THE IMPORTANCE OF PHEROMONE TRAP DENSITY AND TRAP MAINTENANCE FOR THE DEVELOPMENT OF STANDARDIZED MONITORING PROCEDURES FOR THE CODLING MOTH (LEPIDOPTERA: TORTRICIDAE)

1980 ◽  
Vol 112 (7) ◽  
pp. 655-663 ◽  
Author(s):  
Helmut Riedl

AbstractPheromone trap density is one factor which influences the magnitude of catch and therefore, should be standardized in a monitoring program. Trap catch increased with the area served by a trap, but reached a plateau when the trap density fell below one trap per 7 ha. From these data a quadratic regression was developed which relates the relative increase in trap catch to trap area. This relationship can be used to compare monitoring data obtained with different trap densities.The number of moths previously caught in a sticky trap can affect its future performance. In the Pherocon® 2 trap catches began to decline after a cumulative total of 20 to 30 moths and in the Pherocon 1CP after 50 to 70 moths. The catch totals causing a drop in trapping efficiency were correlated with the size of the adhesive catch surface. The cause for the loss in trapping efficiency appeared to be physical deterioration of the adhesive due to moth scales, other insect parts, or dust rather than an olfactory repellent factor. Trapping efficiency was restored by thoroughly stirring the soiled adhesive. Standard maintenance procedures should be followed to keep the adhesive quality of the catch surface constant and thereby prevent a reduction in catches. Tests with two pheromone dispensers, the Codlemone® rubber septum and the Conrel® microfibres, indicated that both are effective for at least 6 weeks. Codlemone septa resulted in higher catches during the first week of field use. During subsequent weeks there was no difference in attractiveness between the two pheromone lures.

1976 ◽  
Vol 108 (5) ◽  
pp. 449-460 ◽  
Author(s):  
Helmut Riedl ◽  
B. A. Croft ◽  
A. J. Howitt

AbstractThe relationship of pheromone trap catch to emergence and oviposition of the codling moth was defined for the two-generation climate of Michigan. Catch anticipated emergence and oviposition during spring flight when the trap displayed greatest efficiency, but lagged behind emergence and closely followed oviposition during the second generation. Trapping efficiency declined towards the end of the first generation and was generally lower during summer flight. Factors which possibly relate to this efficiency loss are discussed. First catch and the catch peaks in both generations were evaluated as reference points for the prediction of phenological events (particularly egg hatch) in both generations Of four forecasting methods, degree day and developmental unit summations, starting from first catch, for the preoviposition and incubation period were most reliable in predicting the beginning of spring brood egg hatch.


1974 ◽  
Vol 106 (5) ◽  
pp. 525-537 ◽  
Author(s):  
H. Riedl ◽  
B. A. Croft

AbstractA sex pheromone trap was studied as a quantitative sampling device in a biological monitoring scheme for codling moth populations in Michigan apple orchards. Factors influencing trap efficiency and the relationship of trap catch to adult moth density and the overall seasonal dynamics of L. pomonella are considered.By correlating seasonal male moth catches to absolute infestation levels at harvest it was possible to indicate the density response of male moth catches in the pheromone trap (Sectar 1). Catch response was non-linear and the trap ceased to be indicative of higher infestation levels when accumulative catch exceeded about 100 moths/trap. Also, accumulative trap catches from the first few weeks of the season (before damage appeared) correlated well with eventual infestation levels indicating possible use of the pheromone trap as a predictive tool. Of the many factors influencing trap catch size the number of moth productive trees serviced by a trap (trap/tree ratio) was shown to be of critical importance.


1995 ◽  
Vol 85 (4) ◽  
pp. 463-472 ◽  
Author(s):  
M.C.A. Downham ◽  
L.J. McVeigh ◽  
G.M. Moawad

AbstractA series of trials examining the feasibility of an attracticide technique for control of Spodoptera littoralis (Boisduval) are described. The technique combined the sex pheromone of S. littoralis with pyrethroid insecticide, λ-cyhalothrin, in 500 point-sources/ha at low rates of application of both components. It was envisaged that male moths would be attracted to contact the sources and subsequently suffer lethal or sub-lethal effects which would prevent mating. The pheromone was applied either as a sprayable microencapsulated (MC) formulation or in polyvinyl-chloride lures; emulsifiable concentrate and MC formulations of the insecticide were employed. Treatments were assessed by monitoring pheromone trap catches, mating of tethered females and, in one trial, numbers of eggmasses found in experimental areas. Mating levels and trap-catch in treatment plots were siginificantly reduced, compared to controls, for periods up to 5 and 24 nights after treatment, respectively. However despite a continuous period of mating suppression, achieved by repeated applications, no treatment-related reduction in egg-masses was observed. Two trials compared attracticide with mating-disruption treatments in which the insecticide was omitted. Similar levels of mating and trap-catch suppression were observed in the two treatments. It was concluded that the mating suppression observed in attracticide plots was due principally to disruption of chemical communication between the sexes, not to male mortality arising from contact with the insecticide sources. None of the attracticide treatments represented a viable control technique. Other practical and theoretical considerations arising from the results are discussed.


