Studies on the Starvation of Last-Instar Larvae of the Larch Sawfly, Pristiphora erichsonii (Htg.) (Hymenoptera: Tenthredinidae)

1955 ◽  
Vol 87 (10) ◽  
pp. 417-427 ◽  
Author(s):  
R. J. Heron
Keyword(s):  
Population Size ◽  
Marked Reduction ◽  
Larval Mortality ◽  
Reproductive Capacity ◽  
Larval Feeding ◽  
Lethal Effects ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Native Host

Larvae of the larch sawfly, Pristiphora erichsonii (Htg.), feed on the foliage of conifers of the genus Larix. In Manitoba and Saskatchewan, where the studies described here were conducted, the native host is tamarack, L. laricina (Du Roi) K. Koch. At outbreak population levels larval feeding commonly causes complete defoliation. Trees show a marked reduction in foliage production after three or four successire vears af severe defoliation (6). As a consequence, larval starvation is commonly associated with declining host vigour. Starvation reduces the population size directly by causing larval mortality and indirectly by reducing the reproductive capacity of the partially starved survivors. This paper deals primarily with the measurement of the sub-lethal effects of starvation during the last larval stadium as studied in laboratory-reared and field-collected insects.

Population and Mortality Assessment During the Egg and Larval Stages of the Larch Sawfly, Pristiphora erichsonii (Htg.)

1962 ◽  
Vol 94 (3) ◽  
pp. 256-268 ◽  
Author(s):  
W. G. H. Ives
Keyword(s):  
Population Studies ◽  
Alternative Methods ◽  
Larval Feeding ◽  
Sampling Techniques ◽  
Larval Stages ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Foliage Weight

This contribution is the eighth in a series of papers on sampling techniques used in population studies of the larch sawfly (Ives, 1955; Ives and Prentice, 1958; Buckner, 1959; Ives, 1959; Ives and Prentice, 1959; Ives and Turnock, 1959; and Turnock, 1960). Although the greatest proportionate mortality usually occurs in the cocoon stage of this insect, the largest amount of mortality in terms of absolute numbers occurs between oviposition and the completion of larval feeding. This paper presents a method for estimating seasonal increments to the egg and larval populations and alternative methods for estimating mortality during these stages. Examples are also provided of the integration of these methods with previously developed techniques for estimating egg populations and foliage weight.

Pristiphora erichsonii. [Distribution map].

1959 ◽  
Author(s):  
Keyword(s):  
North America ◽  
Geographical Distribution ◽  
Distribution Map ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
New Distribution ◽  
Distribution In Europe

Abstract A new distribution map is provided for Pristiphora erichsonii (Htg.) (Hymenopt., Tenthredinoidea) (Larch Sawfly). Hosts: Larix spp. Information is given on the geographical distribution in EUROPE (excl. USSR), Austria, Britain, Czechoslovakia, Denmark, Finland, France, Germany, Ireland, Netherlands, Norway, Poland, Rumania, Sweden, ASIA (excl. USSR), Japan, USSR, NORTH AMERICA, Canada, U.S.A.

Estimation of Parasitism of Larch Sawfly Cocoons by Bessa harveyi Tnsd. in Survey Collections

1959 ◽  
Vol 91 (8) ◽  
pp. 496-500 ◽  
Author(s):  
W. G. H. Ives ◽  
R. M. Prentice
Keyword(s):  
Forest Insect ◽  
Small Areas ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Insect Survey ◽  
Forest Biology ◽  
Biology Laboratory ◽  
Total Parasitism

The Forest Insect Survey at the Forest Biology Laboratory, Winnipeg, has been compiling records for a number of years on the percentage of cocoons of the larch sawfly, Pristiphora erichsonii (Htg.), parasitized by the tachinid Bessa harveyi Tnsd. Sawfly cocoons were collected each fall from the soil in infested stands, and those containing living larvae were dissected to determine the percentage of parasitism by B. harveyi. These estimates have been used to provide an index of parasitism (Lejeune and Hildahl, 1954), but are of limited value for a number of reasons: (1) estimates can be expressed only as percentage of sound cocoons parasitized; (2) total parasitism cannot be estimated because a portion of the parasites emerge from the cocoons before collection; and (3) estimates of parasitism may not be representative of the stand because there is a tendency to collect cocoons where they are easiest to find; hence all the cocoons in a collection may be from one or two small areas. If the proportion of cocoons containing B. harveyi varies within a stand such collections may give unreliable estimates of parasitism.

