Terms Of Fecundity Research Articles

Spotlight on Eupeodes americanus: Oviposition and fertility under HPS- and full spectrum LED-extended photoperiod in northern greenhouses

In northern temperate regions, high-pressure sodium vapor (HPS) or light-emitting diode (LED) lights for supplemental lighting in winter greenhouses are used to extend the photoperiod and increase plant production. These different greenhouse light treatments influence crop pests and their natural enemies. In this study, different greenhouse light treatments were evaluated for their effect on the green peach aphid, Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae) and its predator the American hoverfly, Eupeodes americanus (Wiedemann, 1830) (Diptera: Syrphidae). In particular, the development of M. persicae and the oviposition and egg hatchability of E. americanus were studied under three light treatments in winter greenhouse: 1) short photoperiod of natural sunlight, and extended photoperiod using either 2) full spectrum LED or 3) HPS lights. The results showed that both extended photoperiod treatments significantly increased M. persicae population growth by 103–130 %, after 12 days compared to short photoperiod of sunlight. Compared to the winter short photoperiod of sunlight, extending the photoperiod did not affect the oviposition of female hoverflies in terms of fecundity, fertility, and niche use (i.e., position of eggs on the plant). Nevertheless, extended photoperiod significantly increased the egg hatchability of E. americanus by 9 % (HPS) and 16 % (LED) compared to short photoperiod of sunlight. This treatment had the highest proportion of unhatched eggs (13 %). Finally, LED lights decreased the proportion of unhatched eggs by 71 % compared to HPS lights. This study, therefore, confirms the potential of the American hoverfly as a biological control agent in winter greenhouses, both with or without artificial light.

Dietary assessment across various life stages of seven-spotted lady beetle Coccinella septempunctata (Coleoptera: Coccinellidae)

BackgroundCoccinella septempunctata (L.) is an important predator in fighting against aphids on edible crops and vegetables. However, to establish a successful mass-rearing technique, it is crucial to determine the optimal diets for larvae, pupae, and adults in terms of fecundity, longevity, and ingredient ratios. The current study aims to learn more about the biology of ladybird beetle using both artificial and natural food components.ResultsThis study tested six different ratios of natural and artificial diets, ranging from a natural aphid diet to a variety of artificial diets containing protein hydrolyzate, casein protein, honey, dry aphids, yeast, and agar. The results showed that the natural diet (D1) produced from aphids showed approximately 290.2 eggs, while artificial diets D2 and D4 produced 56.5 and 40.2 eggs, respectively. The effect of different diets on the longevity of different life stages was also tested. The minimum longevity of egg, larval, pupal, and adult stages were recorded for D1 and D4. Furthermore, the maximum percentage emergence of larval, pupal, and adult stages was observed for D1 and D2. D6 produced the longest adult duration, with a maximum of 84.60 days. However, there was no significant difference in sex ratio among the various diet components.ConclusionsIn conclusion, the results suggest that artificial diets are essential for sustaining C. septempunctata cultures in laboratories, especially during periods when natural prey is scarce. The most effective and efficient mass-rearing approach would be to provide both natural and artificial foods simultaneously. These findings may have significant implications for the development of biological control strategies for aphids in agriculture.

Effect of Differences in Betta Fish (Betta Splendes) Strains on Fecundity, Fertility, Egg Diameter and Hatchability

Betta fish (Betta splendens) has export and import potential. Several popular betta fish strains include halfmoon, crown tail, double tail, and placard. We used the observation method to observe four betta fish strains with five replications. The four fish strains were spawned and will be dissected to obtain the female betta fish's gonads. The parameters observed in this study were fecundity, egg diameter, fertility, and hatchability. This study's data analysis method was analysis of variance (ANOVA) with Duncan's multiple range test. Based on the findings of the observations, it is known that the results of betta fish spawning and gonadal dissection on these various betta fish strains show a significant difference in fish fecundity (P 0.05). However, no significant difference in egg diameter, fertility, or hatchability was observed (P > 0.05). Betta splendes strains differ in terms of fecundity, fertility, hatching rate, and egg size.

