SILKING BEHAVIOR OF THE GYPSY MOTH, PORTHETRIA DISPAR

1967 ◽  
Vol 99 (11) ◽  
pp. 1145-1149 ◽  
Author(s):  
David E. Leonard
Keyword(s):  
Gypsy Moth ◽  
Larval Instar ◽  
Diel Periodicity ◽  
First Instar ◽  
Porthetria Dispar ◽  
Late Instar

AbstractAfter feeding, gypsy moth larvae construct a silk mat (resting mat) on which they remain. Prior to molting, this mat is reinforced, or a new, dense mat is constructed (molting mat). Late in the last larval instar, a sparse cocoon is constructed. When larvae are starved, a shift in behavior is noted, with increased locomotion, irritability, and the trailing of a strand of silk as larvae wander. First-instar larvae, quiescent and anchored on resting mats, are not readily induced to spin down on silk threads; hence are not readily dispersed by wind. Hungry first-instar larvae, more apt to be spinning down, are presumed to be more readily dispersed by wind. Larvae which undergo an additional instar have a longer prefeeding phase and might be more readily dispersed than "normal' larvae. The effects of hunger may also cause the shift in diel periodicity of mid- and late-instar larvae, resulting in some dispersal of these larvae away from areas where food will be depleted.

DEVELOPMENT OF NUCLEAR POLYHEDROSIS VIRUS FOR CONTROL OF GYPSY MOTH (LEPIDOPTERA: LYMANTRIIDAE) IN ONTARIO. II. REDUCTION IN DOSAGE AND EMITTED VOLUME (1989 AND 1990)

1993 ◽  
Vol 125 (3) ◽  
pp. 489-498 ◽  
Author(s):  
J.C. Cunningham ◽  
W.J. Kaupp ◽  
R.A. Fleming ◽  
K.W. Brown ◽  
T. Burns
Keyword(s):  
Gypsy Moth ◽  
Inclusion Bodies ◽  
Nuclear Polyhedrosis Virus ◽  
Larval Instar ◽  
Egg Mass ◽  
Current Recommendation ◽  
First Instar ◽  
Untreated Check ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis

AbstractA double application of 1.25 × 1012 (total 2.5 × 1012) polyhedral inclusion bodies (PIB) of Disparvirus (nuclear polyhedrosis virus) in an emitted volume of 10.0 L per ha gave acceptable control of gypsy moth, Lymantria dispar (L.), larvae in 1988. More aerial spray trials were conducted in 1989 and 1990 to test a reduced dosage and volume of Disparvirus. Dosage on all plots, applied when larvae were mainly in their first instar, was a double treatment of 5 × 1011 PIB per ha, 3–5 days apart, giving a total of 1012 PIB per ha. The aqueous tank mix contained 25% (v/v) molasses, 10% (w/v) Orzan LS, and 2% (v/v) Rhoplex B60A sticker. Emitted volumes of 10.0 L per ha and 5.0 L per ha were each tested on three replicated plots in 1989, and 5.0 L per ha and 2.5 L per ha were each tested on three replicated plots in 1990. In both 1989 and 1990, three untreated check plots were paired with treated plots on the basis of pre-spray egg-mass densities.The treatments were assessed by counts of pupae in burlap traps, estimates of defoliation, and change in numbers of egg masses in the treated and check plots. Better control was obtained with the reduced dosage at 10.0 L per ha and 5.0 L per ha than at 2.5 L per ha. Using the aqueous formulation described above, a double application of 5 × 1011 PIB per ha at 5.0 L per ha applied at the peak of the first larval instar is the current recommendation for control of gypsy moth in Ontario using nuclear polyhedrosis virus.

