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1.
Dejan Marcic 《Experimental & applied acarology》2003,30(3):249-263
Sublethal effects of the growth inhibitor, clofentezine, on life-table parameters of Tetranychus urticae Koch females treated at different developmental stages with a concentration causing ≥90% mortality were investigated. Females
which survived treatment as ‘early’ (0–24 h old) eggs produced 12% more offspring than the untreated females during the first
five days of oviposition. This resulted in a significant rise in the intrinsic rate of increase (r
j
): 0.324, compared to 0.299 in the untreated females. This effect may be interpreted as hormoligosis. Clofentezine treatment
at any other developmental stage of T. urticae significantly decreased both longevity and fertility of female survivors. Females which survived treatment either as ‘late’
(72–96 h old) eggs or larvae had 2.6 times lower net reproductive rate (R
0) than the untreated females, and the r
j
values were significantly lower: 0.242 and 0.215, respectively (0.285 in the untreated females). Females which survived treatment
either as protonymphs or deutonymphs had 3.9 times and 6 times lower R
0, respectively. Corresponding r
j
values were 0.178 and 0.146, respectively (0.247 in the untreated females). The clofentezine treatment at all stages influenced
the age distribution of survivors. The sublethal effects of clofentezine and their impact on T. urticae management are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
Overwintering population of Cercopagis is represented by resting eggs which hatch generally in May. Although representatives of the first parthenogenetic generation
(the spring form individuals) differ morphologically from individuals of the subsequent generations (the summer form individuals)
and could be keyed to a separate species – Cercopagis (Apagis) ossiani – our analysis confirm that there is only one Cercopagis species in the Gulf of Riga: Cercopagis pengoi. Notable seasonal dynamics was observed for the gamogenetic mode of reproduction, being strongly associated with the total
population density. Gamogenetic females develop since the end of June and reach the maximum absolute abundance in July whereas
their proportion is generally the highest in fall. The gamogenetic absolute fecundity drops to the lowest level late July
but increased afterwards until the late August. One resting egg was, an average, found in 45.4%, two in 53.4% and three in
1.2% of females. Parthenogenetic fecundity was significantly higher in May–June compared to other months studied. Brood pouch
of parthenogenetic females was found to contain 11.6 ± 1.0 and 10.2 ± 0.3 embryos in the spring and summer form individuals,
respectively. Variation in the two modes of reproduction and fecundity is probably solely not controlled by temperature, but
also by food availability and population density. 相似文献
3.
E. W. Riddick 《BioControl》2007,52(5):613-618
Laboratory experiments were conducted to determine the impact of feeding status and maternal age on egg load of Cotesia
marginiventris (Cresson) (Hymenoptera: Braconidae), a solitary, koinobiont endoparasitoid of noctuid pests. Egg load was defined as the
number of mature (i.e., fully-chorionated) eggs found in the ovaries and oviducts. Significantly more mature eggs were stored
in honey-fed than starved females. For honey-fed females, egg load increased within several days of isolation from hosts.
This study suggests that C. marginiventris is weakly synovigenic because females emerge with a considerable number of mature eggs and are capable of maturing many more
eggs. Feeding on a suitable source of carbohydrate should increase the egg load (i.e., potential fecundity) of this insect
within 3–4 days in an in vivo rearing system. 相似文献
4.
Marcic D 《Experimental & applied acarology》2007,42(2):121-129
Laboratory bioassays were conducted to evaluate the effects of spirodiclofen on life history and life-table parameters of
two-spotted spider mite (Tetranychus urticae Koch) females treated at pre-ovipositional period with a series of acaricide concentrations starting with the concentration
discriminative for eggs and immatures i.e. the lowest concentration that causes 100% mortality of those stages. After a 24 h
exposure, the proportion of females that survived treatments was 0.71 (6 mg/l), 0.51 (12 mg/l), 0.41 (24 mg/l), 0.30 (48 mg/l)
and 0.25 (96 mg/l). At the end of the trial, the survival rate of females treated with the lowest concentration was significantly
lower than the survival rate of untreated females but it remained above that of females treated with higher concentrations.
