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

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.

Parasitology ◽  
1975 ◽  
Vol 70 (3) ◽  
pp. 341-346 ◽  
Author(s):  
S. S. Wasti ◽  
G. C. Hartmann

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.


1897 ◽  
Vol 29 (5) ◽  
pp. 115-118
Author(s):  
A. H. Kirkland

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.


1964 ◽  
Vol 57 (6) ◽  
pp. 986-990 ◽  
Author(s):  
P. A. Godwin ◽  
H. D. Rule ◽  
W. E. Waters

1992 ◽  
Vol 27 (3) ◽  
pp. 280-284 ◽  
Author(s):  
B. A. Leonhardt ◽  
V. C. Mastro ◽  
E. D. DeVilbiss

Seven controlled-release dispenser formulations containing 500 μg of gypsy moth pheromone (+)-disparlure, were compared in laboratory and field tests. Pheromone release rates, residual pheromone contents, and male moth captures in traps baited with the dispensers were compared following pre-aging of the dispensers in a greenhouse at 35 °C for 0, 4, 12, and 16 wk. The laminate dispenser, now used in USDA detection traps, became less attractive over time as its pheromone release rate and content dropped below the threshold values previously reported as necessary for effective attraction. A polyvinyl chloride coated twine dispenser produced high male moth captures and gave release rates and residual contents above these thresholds (30 ng/h release rate and 100 μg content) at all aging periods. The tube-A dispenser was the most effective of the new commercially prepared formulations, followed by the membrane and tube-B whose male moth captures and release rates tended to increase with aging time. The capsule and film dispensers were the least effective of the formulations tested.


1967 ◽  
Vol 99 (11) ◽  
pp. 1145-1149 ◽  
Author(s):  
David E. Leonard

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.


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