Growth, Development and Innate Capacity for Increase in Aphytis Chrysomphali Mercet and A. Melinus Debach, Parasites of California Red Scale, Aonidiella Aurantii (Mask.), In Relation to Temperature.

1974 ◽  
Vol 22 (2) ◽  
pp. 213 ◽  
Author(s):  
I Abdelrahman
Keyword(s):  
Negative Relationship ◽  
Differential Mortality ◽  
Female Progeny ◽  
Annual Fluctuation ◽  
Adaptation To Cold ◽  
Rate Of Increase ◽  
Total Progeny ◽  
Searching Ability ◽  
Pupal Mortality ◽  
Threshold Of Development

A, melinus produced more female progeny and more than twice as many total progeny as A. chrysomphali; it also destroyed almost twice as many hosts through oviposition and mutiliation. A. chrysomphali had a longer post-oviposition period than A. melinus, especially at 30�C. The proportion of single progeny in a host was higher for A, chrysomphali than for A. melinus at all temperatures, and was related to temperature positively in A. chrysomphali and inversely in A. melinus. Large old female A. melinus produced only males at the end of their lives; they did not mate at that stage when offered males, not because they were aged but because they mate only once in their lives. As temperature decreased, female A. melznus ceased producing females earlier, probably because temperature affected either longevity of sperms or the mechanism controlling their release. Differential mortality, temperature, and age of mothers all influenced sex ratio. Pupal mortality was inversely related to temperature within the observed range 20-30�C; in female pupae of A. chrysomphali it was lower than that in either female or male pupae of A. melinus; it was higher in male than female pupae in A. melinus. A. melinus lived longer than A. chrysomphali at all temperatures. Duration of development was longer for A. chrysomphali than for A. melinus at 30�C, but shorter at 20 and 25�C. The threshold of development was 8.5C for A. chrysomphali and 11C for A. melinus. A. chrysomphali had a higher rm at 20 and 25�C than A. melinus, but much lower at 30�C. The highest rate of increase was at > 30�C for A. melinus, and at about 25�C for A. chrysomphali. The rm of the parasites was 3.1-5.0 times that of red scale, depending on parasite species and temperature. A. chrysomphali is smaller than A. melinus, and from the positive relationship between adaptation to cold and speed of development, and the negative relationship between speed of development and size, a negative relationship between size and adaptation to cold within Aphytis spp. may be postulated. A. chrysomphali is more adapted to cold and less to heat than A. melinus. This explains the seasonal and annual fluctuation in their relative abundance in southern Australia. The species would complement each other in controlling red scale; from the data presented here it is possible that Aphytis spp. in Australia may have evolved into more efficient control agents of red scale than elsewhere. Knowledge on the searching ability of Aphytis at different host densities is wanting.

scholarly journals Comparative evaluation of Cotesia flavipes and C. sesamiae (Hymenoptera: Braconidae) for the management of Chilo partellus (Lepidoptera: Pyralidae) in Kenya

1999 ◽  
Vol 89 (2) ◽  
pp. 185-191 ◽  
Author(s):  
M.N. Sallam ◽  
W.A. Overholt ◽  
E. Kairu
Keyword(s):  
Chilo Partellus ◽  
Sesamia Calamistis ◽  
Cotesia Flavipes ◽  
Cotesia Sesamiae ◽  
Female Progeny ◽  
Northern Tanzania ◽  
Significant Difference ◽  
Total Progeny ◽  
Lepidoptera Pyralidae ◽  
Searching Ability

AbstractCotesia flavipes Cameron, a gregarious larval endoparasitoid native to the Indo-Australian region, was imported from Pakistan and released in Kenya in 1993 for management of the exotic stemborer, Chilo partellus (Swinhoe). Recent reports confirmed the successful establishment of the parasitoid in three locations in Kenya and in northern Tanzania. Functional response studies on this parasitoid and an indigenous congener, Cotesia sesamiae (Cameron), indicated that C. flavipes had a higher searching ability and attacked more larvae when Chilo partellus was the host. When a native stemborer, Sesamia calamistis Hampson, was the host, there was no significant difference between numbers attacked by both parasitoids. Numerical response studies showed that Cotesia flavipes produced more total progeny and female progeny per female parasitoid on Chilo partellus than did Cotesia sesamiae. No significant difference in progeny production was detected between the two parasitoids on S. calamistis. Functional and numerical responses tested in the laboratory gave the same ranking of the two parasitoids on the two hosts as in the field. This study suggests that Cotesia flavipes is a more efficient parasitoid and it is anticipated that it will contribute to the control of both exotic and native stemborers in Kenya.