Total fecundity/fertility significantly decreased as concentrations of spirodiclofen increased. Viable eggs were laid by females
treated with 6, 12 and 24 mg/l, and total fertility was reduced by 42, 84 and 97%, respectively. Compared with control, the
gross fecundity/fertility of the treated females was significantly reduced throughout the trial, except in females treated
with 6 mg/l. All concentrations caused a significant reduction in the net fecundity/fertility throughout the trial. The females
treated with 12 mg/l had significantly reduced net reproductive rate (R
0 = 6.45), compared to females treated with 6 mg/l (R
0 = 23.35) and to untreated females (R
0 = 28.92); there was no significant difference between the last two treatments. The intrinsic rate of increase (r
m
) and finite rate of increase (λ) were significantly reduced in treated females (r
m
= 0.141, λ = 1.156 and r
m
= 0.214, λ = 1.232; 12 and 6 mg/l, respectively), compared to control (r
m
= 0.251, λ = 1.276). The reduction was significantly greater in females treated with the highest concentration. As a result of the lowered
r
m
, the doubling time in treated females was significantly extended. Sublethal effects of spirodiclofen and its impact on T. urticae management are discussed. 相似文献
5.
The effect of fungal infection on the reproductive potential of two-spotted spider mite, Tetranychus urticae, was evaluated as part of the full biocontrol potential of three entomopathogenic fungi by modeling of fecundity probability.
Female mites (≤2-day-old) on leaves were exposed to the sprays of Beauveria bassiana, Paecilomyces fumosoroseus and Metarhizium anisopliae at the concentrations of 1.13 × 103, 1.55 × 103 and 0.95 × 103 deposited conidia mm−2 and then individually reared at 25°C and 12:12 L:D for oviposition. Mite mortalities 10 days after spraying were 73.1, 75.4
and 67.9% in the fungal treatments versus 15.5% in control. On average, females infected by the three fungal species survived
5.8, 6.2 and 6.3 days, and laid 3.1, 4.0 and 4.0 eggs per capita, respectively. These were 3–4 fold lower than the control
fecundity at 12.3. The cumulative probabilities [P(m ≤ N)] for the counts of infected and non-infected (control) females laying m eggs per capita (m ≤ N) during 10 days fit very well the equation P(m ≤ N) = 1/[1 + exp(a + bm)] (r
2 ≥ 0.98), yielding a solution to the probability for the female mites to achieve a specific fecundity {P(m ≤ N)−P[m ≤ (N − 1)]}. Consequently, the infected mites had 71–78% chance to lay ≤5 eggs per capita but only 5–8% to deposit >10 eggs despite
some variation among the tested fungi. In contrast, the chances for the non-infected mites to achieve the low and high fecundities
were 23 and 55%. The fitted probabilities provide a full coverage of the fecundity potential of infected versus non-infected
mites and are more informative than the mean fecundities. 相似文献
6.
A total of 370 specimens of Paracobitis malapterura in the Zarrin-Gol River (east of the Elburz Mts, Iran) were caught by regular monthly collection throughout one year from
November 2006 to October 2007. The specimens were then examined for age and growth, reproduction and feeding attributes. Based
on otolith readings the maximum ages of the population observed were 3+ years for males and 4+ years for females. The specimens ranged in size from 38 to 130 mm total length, weighing from 0.68 to 30.55 g total weight.
Length-weight relationship was estimated as W = 0.020L
2.62 for males, W = 0.002L
3.81 for females and W = 0.008L
3.08 for the population. Sex ratio was 1: 1.27 in favor of females. The Gonadosomatic index indicated that reproduction of the
loach in the river occurred around April–May, with the highest average value of 1.48 for males and of 5.36 for females in
May. The absolute fecundity ranged between 92–1180 eggs with a mean of 456.31 eggs. Diameter of oocytes ranged from 0.11 to
2.80 mm with a mean value of 0.95 mm. The absolute fecundity and oocyte diameter to fish size (length and weight) and age
were not significantly correlated. Plecoptera and Trichoptera dominated the diet contents composing 72.43% and 20.80% of total
frequency of food items, respectively. 相似文献
7.
