Crystalline wax coverage of the cuticle in easy bleeding sawfly larvae

2011 ◽  
Vol 40 (2) ◽  
pp. 186-189 ◽  
Author(s):  
Jean-Luc Boevé ◽  
Dagmar Voigt ◽  
Stanislav N. Gorb
Keyword(s):  
Chemoecology ◽  
2005 ◽  
Vol 15 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Jean-Luc Boev� ◽  
Caroline M�ller

2004 ◽  
Vol 94 (3) ◽  
pp. 283-289 ◽  
Author(s):  
L. Vlieger ◽  
P.M. Brakefield ◽  
C. Müller

AbstractThe turnip sawfly, Athalia rosae Linnaeus, is a pest on cruciferous crops. Larvae sequester secondary plant compounds, namely glucosinolates, in their haemolymph. When attacked, their integument is easily disrupted and a droplet of haemolymph is exuded (‘easy bleeding’). This has been shown to be an effective, chemical-based, defence against invertebrate predators. The efficiency of this proposed defence was tested against a vertebrate predator, using groups of the iguanid lizard Anolis carolinensis Voigt as a model predator. Caterpillars of Pieris rapae Linnaeus and Pieris brassicae Linnaeus served as control prey species that do not sequester glucosinolates. Lizards attacked far fewer sawfly larvae than pierid caterpillars. Several of the sawfly larvae were rejected after an initial attack, demonstrating unpalatability to the lizards, while the Pieris larvae were not rejected. However, P. rapae larvae topically treated with extracts of haemolymph of A. rosae had no deterrent effect on the lizards and no avoidance learning occurred over a period of two weeks. Adult sawflies do not easy bleed but have glucosinolates carried over from the larval stage. Lizards attacked them at a higher rate than larvae and they were never rejected. The results suggest that for the defensive effectiveness of the pest sawfly species against vertebrates the chemical cue is not necessarily sufficient. Movement and colour may be important additional factors triggering the behaviour of vertebrate predators.


Oikos ◽  
1997 ◽  
Vol 79 (3) ◽  
pp. 450 ◽  
Author(s):  
P. Weinstein ◽  
D. A. Maelzer

1956 ◽  
Vol 88 (1) ◽  
pp. 17-23 ◽  
Author(s):  
A. W. Ghent

Interest in the growth of insect head capsules was aroused by the observation of Dyar (2) that for a number of lepidopterous larvae the ratio of the width of the larval head capsule in a given instar to that in the following instar tends to be constant throughout development, This observation, generally known as “Dyar's Law” or “Dyar's Rule”, has proven valid for many lepidopterous larvae, for whch it was proposed. Many attempts have been made to apply Dyar's Rule to insects of other orders. Various authors, notably Miles (6) and Taylor (71, have considered the application of Dyar's Rule to sawfly larvae, and although they report some inconsistencies, they conclude that the rule is useful if its application is restricted to checking upon the number of feeding instars. The head capsules of non-feeding prcpupal sawfly larvae are generally of the same size as those of the last feeding instar, so that this stage is not expected to satisfy Dyar's Rule.


2007 ◽  
Vol 53 (7) ◽  
pp. 668-675 ◽  
Author(s):  
Charles-Albert Petre ◽  
Claire Detrain ◽  
Jean-Luc Boevé

2017 ◽  
Vol 7 (11) ◽  
pp. 3689-3702 ◽  
Author(s):  
John W. Terbot ◽  
Ryan L. Gaynor ◽  
Catherine R. Linnen

2018 ◽  
Vol 285 (1884) ◽  
pp. 20180466 ◽  
Author(s):  
Carita Lindstedt ◽  
Antti Miettinen ◽  
Dalial Freitak ◽  
Tarmo Ketola ◽  
Andres López-Sepulcre ◽  
...  

The evolution of cooperation and social behaviour is often studied in isolation from the ecology of organisms. Yet, the selective environment under which individuals evolve is much more complex in nature, consisting of ecological and abiotic interactions in addition to social ones. Here, we measured the life-history costs of cooperative chemical defence in a gregarious social herbivore, Diprion pini pine sawfly larvae, and how these costs vary under different ecological conditions. We ran a rearing experiment where we manipulated diet (resin content) and attack intensity by repeatedly harassing larvae to produce a chemical defence. We show that forcing individuals to allocate more to cooperative defence (high attack intensity) incurred a clear cost by decreasing individual survival and potency of chemical defence. Cooperative behaviour and the magnitude of its costs were further shaped by host plant quality. The number of individuals participating in group defence, immune responses and female growth decreased on a high resin diet under high attack intensity. We also found some benefits of cheating: non-defending males had higher growth rates across treatments. Taken together, these results suggest that ecological interactions can shape the adaptive value of cooperative behaviour and maintain variation in the frequency of cooperation and cheating.


1965 ◽  
Vol 13 (4) ◽  
pp. 593 ◽  
Author(s):  
PB Carne

The distribution of the sawfly is discussed at several levels, ranging from that within a study region which comprised a substantial proportion of the known range of the insect, to that within the crowns of individual trees. A mosaic of areas was recognized within the region, each characterized by a degree of ecological uniformity and in which saivfly populations maintained relatively high or low levels of abundance during 6 yr of observation. The distribution of the insect is influenced strongly by climatic factors, the rainfall and temperature statistics for the critical period October-March for all areas in which it occurs being closely grouped. Such grouping is even more marked for those areas in which the sawfly was consistently most abundant. The cool wet limit of the sawfly's distribution coincides with that of a favoured host species, but the hot dry limit appears to be determined by the insect's susceptibility to desiccation. Although many naturally occurring and planted eucalypts will support sawfly larvae, persistent infestations were recorded only where one or more of three species grew - Eucalyptus blakelyi, E. camaldulensis, or E. melliodora. The sawfly is an inhabitant of river valley woodland, rarely becoming abundant in other situations and being absent from sclerophyll forest formations. Survival of the insect is greatly influenced by the ease with which it can penetrate into the soil for cocoon formation; it tends to be most abundant in areas of light soil, or where large trees provide a deep litter accumulation. The susceptibility of trees to infestation is influenced by seasonal production of new foliage. Those growing in sites where the water table is high, and whose leaf production is to a large extent independent of rainfall patterns, may be subject to chronic attack. Distribution between trees is affected by their leaf shape and texture, and by their history of previous defoliation. Small trees are particularly prone to attack, and infestation of mature trees is generally an indication of outbreak abundance of the insect. Similarly, marginally favoured species are attacked only when oviposition sites on more favoured trees are virtually saturated. Field experiments indicated that an observed contagious distribution of sawfly eggs in portions of the crowns of individual trees is not the result of overt gregariousness on the part of the females, but results from the attraction of the latter to foliage of certain physical characteristics and position on the tree.


Toxicon ◽  
1983 ◽  
Vol 21 ◽  
pp. 321-323 ◽  
Author(s):  
Peter B. Oelrichs ◽  
John K. Macleod ◽  
Dudley H. Williams
Keyword(s):  

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