The aptness of entompathogenic bacteria against sawtoothed grain beetle (Oryzaephilus surinamensis [L.]) (Coleoptera: Silvanidae) in dates under laboratory conditions

ObjectiveThe sawtoothed grain beetle, Oryzaephilus surinamensis (L). is known as one of the most devastating insect pests in stored date fruits, infrequently found in newly harvested date fruits and raisins but developed a high plenty in dry fruits particularly after long storage. Indiscriminate use of pesticides and fumigants to control insects have resulted in insecticide resistance, environmental hazards, residual toxicity, and pest resurgence so the control trends have been changed and particularly biological control agents like entomopathogenic bacteria Photorhabdus temperata and Xenorhabdus nematophila being used to manage sawtoothed grain beetle. MethodsDuring present study, the pathogenicity of P. temperata and X. nematophila was evaluated against this crucial pest of stored grains. The bacterial concentrations, 1 × 104, 1 × 105, 1 × 106, 1 × 107 and 1 × 108 cells/ml of both bacteria were prepared and used for the experiments. The prepared solutions were applied directly to the date fruits infested with sawtoothed grain beetles and data were recorded. ResultsSignificant results were observed for both bacterial treatments as the highest concentration of 108 cells/ml showed to be very effective against the beetle in terms of fecundity, adult emergence, and mortality. In terms of fecundity, 8.66 to 4.33 mean number of eggs were produced at bacterial P. temperata concentrations of 1 × 104 and 1 × 108 cells/ml, respectively. Similarly, the F1 adult emergence for P. temperata was recorded 15.33 and 9 adults at concentrations of 1 × 104 and 1 × 108 cells/ml, respectively. Results showed a similar trend for the X. nematophila species. ConclusionsThese results indicate that utilizing bacteria as biological control agents can be advantageous for reducing insect populations in storage facilities and preventing the loss of grains and date fruits that have been stored in storage.

Влияние содержания стронция в воде на фито- и зоопланктон

The article presents the results of experimental studies to assess the impact of heavy metals on the functioning of phyto- and zooplankton (Scenedesmus quadricaud, Daphnia magna). Determination of inactive and threshold concentration of strontium, toxicity parameters and the degree of acute toxicity has been carried out. As a result of the studies the data on the effect of strontium on hydrobionts of different trophic links were obtained. For zooplankton in terms of survival rate the maximum allowable concentration of strontium was 4 mg/l, in terms of fecundity - 2 mg/l in terms of fecundity. According to the indicator of single-celled algae Sc. quadricauda viability (cell number) in the chronic experiment the maximum allowable concentration of strontium is 2 mg/l.

¿Cómo afecta el ganado doméstico a la biomasa y la fecundidad de distintos tipos sucesionales de especies en el Monte Patagónico?

Plants respond to disturbances according to their physiological characteristics, their lifeform, and their ecological role or function within the community. We assessed the response, in terms of biomass and fitness, to a gradient of stocking density (measured as livestock units.year.ha-1) considering different successional types of species (early, intermediate and late species) from Patagonian Monte Desert. We estimated plant biomass and fitness through different variables such as plant size (diameter x height of the plant), reproductive effort (% flowering or fruiting branches) and percentage of viable seeds (seed set). We observed that browsing decreased plant biomass and fitness, both through reproductive effort and seed set. However, the successional types of species showed different seed set in response to grazing intensity. With increased stocking density, the size of early species decreased, the size of intermediate species increased and the size of late species did not show significant changes. In general, browsing negatively affected the reproductive effort of all species, and the seed set only in late specie, while early and intermediate species showed an increase in seed set. These results suggest that late species are the most affected by livestock in terms of fecundity, which might reduce their recruitment. The increase in their biomass with stocking density in intermediate species suggests a compensatory response, which could give them a short-term advantage. Tissue loss suffered by plants due to livestock consumption impacts the seed set, with possible consequences on the rate and time of seedling emergence. These results aid to understand plant population dynamics under disturbances, providing useful information to elaborate adequate conservation, sustainable management and restoration strategies for arid ecosystems.

