scholarly journals Anticipatory flexibility: larval population density in moths determines male investment in antennae, wings and testes

2017 ◽  
Vol 284 (1866) ◽  
pp. 20172087 ◽  
Author(s):  
Tamara L. Johnson ◽  
Matthew R. E. Symonds ◽  
Mark A. Elgar
Keyword(s):  
Population Density ◽  
Developmental Plasticity ◽  
Adult Population ◽  
Larval Density ◽  
Fertilization Success ◽  
Mate Location ◽  
Distinct Advantage ◽  
Male Reproductive Success ◽  
Larval Population ◽  
Male Investment

Developmental plasticity provides individuals with a distinct advantage when the reproductive environment changes dramatically. Variation in population density, in particular, can have profound effects on male reproductive success. Females may be easier to locate in dense populations, but there may be a greater risk of sperm competition. Thus, males should invest in traits that enhance fertilization success over traits that enhance mate location. Conversely, males in less dense populations should invest more in structures that will facilitate mate location. In Lepidoptera, this may result in the development of larger antennae to increase the likelihood of detecting female sex pheromones, and larger wings to fly more efficiently. We explored the effects of larval density on adult morphology in the gum-leaf skeletonizer moth, Uraba lugens , by manipulating both the number of larvae and the size of the rearing container. This experimental arrangement allowed us to reveal the cues used by larvae to assess whether absolute number or density influences adult responses. Male investment in testes size depended on the number of individuals, while male investment in wings and antennae depended upon larval density. By contrast, the size of female antennae and wings were influenced by an interaction of larval number and container size. This study demonstrates that male larvae are sensitive to cues that may reveal adult population density, and adjust investment in traits associated with fertilization success and mate detection accordingly.

scholarly journals Larval densities of the protected Striped lychnis moth Shargacucullia lychnis (Lepidoptera: Noctuidae) in Buckinghamshire

2021 ◽  
Author(s):  
Juliano Morimoto ◽  
Lucy Kerr
Keyword(s):  
Natural History ◽  
Population Density ◽  
Developmental Stages ◽  
Larval Density ◽  
Natural Populations ◽  
Adaptive Responses ◽  
Larval Population ◽  
History Information ◽  
The Uk ◽  
Lepidoptera Noctuidae

Natural history information is essential for ecologically-relevant inferences about (adaptive) responses in organismal biology. Yet, natural history data can be difficult to obtain, particularly for the developmental stages of holometabolous insects. This gap can compromise our ability to design controlled experiments that provide useful understanding of insect responses to changing environments and precludes our ability to understand how natural populations may respond to unpredictable climatic changes in their natural environment. In this study, we collated data from previous reports from the Butterfly Conservation Upper Thames Branch on the larval population density of Shargacucullia lychnis (Lepidoptera: Noctuidae) in Buckinghamshire. In the UK, S. lychnis is a protected species, for which natural history information can be invaluable for its effective conservation. We report here that the natural range of larval densities observed for S. lychnis across locations and years is 0.001 to 6.417 larvae per spike. More importantly, S. lychnis larval density has overall declined from 1996 to 2020, which could support previous reports of a contraction in population range for this species. Overall, this study provides invaluable information about larval population density for an important protected Lepidopteran species of the UK.

scholarly journals The Effects of Population Density on the Incidence of Developmental Deformities in Chemosensory Organs of Tobacco Hornworm Larvae (Lepidoptera: Sphingidae)

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Frank Hanson ◽  
Elizabeth Stanwyck ◽  
Alexander Bohorquez
Keyword(s):  
Life History ◽  
Population Density ◽  
Manduca Sexta ◽  
Life History Traits ◽  
Larval Density ◽  
Population Densities ◽  
Larval Population ◽  
Rate Of Development ◽  
Rearing Conditions ◽  
Chemosensory Organs

