Comparative studies on the growth and reproductive performances of Rhodnius prolixus reared on different blood sources

Host blood source was found to affect both the development and the reproductive performance of Rhodnius prolixus. The insects were reared on citrated human, rabbit, chicken, sheep and horse blood sources, through a membrane feeder, during an entire life cycle, from eggs to adults. Development and reproduction in terms of the number of unfed insects, number of moulting, mortality intermoulting period, number of egg/female, conversion of blood into egg (mg meal/egg) and percentage of hatch as effective physiological parameters were investigated. Our results showed that human or rabbit blood meals were more nutritionally efficient than the other blood samples used because (i) the insects developed faster, presented low mortality and about 80% of them reached the adult stage; and (ii) females oviposited an average of at least 100% more eggs. The inefficiency of chicken and horse blood sources as diets for R. prolixus was manifested in (i) a decrease of the amount of ingested blood and (ii) only a reasonable nutritional quality. The inadequacy of sheep blood was observed by a mortality extremely high, poor moulting response and drastic reduction in egg production.

Comparison of the reproductive behavior between isolated Peckia chrysostoma (Wiedemann, 1830) and Adiscochaeta ingens (Walker, 1849) (Diptera: Sarcophagidae) females reared in laboratory

In both species, maintained under laboratory environmental conditions, anautogeny was comproved and all females that had free access to proteic source were fertiles. We obtained the following average values for Peckiachrysostoma: 59.7 ± 15.6 and 81.8 ± 15.4 days of longevity in the respective cases of free access and no access to proteic source, 21.4 ± 4.3 days of pre-larviposition period and 35.2 ± 16.5 days of larviposition period, 5.3 ± 1.8 larvipositions female with 7.0 ± 1.1 days of periodicity, 35.7 ± 6.1 larvae per larviposition leading to a total number of 183.8 ± 69.2 viable larvae per female and 94.8% ± 5.3% of productivity. The mean number of ovarioles per female was 56.4 ± 9.8, resulting in a reproductive potential of 63.3%. For Adiscochaeta ingens, the obtained average values were: 41.3 ± 6.3 and 52 ± 13.1 days of longevity in the respective cases of free access and no access to proteic source, 15.3 ± 1.7 days of pre-larviposition period and 21.5 ± 7.5 days of larviposition period, 3 ± 0.7 larvipositions per female with 10.4 ± 0.8 days of periodicity, 30.3 ± 8.2 larvae per larviposition leading to a total number of 78.5 ± 21.7 viable larvae per female and 90.1% ± 16% of productivity. The mean number of ovarioles per female was 54.6 ± 5.2, resulting in a reproductive potential of 55.5%. Within applied parameters, the values obtained for P. chrysostoma demonstrate its superior productivity in comparison with A. ingens

The reproductive capacity of Panstrongylus megistus (Hemiptera: Reduviidae) males treated with precocenes

Reproductive performance including mating, semen transfer, egg production and hatching rate were investigated in pairs of Panstrongylus megistus in wich the male was treated with either precocene II or ethoxyprecocene II, topically applied shortly after imaginal molt. Eighty percent of the males were not able to mate for a period as long as 40 days after treatment. Those males wich did mate (20%) produced small spermatophores; a few (10%) were unable to transfer spermatozoa to female, while the others (10%) exhibited reproductive performance similar to that of non-treated males. The cumulative effects of the precocene on the different stages of reproduction resulted in a drastic reduction of offspring production. The anti-allatal compound precocene seems to inhibit successful reproduction through a corpus allatum inactivation and subsequent lack of secretory activity of the male accessory glands.