The Influence of Ephestia Kuehniella on the Development of its Parasite Nemeritis Canescens

1968 ◽  
Vol 48 (2) ◽  
pp. 291-304
Author(s):  
SARAH A. CORBET
Keyword(s):  
Protein Concentration ◽  
Freezing Point ◽  
Larval Instar ◽  
Behavioural Response ◽  
Freezing Point Depression ◽  
Rate Of Development ◽  
First Instar ◽  
Rapid Changes ◽  
Fast Development ◽  
Insect Parasites

1. The first larval instar of Nemeritis lasts longer in young caterpillars of Ephestia than it does in older caterpillars. First-instar Nemeritis larvae in young hosts feed and grow very slowly, but they remain capable of fast growth if transferred to older host caterpillars. 2. Measurements of the protein concentration, the amino acid concentration and the freezing-point depression show rapid changes in the composition of the haemolymph of Ephestia caterpillars at that stage of larval development at which they first become capable of supporting the fast development of first-instar larvae of Nemeritis. 3. It is suggested that the rate of development of Nemeritis larvae depends on their rate of feeding, and that their rate of feeding is determined by a behavioural response to the composition of their food, the host's haemolymph; they feed slowly in young host caterpillars because the concentration of solutes (notably amino acids) in their food is so high. 4. A similar situation may hold when the development of insect parasites is delayed in diapausing hosts.

Experimental parasitization of larvae of the gypsy moth, Porthetria dispar (L.), with the entomogenous fungus, Beauveria bassiana (Balsamo) Vuill

Parasitology ◽  
1975 ◽  
Vol 70 (3) ◽  
pp. 341-346 ◽  
Author(s):  
S. S. Wasti ◽  
G. C. Hartmann
Keyword(s):  
Beauveria Bassiana ◽  
Gypsy Moth ◽  
Post Inoculation ◽  
Entomogenous Fungus ◽  
Porthetria Dispar ◽  
Host Penetration ◽  
Fungus Beauveria Bassiana ◽  
Wax Moth

Second-instar larvae of the gypsy moth, Porthetria dispar (L.) were infected with Beauveria bassiana (Balsamo) Vuill. by allowing larvae to crawl over sporulating cultures of the fungus. Virulence of the pathogen was increased by inoculating larvae of the wax moth, Galleria melonella (L.), twice in serial succession. Observations were made on the infectivity and histopathology of the parasite in the host. Penetration of the cuticle occurred 24 h after inoculation and at 64 h post-inoculation the interior was completely filled with hyphae. Penetration of the gut wall was also observed.

scholarly journals Efficacy of Bacillus thuringiensis (Berliner) isolates on fig moth, Ephestia cautella (Walker) Larvae

2014 ◽  
Vol 11 (2) ◽  
pp. 943-951
Author(s):  
Baghdad Science Journal
Keyword(s):  
Bacillus Thuringiensis ◽  
Larval Stage ◽  
Filter Paper ◽  
Larval Instar ◽  
Ephestia Cautella ◽  
Larval Stages ◽  
The Third ◽  
Total Percentage ◽  
First Instar ◽  
Paper Method

The following dilution 5×10-1, 10-1, 10?2 , 10-3 gm/L for the indigenous isolate of Bacillus thuringiensis bacteria and the commercially isalate were used for experiments against the different stages of fig moth of E.cautella which exposed by filter paper method. The results showed that mortality of larval stages was increased with the increasing concentration of the biocide, in addition to increase in the mortality of the larval stages reached to the highest percentage in the third days of treatment of the larval stage in comparison with the first and second days of exposure. The results also showed that the sensitivity of larval stages was increased in first and second instars while reduced in the last instars .The high percentage of first instar mortality for the indigenous isolate in the concentration of 5×10-1 was 72.8% , while the low percentage of mortality showed in the concentration of 5×10-1 for the fifth instar larvae which was 13.3% in third days of treatment while a high percentage of mortality was showed for the first instar larvae for the commercially isulate in the concentration of 5×10-1 was 59.4% Furthermore, low percentage of mortality was shown in the concentration of 5×10-1 in fifth instar larval which was 8.3% in the third days of treatment. The results also showed that the indigenous isolated was more effective than the commercially produced bacteria for killing larval instars of fig moth E.cautella .The total percentage of larval instar mortality reached to 44.5 % after the third days of treatment in concentration 5×10-1 in the indigenous isolate , and it was 33.8 % in the commercially produced bacteria .

scholarly journals NOTES ON PREDACEOUS HETEROPTERA, WITH PROF. UHLER'S DESCRIPTION OF TWO SPECIES

