Delayed mating in tortricid leafroller species: simultaneously aging both sexes prior to mating is more detrimental to female reproductive potential than aging either sex alone

2008 ◽  
Vol 99 (3) ◽  
pp. 245-251 ◽  
Author(s):  
L.L. Stelinski ◽  
L.J. Gut

AbstractThe effect of delayed mating on reproductive potential, longevity and oviposition period of female redbanded leafroller,Argyrotaenia velutinana(Walker) and Pandemis leafroller,Pandemis pyrusanaKearfott, was investigated in the laboratory. Virgin female or male moths of each species were held for 1, 2, 4, 6 or 10 days prior to pairing with one-day-old virgin conspecifics of the opposite sex. In addition, reproductive potential was assessed when both sexes of each species were aged for those periods prior to pairing. The expected reproduction of femaleA. velutinanawas reduced by 34, 53, 71 and 81% for 2, 4, 6 and 10-day delays in female mating, respectively. ForP. pyrusana, expected reproduction was reduced by 47, 74, 85 and 93% for 2, 4, 6 and 10-day delays in female mating, respectively. Increasing male age at mating in both species had a lesser effect on female reproductive output compared with increasing female age at mating. As maleA. velutinanaage at mating increased, the expected reproduction of femaleA. velutinanawas reduced by 15, 45, 54 and 70% for 2, 4, 6 and 10-day delays, respectively. Comparing maleP. pyrusanaof various ages at mating, expected reproduction was reduced by 14, 42, 64 and 79% for 2, 4, 6 and 10-day delays in mating, respectively. The decrease in female reproduction when both sexes were aged prior to mating was higher than when either sex alone was aged prior to pairing with a one-day-old virgin of the opposite sex. The expected reproduction of femaleA. velutinanawas reduced by 60, 83, 96 and 98% for 2, 4, 6 and 10-day delays in mating of both sexes, respectively. Only 7.5% of female eggs hatched when both sexes ofA. velutinanawere aged ten days prior to mating. When simultaneously aging both sexes ofP. pyrusanaprior to mating, expected reproduction was reduced by 71, 93, 96 and 99% for 2, 4, 6 and 10-day delays in mating, respectively. NoP. pyrusanaeggs hatched after a ten-day delay of mating for both sexes. For both species, female longevity increased and duration of oviposition period decreased with increasing female age at mating. Our results demonstrate that delayed mating in both females and males negatively affects female reproductive output in both species and that simultaneous aging of both sexes prior to mating has a greater effect than aging either sex alone. Our results suggest that laboratory studies that have paired aged females or aged males with conspecifics of optimal reproductive maturity have likely underestimated the effects of delayed mating on reproductive output.

2002 ◽  
Vol 92 (3) ◽  
pp. 241-249 ◽  
Author(s):  
L.M. Torres-Vila ◽  
M.C. Rodríguez-Molina ◽  
J. Stockel

AbstractVirgin females of Lobesia botrana Denis & Schiffermüller were mated at ages of 1, 3, 5, 8, 12 and 16 days and the effect of mating delay on reproductive output assessed. Delayed mating did not affect female mating success but fertilization was reduced in 16-day-old females. Increased mating delays substantially affected daily oviposition pattern and resulted in a significant reduction of both fecundity and fertility, so that mean number of viable eggs laid decreased from 150 to 22 in 1- and 16-day-old mated females, respectively. Heavier females were more constrained than lighter ones by mating delays and female reproductive efficiency (no. viable eggs/female body weight) was also significantly reduced. Female longevity significantly increased and oviposition period gradually declined with mating delay. The number of viable eggs was positively correlated with both female weight and oviposition period; female longevity and female weight were also significantly correlated. However, the significance of these correlations declined with increased mating delay. Results overall indicated that mating delay drastically reduces female L. botrana reproductive output. The implications of delayed mating of females are discussed from an ecological perspective in relation to L. botrana control using mating disruption.


