BIONOMICS OF THE DAMSEL BUG, NABIS AMERICOFERUS CARAYON (HEMIPTERA: NABIDAE), A PREDATOR OF THE ALFALFA BLOTCH LEAFMINER (DIPTERA: AGROMYZIDAE)

1986 ◽  
Vol 118 (8) ◽  
pp. 745-751 ◽  
Author(s):  
J.C. Guppy
Keyword(s):  
Second Generation ◽  
Acyrthosiphon Pisum ◽  
Developmental Rate ◽  
Temperature Threshold ◽  
Nymphal Stage ◽  
Two Generations ◽  
Highly Correlated ◽  
Diapause Development ◽  
Increasing Temperature ◽  
Alfalfa Blotch Leafminer

AbstractThe damsel bug, Nobis americoferus Carayon, develops through two generations a year in eastern Ontario. In early fall, females of the second generation develop a reproductive diapause but both sexes continue to feed until freeze-up. Post-diapause development begins in late March. Eggs are deposited singly in plant stems but several may be laid in close proximity. In alfalfa, most eggs were found where stem diameter measured from 0.8 to 1.9 mm but height of oviposition site was not related to length of stem. Females reared at 23°C laid an average of 157 eggs during a 3-week oviposition period. The immature stages of the first generation occurred from mid-April to mid-July and those of the second generation from mid-July to early September. The duration of each stage of N. americoferus, fed pea aphids, Acyrthosiphon pisum (Harr.), and held at four constant temperatures, 18, 23, 28, and 31°C, decreased with increasing temperature. There was a highly correlated linear relationship between rate of development and temperature for all stages. The theoretical temperature threshold for development of eggs was 11.1°C and that for the nymphal stage was 10.6°C; degree-day requirements for these stages were 123.5 and 370.4, respectively. Developmental rate of nymphs varied with host as well as temperature; nymphs fed larvae of the alfalfa blotch leafminer, Agromyza frontella (Rondani), developed significantly faster than those fed pea aphid.

Reproductive Potential and Development of Rose Leafhopper, Edwardsiana rosae (L.) (Homoptera: Cicadellidae), at Constant Temperatures on Apple

1996 ◽  
Vol 31 (4) ◽  
pp. 427-431 ◽  
Author(s):  
M. L. Day ◽  
H. W. Hogmire ◽  
M. W. Brown
Keyword(s):  
Body Length ◽  
Reproductive Potential ◽  
Developmental Rate ◽  
Head Capsule ◽  
Temperature Threshold ◽  
Regression Equations ◽  
Egg Hatch ◽  
Male And Female ◽  
Developmental Rates ◽  
Increasing Temperature

Reproductive potential and developmental rates for rose leafhopper, Edwardsiana rosae (L.), were determined in a constant-temperature study at 13, 17, 23, and 30°C. Developmental rate was faster at progressively higher temperatures, except at 30°C, where there was no egg hatch. Developmental rate was faster for males than for females at each temperature. Regression equations yielded an estimate of 7°C as the temperature threshold for development. The largest number of progeny was produced at the lowest temperature, and survival decreased with increasing temperature. Body length and head capsule width of the five nymphal instars and adult stages of rose leafhopper did not vary among temperatures or between male and female.

scholarly journals Comparison of the Hatch of Newly Laid Lycorma delicatula (Hemiptera: Fulgoridae) Eggs From the United States After Exposure to Different Temperatures and Durations of Low Temperature

2021 ◽  
Author(s):  
Melody A Keena ◽  
Anne L Nielsen
Keyword(s):  
Low Temperature ◽  
Abiotic Factors ◽  
Developmental Rate ◽  
The United States ◽  
Predictive Distribution ◽  
Temperature Threshold ◽  
Egg Hatch ◽  
Egg Masses ◽  
Lycorma Delicatula ◽  
Diapause Development

Abstract Comparisons were made of the effects of temperature and duration of low temperature on hatch of newly laid egg masses of the invasive spotted lanternfly, Lycorma delicatula (White). Egg masses were collected in mid-October 2019 and estimated to be less than 14 d old. There was a significant positive nonlinear relationship between temperature and developmental rate (1/d) for eggs held at constant temperatures. The lower threshold for egg development was estimated as 7.39°C. Eggs held at constant 10, 15, and 20°C were estimated to require 635, 715, and 849 DD7.39, respectively, to develop. Egg hatch was variable, egg hatch rates were highest (58.4%) when held at a constant 15°C, though high rates (52.7%) were also obtained when eggs were held for 84 d at 10°C, then moved to 25°C. Almost all eggs enter diapause since very few eggs were able hatch when moved to 25°C after 7 d of chill at either 5 or 10°C. Chilling at 5 or 10°C increased percentage egg hatch as the duration in chill increased up to ~100 d and eggs held at 10°C were able to complete some or all the post-diapause development before being moved to 25°C. All egg masses were held at constant 16:8 (L:D) photoperiod and 65%RH. Our data suggest that temperature is the driving factor for diapause termination in spotted lanternfly, but other abiotic factors should be investigated. These identified developmental temperature threshold and degree day requirements for egg hatch will improve predictive distribution and phenological models.