Ling Cao Biyu Song Jinmiao Zha Chengtai Yang Xinfu Gong Jianbin Li Weimin Wang 《Environmental Biology of Fishes》2009,86(1):75-88
This study presents fundamental information on the reproductive biology, size and age composition, and growth of yellow catfish,
Peltobagrus fulvidraco. Sampling was carried out monthly from Ce Lake in Hubei province from January 2004 and December 2004. Overall female/male
(F/M) sex ratio was 1.08, not significantly different from expected 1.0 ratio. But sex ratio (F/M) of the spawning group was 1.14:1 with skewness towards females (p < 0.05). The smallest sexually mature male and female massed 20.51 and 16.93 g, and measured 100.1 and 94.3 mm in total length,
respectively. Reproductive period for this species is from April to August when GSI is considerably higher than the rest months
(p < 0.05). The highest GSI values were measured from May to July for both sexes and this period was presumably the peak spawn.
First maturation occurred at age 1+ for both sexes. Fish of age 1+ and 2+ comprised the greatest portion of spawners. The absolute fecundity (AF) of P. fulvidraco ranged from 657 to 11,696 eggs per fish, with mean AF value of 3,570 ± 122 (S.D.) eggs per fish, varying considerably at
given length, weight and age. The fecundity relative to total length (F/L) fluctuated from 58 to 680 eggs/mm, with a mean value of 246 ± 34 (SD) eggs/mm, and fecundity relative to total weight (F/W) varied from 29–133 eggs/g, with a mean value of 67 ± 7 (SD) eggs/g. P. fulvidraco is a single spawner, with low fecundity compared with other Bagrid fish. 相似文献
8.
K. D. Simon Y. Bakar A. G. Mazlan C. C. Zaidi A. Samat A. Arshad S. E. Temple N. J. Brown-Peterson 《Environmental Biology of Fishes》2012,93(4):491-503
Various aspects of the reproductive biology of two archer fishes Toxotes chatareus and Toxotes jaculatrix were studied to describe gonad development, spawning season, sex ratio, and fecundity. Spawning season was assessed using
monthly changes in gonadosomatic index (GSI) and histological inspection of the gonads. Both species exhibit two modes of
oocytes; a mode of small primary growth oocytes and a single mode that increases with size as oocytes sequester vitellogenin
and undergo maturation, showing the synchronous oocyte development typical of total spawners. Based on GSI values and advanced
stages of oocyte maturity, T. chatareus and T. jaculatrix, females appear to spawn from November to December. The average fecundity of female T. chatareus was 55 000 ± 5538 eggs, and T. jaculatrix was 50 000 ± 3440 eggs; fecundity ranged from 20 000 to 150 000 eggs for both species, with relative fecundities of 600 to
1100 eggs/g body weight, and a mean value of 800 ± 32 for T. chatareus; relative fecundity ranged from 500 to 1100 with a mean value of 700 ± 23 for T. jaculatrix. Sex ratio, defined as the proportion of males to females, was 2.2 and 2.5 in T. chatareus and T. jaculatrix, respectively. The apparent abundance of males in samples could be due to females being positioned lower in the water column
and therefore being sampled less frequently. Our results indicate that in both species, spawning occurs between the months
of November and December during the monsoon season, which provides the mangrove coastal waters inhabited by these species
with an abundance of food resources and additional floodplain nursery habitat for larvae and juveniles. 相似文献
9.
Noriyuki Shiraishi Tetsuya Taguchi Hideo Kinebuchi 《Biological trace element research》1993,39(2-3):129-137
It was determined if the sensitivity inmacular mutant mouse to copper-induced toxicity was affected by sex or age. The sensitivity in 6–8-d-old or 3–4-wk-oldmacular mutant mouse to copper-induced toxicity was not affected by sex. However, 8–9-wk-old mutant females were more sensitive to
copper-induced toxicity than mutant males. Furthermore, 6–8-d-old or 3–4-wk-old mutant males were more sensitive to copper-induced
toxicity than 8–9-wk-old mutant males. However, age-related differences in sensitivity to copper-induced toxicity did not
occur significantly in mutant females. On the other hand, in the case of normal mice, the sensitivity in 6–8-d-old or 3–4-wk-old
mice to copper-induced toxicity was not also affected by sex. In contrast to mutant, however, 8–9-wk-old normal males were
more sensitive to copper-induced toxicity than 8–9-wk-old normal females. Adult males were also more sensitive to copper-induced
toxicity than 6–8-d-old or 3–4-wk-old males. However, age-related differences in sensitivity to copper-induced toxicity did
not occur significantly in normal females. These results indicate that sex- and age-related differences in the copper-induced
toxicity exist inmacular mutant mice. 相似文献
10.