The Effects of a DNA Virus Infection on the Reproductive Potential of Female Tsetse Flies, Glossina morsitans centralis and Glossina morsitans morsitans (Diptera: Glossinidae)

Reproductive anomalies associated with the tsetse DNA virus infection in the female tsetse hosts, Glossina morsitans centralis Machado and Glossina morsitans morsitans Westwood, inoculated with the virus during the 3rd instar larval stage were studied and the data compared to those obtained from the control females injected with sterile physiological saline. Virus infected flies had significantly longer first and second pregnancy cycles (P<0.0001) and produced pupae that were of significantly less weight in milligrams (P<0.0001) compared to controls. Transmission of the virus to progeny was not absolute and only 21% of G. m. centralis and 48% of G. m. morsitans first progeny flies from infected females developed salivary gland hypertrophy as a result of transmission from mother to progeny. The virus infected females produced significantly fewere pupae compared to the controls during the experimental period (P<0.00001).

Variation of transaminases, HCV-RNA levels and Th1/Th2 cytokine production during the post-partum period in pregnant women with chronic hepatitis C.

This study analyses the evolution of liver disease in women with chronic hepatitis C during the third trimester of pregnancy and the post-partum period, as a natural model of immune modulation and reconstitution. Of the 122 mothers recruited to this study, 89 were HCV-RNA+ve/HIV-ve and 33 were HCV-RNA-ve/HIV-ve/HCVantibody+ve and all were tested during the third trimester of pregnancy, at delivery and post-delivery. The HCV-RNA+ve mothers were categorized as either Type-A (66%), with an increase in ALT levels in the post-partum period (>40 U/L; P<0.001) or as Type-B (34%), with no variation in ALT values. The Type-A mothers also presented a significant decrease in serum HCV-RNA levels in the post-delivery period (P<0.001) and this event was concomitant with an increase in Th1 cytokine levels (INFγ, P = 0.04; IL12, P = 0.01 and IL2, P = 0.01). On the other hand, the Type-B mothers and the HCV-RNA-ve women presented no variations in either of these parameters. However, they did present higher Th1 cytokine levels in the partum period (INFγ and IL2, P<0.05) than both the Type-A and the HCV-RNA-ve women. Cytokine levels at the moment of delivery do not constitute a risk factor associated with HCV vertical transmission. It is concluded that differences in the ALT and HCV-RNA values observed in HCV-RNA+ve women in the postpartum period might be due to different ratios of Th1 cytokine production. In the Type-B women, the high partum levels of Th1 cytokines and the absence of post-partum variation in ALT and HCV-RNA levels may be related to permanent Th1 cytokine stimulation.

Biotic potential and reproductive parameters of Spodoptera eridania (Stoll) (Lepidoptera, Noctuidae) in the laboratory

Biotic potential and reprodutcive parameters of Spodoptera eridania (Stoll) (Lepidoptera, Noctuidae) in the laboratory: This study aimed to evaluate the biotic potential and reproductive parameters of Spodoptera eridania (Stoll, 1782) under controlled conditions (25 ± 1ºC, 70 ± 10% RH and 14 hour photophase). The longevity, pre-, post- and oviposition periods, fecundity and fertility of 15 couples was evaluated. The longevity of females (10.80 days) was not significantly higher than those of males (9.27 days). The mean durations of the pre, post and oviposition periods were 2.067, 0.600 and 8.133 days, respectively. The mean fecundity per female was 1,398 eggs and the mean fertility was 1,367.50 larvae. On average, females copulated 1.133 times. A strong positive correlation was observed between the number of mating and fecundity (r = 0.881, P <0.001). However a strong negative correlation was observed between the number of copulations and the duration of the pre-oviposition period (r = -0.826, P = 0.002) and longevity (r = -0.823, P = 0.001). The biotic potential of S. eridania was estimated at 1.894 x 10(25) individuals/female/year. The net reproductive rate (Ro) was 560.531 times per generation and the mean generation time (T) was 35.807 days. The intrinsic rate of increase (rm) was 0.177, with a finite rate of increase (l) of 1.193, per week

Reproductive and post-reproductive life history of wild-caught Drosophila melanogaster under laboratory conditions.

