DIFFERENCES IN POSTDIAPAUSE DEVELOPMENT AMONG GEOGRAPHICALLY DISTINCT POPULATIONS OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE)

1972 ◽  
Vol 104 (8) ◽  
pp. 1307-1312 ◽  
Author(s):  
R. J. Heron
Keyword(s):  
Relative Humidity ◽  
Northwest Territories ◽  
Cold Treatment ◽  
Adult Emergence ◽  
Population Differences ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
C 50 ◽  
The Times ◽  
Prolonged Diapause

AbstractDistinct differences were observed in postdiapause development and prolonged diapause of the larch sawfly, Pristiphora erichsonii (Hartig), obtained from the vicinity of Tazin River, Northwest Territories; near Riverton, Manitoba; and near Renovo, Pennsylvania. All populations had been reared under controlled laboratory conditions (21°±0.5 °C, 50±10% relative humidity, and a 15-hr daily photophase) for two or more generations.After 280 days cold treatment at 3°±1 °C, cocoons were dissected and the number of pronymphs and eonymphs was determined. Insects from each population were then reared at 5°, 10°, and 15 °C. Times to adult emergence, duration of individual stages, and numbers remaining in prolonged diapause at each temperature were determined.The most significant differences occurred among populations reared at 5 °C. At this temperature, the times to adult emergence and the duration of individual stages of development and the proportions remaining in prolonged diapause or arrested development, increased from northern to southern latitudes. Less significant population differences were noted at 10° and 15° than at 5 °C.

HEAT TOLERANCE OF LAST-INSTAR LARVAE OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE)

1967 ◽  
Vol 99 (11) ◽  
pp. 1150-1156 ◽  
Author(s):  
R. J. Heron
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Heat Tolerance ◽  
Free Water ◽  
Temperature Acclimation ◽  
Mortality Factor ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Conditioning Temperature

AbstractLaboratory tests of heat tolerance of last-instar larvae of the larch sawfly, Pristiphora erichsonii (Htg.), were made to provide information for the evaluation of the role of high temperature as a mortality factor in field populations.Test larvae were reared from eggs at 21 ± 1.5 °C and 50 ± 10% relative humidity. LT50's were determined at 37°, 39°, 40°, and 41 °C for larvae conditioned at 30 °C and 75% relative humidity.Larvae were less heat resistant during the first 24 hours after molting than they were 24 to 48 hours after molting. The conditioning temperature and the duration of conditioning had very significant effects on heat tolerance. Differences in acclimation due to heat treatment could not be accounted for by differences in free water content.Temperature acclimation will occur in field populations and must be considered in evaluating the role of high temperature as a natural mortality factor.Larvae may encounter lethal temperatures when wandering on branches or tree trunks or crawling on dry ground in open sunshine.

Effects of Water Levels on the Overwintering Survival and Emergence of the Larch Sawfly in a Bog Habitat

1966 ◽  
Vol 98 (7) ◽  
pp. 768-777 ◽  
Author(s):  
W. G. H. Ives ◽  
L. D. Nairn
Keyword(s):  
Water Table ◽  
Adult Emergence ◽  
Water Levels ◽  
Pristiphora Erichsonii ◽  
Late Fall ◽  
Water Tables ◽  
Larch Sawfly ◽  
Maximum Water ◽  
Different Depths ◽  
Overwintering Survival

AbstractThe effects of fluctuating water tables on the survival of the larch sawfly, Pristiphora erichsonii (Hartig) (Hymenoptera: Tenthredinidae), were studied by burying cocoons at different depths in a tamarack bog. Most larvae in cocoons flooded during August or September died before winter. The percentage of overwintering survival of unflooded cocoons remained constant from late fall until development began in the spring. The higher the cocoons were above the maximum water table during August and September, the greater was the percentage of overwintering survival and subsequent adult emergence.