No evidence of a generalized potential ‘cost’ of apical dominance for species that have strong apical dominance

Abstract When the shoot apical meristem of plants is damaged or removed, fecundity and/or plant growth may suffer (under-compensation), remain unaffected (compensation) or increase (overcompensation). The latter signifies a potential ‘cost’ of apical dominance. Using natural populations of 19 herbaceous angiosperm species with a conspicuously vertical, apically dominant growth form, we removed (clipped) the shoot apical meristem for replicate plants early in the growing season to test for a potential cost of apical dominance. Clipped and unclipped (control) plants had their near neighbours removed, and were harvested after flowering production had finished but before seed dispersal. Dry mass was measured separately for aboveground body size (shoots), leaves, seeds and fruits; and number of leaves, fruits and seeds per plant were counted. We predicted that: (i) our study species (because of their strong apically dominant growth form) would respond to shoot apical meristem removal with greater branching intensity, and thus overcompensation in terms of fecundity and/or biomass; and (ii) overcompensation is particularly enabled for species that produce smaller but more leaves, and hence with a larger bud bank of axillary meristems available for deployment in branching and/or fruit production. Widely variable compensatory capacities were recorded, and with no significant between-species relationship with leaf size or leafing intensity—thus indicating no generalized potential cost of apical dominance. Overall, the results point to species-specific treatment effects on meristem allocation patterns, and suggest importance for effects involving local variation in resource availability, and between-species variation in phenology, life history traits and susceptibility to herbivory.

Is developmental rate polymorphism constant? Influence of temperature on the occurrence and constancy of slow and fast development in Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae).

Temperature plays an important role in different biological activities of organisms. The relationship between temperature and insect development has long been recognized as an important environmental parameter in modeling insect population dynamics. Although few studies have investigated the existence of developmental rate polymorphism within a cohort, the role of abiotic and biotic factors on such developmental variation has so far been meagerly investigated. The present study was designed to investigate the effect of thermal extremes on the developmental rate polymorphism and its influence on reproductive potential of Parthenium beetle, Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae). The study will also be helpful in solving hitherto whether the existence of slow and fast developers within a cohort has a purely genetic basis or this developmental polymorphism is presided by environmental factors. Our result reveals a clear bimodal pattern of distribution with two peaks at each temperature (20, 25, 27, 30 and 35°C) where the first peak represents the fast developers and second peak represents the slow developers. Both developmental variants took the longest duration for development at 20°C followed by 25, 27, 30°C and minimum at 35°C. More fast developers were found at higher temperatures. Slow developing individuals were heavier than the fast developing individuals regardless of rearing temperature. Slow developers have higher reproductive success in terms of fecundity and egg viability than the fast developers. The results of this study denote the constancy of the developmental rate polymorphism within a cohort and the possibility that this polymorphism was owing to the exogenous cues inclined differential rates of mortality.

Reproductive performance of gilthead seabream (Sparus aurata) broodstock showing different expression of fatty acyl desaturase 2 and fed two dietary fatty acid profiles