Author(s):  
Carolina Manzano ◽  
Eduardo G. Virla ◽  
Maria V. Coll Araoz ◽  
Erica Luft-Albarracin

Abstract The reproductive traits of the mymarid wasp Cosmocomoidea annulicornis (Ogloblin) (Hymenoptera: Mymaridae) attacking eggs of the sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae) were evaluated under laboratory conditions. Bioassays were carried out to estimate the realized fecundity and egg load of females. The ovigeny index was calculated and different biological traits, such as body size, oöcyte length, gaster length and wing length, were analysed to assess significant associations between these traits and the species fitness. In addition, the effect of host availability and feeding on longevity and potential fecundity throughout life and the effect of female age on egg maturation dynamics were assessed. The results showed that C. annulicornis is a strongly synovigenic species. A positive correlation was found between fecundity and longevity of the females and between body size and oöcyte length. Contrary to expected, body size was not related to fecundity and longevity. Females lived significantly longer in the presence of hosts and honey than when they were host-deprived and honey-fed or both host and honey deprived. Host availability had a significant effect on the amount of eggs laid by C. annulicornis females. Female age was negatively associated with oöcyte length. Furthermore, females were able to mature additional eggs as they aged, nevertheless, when host-deprived, senescent females presented significantly less mature eggs than younger ones, suggesting a possible egg oosorption. These results might contribute to a better understanding of the reproductive potential of this species as a biocontrol agent.


2001 ◽  
Vol 133 (2) ◽  
pp. 219-227 ◽  
Author(s):  
H.W. Fraser ◽  
R.M. Trimble

AbstractThe effect of delayed mating on the reproductive biology of females of the Oriental fruit moth, Grapholita molesta (Busck), was studied in the laboratory. Expected reproduction, defined as t-th day survival rate × percent successful mating × total viable eggs, was reduced by 13, 36, and 74%, respectively, after a 2-, 5-, and 10-d delay in pairing with a male compared with females that were paired with a male on their day of emergence. Female fertility (percentage of females laying fertile eggs), fecundity (total number of eggs laid), egg fertility (percentage of eggs developing to black head stage), and egg hatch (percentage of eggs hatching) were reduced by delays in mating. The pre-oviposition period of females mated within 24 h of emergence was longer than that of females mated 2, 5, or 10 d after emergence. The duration of the oviposition period declined with delays in mating. Female longevity increased with delays in mating and was greatest in virgin females. The number of eggs laid per day was similar in females paired with a male 2, 5, and 10 d after their emergence. Commencing 2 d after pairing, females paired on their day of emergence exhibited a daily oviposition rate similar to that of females paired 2–10 d after emergence. These observations suggest that the successful control of the Oriental fruit moth using sex-pheromone-mediated orientation disruption (mating disruption) is more likely accomplished by preventing mating than by delaying mating.


1993 ◽  
Vol 50 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Andrew R. Lewis ◽  
J. Howard Choat

Reproductive biology of the tropical sepioid cephalopod Idiosepius pygmaeus was investigated in wild specimens and in individuals maintained in aquaria through the adult life span. This species produced multiple egg batches over 80% of the observable adult weight range, indicating a coordination of reproductive and somatic growth. Reproductive output was consistent within, but variable between, individuals. Oocyte synthesis and maturation occur continuously after sexual maturation has been reached. Senescence and death are not related to an exhaustion of reproductive potential. On average, captive female I. pygmaeus with access to unlimited food produced 640 eggs in 11 batches over 18 d. When reproductive output was expressed as a ratio of dry female body weight, on average, specimens had incorporated five times their body weight into eggs and egg coatings. Under food stress, captive specimens laid fewer eggs but maintained egg size and periodicity of egg laying. Food stress had no effect on either laying duration or weight at death. This study provides further evidence that terminal spawning modes are not ubiquitous amongst cephalopods.


Botany ◽  
2017 ◽  
Vol 95 (8) ◽  
pp. 809-817 ◽  
Author(s):  
Ashley M. Hembrough ◽  
Victoria A. Borowicz

