Viability and Fecundity of Alate Alienicolae of Aphis Fabae Scop. After Flights to Exhaustion

1961 ◽  
Vol 38 (1) ◽  
pp. 181-187
Author(s):  
A. J. COCKBAIN

1. Laboratory-reared 24 hr.-old alate alienicolae of A. fabae were flown for variable periods, but all to apparent exhaustion; their subsequent longevity and fecundity on broad beans, or their survival times during starvation, were compared with controls. 2. Adult longevity, reproductive rate and capacity, and nymph viability were similar in exhausted and control aphids that settled on host plants after flight. Mean adult life was 31 days in exhausted aphids and 32 days in the controls. Both exhausted and control aphids produced an average of 84 larvae per adult. 3. The only major difference noted between exhausted and control aphids that fed after flight was a reluctance, or inability, of exhausted aphids to fly on the following day. 4. Exhausted aphids starved after flight lived for a significantly shorter time (mean of 30 hr.) than control aphids starved without flight (55 hr.). 28% of the exhausted and 88% of the control aphids could take-off on the next day. 5. The results indicate that long migratory flights are unlikely to affect the reproductive potential of aphids, and that alate alienicolae of A. fabae, having settled on a suitable host after an exhaustive flight, are unlikely to fly again.

2021 ◽  
Author(s):  
Patrick Tobin

Abstract The gypsy moth is likely to ultimately occupy virtually all portions of the temperate world where oaks and other suitable host plants occur. Consequently, the northern hemisphere is more at risk for establishment than the southern hemisphere though some suitable hosts do occur in these areas. The gypsy moth is apparently not able to persist in very cold (e.g. Finland) or warm (subtropical to tropical) regions. The gypsy moth is a 'proven' invader. The broad range of host plants that it utilizes (Liebhold et al. 1995), along with its high reproductive rate combine to make this insect a very successful invader of many types of forest and urban landscapes. Another characteristic that contributes to the gypsy moth's invasiveness is its propensity to be transported on human-made objects (e.g., egg masses can be laid on vehicles, logs, etc.). Perhaps the greatest limitation this species has as an invader is that females (of the European strain) are incapable of flight and this limits its rate of unassisted range expansion. However, as females of the Asian strain are capable of flight and all strains can lay their eggs on human-made objects, established populations are nevertheless able to spread.


1996 ◽  
Vol 128 (5) ◽  
pp. 859-863 ◽  
Author(s):  
P. Shishehbor ◽  
P.A. Brennan

AbstractLongevity and reproductive potential of adult males and females of Trialeurodes ricini Misra were determined under laboratory conditions at four constant temperatures (20, 25, 30, and 35 ± 1°C). The resulting data were used to calculate life tables and rates of increase at each temperature. Females of T. ricini oviposited means of 183, 224, 294, and 132 eggs at 20, 25, 30, and 35°C, respectively, and had a mean longevity of 38.52, 28.15, 15.78, and 10.11 days at the same four temperatures. The net reproductive rate was 49.92, 72.26, 111.08, and 38.44, and the daily intrinsic rate of increase was 0,05, 0.11, 0.18, and 0.15 at 20, 25, 30, and 35 °C, respectively. Generation times decreased from 69.88 to 24.92 days with increasing temperature. The results indicate that T. ricini can, in otherwise unlimited conditions, persist and increase in numbers within the range 20–35°C.


2018 ◽  
Vol 111 (3) ◽  
pp. 535
Author(s):  
Fouad MERADSI ◽  
Malik LAAMARI

We studied the behavioral and biological parameters of <em>Aphis fabae</em> (Homoptera: Aphididae, Scopoli, 1763) on seven local <em>Vicia faba</em> L. cultivars. The antixenosis was conducted under laboratory controlled conditions of the temperature, light regime and relative humidity (18 ± 0.25 °C; L16: D8; 37.5 ± 0.6 %) for test in light, and (19 °C; 42 % relative humidity) for test in dark. The least preferred host plants for attractivity was the cultivar 141 in both tests while the cultivar 145 was the most preferred in light test, and the cultivar 107 in dark test. The antibiotic experiment was conducted also under laboratory conditions (L16: D8 photoperiod, 17 ± 1 °C, and 43.5 ± 5 % r. h.). Antibiosis was determined by studying the pre-reproductive period, reproductive period, adult longevity, survival, daily and total fecundity. The analysis of variance indicated that no significant differences on pre-reproductive period and daily fecundity of the <em>A. fabae </em>among the cultivars. However, the longest times of reproductive period, adult longevity, and survival were recorded on cultivar 135 followed by cultivar 141. The highest (85.8) and the lowest (15.8) number of progeny were observed on 135 and 141 cultivars, respectively.


