Effect of light–dark cycles on adult emergence in the aphid parasite Aphidius smithi

1975 ◽  
Vol 53 (9) ◽  
pp. 1201-1206 ◽  
Author(s):  
M. Mackauer ◽  
D. H. Henkelman

Adult emergence in Aphidius smithi is asynchronous in continuous light. A regime of alternating light and dark phases during pupal development and emergence generates a population rhythm. Under long-day conditions (LD 16:8), eclosion is restricted to the photophase, or largely so. When the scotophase is extended (LD 12:12 and 8:16), a variable proportion of adults emerges in the absence of light. Estimates of the time-to-adult that are based on the mean of the discontinuous frequency distribution of emergence time in LD are biased and may not be biologically meaningful. It is suggested that an apparently longer mean developmental time of females than of males in A. smithi may be a statistical artifact that can be produced by the sampling schedule and the "gating" effect of the photoperiod.

2017 ◽  
Vol 77 (1) ◽  
pp. 38-42 ◽  
Author(s):  
T. N. Lima ◽  
D. C. R. Silva

Abstract Antlion larvae Myrmeleon brasiliensis Návas, 1914 (Neuroptera, Myrmeleontidae) are sit-and-wait predators who build traps to catch their prey. The aim of this study was to observe under laboratory conditions, how the energy cost spent on maintenance of their traps affects: the larval developmental time, time spent as a pupa, mortality rate of larvae and adult size. M. brasiliensis larvae were collected in the municipality of Aquidauana, Mato Grosso do Sul, Brazil and were individually maintained in plastic containers and subjected to two treatments. In the control treatment larvae did not have their traps disturbed while in the manipulated treatment, larvae had their traps disturbed three times a week. The experiments were followed until adult emergence. When the adults emerged, their body size (head-abdomen), anterior and posterior wing span and width were measured. Furthermore, the number of larvae that died during the experiment was recorded. The results showed that the larvae whose traps were manipulated had longer larval development time, smaller pupal development time and were smaller adults. It can be concluded that the energy expenditure spent on maintenance of the trap constructed by M. brasiliensis larvae can affect the development of negative ways, represented by a longer larval development and reduced adult size.


Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1257-1265 ◽  
Author(s):  
Hsiao-Pei Yang ◽  
Ana Y Tanikawa ◽  
Wayne A Van Voorhies ◽  
Joana C Silva ◽  
Alexey S Kondrashov

Abstract We induced mutations in Drosophila melanogaster males by treating them with 21.2 mm ethyl methanesulfonate (EMS). Nine quantitative traits (developmental time, viability, fecundity, longevity, metabolic rate, motility, body weight, and abdominal and sternopleural bristle numbers) were measured in outbred heterozygous F3 (viability) or F2 (all other traits) offspring from the treated males. The mean values of the first four traits, which are all directly related to the life history, were substantially affected by EMS mutagenesis: the developmental time increased while viability, fecundity, and longevity declined. In contrast, the mean values of the other five traits were not significantly affected. Rates of recessive X-linked lethals and of recessive mutations at several loci affecting eye color imply that our EMS treatment was equivalent to ∼100 generations of spontaneous mutation. If so, our data imply that one generation of spontaneous mutation increases the developmental time by 0.09% at 20° and by 0.04% at 25°, and reduces viability under harsh conditions, fecundity, and longevity by 1.35, 0.21, and 0.08%, respectively. Comparison of flies with none, one, and two grandfathers (or greatgrandfathers, in the case of viability) treated with EMS did not reveal any significant epistasis among the induced mutations.


Author(s):  
Mervat A. Kandil ◽  
Hemat Z. Moustafa

Abstract Background Cotton bollworms such as Pectinophora gossypiella and Earias insulana are serious pests which destroy the cotton plant, and Bracon brevicornis is a parasitoid which attacked the larvae of bollworms. Results In this study, experiments were performed to investigate and evaluate the toxicity of etofenprox and chlorpyrifos insecticides against newly hatched larvae of Pectinophora gossypiella and Earias insulana. Some biological aspects of compound effects on larval and pupal duration, percentage of mortality, and percentage of adult emergence which resulted from treated newly hatched larvae were studied. The results revealed that LC50 was 0.7 and 0.87 ppm when P. gossypiella was treated with etofenprox and chlorpyrifos, respectively, while LC50 was 0.09 and 0.73 ppm when E. insulana was treated with etofenprox and chlorpyrifos, respectively. The obtained results showed that the percentage of mean larval mortality was 65.0 and 63.0% for treated P. gossypiella, while it was 71.0 and 66.0% for treated E. insulana. The corresponding figure for pupal percentage mortality was 8.0 and 10.0% for treated P. gossypiella, but it was 5.0 and 2.0% for treated E. insulana, with etofenprox and chlorpyrifos, and a prolongation effect in larval and pupal development (total immature stage) resulted from treated both bollworms as follows: 35.5 and 32.4 days for treated P. gossypiella compared with 21.9 days in control and 34.7 and 23.2 days for treated E. insulana compared with 23.1 days in control. The indirect effect of etofenprox and chlorpyrifos on the total immature stage of Bracon brevicornis was 18.2 and 19.5 days compared with 14.3 days in control when B. brevicornis parasitized on P. gossypiella larvae while it was 19.8 and 20.6 days compared with 15.2 days when B. brevicornis parasitized on E. insulana larvae. Conclusion The life cycle of B. brevicornis after parasitism on P. gossypiella and E. insulana larvae treated with etofenprox and chlorpyrifos were increased than the control larvae.