scholarly journals Toxicity and bioaccumulation of 2,2', 4,4'-tetrabromodiphenyl ether (BDE47) in a laboratory aquatic food chain

2021 ◽  
Author(s):  
Emily Rachel Awad
Keyword(s):  
Polybrominated Diphenyl Ethers ◽  
First Generation ◽  
Second Generation ◽  
Dietary Exposure ◽  
Maternal Exposure ◽  
Water Exposure ◽  
Aquatic Food Chain ◽  
Two Generations ◽  
Survival And Reproduction ◽  
Aquatic Food

Rising levels of polybrominated diphenyl ethers (PBDEs) have been ovserved in the environment, humans, and animlas. Studies have shown that these compounds can elicit toxic effects in animals (e.g. neurotoxicity and thyroid toxicity). This research investigated the effects of BDE47 on the survival and reproduction of Daphnia magna over two generations. The impacts of water-borne exposure were compared to dietary exposure using the following treatments: dosed water (DW), dosed algae (DA) and dosed water and algae (DWA). In the first generation, significant impacts on reproduction were observed in daphnids in the DA and DWA treatments. In the second generation, no significant impacts on reproduction were observed indicating a recovery from maternal exposure. When second generation daphnids were exposed to BDE47, there was high mortality in the DWA treatment anad reduced reproduction in all dosed treatments. Dietary exposure to BDE47 had a more profound impact on daphnid reproduction than water exposure. In the second generation, dietary exposure affected both survival and reproduction and water exposure reduced reproduction, indicating that maternal exposure was a factor.

Temperature-dependent development of Amblyseius swirskii (Acari: Phytoseiidae) on Tetranychus urticae (Acari: Tetranychidae)

2020 ◽  
Vol 25 (3) ◽  
pp. 538-547 ◽  
Author(s):  
Azadeh Farazmand ◽  
Masood Amir-maafi ◽  
Remzi Atlihan
Keyword(s):  
Nonlinear Models ◽  
Information Criterion ◽  
Weather Conditions ◽  
Developmental Rate ◽  
Developmental Time ◽  
Thermal Constant ◽  
Temperature Threshold ◽  
Immature Stages ◽  
Amblyseius Swirskii ◽  
Wide Range

In this study, developmental time of Amblyseius swirskii Athias-Henriot feeding on immature stages of Tetranychus urticae Koch was evaluated at eight constant temperatures (15, 20, 25, 27.5, 30, 32.5, 35, and 37.5 °C) providing 60±5% RH and a photoperiod of 16 L: 8 D. Duration of the egg to adult developmental time decreased sharply with increasing temperature, except at 37.5°C. To describe the developmental rate of A. swirskii as a function of temperature, one linear and 9 nonlinear models (Logan-6, Logan-10, Lactin-1, Lactin-2, Briere-1, Briere-2, Analytis-3, Polynomial, and Equation-16) were fitted. The lower temperature threshold (T0) and the thermal constant (K) were estimated by the linear model for the total immature stage as 7.90 °C and 140.85 DD, respectively. Based on the Akaike Information Criterion (AIC) and R2adj, Polynomial, Analytis-3, Analytis-3, Logan-10 and Briere-2 were the best models for eggs, larvae, protonymphs, deutonymphs and total immature stages of A. swirskii, respectively. Our findings showed that development and predation of A. swirskii occurs in a wide range of temperatures. Therefore, this predatory mite could be applied in control of T. urticae in different weather conditions.

Variation in Australian and Some Overseas Populations of Emex australis and E. spinosa

1979 ◽  
Vol 27 (5) ◽  
pp. 631 ◽  
Author(s):  
PW Weiss ◽  
DM Simmons
Keyword(s):  
South Africa ◽  
Western Australia ◽  
First Generation ◽  
Second Generation ◽  
Emex Australis ◽  
Hierarchical Grouping ◽  
Two Generations

Australian populations of the widespread Emex australis and the more restricted E. spinosa were tested for subspecific variation. The plants were grown for two generations in a glasshouse from seed collected from field populations. The results from growing the first generation showed that two groupings of E. australis could be made on the basis of hierarchical grouping analysis, but the populations were much more similar in the second generation and such groupings could not be made. There were no marked differences between E. australis populations from Australia and South Africa, although one from Hawaii was less vigorous than the others. Amongst Australian populations of E. spinosa, one from Western Australia was less vigorous than the others. It was also found that Australian populations of E. spinosa were generally similar to those from Portugal and slightly more vigorous than those from Morocco.