Two aspects of mating effects on the fecundity, sex ratio and longevity of Neoseiulus cucumeris (Acari: Phytoseiidae) were examined in laboratory experiments: (1) females mated by one, two or three different males (unmated
and 3 days old) at 5-day intervals, and (2) females mated by males with different age/mating status (number of females mated
previously by the male). Females allowed to mate with a second or third male at 5-day intervals produced 39 eggs on average,
but those mated with a single male produced 28 eggs on average. Matings with additional males 5 or 10 days after the first
male increased the duration of the oviposition period of these females by 5–7 days and at the same time reduced the post-oviposition
period by about 10 days. Overall, females with additional matings by one or two different males at 5-day intervals survived
a few days shorter than females without additional males. Mating with a different female each day, a male of N. cucumeris could mate with 5–8 females, which produced a total of 85–116 eggs: females mated with a male during days 1 and 2 in its
adulthood and with a male of the last 2 days of life (days 7 and 8) produced about half as many eggs as females mated with
a male during 3–6 days of its adulthood. Females mated with males that are too young or too old had a shorter oviposition
period and a longer post-oviposition period and longevity than females mated with middle-aged males. In both experiments,
rates of oviposition remained similar in females with high or low fecundity. This indicates that in both cases, the increased
fecundity is due to the extension of the oviposition period through additional sperm supplied by the second male and or third
male (in experiment 1) or more sperm by males not too young nor too old (experiment 2). 相似文献
11.
A new species Dolichopteryx minuscula is described on the basis of three specimens [49.4–59.6 mm in standard length (SL)] collected from the Indo-West Pacific.
The new species is characterized by pouchlike eyes with a small lens (lens diameter 2.2% SL), an adipose fin, the anal fin
base originating posterior to the dorsal fin base, and 16–17 (= 5–6 + 1 + 10–11) gill rakers. Total fecundity was relatively
low, only 658 ova being obtained from one specimen, despite the ovary being mature. Ovarian eggs were clearly subdivided into
“undeveloped” (0.1–0.7 mm diameter classes, n = 561) and “developed” (1.0–1.3 mm classes, n = 97) groups, based on their frequency distribution. Such relatively low fecundity and frequency distributions of ovarian
eggs suggest that Dolichopteryx species spawn iteratively during spawning season. 相似文献
12.
Population of the freshwater amphipod Gammarus fossarum was investigated in a calcareous stream with almost constant temperature (7–8°C) in the Chočské Vrchy Mts (West Carpathians,
Slovakia). Quantitative samples of G. fossarum taken during 2005 showed population densities varying from 100 m−2 in August to 585 m−2 in late November. The population was split into juveniles, mature males, mature females without eggs and females with eggs.
The percentage of juveniles (40–64%) was always the highest of any of the categories. Ovigerous females occurred throughout
the year. The mean sex ratio was 1: 2.4 (male: female), although its values varied considerably with the time of year. Breeding
was continuous, although juvenile recruitment peaked in early spring, summer and early winter. Three discrete cohorts were
distinguished from the size frequency distributions. The life span was 6–7 months and the individuals matured approximately
in the half of life cycle. The mean fecundity was 9.6 embryos per brood. Variation in fecundity was mostly explained by size
of the incubating females. The absolute growth of this species was best described by the Gompertz growth function. Relative
growth rates (% body DM day−1) fluctuated in a nonlinear manner with size and age. The highest values of daily growth (2–4% of dry mass per day) were noted
approximately in the half of life cycle. Annual production, estimated by the size-frequency method, was 1618.9 g dry mass
m−2 and P/B ratio was 5.15. 相似文献
13.