Baptisia alba (L.) Vent., an herbaceous, perennial legume, produces more flowers than will mature into pods. Single-year experiments on two reconstructed prairies tested the hypothesis that reproductive potential of B. alba depends on nutrients, but pollen limitation and pre-dispersal seed predation by weevils reduce final production. Ramets were assigned one of four treatments that were combinations of fertilizer (none/70 g fertilizer twice) and insect barrier (none/application of Tanglefoot). Within inflorescences, flowers were naturally pollinated or supplemented with pollen. Fertilizer produced no effects, suggesting that B. alba are unresponsive within a season to nutrient supplementation. Pollen supplementation increased pod initiation at the two sites by 6.7% and 2.3%, respectively, but did not affect the proportion of initiated pods that matured or seed number within pods. Where Tychius sordidus occurred, only 67 pods matured on 19 ramets and only four seeds survived. Where only Trichapion rostrum was present, insect barrier increased pod maturation almost three-fold, but did not affect seed number within pods. Barrier treatment increased the reproductive output of entire ramets by increasing seed production, from 3.6 seeds·ramet−1 to 60.5 seeds·ramet−1. Prairie restoration frequently uses fruit collected from other populations. Managers should be careful to avoid the unintended introduction of voracious seed predators.


2017 ◽  
Vol 107 (4) ◽  
pp. 506-512 ◽  
Author(s):  
Z. Yan ◽  
J.J. Yue ◽  
C. Bai ◽  
Z.Q. Peng ◽  
C.H. Zhang

AbstractThe endoparasitoid Microplitis prodeniae Rao and Chandry is an important potential augmentative biological control agent for lepidopteran pests of vegetables and tobacco. However, cold storage of pupae is required to ensure that sufficient parasitoids are available when they are needed in the field. In this study, pupae were maintained at 0, 4 or 10°C for 5–50 days after which the adults were evaluated for emergence, pre-emergence period, sex ratio, female longevity, oviposition period, and fecundity. Cold storage did not affect the pre-emergence period or proportion of females; however, there was a significant reduction in emergence, female longevity, oviposition period, and fecundity with increased exposure to cold. The pre-emergence period was approximately 5 days, and approximately 50% of the emergent parasitoids were females. A cold storage regime of 10 days at 10°C had no effect on the parasitoids and adult emergence was greater than 50% even after 20 days at 10°C. There was no carryover of the cold treatment from parental to F1 and F2 generations. Thus, M. prodeniae can be stockpiled for field release by exposing the pupae to a cold regime and subsequently holding them for adult emergence at 28°C.


2019 ◽  
Vol 11 (5) ◽  
pp. 334 ◽  
Author(s):  
Silvana Aparecida de Souza ◽  
Irys Fernanda Santana Couto ◽  
Mateus Pereira ◽  
Claudia A. L. Cardoso ◽  
Silvana de Paula Quintão Scalon ◽  
...  

Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae) is an insect pest that causes great damage to Brassica cultures. It is necessary to develop alternative control methods, because this pest is resistant to many synthetic insecticides that are harmful to the environment. The objective of this study was to evaluate the effects of aqueous extracts of Campomanesia adamantium, C. guazumifolia, and C. xanthocarpa on the life cycle of P. xylostella. These aqueous extracts were prepared in a concentration of 10 g/mL and then applied on cabbage disks of 4 cm2 to feed the larvae until they reached pupal stage. The disks were evaluated daily during the larval stage and replaced every 24 hours. The experiment consisted of ten replicates, each replicate containing five subsamples. The parameters evaluated were larval and pupal survival, pupal biomass, gender ratio, male and female longevity, number of eggs, fecundity, oviposition period and egg survival. The C. xanthocarpa extract increased larval stage and decreased pupal biomass and oviposition period. The C. adamantium extract decreased larval duration, pupal biomass, male longevity, and oviposition period. The C. guazumifolia extract decreased larval stage, male longevity, and oviposition period. The chemical composition of the extracts of Campomanesia species presented flavonoids such as quercetin, phenolic compounds, and tannins, and the highest retention time occurred in C. adamantium. Thus, the extracts of Campomanesia species were effective in decreasing and controlling the oviposition period of P. xylostella, probably because of the presence of flavonoids, which indicates a possible antioxidant potential and, therefore, the observed antibiosis.