Previous studies have shown that it is possible to nutritionally program gilthead seabream offspring through fish oil (FO) replacement by vegetable oils (VO) in the broodstock diet, to improve their ability to grow fast when fed low fish meal (FM) and FO diets during grow-out phase. However, in those studies broodstock performance was reduced by the VO contained diet. Therefore, the present study aimed to determine if it is possible to replace FO by a mixture of FO and rapeseed oil (RO) with a specific fatty acid profile in broodstock diets, without altering gilthead seabream broodstock reproductive performance. Besides, the study also aimed to evaluate the reproductive performance of broodstock with different expression of fatty acid desaturase 2 gene (fads2) a key enzyme in synthesis of long chain polyunsaturated fatty acids. For that purpose, broodfish having either a high (HD) or low (LD) expression of fads2 were fed for three months during the spawning season with two diets containing different fatty acid profiles and their effects on reproductive hormones, fecundity, sperm and egg quality, egg biochemical composition and fads2 expression were studied. The results showed that blood fads2 expression in females, which tended to be higher than in males, was positively related to plasma 17β-estradiol levels. Moreover, broodstock with high blood fads2 expression showed a better reproductive performance, in terms of fecundity and sperm and egg quality, which was correlated with female fads2 expression. Our data also showed that it is feasible to reduce ARA, EPA and DHA down to 0.43, 6.6 and 8.4% total fatty acids, respectively, in broodstock diets designed to induce nutritional programming effects in the offspring without adverse effects on spawning quality. Further studies are being conducted to test the offspring with low FM and FO diets along life span.

Variation in Reproductive Investment among Ohio Reservoir Largemouth Bass Populations

AbstractReproductive investment, expressed in terms of fecundity and egg quality produced by individual female fish, varies among populations for many species, reflecting plasticity in life history strategies related to intraspecific density dependence or environmental variability. Fisheries scientists and managers have long sought to understand differences in Largemouth Bass Micropterus salmoides population dynamics, yet basic life history traits, such as variation in reproductive investment, remain largely unknown. We determined the fecundity–weight and ovary energy density–weight relationships (where fecundity indexes egg quantity and ovary energy density indexes egg quality) for Largemouth Bass populations from 19 Ohio reservoirs and examined factors that were correlated with population‐specific differences. We found that both relationships varied among reservoir populations, with some interannual variation in reservoirs sampled in multiple years. We then related fecundity and ovary energy density to (1) population characteristics, including population density (as indexed by standard shoreline boat electrofishing CPUE, fish/h) and growth (as indexed by the growth coefficient k from the von Bertalanffy growth function); and (2) reservoir characteristics, including reservoir size (as surface area) and productivity (as Secchi transparency depth). We found that populations with greater fecundity also exhibited greater ovary energy density, indicating that the quantity and quality of reproductive output were greater in some populations than in others. Populations with high reproductive investment were associated with low Largemouth Bass density, fast growth, large reservoir size, and high productivity (i.e., low Secchi transparency). The among‐population variation in reproductive investment provides evidence of density‐dependent control of fecundity and egg quality.

Phytochemical defences and performance of specialist and generalist herbivores: a meta‐analysis

1. Phytochemical coevolution theory, a long‐standing paradigm in plant–insect interactions, predicts that specialist herbivores are less negatively affected by the allelochemicals of their host plants than are generalist herbivores. Although this theory is prevalent in plant–insect science, it is not always supported by empirical studies measuring the performance of specialist and generalist insects in response to allelochemicals.2. The present study aimed to investigate: (i) whether there a difference between specialist and generalist performance in response to allelochemicals and (ii) whether the effect of allelochemicals on specialists and generalists depend upon allelochemical class or insect order.3. A meta‐analysis was conducted incorporating 76 effect sizes drawn from studies that directly compared the performance of specialist and generalist insects in response to treatment and control diets. Most of the effect sizes were related to the performance metric growth, the insect order Lepidoptera, and the allelochemical class nitrogen‐containing compounds.4. As predicted by phytochemical coevolution theory, specialist insects responded less negatively to allelochemicals of their hosts than generalist insects in terms of growth. There were no significant differences in terms of fecundity or survival, or among allelochemical classes or insect orders.5. These results support the prediction of phytochemical coevolution theory that specialist insects respond less negatively to allelochemicals of their hosts than generalists, although only in terms of growth.