2014 ◽  
Vol 49 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Julianne Milléo ◽  
Francisco Sales Fernandes ◽  
Wesley Augusto Conde Godoy

The objective of this work was to compare biological aspects and life table parameters of the coccinellids Harmonia axyridis, Cycloneda sanguineaand Hippodamia convergens. Insects were fed eggs of Anagasta kuehniella, and reared at 24.5±1ºC, 70±10% relative humidity, with a 12 hour photophase. Hippodamia convergenstook about 1.6 day to complete development, longer than H. axyridis, and 2.4 day longer than C. sanguinea.At immature stages, H. axyridisexhibited the highest survival percentage (49.2%), in comparison to the other coccinellids. For mean adult longevity, H. convergenswas deficient, in comparison with the other species. Mean period of pre oviposition was the longest in C. sanguinea; the longest oviposition time occurred for H. axyridis; and the post oviposition period was similar between the coccinellids. Considering the reproductive parameters, H. axyridisshowed the best performance in all aspects. For life table, the values of H. convergenswere higher than, although close, to those of H. axyridis. Nevertheless, the high net reproductive rate of H. axyridis showed this species potential to increase population size. The biological characteristics of the exotic H. axyridis favors its invasion and establishment in Brazil, corroborating results noticed in other countries.


Much of the information which can be obtained about a plant virus agent is ultimately derived from the quantity as well as the type of the infections resulting from inoculations to suitable host plants. The number ofinfections obtained does not depend solely on the nature of the particular virus concerned. It is dependent on other variable factors, such as the efficiency of the means of infection introducing the virus, the susceptibility of the plants receiving it, and the concentration of the virus in the source from which it was obtained. In this paper a'n attempt has been made to estimate the effect of some of these variables on infection by insects.


2021 ◽  
Vol 14 (4) ◽  
pp. e241417
Author(s):  
Tânia Ascensão ◽  
Maria Inês Marques ◽  
Helena Barros Leite

Ewing’s sarcoma is an aggressive tumour, common in paediatric age, in which treatment often implies a decrease in reproductive potential. We describe a case of a woman who had a lumbar Ewing’s Sarcoma in 1991, at the age of 8. She was submitted to extended tumourectomy, chemotherapy and local radiotherapy without preservation techniques. In adult life, and after two in vitro fertilization (IVF) reproductive cycles without success, she spontaneously conceived at the age of 32. After an uneventful pregnancy, she delivered a healthy child by caesarean section. This is a rare successful case of a spontaneous and uneventful pregnancy without previous preservation techniques. In the last 30 years, there has been significant development in this area, and currently, there are solutions for these patients, including in prepubertal age.


1964 ◽  
Vol 15 (3) ◽  
pp. 927-930 ◽  
Author(s):  
Andrew K. Solarz

250 adult female beagles were tested for emotional display late in adult life after having been exposed or sham exposed to X-irradiation at 10 to 12 mo. of age. The control dogs were interspersed in pens among experimentals. Emotional display was stimulated by the presentation of a person relatively strange to the kennel area. The dogs' responses were classified as “friendly,” “wary,” “aggressive” or “staying.” No significant differences were obtained in the comparison of experimental and control groups in regard to frequency of dogs falling within each of the behavioral categories.


1994 ◽  
Vol 56 (1-4) ◽  
pp. 93-97 ◽  
Author(s):  
J.P. Morlier ◽  
M. Morin ◽  
G. Monchaux ◽  
P. Fritsch ◽  
J.F. Pineau ◽  
...  

Abstract To study the effect on lung cancer incidence of a long exposure to low levels of radon, 500 male 3-month-old Sprague-Dawley rats, were exposed to a cumulative dose of 25 WLM of radon and its daughters, 6 hours a day, 5 days a week, during 18 months. Exposure conditions were controlled in order to maintain a defined PAEC: 42 x 10-6 J.m-3 (2 WL), in the range of domestic and environmental exposures. Animals were kept until they died or given euthanasia when moribund. Mean survival times were similar in both irradiated and control groups: 828 days (SD = 169) and 830 days (SD = 137), as well as lung cancer incidence, 0.60% at 25 WLM and 0.63% for controls. The incidence of lung lesions was compared statistically with controls and those previously obtained at cumulative exposures of 25 and 50 WLM delivered over a 4-6 month period, inducing a significant increase of lung cancer, 2.2% and 3.8% respectively. Such a comparison showed a decreased lung cancer incidence related to a decrease in the dose rate for low levels of radon exposure.


Author(s):  
Samira Khodayari ◽  
Maryam Hashemian Shalilvand

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is an important pest of pepper (Capsicum annuum L.). Control of this pest is usually dependent on chemical pesticides. The use of resistant plant cultivars in conjugation with other control tactics generates more effective and long lasting results in management of many pests. In this study we used two-sex life table to evaluate the performance of T. urticae on five pepper cultivars (11983, ES4, Hashemi, Mahali and USL) before and after blooming of host plants. The results showed that the immature time, adult longevity and fecundity differed significantly among cultivars. Before blooming on 11983, the values for the intrinsic rate of increase (r) and the finite rate of increase (λ) were 0.0645 and 1.066 day-1 respectively, which were significantly the lowest; the highest r and λ values was recorded on ES4 which were 0.1347 and 1.144 day-1 respectively. After blooming there was no significant difference in these values among cultivars except for Mahali in which these values were significantly the highest (0.0751 and 1.078 day-1 respectively). Comparing between the phenological stages of host plants (before and after blooming) indicated that after blooming all of the tested pepper cultivars were more resistant to T. urticae. In summary, among the different cultivars tested, the most suitable was ES4 and the least suitable was 11983 before blooming of host plants. After blooming the suitability of host plants changed and decreased significantly.


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