primary (non-native) foodplant for six of the eight extant Taylor’s checkerspot butterfly populations (Euphydryas editha taylori, endangered species), has altered eco-evolutionary foodplant interactions to a degree that threatens butterfly populations with extinction. Patterns of butterfly, larval food plant, and P. plantaginis disease development suggested the ancestral relationship was a two-foodplant system, with perennial Castilleja spp. supporting oviposition and pre-diapause larvae, and the annual Collinsia parviflora supporting post-diapause larvae. Plantain, in the absence of P. plantaginis disease, provided larval food resources throughout all butterfly life stages and may explain plantain’s initial adoption by Taylor’s checkerspot. However, in the presence of severe P. plantaginis disease, plantain-dependent butterfly populations experience a six-week period in the winter where post-diapause larvae lack essential plantain resources. Only C. parviflora, which is rare and competitively inferior under present habitat conditions, can fulfill the post-diapause larval feeding requirements in the presence of severe P. plantaginis disease. However, a germination timing experiment suggested C. parviflora to be suitably timed for only Washington Taylor’s checkerspot populations. The recent invasion by P. plantaginis appears to have rendered the ancestrally adaptive acquisition of plantain by Taylor’s checkerspot an unreliable, maladaptive foodplant interaction.

A two-diet system andad libitumlactation feeding of the sow 1. Sow performance

1996 ◽  
Vol 62 (2) ◽  
pp. 337-347 ◽  
Author(s):  
M. Neil ◽  
B. Ogle ◽  
K. Annèr
Keyword(s):  
Food Consumption ◽  
Post Partum ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Backfat Thickness ◽  
Conventional Diet ◽  
Feeding Regimes ◽  
Ad Libitum ◽  
The Difference ◽  
Depth Condition

AbstractEffects of a two-diet system combined withad libitumlactation feeding of sows on food consumption, sow live weight (LW), backfat depth, condition scoring, rebreeding interval, symptoms of agalactia and culling were studied on 60 sows followed for four parities. Feeding regimes were: CR, conventional i.e. restricted during gestation and lactation; SA, a simplified diet offered at a restricted level during gestation and a conventional dietad libitumduring lactation; CA, conventional during gestation and the same dietad libitumduring lactation. During lactation CR sows consumed 5·9 kg food daily (71 MJ metabolizable energy (ME)), whereas SA and CA sows consumed on average 7·0 kg (85 MJ ME), the difference being larger in multiparous than in primiparous sows and larger in the first than in later weeks of lactation. From the second farrowing onward sows on CR treatment were lighter and had thinner backfat and lower condition scores than sows on CA treatment, with sows on SA treatment in between, i.e. approaching the CR sows in the gestation periods and the CA sows in the lactation periods. At first service LW was 130 kg and backfat thickness 14 mm. During the fourth lactation LW averaged 190 kg in CR sows and around 220 kg for SA and CA sows, and backfat thickness was 11 mm in CR sows and around 16 mm in SA and CA sows. SA sows tended to rebreed earlier after weaning than did CR or CA sows. CA sows and in particular SA sows had higher incidences of agalactia symptoms and higher rectal temperatures post partum than CR sows. The culling rates did not differ between feeding regimes, although the predominant causes for culling did, being shoulder lesions and abscesses in thin CR sows and leg disorders in SA and CA sows. At the end of the experiment, however, more SA sows than others were retained in the experimental herd. It was concluded that the SA feeding regime was superior in terms of sow performance, despite an increased incidence of agalactia symptoms.

scholarly journals Laboratory Evaluation of Neem formulation bioactivity against Crocidolomia pavonana F. larvae

2019 ◽  
Vol 1 (1) ◽  
pp. 37
Author(s):  
Raden Arif Malik Ramadhan ◽  
Neneng Sri Widayani ◽  
Lindung Tri Puspasari ◽  
Yusup Hidayat ◽  
Danar Dono
Keyword(s):  
Mortality Rate ◽  
Food Consumption ◽  
Azadirachta Indica ◽  
Dry Weight ◽  
Laboratory Evaluation ◽  
Feeding Method ◽  
Lc50 Value ◽  
And Control

This study aims to evaluate the bioactivity of the formulation of Neem 50 EC  against Crocidolomia pavonana larvae in the laboratory. The study using six treatments and three replications. The treatment consisted of the formulation of neem 50 EC at concentrations of 0.3%, 0.5%, 0.8%, 1.3%, 2.3%, and control. The treatment was done by leaf feeding method and tested on C. pavonana instar II. The results of the research showed that the formulation of neem 50 EC at concentration of 2.3% caused mortality of C. pavonana larvae with mortality rate of 95% and has LC50 value aqual to 0.83%. Neem formulation can inhibit the development of C. pavonana larvae from instar I to instar IV, decrease food consumption, and decrease the dry weight of C. pavonana larvae instar IV.Keywords: Azadirachta indica, Bioactivity, Crocidolomia pavonana, neem formulation

Population ecology of the freshwater mussel Anodonta grandis grandis in a Precambrian Shield lake

1990 ◽  
Vol 68 (9) ◽  
pp. 1931-1941 ◽  
Author(s):  
J. D. Huebner ◽  
D. F. Malley ◽  
K. Donkersloot
Keyword(s):  
Yellow Perch ◽  
Live Weight ◽  
Freshwater Mussel ◽  
Dry Weight ◽  
Fine Sand ◽  
Turnover Time ◽  
Experimental Lakes Area ◽  
Precambrian Shield ◽  
Sublittoral Zone ◽  
Anodonta Grandis