Influence of host size variation on the development of a koinobiont aphid parasitoid,Lysiphlebus ambiguusHaliday (Braconidae, Hymenoptera)

2008 ◽  
Vol 98 (4) ◽  
pp. 389-395 ◽  
Author(s):  
Q. Xu ◽  
L. Meng ◽  
B. Li ◽  
N. Mills
Keyword(s):  
Development Time ◽  
Size Variation ◽  
Aphis Fabae ◽  
Host Size ◽  
Differential Mortality ◽  
Adult Size ◽  
Female Progeny ◽  
Aphid Parasitoid ◽  
Secondary Sex Ratio ◽  
Body Sizes

AbstractTo determine whether host body size is the currency used by the aphidiine parasitoid,Lysiphlebus ambiguus Haliday (Hymenoptera: Braconidae), in assessing host quality, the aphid,Aphis fabaeScopoli (Homoptera: Aphididae), was reared at either high or low temperature to yield hosts of the same instar with different body sizes. Cohorts ofA. fabae raised at 15°C and 30°C and exposed to individual femaleL. ambiguusin no-choice tests were successfully parasitized in all host stages from 1st instar nymphs to adults. However, younger and smaller aphids were more susceptible to parasitism than older and larger nymphs or adults, as measured by the number of mummies produced. For aphid cohorts reared at 15°C, the proportion of female progeny, progeny adult size, and development time all increased linearly with aphid size at the time of attack. In contrast, for aphid cohorts raised at 30°C, the proportion of female progeny and progeny adult size declined with aphid size, while development time remained unaffected. Through manipulation of host rearing temperature, we have shown that at cooler temperatures the koinobiont parasitoid,L. ambiguus, responds to host size in the same way as an idiobiont parasitoid, but that this response is compromised at higher temperatures. Our results suggest that differential mortality during development is likely to influence the observed secondary sex ratio in relation to aphid size for aphid cohorts raised at higher temperatures due to disruption of the activity of the host's primary endosymbiont and that such reduced nutritional quality of aphids cannot be compensated by increased development time.

scholarly journals Multiple Mating of Aphelinus asychis Enhance the Number of Female Progeny but Shorten the Longevity

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 823
Author(s):  
Shengyin Wang ◽  
Libo Wang ◽  
Jiawen Liu ◽  
Dayu Zhang ◽  
Tongxian Liu
Keyword(s):  
Multiple Mating ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Control Group ◽  
Mating Frequency ◽  
Female Progeny ◽  
Control Efficiency ◽  
Aphelinus Asychis ◽  
Rate Of Increase ◽  
Negative Effect

The Aphelinus asychis female adult is an important arrhenotocous parthenogenesis parasitoid of Myzus persicae, and its reproductive mode is beneficial for the population continuation of A. asychis by way of multiple mating and backcross. To explore the effect of mating on the population fitness and control efficiency of A. asychis, its mating frequency and backcross were observed under laboratory conditions. The results showed that most matings in A. asychis involved four distinct stages: courtship, pre-copulatory, copulation, and post-copulatory behaviours. Only the duration of courtship increased significantly with an increase in copulation frequency for females, and the courtship duration of A. asychis females mated with different males were significantly shorter than those mated with the same male at the same mating times, which suggested that A. asychis females might prefer to mate with different males to enrich the genotype of their offspring. The total number of mummified aphids and the female and male longevity decreased significantly with an increase in mating frequency. On the contrary, female progenies increased significantly with an increase of mating frequency, suggesting that sperm limitation might occur in females when they only mated once. These results imply that females might prefer to receive more sperm by mating multiple times in their life span. In addition, we found that the intrinsic rate of increase (r) of A. asychis of the control group (0.2858 d−1) was significantly greater than that in the backcross treatment (0.2687 d−1). The finite killing rate (θ) of A. asychis of the control group was similar to that in the backcross treatment, which showed that this treatment had a negligible negative effect on the control efficiency of A. asychis. In conclusion, the results showed that multiple mating increased the number and proportion of A. asychis female progenies but shortened the longevity of female and male adults, while the negative effect of backcross on the control efficiency of A. asychis was negligible.