2017 ◽  
Vol 9 (1) ◽  
pp. 18-30
Author(s):  
Barbara Némethné Major ◽  
Rita Ledóné Ábrahám ◽  
Erzsébet Enzsöl ◽  
Gábor Jenser

Abstract Considerable damage caused by the red-belted clearwing was observed in the biologically controlled apple orchard. In all cases, the larvae were found in the tumourlike tissue proliferations developing at the grafting point of the rootstock (M9) and scion, while no larva was found in crowns and cut surfaces. Samplings involving different cultivars were implemented in two apple orchards; in Bősárkány, where trees are grafted on M9 rootstocks and tumours were found at grafting points, and in Mosonmagyaróvár, where trees are grafted on M26 rootstocks and no proliferations were found at graft unions. During the aforementioned samplings, the numbers of larvae living in the tissue proliferations were counted, the sizes of tumours were measured, and the flight dynamic of adult clearwings was investigated. Research results reveal that damage caused by the clearwing larvae was only observed in trunks with tumour-like disorders (Bősárkány), where feeding larvae were found in 15.3% of the examined trunks in cultivar Royal Gala, 4.6% in Idared, 2.6% in Jonagold, and 1.3% in Florina. We investigated whether there is a correlation between the size of tumours and the degree of damage. The highest rate of proliferations was found on cultivar Florina, where only a minimum degree of damage was experienced. The lowest rate of proliferations was observed on cultivar Gala, which suffered the highest degree of damage done by clearwing larvae. According to sex-pheromone trap catches, the flight period of male clearwings occurred simultaneously in both studied orchards from mid-May to mid-August. On the basis of scent trap catch results, however, it has to be highlighted that females were only present at the Bősárkány research site. It is assumed that the absence of females in the Mosonmagyaróvár orchard can be attributed to the fact that they did not find such suitable oviposition sites as tissue proliferations. Hence, egg-laying and damage caused by the larvae did not happen there either.


2003 ◽  
Vol 93 (2) ◽  
pp. 107-113 ◽  
Author(s):  
A. Cork ◽  
S.N. Alam ◽  
F.M.A. Rouf ◽  
N.S. Talekar

AbstractDelta and wing traps baited with synthetic female sex pheromone of Leucinodes orbonalis Guenée were found to catch and retain ten times more moths than either Spodoptera or uni-trap designs. Locally-produced water and funnel traps were as effective as delta traps, although ‘windows’ cut in the side panels of delta traps significantly increased trap catch from 0.4 to 2.3 moths per trap per night. Trap catch was found to be proportional to the radius of sticky disc traps in the range 5–20 cm radius, discs with a 2.5 cm radius caught no moths. Wing traps placed at crop height caught significantly more moths than traps placed 0.5 m above or below the crop canopy. Replicated integrated pest management (IPM) trials (3 × 0.5 ha per treatment) were conducted in farmers fields with young and mature eggplant crops. Farmers applied insecticides at least three times a week in all check and IPM plots. In addition pheromone traps were placed out at a density of 100 per ha and infested shoots removed weekly in the 0.5 ha IPM plots. Pheromone trap catches were reduced significantly from 2.0 to 0.4 moths per trap per night respectively in check and IPM plots in a young crop and 1.1 to 0.3 moths per trap per night in check and IPM plots respectively in a mature crop. Fruit damage was significantly reduced from an average of 41.8% and 51.2% in check plots of young and mature crops respectively to 22% and 26.4 respectively in the associated IPM plots. Significant differences in pheromone trap catches and fruit damage were attained four and two weeks respectively after IPM treatments began in the mature crop whereas in the immature crop significant differences were not observed for the first eight to nine weeks respectively. The relative impact of removing infested shoots and mass trapping on L. orbonalis larval populations was not established in these trials but in both cases there was an estimated increase of approximately 50% in marketable fruit obtained by the combination of control techniques compared to insecticide treatment alone.


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