Peristenus digoneutis Loan and Peristenus stygicus Loan, parasitoids of the European tarnished plant bug Lygus rugulipennis Poppius, are established in the United States for biological control of native North American Lygus species, and are being considered for deliberate release in Canada. High lifetime fecundity of parasitoids is considered a desirable attribute of biological control agents and therefore, an understanding of parasitoid reproductive biology is required. In the present study, the potential lifetime fecundity of both agents was compared under laboratory conditions to estimate the potential impact of Peristenus species on Lygus. Synovigenic P. digoneutis and P. stygicus females oviposited most actively in the first two weeks of their lifetime, with a maximum average daily oviposition rate after five days. The maximum number of eggs laid per day was 83 eggs for P. stygicus, and 36 eggs for P. digoneutis. P. digoneutis has an average potential lifetime fecundity of 385 ± 35 SE eggs produced over 22 ± 3 SE days. In contrast, P. stygicus females have a 50% higher mean potential lifetime fecundity reaching 782 ± 65 SE eggs over 28 ± 1 SE days. A positive correlation between lifetime fecundity and body size was found only for P. stygicus, and both species showed a significant relationship between lifetime fecundity and oviposition period. The present study demonstrates that the fecundity of P. digoneutis and P. stygicus is considerably higher than previously reported. Based on these findings, P. stygicus appears to be the most effective biological control agent for Lygus lineolaris (Palisot de Beauvois) when only fecundity is taken into consideration. 相似文献
14.
Laboratory studies showed that ♀♀ ofTrichogramma embryophagum (Hartig) andT. semblidis (Aurivillius) when offered an alternative of young and old eggs of the grain moth,Sitotroga cerealella Oliv., prefer ovipositing into young eggs. The fecundity of ♀♀ that are simultaneously offered both young and old eggs was
lower in comparison to ♀♀ offered only young eggs (inspite of the fact that in both variants young eggs were in excess). The
results suggest that old eggs can inhibit the oviposition of some species ofTrichogramma.
相似文献
15.
Jian Jun Duan Ronald J. Prokopy Chih-Ming Yin Chris Bergweiler H. Oouchi 《Entomologia Experimentalis et Applicata》1995,77(1):17-21
Three-day old female apple maggot flies,Rhagoletis pomonella (Walsh), were topically exposed to different doses (0.1, 1, 10, and 100 μg per fly) of a juvenile hormone mimic, pyriproxyfen,
in the laboratory. Pyriproxyfen had little lethal effect on females except at the extremely high dose of 100 μg. It also had
no significant effect on egg viability of treated females. A non-lethal dose of 1 μg per fly did, however, enhance significantly
the fecundity (egg production) as well as the ovarian development (number of eggs in ovaries and length of egg folicles) of
treated flies. We conclude that pyriproxyfen could be a useful aid in exploring endocrine regulation of feeding and reproductive
physiology behavior inR. pomonella, about which current knowledge is scant. 相似文献
16.
K. P. Singh R. K. Jaiswal Niranjan Kumar 《World journal of microbiology & biotechnology》2007,23(2):291-294
Summary
Catenaria anguillulae parasitized and killed the eggs and second stage juveniles (J2) of Meloidogyne graminicola under natural conditions. The percentage of infection in eggs was higher than J2 of M.␣graminicola, which ranged between 0–50.3% and 0–18.9% in 2004 and 0–46.6% and 0–21.7% in 2005, respectively. The higher parasitism of
eggs and J2 was recorded from those fields in which plants were severely infected with M. graminicola. The degree of parasitism of eggs and J2 by C. anguillulae varied with severity of root knot disease. The fields with a higher root gall index recorded a higher percentage of infection
in eggs and J2 of M. graminicola. In general, old galls when teased and incubated, recorded higher parasitism of eggs and juveniles than young galls. 相似文献
17.
In the fell-field habitat at 140–270 m altitude on the sub-Antarctic Ile de la Possession, Iles Crozet, the dimorphic beetle
Amblystogenium pacificum Putzeys (Coleoptera: Carabidae) was studied monthly throughout the southern year 1993–1994 by timed hand collections involving
turning stones on the rocky fell-field. There were many mating couples and females containing well-developed eggs in every
month and the species reproduced throughout the year, with no evidence of a winter cessation of egg production. However, the
frequency of mating couples was about twice as great in the summer half-year (October–March) as in the winter half (April–September).
