Modification of pheromonal behaviour in wild Coleophora laricella male moths by (Z)-5-decenyl acetate, an attraction-inhibitor

2009 ◽  
Vol 98 (1-5) ◽  
pp. 118-135 ◽  
Author(s):  
E. Priesner ◽  
P. Witzgall
1967 ◽  
Vol 99 (3) ◽  
pp. 326-331 ◽  
Author(s):  
F. W. Quednau

AbstractChrysocharis laricinellae (Ratz.) mated readily in the laboratory when several individuals of both sexes were held together in a vial. The courtship dance performed by the male is described. Parasite females develop mature eggs 3 days after emergence and are apparently capable of resorbing the eggs if hosts are not available, and to produce new ones after host-feeding. Storage of eggs in the ovary for 5 months at 55°F and sterility (phasic castration) of certain individuals is reported. Longevity of egg-laying females at 75°F was about 1 month less than that of parasites that had been denied contact with hosts. Odor apparently plays little or no role in the location of the larch casebearer larvae by C. laricinellae, but chemical surface stimuli seem to exist on the surface of a mine or case of Coleophora laricella (Hbn.). The parasite is also stimulated by vibrations of the host in its case. The oviposition and host-feeding pattern of C. laricinellae is described. Host-feeding on fourth-instar larvae of the larch casebearer contributed little to host mortality.


1988 ◽  
Vol 64 (3) ◽  
pp. 190-192 ◽  
Author(s):  
Paul Benoit ◽  
Robert Blais

Tamarack (Larix laricina [DuRoi] K. Koch) was severely defoliated by the larch casebearer (Coleophora laricella) in most areas of Quebec during 1979 and 1980. Increment core samples were taken in late September 1982 from 20 tamaracks in each of two stands to determine the effect of defoliation on radial growth. In one stand, the trees were 80% defoliated in 1980 and during this year radial growth was reduced by 52%. Growth returned to predefoliation level the following year when the trees were not defoliated. In the other stand, trees were 60% defoliated in 1979 and 70% in 1980. During these years, radial growth was reduced by 48 and 70% respectively. Growth in this stand had not fully returned to predefoliation level two years after the collapse of the infestation. In both stands, variations in defoliation among trees did not exceed 10% of the average. Key Words: Coleophora laricella, larch casebearer, tamarack, larch, defoliation.


2006 ◽  
Vol 138 (2) ◽  
pp. 218-227 ◽  
Author(s):  
R.M. Trimble ◽  
Ashraf M. El-Sayed

AbstractThe effect of certain monounsaturated dodecene and tetradecene acetates and alcohols on electroantennogram (EAG) response and pheromone-mediated trap catch was examined in male obliquebanded leafroller moths, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). The stimulation of antennae with 0.1 ng of (Z)-11-tetradecenyl acetate (Z11-14:Ac), the major pheromone compound of this species, elicited an EAG response. The use of 1 ng of (Z)-9-tetradecenyl acetate (Z9-14:Ac) or (E)-9-tetradecenyl acetate (E9-14:Ac) or 10 ng of (Z)-9-dodecenyl acetate (Z9-12:Ac) or (E)-9-dodecenyl acetate (E9-12:Ac) was required to elicit a response. One hundred nanograms of (E)-9-tetradecenol (E9-14:OH) were required to elicit a response from antennae. The stimulation of antennae with up to 100 ng of (Z)-9-tetradecenol (Z9-14:OH) did not elicit a response. The addition of 0.1 mg of Z9-12:Ac to 1 mg of synthetic C. rosaceana pheromone consisting of a 100:2:1.5:1 blend of Z11-14:Ac, (E)-11-tetradecenyl acetate, (Z)-11-tetradecenol, and (Z)-11-tetradecenal reduced the capture of moths in pheromone-baited traps by more than 72%. Trap catch was reduced by more than 90% by the addition of 0.01 mg of Z9-14:Ac or E9-14:Ac to 1 mg of C. rosaceana pheromone. There was no detectable reduction in trap catch when 1 mg of E9-12:Ac, Z9-14:OH, or E9-14:OH was added to 1 mg of C. rosaceana pheromone. There was a greater than 95% reduction in trap catch when sources of Z9- or E9-12:Ac were mounted at the entrances to traps, 10 cm from the pheromone source. Trap catch was not affected by placing sources of Z9- or E9-14:Ac at trap entrances. Four 1 or 10 mg sources of E9-14:Ac placed 1 m from a trap did not affect the number of male C. rosaceana captured. The study demonstrates that although a compound may have profound attraction inhibiting activity when mixed directly with C. rosaceana pheromone, this activity may be lost if the inhibitor is emitted a short distance from the pheromone. The study also demonstrates that a potent attraction inhibitor such as E9-14:Ac does not repel C. rosaceana males and must be present along with pheromone to affect the behavior of this species.


1988 ◽  
Vol 120 (11) ◽  
pp. 1035-1036
Author(s):  
R.B. Ryan

In an attempt to control the larch casebearer, Coleophora laricella (Hübner), in western North America with biological agents, insect parasites from Europe and Japan were introduced (Denton 1972, 1979; Ryan et al. 1987). The braconid Agathis pumila (Ratz.) has become widely established and apparently has been responsible for markedly reduced casebearer densities (Ryan 1983, 1986; Ryan et al. 1987). Parasitization by it in many research plots reached 80-95% (unpublished data), then declined following reductions in the casebearer populations in a typically delayed density-dependent manner. I present here a partial explanation for why casebearer densities declined so drastically, to levels even lower than could perhaps be explained by parasitization at such high levels.


1967 ◽  
Vol 99 (4) ◽  
pp. 397-401 ◽  
Author(s):  
F. W. Quednau

AbstractMating in Coleophora laricella (Hbn.) took place 1 or 2 days after emergence and was stimulated by decreasing light intensity ranging from 3000 ft-c to 200 ft-c within 2 hours. The female is pro-ovigenic, with peak opposition during the first week. Optimum temperature for egg laying was 70 to 80°F; the average number of eggs deposited was about 66; average longevity of female adults was about 10 days at room temperature, but considerably longer at lower temperatures. A few eggs were laid at 50° and 95°F. Incubation period of the eggs was 12 days at 80° to 85°F and 40 days at 55°F. Hatching of eggs did not occur above 85°F or below 55 °F.


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