Abstract Cultures of Manduca sexta Johanssen in our laboratory were found to have larvae with missing or deformed mouthparts or antennae. Hypothesizing that these developmental deformities were caused by crowded rearing conditions, we reared larvae in four different population densities and recorded the incidence (% of larvae affected) and types of chemoreceptor deformities. Results showed that the incidence of these deformities was directly proportional to larval population density. Deformities of the maxilla and palp were the most frequent, followed by those of the antenna, epipharynx and maxillary styloconica. Life history traits of larval mass, food consumption, and rate of development were inversely related to larval density for both normal and deformed larvae. We discuss possible causes and mechanisms of these deformities and of changes to life history traits.

scholarly journals Influence of larval density on biological fitness of Ephestia kuehniela Zeler (Lepidoptera Pyralidae )

2007 ◽  
Vol 60 ◽  
pp. 199-202 ◽  
Author(s):  
J. Xu ◽  
Q. Wang ◽  
X.Z. He
Keyword(s):  
Biological Control ◽  
Survival Rate ◽  
Population Density ◽  
Reproductive Output ◽  
Larval Density ◽  
Ephestia Kuehniella ◽  
Stored Products ◽  
Larval Population ◽  
Control Programmes ◽  
Lepidoptera Pyralidae

Mediterranean flour moth Ephestia kuehniella is a cosmopolitan pest of stored products and its eggs are widely used to rear parasitoids and predators for biological control programmes This experiment investigated how larval population density affected the survival rate and reproductive output of this species under four rearing densities (1 larva per 2 g food per vial; or 100 500 or 1000 larvae per 50 g food per jar) The survival rate and reproductive output significantly decreased (P

scholarly journals Neighbourhood characteristics as a predictor of adherence to dietary recommendations: A population-based cohort study of Finnish adults

2020 ◽  
pp. 140349482097149
Author(s):  
Hanna Lagström ◽  
Jaana I. Halonen ◽  
Sakari Suominen ◽  
Jaana Pentti ◽  
Sari Stenholm ◽  
...  
Keyword(s):  
Population Density ◽  
Dietary Habits ◽  
Metabolic Diseases ◽  
Adult Population ◽  
Age Groups ◽  
Population Based ◽  
Dietary Recommendations ◽  
Neighbourhood Characteristics ◽  
Severe Life Events ◽  
Dietary Score

Aims: To investigate the association of six-year cumulative level of socioeconomic neighbourhood disadvantage and population density with subsequent adherence to dietary recommendations, controlling for preceding dietary adherence, in adults in Finland. Methods: Population-based Health and Social Support (HeSSup) study participants from four age groups (20–24, 30–34, 40–44 and 50–54 years at baseline in 1998). Data on diet and alcohol consumption were obtained from the 2003 and 2012 surveys and information on neighbourhoods from Statistics Finland Grid database ( n = 10,414 men and women). Participants diet was measured as adherence to Nordic Nutrition recommendation (score range 0–100). Neighbourhood disadvantage was measured by median household income, proportion of those with primary education only and unemployment rate, and population density by the number of adult population between years 2007 and 2012. Linear models were used to assess the associations of neighbourhood characteristics with the score for adherence to dietary recommendations in 2012. Results: Cumulative neighbourhood socioeconomic disadvantage was associated with slightly weaker (1.49 (95% confidence interval (CI) −1.89 to −1.09) point decrease in dietary score) adherence while higher population density was associated with better (0.70 (95% CI 0.38−1.01) point increase in dietary score) adherence to dietary recommendations. These associations remained after controlling for prior dietary habits, sociodemographic, chronic cardio-metabolic diseases, and severe life events. Conclusions: These longitudinal findings support the hypothesis that neighbourhood characteristics affect dietary habits.

Copulation order, density cues and variance in fertilization success in a cestode

Parasitology ◽  
2014 ◽  
Vol 141 (7) ◽  
pp. 934-939
Author(s):  
D. ANDREOU ◽  
D. P. BENESH
Keyword(s):  
Reproductive Success ◽  
Intermediate Host ◽  
Fertilization Success ◽  
Final Host ◽  
Fish Host ◽  
Multiple Infection ◽  
Single Infection ◽  
Male Reproductive Success ◽  
Mating Order ◽  
Potential Partner