Relatively small differences in monthly mean temperatures between the summer and winter at Iles Crozet render all-year reproduction
not unexpected when comparisons are made with the temperatures and phenology of Carabidae in cool habitats in other parts
of the world. Mating pairs were collected at unusually high frequencies for carabids. The frequency of such pairs, taken per
unit effort by hand collecting, was highest in October–December, lower from January to May and intermediate from June to September.
Comparison of beetles taken as solitary, non-mating individuals with those taken as mating couples showed that in summer,
females of the black morph of this dimorphic species were more frequently involved in mating than expected, but no differences
were detected in winter. Female beetles were divided into younger individuals (putative age 1–2 years) and older females (putative
age 3–5 years or more) by the amount of claw-wear on individuals of this species. This division indicated that about 40% of
the older females showed no egg development when captured, but only about 20% of the younger females were non-breeding. However,
of the reproducing beetles, young and old females matured similar numbers of eggs. An altitude transect showed that the proportion
of the black morph increased significantly with altitude. Studies at 140–270 m showed that a significantly smaller proportion
of the older females of the brown morph were breeding than in the younger brown individuals, and this effect was particularly
evident in the colder winter period. No such age differences existed amongst the black morph. 相似文献
18.
Yu. N. Poltev 《Journal of Ichthyology》2011,51(4):324-330
According to data obtained off the eastern coast of the Northern Kurils in October–December 1998, the body length of spawning
females of the longfin thornyhead Sebastolobus macrochir is 26–41 cm (on average, 31.5 ± 0.27). Mass spawning is recorded in females 28 cm in length and longer. The individual absolute
fecundity of females is 69355-411710 (on average, 189086 ± 13662) eggs. The reproductive potential of females of the longfin
thornyhead is estimated as 189 million eggs. It is supposed that all females participate in spawning. 相似文献
19.
C. F. von Dorrien 《Polar Biology》1996,16(6):401-407
State of maturity, egg numbers, as well as gonadosomatic index (GSI), and relative fecundity were determined in 209 females
of the cottid species Artediellus atlanticus. Specimens were caught by Agassiz and bottom trawls during two expeditions of RV “Polarstern” to the shelf off northeast Greenland (ARK VII/2; July/ August 1990) as well as to the Barents Sea and the shelf areas surrounding
Svalbard (ARK VIII/2 – Arctic EPOS; June/July 1991). Analysis of the state of maturity showed that A. atlanticus spawns from late summer to autumn. Individuals from northern populations spawn later (November) than those from more southern
locations (July to September). The total number of eggs (40–216) was small due to their large diameter and the small size
of the fish. The mean GSI of females from the central Barents Sea (36.9±6.5%; n=24) was significantly higher (P<0.001) than the GSI of females caught off eastern Svalbard (18.7±4.0%; n=14), compared at stage IV of maturity. The mean relative fecundity was significantly higher (P<0.001) for females of the central Barents Sea (17.9±2.3; n=19) than for females caught on more northern stations east of Svalbard (6.9±1.8; n=17) and north of Svalbard (6.4±0.5; n=7). Individuals of A. atlanticus that were maintained at 0°C spawned in the aquaria, allowing observation of the development of their eggs and larvae for
1 year. The eggs needed more than 200 days to develop. The larvae hatched at a very advanced stage and were similar to the
adults in appearance and behaviour. The larvae grew at a rate of 0.02 mm per day and showed a benthic mode of life.
Received: 7 April 1995/Accepted: 30 July 1995 相似文献
20.
Larvae of the tephritid flyChaetorellia australis Hering, which infests flowerheads of the yellow starthistleCentaurea solstitialis L. (Asteraceae), and which is a candidate species for biological control, of that weed, were reared for the first time and for two consecutive
generations on an artificial diet. At a density of 0.5 eggs per g diet a yield of 18.5% F1 adults (over hatched eggs), was obtained. When the density of eggs per g diet increased, the yield decreased. At 25°C the
duration of development from egg to adult was 20–25 days for both generations. F1 adults reared on artificial diet had an average longevity of 32.0 days for males and 34.9 days for females. The fecundity
was 53.3 eggs per female and the egg hatchability 88.8%. These and other biological parameters are similar to those of wild
flies.
相似文献