The life history of the fruit fly (Drosophila melanogaster) is well understood, but fitness components are rarely measured by following single individuals over their lifetime, thereby limiting insights into lifetime reproductive success, reproductive senescence and post-reproductive lifespan. Moreover, most studies have examined long-established laboratory strains rather than freshly caught individuals and may thus be confounded by adaptation to laboratory culture, inbreeding or mutation accumulation. Here, we have followed the life histories of individual females from three recently caught, non-laboratory-adapted wild populations of D. melanogaster. Populations varied in a number of life-history traits, including ovariole number, fecundity, hatchability and lifespan. To describe individual patterns of age-specific fecundity, we developed a new model that allowed us to distinguish four phases during a female's life: a phase of reproductive maturation, followed by a period of linear and then exponential decline in fecundity and, finally, a post-ovipository period. Individual females exhibited clear-cut fecundity peaks, which contrasts with previous analyses, and post-peak levels of fecundity declined independently of how long females lived. Notably, females had a pronounced post-reproductive lifespan, which on average made up 40% of total lifespan. Post-reproductive lifespan did not differ among populations and was not correlated with reproductive fitness components, supporting the hypothesis that this period is a highly variable, random 'add-on' at the end of reproductive life rather than a correlate of selection on reproductive fitness. Most life-history traits were positively correlated, a pattern that might be due to genotype by environment interactions when wild flies are brought into a novel laboratory environment but that is unlikely explained by inbreeding or positive mutational covariance caused by mutation accumulation.

Additive effects of ectoparasites over reproductive attempts in the long-lived Alpine swift

1. Parasitism is a non-negligible cost of reproduction in wild organisms, and hosts are selected to partition resources optimally between current and future reproduction. While parents can compensate for the cost of parasitism by increasing their current reproductive investment, such change in resource allocation is expected to carry-over costs on future reproduction. 2. Life history theory predicts that because long-lived organisms have a high residual reproductive value, they should be more reluctant to increase parental effort in response to parasites. Also, when rearing successive infested broods, the cost of parasitism can cumulate over the years and hence be exacerbated by past infestations. 3. We tested these two predictions in the alpine swift Apus melba, a long-lived colonial bird that is infested intensely by the nest-based blood sucking louse-fly Crataerina melbae. For this purpose, we manipulated ectoparasite load over 3 consecutive years and measured reproductive parameters in successive breeding attempts of adults assigned randomly to 'parasitized' and 'deparasitized' treatments. 4. In current reproduction, fathers of experimentally parasitized broods produced a similar number of offspring as fathers from the deparasitized treatment, but the rearing period was prolonged by 4 days. Fathers that were assigned to the parasitized treatment in year x produced significantly fewer fledglings the following year x + 1 than those of the deparasitized treatment. The number of young produced by fathers in year x + 1 was correlated negatively with the number of days they cared for their brood in the previous year x. We also found a significant interaction between treatments performed over 2 successive years, with fathers of parasitized broods suffering a larger fitness loss if in the past they had already cared for a parasitized brood rather than for a deparasitized one. Similar effects of parasitism, although partly non-significant (0.05 < P-values > 0.10), were found in mothers. 5. Altogether, our results show that parasites can modify resource allocation between current and future reproduction in long-lived hosts, and that the cost of parasitism can cumulate over the years. It emphasizes the fact that effects of parasites can depend on past infestations and become apparent in future reproduction only.

Reproductive characteristics of the predator Podisus nigrispinus fed with an insect resistant soybean variety

The objective of this research was to evaluate the effect of the insect resistant soybean genotype IAC 17 on reproductive characteristics of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) females compared to the soybean insect susceptible genotype UFV 16. Treatments were: T1) females of P. nigrispinus fed on plants of the UFV 16 and Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) caterpillars reared on leaves of this variety; T2) females of P. nigrispinus fed on plants of the IAC 17 and A. gemmatalis caterpillars reared on leaves of this variety. Longevity of females, pre-oviposition, oviposition and pos-oviposition periods, number of eggs and egg masses/female, egg weight, interval between egg mass laying, number of eggs/egg mass, percentage of nymphs, number of nymphs/female and total number of prey killed/female of P. nigrispinus were evaluated. Most of the characteristics evaluated showed similar results between treatments, but the oviposition period was longer for females reared on the resistant genotype than on the susceptible one and the percentage of total females that laid eggs was lower on the IAC 17. Also, the resistant genotype caused higher mortality of P. nigrispinus females at the beginning of its adult stage and egg production by females of this predator was better spread along its adult stage with this resistant genotype. On the other hand, results suggest no effect of the resistant genotype on the offspring of this predator.