Variability of the «mass of seeds from a plant» sign in the soybeans hybrids of the different groups of ripeness

Aim. The purpose of the research is to determine the manifestation of the feature “seed weight from a plant” (the, parental forms) and hybrids, to establish the level of variability behind the soybean varieties in the F2–F5 hybrid combinations, to determine the effectiveness of selections for productivity in terms of the “seed weight from a plant” indicator from the hybrid populations of the F2–F5. Methods. The field, selection and genetic, calculation and comparative methods of the research were used. The varieties that are different in terms of fecundity and origin, also hybrids F1 and hybrid populations F2–F5 were studied. Selections on the basis of the “seed weight from a plant” were carried out in the F2–F5 populations. Results. It has been established that in soy characteristic “seed mass from a plant” has significant genotypic variability and has significant differences in varieties of different groups of ripeness, which may be a prerequisite for predicting the effective selection for this factorial trait. A high correlation of this trait with seed yield was also established. The proportion of the families from the selections, that were carried out in the F3 populations, exceeded the seed yield standard and was in the range of 28.0–37.5%. In the second generation of hybrids the efficiency of selection was 1.5–2 times lower. Conclusions. The highest yield of high-yielding genotypes, reached by the “seed mass from a plant” indicator was obtained from the F3 populations. To create the new high-yielding soybean varieties with a 3.5–5.5 t/ha yield under irrigation conditions, it is promising to use in the crossings the variety samples which are contrastive by groups of ripeness and genetic pedigree. Keywords: variety, soybean, hybrid, population, yield, irrigation.

The fitness effects of a pale mutant in the aposematic seed bug Lygaeus simulans indicate pleiotropy between warning coloration and life history.

Conspicuous warning colors that signal chemical or other defenses are common in the natural world. For instance, such aposematic warning patterns of red‐and‐black or yellow‐and‐black are common among insect taxa, particularly in the order Hemiptera, often forming the basis of Batesian and/or Müllerian mimicry rings. In addition, it has been repeatedly noted that color polymorphisms or mutants that influence pigmentation can show pleiotropy with other behavioral, physiological, or life‐history traits. Here, we describe a pale mutant of the seed bug Lygaeus simulans that appeared in our laboratory population in 2012, which differs in color to the wild‐type bugs. Through multigenerational experimental crosses between wild‐type and pale mutant L. simulans, we first show that the pale phenotype segregates as a single Mendelian locus, with the pale allele being recessive to the wild type. Next, we show (a) that there is a large heterozygous advantage in terms of fecundity, (b) that pale females suffer reduced longevity, and (c) that pale males have increased body length compared to wild‐type homozygotes. Our data therefore suggest that the color locus is pleiotropic with a number of life‐history traits, opening the door for a more complete genetic analysis of aposematic coloration in this species. In addition, this phenotype will be useful as a visible genetic marker, providing a tool for investigating sperm competition and other post‐copulatory drivers of sexual selection in this species.

Life History Parameters of Aleyrodes proletella (Hemiptera: Aleyrodidae) on Different Host Plants.

The whitefly Aleyrodes proletella L. (Hemiptera: Aleyrodidae) has become a major agricultural pest on a broad range of Brassica crops in Europe and has spread to North and South America and Australia. In order to understand its present outbreak, information about its life history parameters in relationship to different host plants is needed. Therefore, we tested the reproduction potential of A. proletella on four different host plants under greenhouse conditions: Kohlrabi, kale, white cabbage, and winter oilseed rape. The influence of host plant on preoviposition period, fecundity, survival rate, and sex ratio was examined. Additionally the effect of mating scenario (45-d mated females and males; virgin females and males; 6-d mated females) on life history parameters of A. proletella adults was evaluated. The mating scenario did not significantly influence the survival rate of A. proletella females and males and did not impact female fecundity and preoviposition period. Fecundity of A. proletella was significantly affected by host plant species: the shortest preoviposition period and highest oviposition rate was observed on winter oilseed rape, while the longest and lowest was recorded on white cabbage. The survival rate on white cabbage was significantly lower compared with those reared on the other host plants. The sex ratio of A. proletella progeny was also significantly affected by the host plant species. Our research indicates that winter oilseed rape is a highly suitable host for A. proletella in terms of fecundity, survival rate, and sex ratio, which might explain the current outbreak of A. proletella.