SUMMARYSimultaneous hermaphrodites maximize their fitness by optimizing their investment into male or female functions. Allocation of resources to male function (tissues, traits, and/or behaviours increasing paternity) is predicted to increase as density, and the associated level of sperm competition, increases. We tested whether the simultaneous hermaphroditic cestode Schistocephalus solidus uses cues of potential partner densities in its fish intermediate host to improve its male reproductive success in the final host. We had two worms, one originating from a multiple infection in the fish intermediate host and one from a single infection, sequentially compete to fertilize the eggs of a third worm. The fertilization rates of the two competitors nearly always differed from the 50–50 null expectation, sometimes considerably, implying there was a ‘winner’ in each experimental competition. However, we did not find a significant effect of density in the fish host (single vs multiple) or mating order on paternity. Additional work will be needed to identify the traits and environmental conditions that explain the high variance in male reproductive success observed in this experiment.

scholarly journals Effectiveness of Diflubenzuron and Bacillus thuringiensis Against Gypsy Moth Populations

1997 ◽  
Vol 14 (3) ◽  
pp. 135-140 ◽  
Author(s):  
Kevin W. Thorpe ◽  
Richard L. Ridgway ◽  
Ralph E. Webb
Keyword(s):  
Bacillus Thuringiensis ◽  
Population Density ◽  
Gypsy Moth ◽  
Mass Density ◽  
Larval Mortality ◽  
Larval Density ◽  
Egg Mass ◽  
Percent Reduction ◽  
Moth Population ◽  
Oak Trees

Abstract Aerial applications of Bacillus thuringiensis Berliner subsp. kurstaki (74.1 billion international units/ha per application; single and double applications), diflubenzuron [69 g (ai)/ha], and no treatment were evaluated. Treatment effects were estimated from frass collections, defoliation, counts of pupae under burlap, and egg-mass counts. Estimates of larval density in the canopy 20 days after treatment ranged from 318.3 to 55.5 larvae per m² in the control- and diflubenzuron-treated plots, respectively. Larval density was reduced in all treatments, and was lowest in the plots treated with diflubenzuron and two applications of B. thuringiensis. Population density rapidly declined in the control plots, and by June 20, when larvae were predominantly in the fifth and sixth instars, no significant differences in larval density were detected among the treatments. Significantly less defoliation occurred to oak trees in the treated plots, but no differences were detected among the spray treatments. Counts of pupae under burlap, postseason egg-mass counts, and percent reduction in egg-mass density did not differ significantly among treatments or versus controls. These results suggest that diflubenzuron and double B. thuringiensis treatments caused higher levels of larval mortality than occurred with a single B. thuringiensis application, but that with a naturally declining gypsy moth population the final levels of damage were the same under all treatments. North. J. Appl. 14(3):135-140.

scholarly journals Food availability and larval density affect ovarian development in Plutella xylostella (L.) (Lepidoptera: Yponomeutidae)

1999 ◽  
Vol 28 (4) ◽  
pp. 611-616 ◽  
Author(s):  
Marina Castelo Branco ◽  
Alexander G. Gatehouse
Keyword(s):  
Population Density ◽  
Food Availability ◽  
Plutella Xylostella ◽  
Ovarian Development ◽  
Diamondback Moth ◽  
Larval Density ◽  
Leaf Disk ◽  
Plant Age ◽  
Insect Migration ◽  
Petri Dishes

The effect of Diamondback Moth (Plutella xylostella L.) population density and plant age on the rate of ovarian development was investigated. In tests carried out in Petri dishes, the density of larvae/leaf disk affected the rate of ovarian development. A high proportion of moths from larvae reared on leak disks from two or four-month-old spring cabbage at a density of seven or 14 larvae/leaf disk were mature at emergence. But moths reared at the same type of plant at a density of 28 larvae/leaf disk were largely immature at emergence. When the larvae were reared at a density of 30 larvae/plant on two or four-month-old spring cabbage plants, a high proportion of females were mature at emergence. Crowding has an important effect on the rate of ovarian development in Diamondback Moth with possible consequences for the migratory potential of moths, as insect migration generally occurs when the ovaries of the females are immature. The density of moths necessary to increase the proportion of immature females in the field is probably higher than 30 larvae/plant.

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