1897 ◽  
Vol 29 (5) ◽  
pp. 115-118
Author(s):  
A. H. Kirkland
Keyword(s):  
Gypsy Moth ◽  
Food Supply ◽  
The Other ◽  
Field Observations ◽  
Large Numbers ◽  
Porthetria Dispar ◽  
The Common ◽  
Tent Caterpillars ◽  
Tent Caterpillar

During the month of May, 1896, while making field observations in Malden and Medford, Mass., upon the insects known to attack the gypsy moth (Porthetria dispar), I found that many of the common predaceous bugs upon emerging from hibernation greedily availed themselves of the food supply offered by the tent caterpillar and destroyed large numbers of this insect. Podisus placidus, P. serieventris, P. modestus, Dendrocoris humeralis, Euschistus fissilis, E. tristigmus, E. ictericus, E. politus n. sp., Menecles insertus and Diplodus lividus were often found feeding upon partially grown tent caterpillars. Podisus placidus and P. serieventris enter the tents and prey upon the inmates, but the other species generally attacked the larvæ while they were feeding. The species of Euschistus are the least predaceous and it is probable that they naturally feed more upon plants than upon insects.

PRE-MATING SEXUAL ACTIVITY OF GYPSY MOTH MALES IN SMALL PLOT FIELD TESTS (LYMANTRIA (= PORTHETRIA) DISPAR (L.): LYMANTRIIDAE)

1976 ◽  
Vol 108 (4) ◽  
pp. 439-448 ◽  
Author(s):  
J. V. Richerson ◽  
E. A. Brown ◽  
E. Alan Cameron
Keyword(s):  
Gypsy Moth ◽  
Sexual Communication ◽  
Field Tests ◽  
Baited Traps ◽  
Gypsy Moths ◽  
Porthetria Dispar ◽  
Relative Attractiveness ◽  
Small Plot ◽  
Previous Mating ◽  
Cotton Wick

AbstractPre-mating behavior of male gypsy moths was investigated in 0.2 ha circular plots containing from 0 to 72 virgin females/plot in untreated areas and in areas treated with an aerial application of 20 g/ha microencapsulated disparlure. Male moths in both treated and untreated plots oriented initially to trees, not directly to females. Mating was disrupted in treated plots but males continued search behavior. No anemotactic behavior was evident in either treated plots or untreated plots with females. In untreated plots, male moths were not caught on sticky panels (panels suspended at 2, 4, and 6 m) higher than pheromone baited traps set at 2 m. In treated plots, equal number of males were caught at all panel heights and in baited traps at 2 m. Previous mating and pheromone exposure histories of males did not affect the response of these males to traps baited with 4–5 mg of disparlure in untreated plots. In a test of the relative attractiveness of a cotton wick and a new laminated bait dispenser in Johnson traps, traps baited with the laminated dispenser had a greater male moth catch/male contact to trap than the traps baited with the cotton wick. Not all males contacting the Johnson trap were caught. A mode of action for disparlure as a disruptive agent in the long range sexual communication system of gypsy moth is proposed.

Population phenology of whitefringed weevil, Graphognathus leucoloma (Coleoptera: Curculionidae), in pasture in a Mediterranean-climate region of Australia

1991 ◽  
Vol 81 (3) ◽  
pp. 283-289 ◽  
Author(s):  
J. N. Matthiessen
Keyword(s):  
Mediterranean Climate ◽  
Larval Growth ◽  
Winter Period ◽  
Larval Recruitment ◽  
Climate Region ◽  
Spring Period ◽  
First Instar ◽  
Late Instar ◽  
One Year ◽  
The One

AbstractIn undisturbed annual pasture in a Mediterranean-climate region of Australia adults of the whitefringed weevil, Graphognathus leucoloma (Boheman), were present from summer to early winter (December–June), with upsurge in numbers of first instar larvae only occurring after the rains began in April. The G. leucoloma population was predominantly first instar larvae in high abundance throughout the winter period (May–August). Larval growth, with high mortality, occurred in the spring period (September–January). The survival of eggs during the dry summer when adults were most abundant, although only at times of unseasonal rainfall, indicated that low larval recruitment at that time resulted primarily from the absence of high-quality legume food essential for oogenesis. It was inferred that most larvae arose from heavy oviposition by the few adults present in autumn when rainfall germinated annual legumes. A steady year-round abundance of late-instar larvae indicated that not all individuals completed their development in the one year.

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