Relationship between menarche and fertility in long-tailed macaques (Macaca fascicularis).

We attempted to elucidate female reproduction in long-tailed macaques (Macaca fascicularis). These monkeys have a non-seasonal menstruation cycle, which makes them suitable subjects for studies in a variety fields including medical science and regenerative medicine. We analyzed individual breeding data including time of menarche, start of regular menstruation, and first pregnancy. These three events are related to the maturation of female long-tailed macaques. All research subjects were female long-tailed macaques bred at the Tsukuba Primate Research Center. The study comprised 45 females; we included time of menstruation, male-female cohabitation, and first pregnancy in their growth records. We extracted age and weight data relating to menarche, start of regular menstruation, and first pregnancy from these records. In the two years typically required from menarche to first pregnancy, the body weight increased by approximately 500 g (21% of the weight at menarche); it is clear that there is a significant physical change after menarche. Our findings suggest that female monkeys are not necessarily mature enough for pregnancy at menarche. Therefore, the use of the word “maturity” in terms of fecundity may be more accurate after the start of regular menstruation. This is what we term “adolescence” in the developmental process. Therefore, M. fascicularis monkeys are candidates for an animal model of human adolescence.

Aspects of the biology of the Antarctic dragonfish Gerlachea australis (Notothenioidei: Bathydraconidae) in the Weddell Sea, Antarctica

The Antarctic dragonfish Gerlachea australis is one of the most common bathydraconid species within the fish community of the Filchner Depression in the Weddell Sea. Nevertheless, several biological aspects of this species remain poorly known. The aim of this study was to provide new data on its population structure in terms of size, sex and age through sagittal otolith readings, as well as some reproductive traits based on macroscopic and histological analyses of gonads. The sex ratio in the sampled population was 1:1, with males being significantly smaller than females. Both sexes attained maximum age estimates of 14 years. Based on a von Bertalanffy growth model, females showed a higher asymptotic length than males at a comparable growth rate, thus reaching a higher growth performance. The spawning season was spread over a relatively long period, lasting at least from late December through late February. The reproductive effort in terms of fecundity and egg size diameter was similar to that of other bathydraconids, ranging from 739 to 1260 eggs/female and 3.2 mm after hydration, respectively. The fish size at first spawning (TL50) was 18.5 and 22.5 cm in males and females, corresponding to 80% of their maximum size. G. australis exhibited a combination of life history traits found in other high-Antarctic notothenioids, such as long gametogenesis, large eggs associated with low fecundity, relatively rapid body growth until reaching a delayed sexual maturity, moderate longevity and maximum size, and overall low growth performance.

Comparative biology, predation capacity and effect of an artificial diet on reproductive parameters of green lacewing Mallada boninensis (Neuroptera: Chrysopidae)

Abstract Investigations were undertaken to clarify the biology of green lacewing Mallada boninensis on its hosts Helopeltis theivora and Oligonychus coffeae, which are two major arthropod pests of tea crop and on an artificial diet. No significant variations were recorded in terms of preoviposition period, oviposition period, oviposition rate, total eggs, hatching success, larval survival and adult emergence when M. boninensis was reared on both hosts. However, all larval instars and pupal development time, as well as adult longevity, were significantly shorter when M. boninesis was reared on H. theivora. We also provide the first report on the predatory potential of M. boninensis against H. theivora. The feeding efficiency of M. boninensis increased with the advancement of each developmental stage. The third‐instar larvae of M. boninensis consumed more H. theivora individuals (28.4 ± 1.50) than the first (7 ± 1.11) and second (24.2 ± 1.81) instars over its entire duration. The artificial diet produced significantly superior results in terms of fecundity, hatching success, larval survival and adult emergence when M. boninensis was reared on it compared with when it was reared on H. theivora and O. coffeae. The findings of the present study indicate that M. boninensis can be effectively utilized in integrated pest management programmes for controlling some major arthropod pests of tea by suitably mass rearing them followed by augmentative release.