INFLUENCE OF PHOTOPERIOD, TEMPERATURE, AND FOOD ON INITIATION OF DIAPAUSE IN THE APPLE MAGGOT

1968 ◽  
Vol 100 (3) ◽  
pp. 318-329 ◽  
Author(s):  
Ronald J. Prokopy
Keyword(s):  
Second Generation ◽  
Temperature Measurements ◽  
Rhagoletis Pomonella ◽  
Larval Food ◽  
Pupal Development ◽  
Laboratory Rearing ◽  
Regulatory Factors ◽  
Highly Sensitive ◽  
Pupal Diapause ◽  
Diapause Development

AbstractThe initiation of the pupal diapause of the apple maggot, Rhagoletis pomonella (Walsh), was found to be regulated by photoperiod and temperature. The stages of R. pomonella sensitive to these two regulatory factors were demonstrated to be the larva in the case of photoperiod and the larva and pupa in the case of temperature. Measurements with a highly sensitive photocell revealed that enough light passes through the skin and pulp of an apple to permit the response of the larvae to photoperiod to be direct. Diapause initiation was found to be independent of the effect of photoperiod or temperature on the adults and eggs and independent of the amount or type of larval food (apple or artificial).Where larvae and pupae were reared at 28°C and a photoperiod of 17 or 19 hours of light per 24-hour day, 1% of the pupae completed development in 23 days, 50% in 28 days, 75% in 30 days, and 100% in 64 days. These were the only regimes tested at which there was 100% non-diapause development, a finding which is directly applicable to continuous laboratory rearing of the apple maggot. Irrespective of temperature, diapause was induced in more than 50% of the pupae at a larval photoperiod of 11 hours. Even where larval photoperiod was favorable for 100% non-diapause development (17 or 19 hr), diapause was induced in more than 25% of the pupae if larval and pupal development occurred at 23°C and in a larger percentage if larval and pupal development occurred at 19°C.These findings are helpful in elucidating those conditions in nature under which a second generation of R. pomonella occurs.

Prenatal stress effects over two generations in rats

1986 ◽  
Vol 109 (2) ◽  
pp. 239-244 ◽  
Author(s):  
I. Pollard
Keyword(s):  
Emergency Response ◽  
First Generation ◽  
Second Generation ◽  
Mature Female ◽  
Plasma Progesterone ◽  
Stress Effects ◽  
Stressed Group ◽  
Two Generations ◽  
Uterine Environment ◽  
Genetic Programme

ABSTRACT Persistent effects of stress were found in second generation rats bred from females whose own mothers had been stressed during pregnancy. The second generation rats grew more slowly, with a plateau in the growth being reached at the same age as in the controls. This resulted in adult animals of both sexes being permanently smaller than their control counterparts. When these offspring were subjected to short-term stress (one session) in adulthood, the response was not significantly different to that for the controls, indicating an intact emergency response. The male offspring from the stressed group, however, had a significantly (P < 0·01) higher plasma progesterone concentration, and a significantly (P < 0·01) lower testicular enzymic 3β-hydroxysteroid dehydrogenase activity at rest, when compared with the control offspring. The fertility of the mature female from the stressed group was not affected as a third generation of litters born did not differ from the controls. It is suggested that a changed genetic programme in the ovarian germ cells of the first generation and/or a changed uterine environment in the second generation may be implicated. J. Endocr. (1986) 109, 239–244

COMPARISON OF SWEEP-NET AND STEM-COUNT TECHNIQUES FOR SAMPLING PEA APHIDS IN ALFALFA

1989 ◽  
Vol 24 (3) ◽  
pp. 344-347
Author(s):  
G. David Buntin ◽  
David J. Isenhour
Keyword(s):  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Density Estimates ◽  
Pea Aphids ◽  
Efficient Alternative ◽  
Highly Correlated ◽  
Sweep Net

The accuracy, precision and efficiency of stem-count and sweep-net techniques were compared for sampling the pea aphid, Acyrthosiphon pisum (Harris), in alfalfa. Density estimates by both techniques were highly correlated (r = 0.87). Both techniques were similar in sample precision and efficiency, but stem counts provided more accurate density estimates than the sweep net technique. The stem count technique is an accurate and efficient alternative to the sweep net for sampling pea aphids in alfalfa.

First Discovery of the Family Tanaostigmatidae (Hymenoptera: Chalcidoidea) from China with a Description of a New Gall-Making Species Utilizing Kudzu Leaves

2004 ◽  
Vol 39 (2) ◽  
pp. 275-280 ◽  
Author(s):  
Yang Zhong-qi ◽  
Sun Jiang-hua ◽  
James P. Pitts
Keyword(s):  
Biological Control ◽  
New Species ◽  
Second Generation ◽  
Biological Control Agent ◽  
First Record ◽  
Control Agent ◽  
The Family ◽  
Two Generations ◽  
A New Species

A new species of Tanaostigmodes (Hymenoptera: Chalcidoidea, Tanaostigmatidae) is described from China—Tanaostigmodes puerariae sp. nov. This is the first record of this family in China. This new species has potential as a biological control agent for control of kudzu, Pueraria lobate, in the U. S., because its preference for making leaf galls on kudzu. It was determined that the wasp has two generations per year, with the second generation overwintering as mature larvae in the gall on leaves that have dropped to the ground. Normally, only one wasp was found per gall, and a single kudzu leaf could have as many as 20 to 50 galls on its surface.

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