Bioecology of the tea thrips, Scirtothrips bispinosus Bagnall (Thysanoptera: Thripidae) infesting tea in south India

ENTOMON ◽  
2019 ◽  
Vol 44 (3) ◽  
pp. 161-172
Author(s):  
P. Mahendran ◽  
B. Radhakrishnan
Keyword(s):  
Relative Humidity ◽  
South India ◽  
Negative Relationship ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Developmental Duration ◽  
Net Reproductive Rate ◽  
Rate Of Increase

Investigations were carried out on the life history and seasonal abundance of the thrips, Scirtothrips bispinosus infesting tea at Coonoor, The Nilgiris, Tamilnadu. The total developmental duration of females from egg to adult stage was 18.15±0.23, 12.55±0.15 and 10.30±0.23 days at 20, 25 and 30oC respectively. The net reproductive rate (Ro), mean generation time (Tc), intrinsic rate of natural increase (rm), finite rate of increase (ë) and weekly multiplication (Wm) rates were high at 25oC followed by 30oC and 20oC. Multiple regression analysis revealed that population density of S. bispinosus showed a negative relationship with rainfall (-0.266), maximum temperature (-38.839) and maximum relative humidity (-3.356) and positive relationship with minimum temperature (63.205), minimum relative humidity (1.686) and sunshine period (2.887). Incidence of thrips was high in the fields recovering from pruning followed by second, third and fourth year in a pruning cycle. The number of thrips per shoot was significantly higher on the plucking table when compared to the shoots present below the plucking table and side branches. In the tea plantations of South India, four species of predatory mites (Amblyseius cucumeris, A. fallacies, A. degenerans and Balaustium sp.), two species of predatory thrips (Franklinothrips vespiformis and Leptothrips mali), an anthocorid predator (Orius sp.) and one parasitoid (Trichogramma sp.) were found feeding and parasitizing on tea thrips, S. bispinosus.

scholarly journals Density of Diachasmimorpha longicaudata (Ashmead) and host Ceratitis capitata (Wied) larvae for the increase of parasitoid female production

2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Carlos Gustavo da Cruz ◽  
Clarice Diniz Alvarenga ◽  
Patricia Cristina do Carmo Oliveira ◽  
Edileuza dos Reis Souza Conceição ◽  
Zenobia Cardoso dos Santos ◽  
...  
Keyword(s):  
Biological Control ◽  
Sex Ratio ◽  
Ceratitis Capitata ◽  
Larval Density ◽  
Mortality Rates ◽  
Female Parasite ◽  
Progeny Production ◽  
Female Progeny ◽  
Diachasmimorpha Longicaudata ◽  
Pupal Mortality

ABSTRACT: The objective of the present study was to evaluate the ratio of Ceratitis capitata larvae/female of Diachasmimorpha longicaudata that results in the increase of parasitism and the production of females in the progeny. We used 8-day-old copulated D. longicaudata females with oviposition parasite experience and third instar larvae of C. capitata from rearing stock maintained at the Laboratory of Biological Control of Universidade Estadual de Montes Claros (Unimontes). Five densities of C. capitata larvae (10, 20, 30, 40, and 50) were offered to parasitoid females that were at five different densities (1, 2, 5, 10, and 15). The larvae were exposed to the parasitoid females by means of “parasitism units” in adapted cages for 1 hour. Sex ratio, percentage of parasitism, and pupal mortality were evaluated. Both host larval density and female parasite density influenced parasitism, female progeny production, and pupal mortality. Higher female production was observed in the progeny in ratios of 1:1 and 2:1 (larvae/females). Ratios above 1:2 reduced the sex ratio, and ratios below 1:1 caused high pupal mortality rates. The females had higher parasitism activity when they were in groups dividing the same space. Equal ratios of Ceratitis capitata larvae and parasitoid females resulted in improved efficiency in progeny females.

scholarly journals Optimizing Photoperiod, Exposure Time, and Host-to-Parasitoid Ratio for Mass-Rearing of Telenomus remus, an Egg Parasitoid of Spodoptera frugiperda, on Spodoptera litura Eggs