1961 ◽  
Vol 36 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Richard Jay Wurtman ◽  
Willard Roth ◽  
Mark D. Altschule ◽  
Judith J. Wurtman

ABSTRACT Either exposure to constant light for 80 days or pinealectomy produced similar changes in the weights of the ovaries and adrenals of female rats. These were not additive when both procedures were employed. Pinealectomy did not share with light-exposure the capacity to induce uterine hypertrophy. Rats exposed to constant light for 56 days had lighter pineals than animals kept in darkness; this decrease was not affected by administration of bovine pineal extracts. The increase in ovarian weight produced in rats by exposure to light for 56 days was prevented by bovine pineal extracts, but these extracts were without effect on the uterine hypertrophy produced under the same conditions. These data suggest that the effect of light upon the weight of the ovary is mediated via the pineal.


Author(s):  
S. Ragul ◽  
N. Manivannan ◽  
K. Iyanar ◽  
N. Ganapathy ◽  
G. Karthikeyan

Background: Blackgram [Vigna mungo (L.) Hepper] is a rich source of protein. It is one of the major crops essentially involved in daily human diets. However, storage pest bruchine [Callosobruchus maculatus (F.)] is a major production constraint for legumes. A research was formulated to assess the bruchine resistance in 20 blackgram genotypes along with the biochemical analysis to find out the active biochemical components responsible for the resistance activity.Methods: The experiment was carried out during August- October, 2019 at Entomology Laboratory, National Pulses Research Center, Vamban, India. The experimental material comprised of 20 blackgram genotypes which were screened for bruchine resistance. Further, confirmatory trial was conducted with selected resistant entries and highly susceptible entries during October- December, 2019. Both experiments were carried out in completely randomized design and replicated three times. GC-MS analysis on the resistant and susceptible entries were performed to ascertain the active biochemical components conferring resistance.Result: Among the genotypes, TU 68 had comparatively late developmental time (days), less number of adult emergence, higher mean developmental period (days), less susceptibility index, less seed damage (%) and less seed weight loss (%). Genotype TU 68 was found to be resistant in the confirmatory trial also. Less number of adult emergence and higher mean developmental period indicated the delayed developmental period which is a mechanism of bruchine resistance. GC-MS analysis on resistant (TU 68) and susceptible (MDU 1) genotypes indicated the presence of active biochemical compounds with insectifuge activity in TU 68. Hence, TU 68 could be utilized in the hybridization programmeas donor for bruchine resistance.


2011 ◽  
Vol 46 (6) ◽  
pp. 669-671 ◽  
Author(s):  
Adrise Medeiros Nunes ◽  
Dori Edson Nava ◽  
Fernanda Appel Müller ◽  
Rafael da Silva Gonçalves ◽  
Mauro Silveira Garcia

The objective of this work was to study the biology and parasitic potential of Doryctobracon areolatus on larvae of Anastrepha fraterculus. The egg-adult period, the sex ratio, the longevity, the pupal viability, and the parasitism rate of D. areolatus were determined in laboratory, using A. fraterculus as host. The parasitoid development from oviposition to adult emergence required 25.00±1.70 days, the sex ratio was 0.62±0.09, and the mean longevity was 16.36±3.62 days for males and 10.24±1.71 days for females. The mean parasitism rate was 53.50±8.93%, varying from 41.60 to 68.60%, which shows the potential of this parasitoid for biological control of A. fraterculus.


1995 ◽  
Vol 24 (1) ◽  
pp. 76-87 ◽  
Author(s):  
D. W. Spurgeon ◽  
P. D. Lingren ◽  
J. R. Raulston ◽  
T. N. Shaver

2019 ◽  
Vol 4 (1) ◽  
pp. 285-292 ◽  
Author(s):  
Kody L Graves ◽  
Bethany R Mordhorst ◽  
Elane C Wright ◽  
Benjamin J Hale ◽  
Kenneth J Stalder ◽  
...  