Polygyny influences the fitness of Parthenium beetle, Zygogramma bicolorata Pallister

Reproduction imposes costs that limit male reproductive capacity, as sperm production inevitably has expenditure. In a number of insects, male mating status affects the fitness of females in terms of fecundity and egg viability with whom they mate. We used an experimental design to assess whether polygyny influences the fitness of Parthenium beetle, Zygogramma bicolorata Pallister. We explored female preference for mating with virgin, once-mated, twice-mated and thrice-mated males. We also observed a concurrent decline in female fecundity and percent egg viability with more sexually experienced male partners. We found that polygyny also affects survival and developmental attributes of the offspring. Progeny of virgin males had higher survival and faster development than the progeny of previously mated males. Thus, the present study suggests that increased male sexual activity diminishes reproductive success and progeny survival and development.

Maternal contribution to spawning and early life-history strategies of the genus Lepidonotothen (Nototheniidae, Perciformes) along the southern Scotia Arc

The coastal fish community of the southern Scotia Arc, including the South Shetland Islands and the Bransfield Strait, is composed of the genus Lepidonotothen, which consists of three widely overlapping species such as L. kempi, L. larseni and L. nudifrons. The life-history strategies of these species driven by environmental and inter-specific interactions remain poorly known. In this paper, we estimate the maternal contribution to spawning of adult females in terms of fecundity and egg size through macroscopic and histological analyses of gonads. We further investigate the size and timing of hatching, growth rate and duration of the larval stage through microstructure analysis of sagittal otoliths collected from larval samples. All three species produced eggs of relatively small size at hatching, showing a trade-off between egg size and fecundity. Total fecundity was positively related to fish size during growth, as well as to maximum size. Female gonad investment was comparable among the species, as they all start spawning at about 65% of their maximum size with a similar gonadosomatic index. All species generated small larvae (altricial) which hatched over widely different periods, resulting in a temporal succession of larval occurrence. Compared to L. kempi, the other two species had relatively slow-growing larvae. Only L. kempi and L. larseni produced overwintering larvae. Differences in maternal contribution to spawning and early life-history traits of these species contribute to reduce interspecific competition for food through ecological niche partitioning.

Efficacy of Blood Sources and Artificial Blood Feeding Methods in Rearing of Aedes aegypti (Diptera: Culicidae) for Sterile Insect Technique and Incompatible Insect Technique Approaches in Sri Lanka

Introduction Selection of the artificial membrane feeding technique and blood meal source has been recognized as key considerations in mass rearing of vectors. Methodology Artificial membrane feeding techniques, namely, glass plate, metal plate, and Hemotek membrane feeding method, and three blood sources (human, cattle, and chicken) were evaluated based on feeding rates, fecundity, and hatching rates of Aedes aegypti. Significance in the variations among blood feeding was investigated by one-way ANOVA, cluster analysis of variance (ANOSIM), and principal coordinates (PCO) analysis. Results Feeding rates of Ae. aegypti significantly differed among the membrane feeding techniques as suggested by one-way ANOVA (p < 0.05). The metal plate method was identified as the most efficient and cost-effective feeding technique. Blood feeding rate of Ae. aegypti was higher with human blood followed by cattle and chicken blood, respectively. However, no significant difference was observed from the mosquitoes fed with cattle and human blood, in terms of fecundity, oviposition rate, and fertility as suggested by one-way ANOVA (p > 0.05). Conclusions Metal plate method could be recommended as the most effective membrane feeding technique for mass rearing of Ae. aegypti, due to its high feeding rate and cost effectiveness. Cattle blood could be recommended for mass rearing Ae. aegypti.