Mortality of Cocoons of the Larch Sawfly, Pristiphora erichsonii (Htg.), in Relation to Distance from Small-Mammal Tunnels

1959 ◽  
Vol 91 (9) ◽  
pp. 535-542 ◽  
Author(s):  
C. H. Buckner
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Natural Mortality ◽  
Mortality Factors ◽  
Forest Reserve ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
The Relationship

The relationship between the fate of cocoons of the larch sawfly, Pristiphora erichsonii (Htg.), and distance from small-mammal tunnels was studied during 1958 in the Whiteshell Forest Reserve of eastern Manitoba. The objects were to determine the distance that small mammals can detect cocoons and to observe possible effects of the interactions of small-mammal predation and other natural mortality factors of the insect. Additional analyses of the data provided information on the behaviour of the predators and the ecology of the prey insect.

larval growth and mortality of japanese spanish mackerel (scomberomorus niphonius) in the central seto inland sea, japan

2005 ◽  
Vol 85 (5) ◽  
pp. 1255-1261 ◽  
Author(s):  
jun shoji ◽  
tsutomu maehara ◽  
m. tanaka
Keyword(s):  
Fish Larvae ◽  
Larval Mortality ◽  
Larval Growth ◽  
Survival Strategies ◽  
Seto Inland Sea ◽  
Larval Feeding ◽  
Spanish Mackerel ◽  
Daily Increments ◽  
Absolute Growth ◽  
Scomberomorus Niphonius

growth and mortality rates of larval japanese spanish mackerel (scomberomorus niphonius) were estimated by using otolith daily increments in 1997 and 1998 in the sea of hiuchi, central seto inland sea. there was no day–night difference in the abundance and size-distribution of s. niphonius larvae in the 3–10 mm size-classes, indicating the larvae were efficiently collected by the larva-net used for sampling (1.3 m mouth diameter, 0.5 mm mesh). mean absolute growth rate (0.748 mm d−1 in 1997, 0.821 mm d−1 in 1998), weight specific growth coefficient (g: 0.402 in 1997, 0.444 in 1998) and mortality coefficient (m: 0.784 in 1997 and 0.625 in 1998) were among the highest reported for marine fish larvae. scomberomorus niphonius seems to have evolved survival strategies characterized by fast growth with strong piscivory that can reduce duration of the larval period with the high mortality. in 1997, spatial distribution of the larvae was not well corresponded to that of their prey, clupeid larvae, and the larval feeding incidence was lower than in 1998. recruitment potential assessed by examining the ratio of g:m was lower in 1997 (0.513 in 1997, 0.711 in 1998) due to the lower g and higher m values. prey fish availability may be one of the important determinants for the recruitment potential by controlling the larval mortality due to starvation and/or starvation-related predation.

VITAL DYES AS MARKERS FOR BEHAVIORAL AND POPULATION STUDIES OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE)

1968 ◽  
Vol 100 (5) ◽  
pp. 470-475 ◽  
Author(s):  
R. J. Heron
Keyword(s):  
Rhodamine B ◽  
Population Studies ◽  
Nile Blue ◽  
Larix Laricina ◽  
Vital Dyes ◽  
Flight Range ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Adult Dispersal ◽  
Dye Retention

AbstractLarvae of the larch sawfly, Pristiphora erichsonii (Htg.), were fed foliage of tamarack, Larix laricina (Du Roi) K. Koch, treated with solutions of the vital dyes, Nile blue sulphate, rhodamine B, and coriphosphine O, to determine their suitability as markers. Coriphosphine O was highly toxic at the concentrations administered but successful tagging was obtained with the other two dyes. Optimal dye retention and survival were obtained when larvae were fed for 3 days early in the last stadium using Nile blue sulphate and throughout the last stadium using rhodamine B.Both dyes persisted throughout development and were incorporated in the cocoons and the oviposited eggs. They could be readily seen in all stages except for the cocoons and for eggs that contained rhodamine B. The dyes could be detected in cocoons by treating them with cold KOH followed by ethanol. The presence of rhodamine B in the eggs could be ascertained by its yellow fluorescence in ultraviolet.The dyes incorporated in the cocoons are relatively stable and laboratory tests indicate they probably can withstand weathering under normal field conditions over a 1-year period.The use of these dyes for internal marking should prove useful in studying adult dispersal and flight range and as a technique for use in population studies of the larch sawfly.

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