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1050
Author(s):  
Wanbin Chen ◽  
Qingfen Weng ◽  
Rui Nie ◽  
Hongzhi Zhang ◽  
Xiaoyu Jing ◽  
...  
Keyword(s):  
Exposure Time ◽  
Spodoptera Frugiperda ◽  
Spodoptera Litura ◽  
Negative Relationship ◽  
Significant Negative Correlation ◽  
Mass Rearing ◽  
Egg Parasitoid ◽  
Female Progeny ◽  
Effective Manner ◽  
Telenomus Remus

Telenomus remus (Nixon) is a dominant egg parasitoid of the destructive agricultural pest Spodoptera frugiperda (J. E. Smith), and so is used in augmentative biocontrol programs in several countries. An optimized mass-rearing system is essential to produce biological control products in a timely and cost-effective manner. In this study, the photoperiod, host egg:parasitoid ratio, and exposure time were evaluated to identify the optimal rearing conditions for T. remus on the alternative host Spodoptera litura (Fabricius) eggs. Results showed that increasing photoperiod above 12L:12D remarkably improved parasitoid progeny yield and life table parameters. Overlong photoperiods shortened female longevity, but within acceptable limits. There was a significant negative correlation between parasitism rate and host egg:parasitoid ratio under exposure times of 12 and 36 h, but not 24 h. Percentage of female progeny increased significantly along with increasing the host egg:parasitoid ratio. A significant negative relationship between the number of emerged adults per egg and the host egg:parasitoid ratio was observed at an exposure time of 36 h. It was concluded that T. remus may be mass-reared most efficiently on S. litura eggs using a photoperiod of more than 12L:12D, a 14–20:1 host egg:parasitoid ratio, and an exposure time of 24 h. These findings can be used to produce T. remus more efficiently and at lower costs.

Kill rates by rabbit hunters before and 16 years after introduction of rabbit haemorrhagic disease in the southern South Island, New Zealand

2014 ◽  
Vol 41 (2) ◽  
pp. 136 ◽  
Author(s):  
Carlos Rouco ◽  
Grant Norbury ◽  
Dave Ramsay
Keyword(s):  
Biological Control ◽  
New Zealand ◽  
Biological Control Agent ◽  
Negative Relationship ◽  
Control Agent ◽  
Geographic Region ◽  
Instantaneous Rate ◽  
Rate Of Increase ◽  
Rabbit Haemorrhagic Disease ◽  
Haemorrhagic Disease

Context European rabbits (Oryctolagus cuniculus) are serious economic and environmental pests in Australia and New Zealand. Since the illegal introduction of rabbit haemorrhagic disease virus (RHDV) in New Zealand in 1997, the disease has persisted in most rabbit populations, with major epizootics occurring usually each autumn. Aims We evaluated the efficacy of the virus as a biological control agent in the southern South Island. Methods We used an index of rabbit abundance (kills per hunter) based on a region-wide annual rabbit-hunting competition to evaluate rabbit population trends 7 years before and 16 years after the first outbreak of RHD. We also evaluated the influence of rainfall and temperature in the preceding year on post-RHD trends in the index. Key results Kill rates declined by 60% following the initial epizootic. They remained low for the following 3 years and then increased steadily to intermediate levels punctuated by occasional declines. The instantaneous rate of increase in kill rates during the increase phase was low, but above zero (0.04 per year). No relationship between kill rates and rainfall was apparent, but there was a negative relationship between kill rates and winter temperature in the preceding season. Conclusions The kill-rate data obtained from this hunting competition suggest that RHD still appears to be killing rabbits. Every 2–3 years over the past decade, kill rates have been as low as they were when government rabbit-control programs were in place before RHD arrived, but the efficacy of RHD as a biological control agent is waning compared with the first outbreaks of the disease. This concurs with findings based on spotlight counts. Implications The data collected from this hunting competition are a good example of how ‘citizen science’ can be used to capture large volumes of pest-monitoring data from a wide geographic region for very little cost. The information is a valuable addition to understanding the effects of a major wildlife disease.