A Trap for Insects Emerging from the Soil

1957 ◽  
Vol 89 (10) ◽  
pp. 455-456 ◽  
Author(s):  
W. J. Turnock
Keyword(s):  
Seasonal Pattern ◽  
Adult Emergence ◽  
Ecological Studies ◽  
Emergence Period ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Require Information

The larch sawfly, Pristiphora erichsonii (Htg.), overwinters in a cocoon in the ground and has an adult emergence period that may last two months. Ecological studies of this insect require information on the number of adults emerging and the seasonal pattern of emergence. Several types of open-bottomed screen emergence cages without traps were tested but the insects caught in such cages were difficult to remove. Also, many of the adults were lost in the vegetation unless the cages were visited more frequently than was practicable. The trap described here, attached to a screen cage, eliminates the objections given above and could be of use to persons interested in insects which emerge from the soil.

DETERMINATION OF PREMATURE LARVAL DROP AND OTHER CAUSES OF LARCH SAWFLY MORTALITY

1967 ◽  
Vol 99 (11) ◽  
pp. 1121-1131 ◽  
Author(s):  
W. G. H. Ives
Keyword(s):  
Adult Emergence ◽  
Large Data ◽  
Curvilinear Relationship ◽  
First Year ◽  
Larval Weight ◽  
Linear Relationships ◽  
Larch Sawfly ◽  
Key Factor ◽  
Causes Of Mortality ◽  
Prolonged Diapause

AbstractFifth-instar larvae of the larch sawfly, Pristiphora erichsonii (Hartig), of different weights, were deprived of food and placed in containers with moist moss. A low percentage of the early fifth-instar larvae were able to spin cocoons, but the percentage rapidly increased to a plateau as the larval weight increased. All but the heaviest larvae suffered appreciable mortality before first-year adult emergence was complete. A curvilinear relationship between larval weight and survival to the adult stage or to larvae in prolonged diapause is evident. The percentage of mature ova in adult females was reduced at the lower larval weights, with corresponding increases in the percentages of near-mature and large immature ova. There were linear relationships between larval weights, adult weights, and numbers of oöcytes. A method for assessing premature larval drop and other causes of mortality under field conditions is described and data for a number of years and plots are presented. Variations in the percentages of unparasitized normal late fifth-instar larvae were large. Data indicate that parasitism by Olesicampe (Holocremnus) sp. nr. nematorum (Tschek) and Bessa harveyi (Townsend) is the most important factor, probably a key factor, contributing to this variation.

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.

DISINFESTATION OF MANGOES HADEN IN-FESTED BY Anastrepha fraterculus (WIED., 1830) (DIPTERA, TEPHRITIDAE), WITH GAMMA RADIATION

2021 ◽  
Vol 9 (1A) ◽  
Author(s):  
Valter Arthur
Keyword(s):  
Relative Humidity ◽  
Radiation Dose ◽  
Gamma Radiation ◽  
Adult Stage ◽  
Mangifera Indica ◽  
Lethal Dose ◽  
Adult Emergence ◽  
Climate Chamber ◽  
Anastrepha Fraterculus

The objective of experiment was determinate the radiation dose for disinfestation to mango Mangifera indica cv. Haden, infested by Anastrepha fraterculus larvae. For realization of the experiment, were collected fruits in the field, which were taking to Entomology laboratory where there was a infestation by the flies in cages during 72 hours period. Waited for the development of the larvae and before 5 – 8 days to infestation, the mangos were irradiated in a Cobalt-60 source with doses of: 0(control), 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1.100, 1.200 and 1.300 Gy. After the irradiation, the fruits were placed in climate chamber with 25 ±5°C of temperature and 70±5% of relative humidity, posteriorly waited the larvae exit to out of the fruit until the transformation in pupae and posteriorly in adult stage. By the results obtained our can concluded that the lethal dose to larvae in mangoes infested with 5-8 days after infestation were 600 Gy and 1.000 Gy (0.6 and 1 kGy) respectively. The dose of 50 Gy prevented the total adult emergence for both treatments. 

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.

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