RESISTANCE TO PYRAZOPHOS IN THE SERPENTINE LEAFMINER LIRIOMYZA TRIFOLII (BURGESS) (DIPTERA: AGROMYZIDAE) IN ONTARIO GREENHOUSES

1989 ◽  
Vol 121 (1) ◽  
pp. 47-53 ◽  
Author(s):  
A.B. Broadbent ◽  
D.J. Pree
Keyword(s):  
Organophosphorus Compound ◽  
Cross Resistance ◽  
Liriomyza Trifolii ◽  
Diethyl Maleate ◽  
Triphenyl Phosphate ◽  
Southern Ontario ◽  
Serpentine Leafminer ◽  
Control Failures

AbstractIn 1986 a greenhouse population of Liriomyza trifolii (Burgess) was shown to be highly resistant (155-fold at LC50) to the organophosphorus compound pyrazophos. However in 1987, the same population had only 35–40% resistant individuals remaining. A survey in 1986 of five other greenhouses reporting leafminer control failures indicated three other resistant populations in southern Ontario. Resistance was not affected by the addition of the synergists diethyl maleate or triphenyl phosphate to pyrazophos. Cross-resistance to the phosphorothioate insecticides demeton, chlorpyrifos, and triazophos was indicated.

Occurrence of resistance to insecticides in populations of the obliquebanded leafroller from orchards

2001 ◽  
Vol 133 (1) ◽  
pp. 93-103 ◽  
Author(s):  
D.J. Pree ◽  
K.J. Whitty ◽  
M.K. Pogoda ◽  
L.A. Bittner
Keyword(s):  
Cross Resistance ◽  
Choristoneura Rosaceana ◽  
Southern Ontario ◽  
Obliquebanded Leafroller ◽  
Selection For ◽  
Production Areas ◽  
Neonate Larvae ◽  
Control Failures ◽  
Wild Hosts ◽  
Laboratory Bioassays

AbstractThe occurrence and distribution of resistance to insecticides in populations of the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), from apple, Malus × domestica Borkhauser (Rosaceae), and pear, Pyrus communis L. (Rosaceae), orchards in the various production areas of southern Ontario were assessed in the laboratory and field from 1993 to 1999. Laboratory bioassays were conducted with neonate larvae from the first laboratory generation. Responses of populations from commercial orchards where control failures had occurred or where populations were large or damaging were compared with populations from unsprayed wild hosts. Resistance to azinphosmethyl and to pyrethroids and methomyl was identified in populations from all areas. Resistance levels ranged from 4- to 27-fold for azinphosmethyl, 4- to 8-fold for cypermethrin (a representative pyrethroid), and 3- to 5-fold for methomyl. In the field, deltamethrin was more effective than azinphosmethyl against a population resistant to both insecticides. Resistance to azinphosmethyl was unstable and rapidly declined in a population newly established in the laboratory and not selected with azinphosmethyl. After selection for nine generations, resistance declined only slowly when selection pressure was removed for four generations. This instability may be exploited in the management of resistance, but the possible cross-resistance between azinphosmethyl and pyrethroids needs clarification.

Differential Probing Response of Serpentine Leafminer, Liriomyza trifolii (Burgess), on Cos Lettuce

1994 ◽  
Vol 29 (3) ◽  
pp. 330-338 ◽  
Author(s):  
Gregg S. Nuessly ◽  
Russell T. Nagata
Keyword(s):  
Lactuca Sativa ◽  
Leaf Surface ◽  
The Other ◽  
Leafy Vegetables ◽  
Liriomyza Trifolii ◽  
Romaine Lettuce ◽  
Lactuca Sativa L ◽  
Leaf Mining ◽  
Choice Tests ◽  
Serpentine Leafminer

Leaf mining damage by serpentine leafminers, Liriomyza trifolii (Burgess) (Diptera: Agromyzidae), is a major problem of many leafy vegetables especially lettuce. A hierarchy of leaf probing preference by L. trifolii on romaine lettuce (Lactuca sativa L.) cultivars ‘Floricos 83’ (FC), ‘Parris Island Cos’ (PI), ‘Tall Guzmaine’ (TG), and ‘Valmaine’ (VL) was determined. Based on stipple counts (puncture wounds in the leaf surface), L. trifolii preferred TG by an experiment-wide average of 3:1 over the other cultivars. In choice tests where L. trifolii were able to select their preferred cultivar, TG was preferred 2.2:1 to 5.5:1 over the over varieties. On 12-leaf stage TG plants, eight female flies produced means ± SEM of 664.2 ± 165.8, 1,581.8 ± 333.8, and 2,084.5 ± 242.6 stipples per plant after 24, 48, and 72 h exposures, respectively. Preference for TG was maintained in no-choice tests where TG was preferred 1.8:1 to 2.6:1 over the other cultivars. Stipple counts on FC, PI, and VL did not vary significantly between choice and no-choice tests, but nearly twice as many stipples per plant were found on TG in choice than in no-choice tests. More probing occurred on all cultivars on the youngest fully expanded leaves in the middle of the plants than on leaves toward the bottom or top of the plants. Preference for these middle leaves was more pronounced on TG than on the other cultivars. The differences in stipple rates followed the pedigrees of the cultivars tested. The character(s) preferred by L. trifolii were apparently introduced into the lineage with a cross to ‘Paris White.’

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