The Control of Pieris rapae with DDT. I. The Natural Mortality of the Young Stages of Pieris

Dempster, J. P.

doi:10.2307/2401350

Cited by 113 publications

(93 citation statements)

References 7 publications

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“…Among agricultural pests, a Pieris rapae life table shows 61% mortality during the first instar mostly due to predation and drowning, with parasitoids gaining in importance later in larval development (Dempster 1967). Codling moth, Cydia pomonella, first-instar larvae on pear suffered 55% mortality in the first larval instar, linked to lignification preventing larval entry to the fruit (Westigard et al 1976).…”

Section: Mortality Rates Of Early Instarsmentioning

confidence: 99%

Effects of phenological synchronization on caterpillar early-instar survival under a changing climate

Despland

2018

Can. J. For. Res.

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Early-instar caterpillars experience very high and often very variable mortality; if it is density dependent, it can be a key factor in outbreak dynamics. Plant physical and chemical defenses can be extremely effective against young caterpillars, even of specialists. Phenological asynchrony with host plants can lead to dispersal and mortality in the early instars and increased predation or poor nutrition in later instars. Predation on early-instar larvae (including cannibalism) can be extremely high, parasitism appears generally low, and pathogens acquired early in larval development can lead to high mortality in later stadia. Four well-studied species reveal very different roles of early-instar mortality in population dynamics. In spruce budworm and gypsy moth, early-instar mortality rates can be very high; they do not drive outbreak cycles because density dependence is weak, but can modulate cycles and contribute to outbreak size and duration. For the autumnal moth, early-instar survival depends on host plant synchrony, but may or may not be density dependent. For monarch butterflies, the relative importance of larval mortality rates in population dynamics remains unclear. Tritrophic interactions between herbivores, host plants, natural enemies, and microbes play complex and species-specific roles in early-instar ecology, leading to emergent dynamics in population fluctuations. The phenology of these relationships is often poorly understood, making their responses to climate change unpredictable.Key words: Lepidoptera, hatchlings, synchronization, outbreaks.Résumé : Les chenilles des premiers stades larvaires connaissent des taux de mortalité très élevés et souvent très variables; si ces taux varient avec la densité, ils peuvent devenir un facteur clé dans la dynamique des épidémies. Les défenses physiques et chimiques des plantes sont souvent extrêmement efficaces contre les jeunes chenilles, même celles des espèces spécialisées. L'asynchronie phénologique avec les plantes hôtes peut entraîner la dispersion et la mortalité chez les premiers stades larvaires, et une augmentation de la prédation ou une mauvaise nutrition chez les derniers stades larvaires. La prédation lors des premiers stades larvaires (incluant le cannibalisme) peut être extrêmement élevée, le parasitisme semble généralement faible et les pathogènes qui infectent tôt dans le développement des larves peuvent entraîner un taux de mortalité élevé chez les stades ultérieurs. Quatre espèces bien étudiées révèlent différents rôles de la mortalité chez les premiers stades larvaires dans la dynamique des populations. Chez la tordeuse des bourgeons de l'épinette et la spongieuse, les taux de mortalité peuvent être très élevés chez les premiers stades larvaires; ils n'ont pas d'effet déterminant sur les cycles épidémiques parce que la dépendance à la densité est faible, mais ils peuvent moduler les cycles et contribuer à l'ampleur et à la durée des épidémies. Dans le cas de l'épirrite automnale, la survie des premiers stades larvaires dépend ...

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Section: Mortality Rates Of Early Instarsmentioning

confidence: 99%

Effects of phenological synchronization on caterpillar early-instar survival under a changing climate

Despland

2018

Can. J. For. Res.

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“…Some factors effeeting the efficiency of pitfall traps have been considered previously, such as vegetation and position of the trap (Greenslade, 1964), weather factors (Mitchell, 1963;Dempster, 1967) and the effects of preservatives (Lull, 1968;Greenslade and Greenslade, 1971). Little work has been done, however, on what constitutes an efficient trap for particular taxa, and what effects different sizes and materials have on the catch.…”

Section: Introductionmentioning

confidence: 99%

Some features influencing the efficiency of pitfall traps

1975

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1. Some of the trap features influencing the ability of pitfall traps to catch Coleoptera, especially Carabidae, were investigated by field and laboratory experiments. 2. It is shown theoretically that the catch of circular and rectangular traps can be compared on a basis of their perimeter lengths. Formulae are given for the reduction in catch per trap when traps are placed close together in a grid. 3. Field experiments compared the catch of six types of trap, from 2.5 cm diameter glass tubes, to 2 m long sections of guttering. Glass traps were most efficient in proportion to their size; plastic and metal traps had a reduced catch. Small traps were most efficient in catching small species, whereas large traps caught relatively more large beetles. 4. The capture efficiency of each type of trap was tested in the laboratory, using six species of Carabidae. Traps caught about 75% of beetles that contacted their perimeter; only small traps caught small beetles efficiently; the largest species was caught poorly by nearly all traps. 5. The rate of escape, from each type of trap, of small, medium and large sized Carabidae was tested. Escape was negligible from glass-sided traps, but was about 4% per day from plastic traps, and 10% from metal ones. Large beetles escaped most from small traps, and small beetles from large ones. 6. The observed differences, between types of trap, in capture and retaining efficiencies accounted for some, but not all, of the variations in catch found in the field.

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“…Carabid species diversity was higher in peak summer, found abundant in samples taken from litter and agricultural fields while lowest in areas near constructions. Carabid bettles considered as bio control agent of different crop pests and polyphagus on wide variety of plants [23], [24], [25]. During our study carabid collected from the agricultural fields have very low weed infestation due to their predation on weed seeds [26] intercropping enhance the beneficial role of carabid bettles.…”

Section: Descriptionmentioning

confidence: 69%

Systematic and Abundance of Ground Beetles (Carabidae: Coleoptera) From District Poonch Azad Kashmir, Pakistan

Rahim¹

2013

IOSR-JAVS

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The Control of Pieris rapae with DDT. I. The Natural Mortality of the Young Stages of Pieris

Cited by 113 publications

References 7 publications

Effects of phenological synchronization on caterpillar early-instar survival under a changing climate

Effects of phenological synchronization on caterpillar early-instar survival under a changing climate

Some features influencing the efficiency of pitfall traps

Systematic and Abundance of Ground Beetles (Carabidae: Coleoptera) From District Poonch Azad Kashmir, Pakistan

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