Abstract A potential indicator of female lifetime productivity in swine is age of puberty, when a gilt achieves her first behavioral estrus. Follicular activity, as determined by tertiary follicle development, in prepubertal gilts begins during postnatal day (PND) 75 to 115. The central hypothesis of this study is that gilts demonstrating tertiary follicle development earlier in life, assessed using vulva size as a proxy, achieve puberty earlier in life compared with counterparts of a similar age and weight that lack tertiary follicle development. The objectives of this project were to identify a developmental time point when variation in ovarian development exists and to determine whether a relationship between the age prepubertal ovarian development and the age at onset of puberty exists. To accomplish this, 155 gilts of similar age (± 2 d) were weighed and vulva size measured on PND 75, 85, 95, 105, and 115. Vulva measures, including vulva width (VW), vulva length (VL), and vulva area (VA), were utilized as developmental proxies for follicular activity. At each time point, gilts (n = 10) were sacrificed and ovarian follicular activity recorded. In a subset of gilts (n = 105), estrus detection was conducted daily on PND days 126 to 200. Mean VA on PND 75, 85, 95, 105, and 115 was 596 ± 206, 683 ± 190, 864 ± 212, 1014 ± 228, and 1265 ± 252 mm2, respectively. Of the gilts demonstrating behavioral estrus, 28 were within PND 140 to 160, 36 between PND 161 to 180, 15 between PND 181 to 200, and 26 did not demonstrate estrus behavior within 200 d of age. All gilts euthanized at PND 75 lacked follicular activity as defined by having a minimum of 2 antral follicles per ovary, whereas 60%, 80%, 90%, and 100% demonstrated follicular activity on PND 85, 95, 105, and 115, respectively. Body weight at PND 75 and VW at PND 115 were correlated to age at first estrus (P < 0.05). Of the gilts whose VA was less than 1 SD from the mean on PND 95 (i.e., <652 mm2), 31% and 50% demonstrated their first behavioral estrus by PND 180 and 200, respectively. However, of gilts whose VA was within or greater than 1 SD of the mean (i.e., ≥652 mm2), 66% and 79% exhibited estrus prior to PND 180 and 200, respectively. These data support utilization of VA changes between 95 and 115 d of age as a useful tool to identify replacement gilts prior to puberty for inclusion into the sow herd.


1976 ◽  
Vol 108 (12) ◽  
pp. 1399-1402 ◽  
Author(s):  
M. Mackauer

AbstractMated females of the aphid parasite Aphidius smithi produced only unfertilized eggs (i.e. sons) for the first 2–3 h after copulation and a variable proportion of fertilized eggs (i.e. daughters) thereafter. As a result, the mean proportion of daughters among the offspring of single females was always less than unity, even in a highly favourable environment; the limiting value of the sex ratio was estimated at approximately 85% females. An argument is presented that in haplodiploid species with a variable and environmentally controlled sex ratio a male-producing mechanism is required to ensure the production of a sufficient number of males for the fertilization of all females.


2019 ◽  
pp. 1025-1030
Author(s):  
Almerinda Amélia Rodrigues Araújo ◽  
Raimunda Nonata Santos Lemos ◽  
José Ribamar Gusmão Araújo ◽  
Paulo Roberto Ramalho Silva ◽  
Solange Maria França ◽  
...  

Fruit flies (Diptera: Tephritidae) are considered important pests of fruticulture due to considerable losses to production and limitation to free transit of fresh fruits. A generalist species is cresature that can live or feed on a wide variety of environemnts or host plants. Although, Anastrepha is a generalist species but infests a small range of plants. The specificity of this species with host plants is a peculiar characteristic of genus Anastrepha. Therefore, it is important to understand the host species and its feeding behaviour on host plants. This way, we will better know its ecology, biology and evolution for rational control ways and measures. Therefore, this study aimed at understanding the biology of Anastrepha alveata Stone (Diptera: Tephritidae). A study was carried out under controlled laboratory conditions (27 ± 2°C temperature, 70 ± 5% RH, photoperiod 12 hours) during the period from November/2015 to October/2017. Anastrepha alveata adults were obtained from wild plum fruits Ximenia americana L. (Olacaceae), collected from Savanna area in two fructification periods. One-hundred and fifty Anastrepha alveata adults were collected (60 females and 90 males) to determine sexual maturity, mating behavior, fecundity and longevity. The sexual maturity for Anastrepha alveata was 8-13 days after emergence for females. At this age they emitted signal of acceptance for mating and copulation. For males, 5-7 days after emergence this mating signals was given, which was characterized by the protrusion of the lateral abdominal pleural glands. The mating rhythm of Anastrepha alveata was crepuscular/nocturnal, beginning around 6 p.m. and extending to/after 9 p.m. Anastrepha alveata females did not mate with more than one male but mated more than once. The number of males did not affect significantly the mating time, the number of eggs and the longevity of Anastrepha alveata. The mean pupal period for Anastrepha alveata was 17.5 days. Two preferential peaks for adult emergence were observed at 10:00 am and 03:00 pm. The longevity of the adult insects was greater than 300 days, surviving until the fructification of its host (wild plum) in the following year. Therefore, A. alveata has a strictly monophagous food habit associated with the Ximenia americana host.


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