AGE, FECUNDITY, WEIGHT, AND THE INTRINSIC RATE OF INCREASE OF THE LUPINE APHID MACROSIPHUM ALBIFRONS (HOMOPTERA: APHIDIDAE)

1981 ◽  
Vol 113 (8) ◽  
pp. 739-745 ◽  
Author(s):  
B. D. Frazer ◽  
B. Gill
Keyword(s):  
Time Scale ◽  
Intrinsic Rate ◽  
Life Tables ◽  
Intrinsic Rate Of Increase ◽  
Thermal Threshold ◽  
Rate Of Development ◽  
Rate Of Increase ◽  
Table Model ◽  
Life Table Model ◽  
Threshold Of Development

AbstractThe fecundity, survivorship, and rate of development of the lupine aphid Macrosiphum albifrons Essig were determined and summarized into life tables from which the intrinsic rate of increase was computed. The life tables, using a time scale in days, were converted to a variable life table model using a physiological time scale based on an estimated thermal threshold of development of 3.59° (± 0.587°). A method of determining age and fecundity of adult aphids was developed from weight and embryo content. The use of intrinsic rate of increase and of the method of aging in field population dynamics are discussed.

scholarly journals Studies on intra-specific variations in the diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae) under different geographical regions

2016 ◽  
Vol 8 (3) ◽  
pp. 1629-1633
Author(s):  
Budhi Ram ◽  
K. C. Sharma ◽  
Nisha Devi ◽  
V. G. S. Chandel
Keyword(s):  
Insect Pests ◽  
Diamondback Moth ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Multiplication Rate ◽  
Female Progeny ◽  
Geographical Variations ◽  
Rate Of Increase ◽  
Geographical Regions ◽  
Table Analysis

Studies on intraspecific variations in insect pests are an important tool for preparation of management strategy in different geographical regions. In this paper we tried to establish that these variations are also found in the diamondback moth (P. xylostella) populations under north Indian conditions with respect to reproductive biology.The pest populations were collected from five different geographical regions viz. Hisar (800feet), Kangra (2200feet), Solan (4200 feet), Theog (7500feet) and Kinnaur (9000feet) and then reared under laboratory conditions at 25±1oC on cauliflower. The life table analysis revealed that the female from the Kangra population laid maximum eggs (332.16 eggs/female) whereas the number of eggs laid by the female from the Hisar, Solan, Theog and Kinnaur population was 189.53, 207, 252 and 270 eggs/female, respectively. The doubling time (DT) was observed to be the lowest for Kangra (3.12 days) and maximum for the Hisar (4.59 days) population, whereas weekly multiplication rate was minimum for the Solan (2.252) and maximum for the kangra (4.73) population. The true generation time was the lowest for the Kangra (18.54 days) and highest for the Hisar (24.38 days) population. The true intrinsic rate of increase (rm) was found to be maximum (0.222 female progeny/female/day) for the Kangra whereas for the Kinnaur, Theog, Solan and Hisar population it was 0.203, 0.202, 0.182 and 0.151 female progeny/female/day thereby indicating that the Kangra population is more prolific as compared to the population from other geographical regions. The results are indicative of geographical variations among different populations of P. xylostella.

Effect of pomegranate fruit supplementation on performance and various markers in athletes and active subjects: a systematic review

2019 ◽  
pp. 1-15
Author(s):  
Alicja Urbaniak ◽  
Anna Skarpańska-Stejnborn
Keyword(s):  
Vessel Diameter ◽  
Whole Body ◽  
Double Blind Study ◽  
Double Blind ◽  
Physically Active ◽  
Highly Active ◽  
Body Strength ◽  
Rate Of Increase ◽  
Study Designs ◽  
Pomegranate Fruit

Abstract. The aim of the study was to review recent findings on the use of POM supplements in athletes of various disciplines and physically active participants. Eleven articles published between 2010 and 2018 were included, where the total number of investigated subjects was 176. Male participants constituted the majority of the group (n = 155), as compared to females (n = 21). 45% of research described was conducted on athletes, whereas the remaining studies were based on highly active participants. Randomised, crossover, double-blind study designs constituted the majority of the experimental designs used. POM supplementation varied in terms of form (pills/juice), dosage (50 ml–500 ml) and time of intervention (7 days–2 months) between studies. Among the reviewed articles, POM supplementation had an effect on the improvement of the following: whole body strength; feeling of vitality; acute and delayed muscle fatigue and soreness; increase in vessel diameter; blood flow and serum level of TAC; reduction in the rate of increase for HR, SBP, CK and LDH; support in the recovery of post-training CK, LDH, CRP and ASAT to their baseline levels; reduction of MMP2, MMP9, hsCRP and MDA; and increased activity of antioxidant enzymes (glutathione peroxidase and superoxide dismutase). In the majority of reviewed articles POM supplementation had a positive effect on a variety of parameters studied and the authors recommended it as a supplement for athletes and physically active bodies.

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