Flight, feeding and reproductive behavior of Phyllophaga cuyabana (Moser) (Coleoptera: Melolonthidae) adults

Phyllophaga cuyabana is a univoltine species and its development occurs completely underground. Its control by conventional methods, such as chemical and biological insecticides, is difficult, so it is important to understand its dispersion, reproduction, and population behavior in order to determine best pest management strategies. The objective of this work was to study the behavior of adults of P. cuyabana. This study was carried out in the laboratory, greenhouse and field sites in Paraná State, Brazil (24º25' S and 52º48' W), during four seasons. The results obtained demonstrate that: a) P. cuyabana adults have a synchronized short-flight period when mating and reproduction occurs; b) adults tend to aggregate in specific sites for mating; c) the majority of adults left the soil on alternate nights; d) the choice of mating and oviposition sites was made by females before copulation, since after copulation adults did not fly from or bury themselves at nearby locations; e) females that fed on leaves after mating, oviposited more eggs than females that had not fed;f) plant species such as sunflower (Helianthus annuus) and the Crotalaria juncea are important food sources for adults.

Problems of allometric scaling analysis: examples from mammalian reproductive biology.

Biological scaling analyses employing the widely used bivariate allometric model are beset by at least four interacting problems: (1) choice of an appropriate best-fit line with due attention to the influence of outliers; (2) objective recognition of divergent subsets in the data (allometric grades); (3) potential restrictions on statistical independence resulting from phylogenetic inertia; and (4) the need for extreme caution in inferring causation from correlation. A new non-parametric line-fitting technique has been developed that eliminates requirements for normality of distribution, greatly reduces the influence of outliers and permits objective recognition of grade shifts in substantial datasets. This technique is applied in scaling analyses of mammalian gestation periods and of neonatal body mass in primates. These analyses feed into a re-examination, conducted with partial correlation analysis, of the maternal energy hypothesis relating to mammalian brain evolution, which suggests links between body size and brain size in neonates and adults, gestation period and basal metabolic rate. Much has been made of the potential problem of phylogenetic inertia as a confounding factor in scaling analyses. However, this problem may be less severe than suspected earlier because nested analyses of variance conducted on residual variation (rather than on raw values) reveals that there is considerable variance at low taxonomic levels. In fact, limited divergence in body size between closely related species is one of the prime examples of phylogenetic inertia. One common approach to eliminating perceived problems of phylogenetic inertia in allometric analyses has been calculation of 'independent contrast values'. It is demonstrated that the reasoning behind this approach is flawed in several ways. Calculation of contrast values for closely related species of similar body size is, in fact, highly questionable, particularly when there are major deviations from the best-fit line for the scaling relationship under scrutiny.

The reproductive cycle of the sea urchin Arbacia lixula in northwest mediterranean: potential influence of temperature and photoperiod

We studied the reproductive cycle of the sea urchin Arbacia lixula in a subtidal population from northeast Spain over four years using a gonadosomatic index (GSI) and gonad histology. Our results show that the GSI of A. lixula follows a seasonal cycle which peaks in May-July and attains its lowest values in October-November every year. The time course of the GSI matched closely the photoperiod cycle. We also found a remarkable inter-annual variability in the maximum value of GSI, which correlated with mean water temperature during the gonad growth period (winter and spring). Gonad histology was also in agreement with a single gametogenic cycle per year in this species. We explored the application of circular statistics to present and analyse gonadal development data, which allowed us to adequately handle the high intra-individual variability detected, with several developmental stages commonly found within the same gonad. The picture that emerged is one of a gametogenic timing driven by photoperiod, while the amount of reproductive output is determined by temperature. This is coherent with the tropical origin of the species and lends support to recent warnings about an increase in the abundance of this species in the Mediterranean as a result of global warming, with associated increased impact potential in sublittoral communities.