Anodonta grandis grandis is found in about half of 50 Experimental Lakes Area lakes surveyed but is abundant in only some of these lakes, including lake 377. Lake 377 is a typical small Precambrian Shield lake, 27.7 ha in area and 17.9 m in maximum depth, with [Ca2+] of [Formula: see text], conductivity of 25 μmho∙cm−1 (1 mho = 1 S), and alkalinity of [Formula: see text]. The water renewal time of approximately 187 days is shorter than that of most Precambrian Shield lakes. Bottom sediments in the sublittoral zone ranged from fine sand through granules to cobbles and boulders. Several species of possible glochidial host fish including yellow perch were collected from lake 377. The size of the mussel population, estimated by depth-stratified random sampling, was 36 800 ± 12 000 (± 95% confidence interval). Mean density was 0.133 mussels/m2 lake surface, and maximum density was 4.3 mussels/m2. Mussels were most abundant in the 1.5- to 3.1-m depth stratum. Mean lengths and weights in collections ranged from 77 to 87 mm and from 43 to 56 g, respectively. Maximum length and weight were 117.9 mm and 109.6 g, respectively. Based on external annuli, mussels live to 15+ years in lake 377. Flesh and shell averaged 25.1 and 23.2% of live weight, respectively. Calcium constituted 44.7% of the ash weight of shell. We estimated a standing dry weight biomass of mussels of 330–390 mg∙m−2 and dry weight production of 60 mg∙m−2∙year−1. This is [Formula: see text] of the estimated annual dry weight algal production. The shells of live mussels contain [Formula: see text] of the total calcium in lake 377. Despite oligotrophic conditions and low [Ca2+], lake 377 supports a substantial population of A. g. grandis growing at a moderate rate. Lake 377 may be a favourable habitat for this species because of its short water-turnover time.

Quantities of Food eaten by the Desert Locust, Schistocerca gregaria (Forsk.), in Relation to Growth

1954 ◽  
Vol 45 (3) ◽  
pp. 539-551 ◽  
Author(s):  
P. M. Davey
Keyword(s):  
Body Weight ◽  
Food Consumption ◽  
Wheat Bran ◽  
Schistocerca Gregaria ◽  
Dry Weight ◽  
Desert Locust ◽  
First Instar ◽  
Males And Females

The weight of fresh grass eaten by Schistocerca gregaria (Forsk.) on each day of its development from hatching until maturation of the adults was investigated. Hoppers in all instars ate on the average about one gram per gram body-weight per day on the middle days of the instars and the adults ate approximately half-a-gram per gram body-weight each day. The percentage of food assimilated, calculated from the dry faeces and estimated dry weight of food eaten, falls from about 78 in the first to 35 in the fifth instar. There were some indication that the food consumption per hopper increases with the number of hoppers per cage.The weight of wheat bran eaten by hoppers was also investigated. The amount eaten by hoppers on the middle day of the first instar is approximately the same, in relation to their body weight, as that eaten per day just before and just after moulting by those in the fourth and fifth instars. More is eaten in the middle of these instars.Measurements of weights and lengths of males and females in the hopper instars and of the weights of adults showed that in the course of their development females become progressively heavier and larger than males. The weight of a newly-hatched hopper is about 10 mg.; a female fledgling weighs about 2 gm. and a male 1·5 gm. Hoppers are approximately 1 cm. long on hatching, and males on reaching maturity are about 4·5 cm. long and females about 5.0 cm.

A note on the performance of Soay ewes, when mated to Soay and Dorset Down rams, and the growth rate and carcass production of their lambs

1980 ◽  
Vol 30 (2) ◽  
pp. 307-310
Author(s):  
R. V. Large
Keyword(s):  
Growth Rate ◽  
Food Consumption ◽  
Growth Rates ◽  
Live Weight ◽  
Weight Changes ◽  
Weight Gains ◽  
Good Nutrition ◽  
Very High

ABSTRACTSoay ewes were mated to a Soay or a Dorset Down ram. Live-weight changes of the ewes, birth weights, growth rates and carcass production of the lambs were recorded, and the food consumption of the ewes and lambs was measured. The use of the Dorset Down ram resulted in significantly heavier birth weights, higher growth rates and heavier carcasses. Under conditions of good nutrition the Soay ewes proved to be capable of carrying very high foetal burdens and it was estimated, from lamb live-weight gains, that they produced a large quantity of milk, relative to their size, particularly when crossed with the Dorset Down ram.

Seasonal Field Analyses of Fat Content, Live Weight, Dry Weight and Water Content of the Aphidophagous Scymnodes Lividigaster (Mulsant) and Mycophagous Leptothea Galbula (Mulsant) (Coleoptera: Coccinellidae).

1981 ◽  
Vol 29 (5) ◽  
pp. 679 ◽  
Author(s):  
JME Anderson
Keyword(s):  
Quantitative Analysis ◽  
Survival Rate ◽  
Water Content ◽  
Seasonal Changes ◽  
Prey Species ◽  
Live Weight ◽  
Dry Weight ◽  
Subjective Assessment ◽  
Fat Content ◽  
Fat Reserves

Over 36 and 24 months, respectively, both the aphidophagous Scymnodes lividigaster (Muls.) and the mycophagous Leptothea galbula (Muls.) accumulated fat before periods of dormancy, but contained little fat after dormancy and during breeding. Over the whole period, there were no significant differences between sexes or between years in either species, except that dormant females contained significantly more fat than males, and that during breeding males of S. lividigaster contained significantly more fat than females. Subjective assessment of fat reserves gave the same results as did quantitative analysis. Live and dry weights of females were higher during breeding and dormancy than after dormancy; live weights of females were higher than those of males. Water content was lower during dormancy than during breeding. In L. galbula, seasonal changes were similar in a dry and a well watered habitat; any differences appeared related to a higher survival rate in females compared with males, especially in the poorer habitat. In S. lividigaster, seasonal changes in fat content were negatively related to changes in abundance of an essential prey species.

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