2016 ◽  
Vol 8 (4) ◽  
pp. 1762-1765
Author(s):  
Richa Varshney ◽  
R. R. Rachana ◽  
R. S. Bisht

Biology and feeding potential of Coccinella septempunctata (Linn.) were studied in laboratory on 3rd instar nymphs of mustard aphid (Lipaphis erysimi Kalt.) at two different temperature regimes. At 30± 20C, fecundity, oviposition period, hatchability of eggs, male and female longevity (232±70.46, 12.8±3.91, 82.87±6.66, 22.70 ± 2.21and 26.60 ± 4.45, respectively) were higher and incubation period, pre-oviposition period, total grub duration and pupal duration (2.6±0.51, 6.5±3.53, 8.7 ± 1.63 and 5.1 ± 1.10, respectively) were lesser in comparison to 25± 20C where fecundity, oviposition period, hatchability of eggs, male and female longevity, incubation period, preoviposition period, total grub duration and pupal duration were 169.8±61.12, 7.9±1.37, 71.68±4.08, 16.2 ± 1.31 and 21.50 ± 1.95, 2.9±0.73, 7.7±2.49, 11.1 ± 1.52 and 5.8 ± 0.918, respectively . At 27± 2 0C, total mustard aphid consumption by a grub of C. septempunctata during the whole life span, was 424.4±2.78 mustard aphids in comparison to 272.64±1.79 mustard aphid at 23± 20C. Similarly an adult male and female consumed 103.2±1.52 and 116.6 ±1.46 aphids per day respectively at 27± 2 0C in comparison to 65.6 ± 1.02 and 71.8 ± 1.60 at 23± 20C. Thus, at both temperatures aphid consumption increased gradually till 4th instar and 30±20C was found to be most suitable temperature as compared to 25±20C for the life history of C. septempunctata. Hence, it could be concluded that C. septempunctata might play a suitable role in biointensive Integrated Pest Management programme because of better longevity and high predatory potential against the mustard aphid.


2015 ◽  
Vol 1 (9) ◽  
pp. e1500401 ◽  
Author(s):  
Nina Vasilieva ◽  
Andrey Tchabovsky

Sexual conflict theory suggests that female breeding success is strongly influenced by individual life history and environmental conditions and is much less affected by mate availability. Female mating failure due to a shortage of males remains poorly studied and understood. We present data on the effects of male availability on female breeding success in a wild colony of yellow ground squirrels (Spermophilus fulvus). A female’s probability of breeding increased with the local density of males and was higher with higher male-biased operational sex ratio (OSR) but was independent of local female density, female age, and body condition, which are factors commonly assumed to influence female reproduction. The positive effect of male availability (as measured by OSR) on female breeding success was consistent across the years, and we conclude that male limitation contributes to female mating failure. This pattern, which is not commonly recorded in species with conventional sex roles, can be explained by a combination of sociodemographic and life history traits (sex differences in age of maturation, female-skewed adult sex ratio and seasonally varying OSR, solitary living at low population density, and low mobility of females combined with mate-searching tactics of males) that are not confined toS. fulvus. Our findings indicate that the role of female mating failure (due to a shortage of males) in shaping mammalian life history may be underestimated.


2008 ◽  
Vol 56 (6) ◽  
pp. 389 ◽  
Author(s):  
Luis Ortiz-Catedral ◽  
Dianne H. Brunton

At least four populations of the red-crowned parakeet (Cyanoramphus novaezelandiae) have been established via translocation within New Zealand over the last 40 years, but reproductive parameters of these populations have not been documented. We quantified differences in clutch parameters and reproductive success for a translocated population of this species on Tiritiri Matangi Island over two breeding seasons. Overall clutch parameters and estimates of reproductive success were consistent with reported values from natural populations. However, we found previously unreported differences in clutch size, hatching success and brood size between breeding seasons. The number of fledglings produced per breeding pair increased significantly from 1.4 to 3.4 fledglings during our two-year study. In contrast, egg volume and fertility per clutch did not vary during the same period. Overall, 7 eggs were laid per breeding pair but only 2.22 nestlings fledged, representing a 63.8% loss of initial reproductive potential. Losses during the incubation stage were caused by partial and total hatching failure, whereas starvation of nestlings caused all losses during the brood-rearing stage. Hatching success during our study was lower than that reported for wild populations of this and other parrot species, and remained lower even during the most productive breeding season. We found no cases of predation on eggs or nestlings during our study despite the presence of native and exotic avian predators on Tiritiri Matangi Island. We show that clutch size, brood size and changes in loss between breeding seasons are determinants of reproductive output in translocated red-crowned parakeet and also that reproductive output can vary greatly between breeding seasons. Finally, if reduced hatching success is the result of small founder size, management of parakeets should consider the movement of larger and more genetically diverse flocks.


Sign in / Sign up

Export Citation Format

Share Document