Reproductive outcome in pregnant women with recurrent pregnancy loss

Abstract PURPOSE: To estimate the future pregnancy success rate in women with a history of recurrent pregnancy loss. METHODS: A retrospective cohort study including 103 women seen at a clinic for recurrent pregnancy loss (loss group) between January 2006 and December 2010 and a control group including 204 pregnant women seen at a low-risk prenatal care unit between May 2007 and April 2008. Both groups were seen in the university teaching hospital the Maternidade Climério de Oliveira, Salvador, Bahia, Brazil. Reproductive success rate was defined as an alive-birth, independent of gestational age at birth and survival after the neonatal period. Continuous variables Means and standard deviations (SD) were compared using Student's t-test and nominal variables proportions by Pearson χ2test. RESULTS: Out of 90 who conceived, 83 (91.2%) had reproductive success rate. There were more full-term pregnancies in the control than in the loss group (174/187; 92.1 versus 51/90; 56.7%; p<0.01). The prenatal visits number was satisfactory for 76 (85.4%) women in the loss group and 125 (61.3%) in the control (p<0.01). In this, the beginning of prenatal care was earlier (13.3; 4.2 versus 19.6; 6.9 weeks). During pregnancy, the loss group women increased the weight more than those in the control group (58.1 versus 46.6%; p=0.04). Although cervix cerclage was performed in 32/90 women in the loss group, the pregnancy duration mean was smaller (34.8 weeks; SD=5.6 versus 39.3 weeks; SD=1.6; p<0.01) than in the control group. Due to gestational complications, cesarean delivery predominated in the loss group (55/83; 64.7 versus 73/183; 39.5%; p<0.01). CONCLUSION: A very good reproductive success rate can be attributed to greater availability of healthcare services to receive pregnant women, through prenatal visits (scheduled or not), cervical cerclage performed on time, and available hospital care for the mother and newborn.

Reproductive biology of Protium spruceanum (Burseraceae), a dominant dioecious tree in vegetation corridors in Southeastern Brazil

We investigated the reproductive biology of Protium spruceanum (Benth.) Engler in vegetation corridors of secondary Atlantic forest in Lavras, southern Minas Gerais State, Brazil. The reproductive phenology was investigated fortnightly over a one year period. Floral biology studies involved pollen viability analysis, nectar production, stigmatic receptivity, pollen tube growth, visiting insect species and visit rates. The small, pale yellowish flowers (0.3-0.4 cm diameter) are functionally unisexual and organized in dense inflorescences (ca. 45 flowers). P. spruceanum presented annual flowering between September and November. Staminate flowers supplied a high percentage of viable pollen (90.6%) and relatively abundant nectar (x = 4.5 μL). Pistillate flowers produced only nectar to flower visitors (x = 4.0 μL). The effective pollinators were Apis mellifera and Trigona sp. (Hymenoptera, Apidae). Pollen tubes of cross-pollinated flowers were observed entering the ovaries 48 h after pollination. The fruiting season is from October to March, with a peak in November, coinciding with the rainfall peak. Ecological implications of these findings, and alternative arguments to explain the high genetic diversity at regional landscape are discussed.

Reproductive isolation between Anastrepha bistrigata and A. striata (Diptera, Tephritidae)

The reproductive isolation between two closely related species, Anastrepha bistrigata and A. striata, was studied in the laboratory. Interespecific copulation attempts were observed, but examination of the spermathecae showed that sperm transference did not occur, even after a prolonged period of contact between the mating pairs. These results indicate prezygotic isolation. The analysis of the hourly distribution of mating activities under laboratory conditions, here described for the first time for A. bistrigata, clearly showed differences for the two species, the activities being concentrated in the afternoon period for A. striata and in the morning for A. bistrigata