Two types of refuge have opposite effects on the size of larval aggregations in a tropical defoliator

@article{Horgan2005TwoTO,
  title={Two types of refuge have opposite effects on the size of larval aggregations in a tropical defoliator},
  author={Finbarr G. Horgan},
  journal={European Journal of Endocrinology},
  year={2005},
  volume={102},
  pages={225-230}
}
  • F. Horgan
  • Published 3 May 2005
  • Biology
  • European Journal of Endocrinology
Many gregarious insects aggregate in naturally occurring refuges on their host plants. However, when refuges are filled, they may be forced to aggregate on exposed areas of the plant. This study examines the effects of refuge saturation on group size and defence against parasitism in larvae of Ammalo helops Cramer (Lepidoptera: Arctiidae) that form day-resting groups on the trunks of weeping laurel, Ficus benjamina L., in El Salvador. Population densities, group sizes and parasitism were… 

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References

SHOWING 1-10 OF 31 REFERENCES
Effect of group size on parasitism in a natural population of the Baltimore checkerspot Euphydryas phaeton
TLDR
The effect of group size of early instars on parasitism of Euphydryas phaeton (Nymphalidae) was examined and lower limit to group size was a function of facilitation of larval numbers in reaching the first feeding site, the top of the host plant.
Contributions of female oviposition patterns and larval behavior to group defense in conifer sawflies (hymenoptera: diprionidae)
TLDR
Results suggest that female oviposition patterns are influenced in part by the defensive benefits gained by offspring in large aggregations, and contribute to the overall antipredator strategy of sawfly larvae.
Larval dispersal from potential hosts within a population of a generalist herbivore, Choristoneura rosaceana
TLDR
Larval dispersal did not match host suitabilities as measured by larval performance, and the relationship between host preference and suitability in the obliquebanded leafroller is discussed in an ecological and evolutionary perspective.
Intraplant distribution of Acalitus essigi (Acari: Eriophyoidea) on blackberries (Rubus fruticosus agg.)
TLDR
It is proposed that biotic factors such as tissue age, microhabitatmorphology and limited ambulatory dispersal capabilities are responsible for the aggregation patterns of this mite.
Direct and indirect effects of predatory wasps (Polistes sp.: Vespidae) on gregarious caterpillars (Hemileuca lucina: Saturniidae)
TLDR
It is suggested that wasps, in addition to killing caterpillars, indirectly affect larval fitness by slowing larval growth, at least in part by forcing larvae into cooler microhabitats where leaves are of lower quality.
RANDOM FORAGING BY HERBIVORES : COMPLEX PATTERNS MAY BE DUE TO PLANT ARCHITECTURE
Insect herbivores can have detrimental effects on the growth and reproduction of the plants they eat. For the plant, the consequences of losing a leaf to a forager may depend on the location of that
Does aggregation benefit bark beetles by diluting predation? Links between a group‐colonisation strategy and the absence of emergent multiple predator effects
TLDR
The hypothesis that decreased risk of predation was a potential benefit to aggregation in aggregation in such circumstances was tested, using the pine engraver, Ips pini and its two major predators.
Gregariousness and repellent defences in the survival of phytophagous insects
TLDR
It is suggested that repellent defences per se do not increase survival of gregarious larvae, and group behaviour is undoubtedly important in affecting the higher larval survival ofGregarious species, but it is currently unclear whether predator learning, dilution of risk, or rapid development contribute most to increasing survival.
Aggregation in Aphis Varians: An Effective Strategy for Reducing Predation Risk
TLDR
By quantifying the per capita population growth rates for aphid colonies of differing sizes, it is found that individual aphids benefited by being clumped together, but a predator—exclusion experiment indicated that clumping was beneficial to aphids only in the presence of predators.
Importance of plant size, distribution of egg masses, and weather conditions on egg parasitism of the European corn borer, Ostrinia nubilalis by Trichogramma ostriniae in sweet corn
TLDR
The results suggest that inundative releases of T. ostriniae should be made every two to three days, with multiple release points per hectare to optimize levels of parasitism, and weather conditions and plant architecture, especially temperature, plant height and leaf area must be taken into consideration.
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