AN ACTION THRESHOLD FOR CONTROL OF LEPIDOPTEROUS PESTS OF CABBAGE IN PRINCE EDWARD ISLAND

1994 ◽  
Vol 126 (2) ◽  
pp. 379-387 ◽  
Author(s):  
Andrew P. Dornan ◽  
Jeff G. Stewart ◽  
Mark K. Sears
Keyword(s):  
Plutella Xylostella ◽  
Trichoplusia Ni ◽  
Prince Edward Island ◽  
Growth Stage ◽  
Pieris Rapae ◽  
Diamondback Moth ◽  
Cabbage Looper ◽  
Fresh Market ◽  
Action Threshold ◽  
Insect Populations

AbstractAction thresholds for imported cabbageworm, Pieris rapae (L.), diamondback moth, Plutella xylostella (L.), and cabbage looper, Trichoplusia ni (Hübner), were evaluated on two cultivars of cabbage, Brassica oleracea var. capitata (L.), in Prince Edward Island. Thresholds were tested on plots of mid-season cabbage, cv. Minicole, and late-season cabbage, cv. Lennox, both grown for fresh market in 1991 and 1992. Management of larval populations at a threshold of 0.25 Cabbage Looper Equivalents (CLE) per plant resulted in yields equal to those obtained with bi-weekly applications or grower treatments. Higher thresholds of 0.50 and 1.0 CLE per plant were not as useful and did’ not consistently result in yields greater than untreated plots. Use of the threshold of 0.25 CLE per plant reduced the number of applications of insecticides by 30% compared with spraying insecticide at bi-weekly intervals from heading to harvest, and 43% compared with management by the grower without regard to insect populations or growth stage of the crop.

APPLICATION OF THE CABBAGE LOOPER EQUIVALENT MODEL TO LEPIDOPTEROUS PESTS OF BRUSSELS SPROUTS IN PRINCE EDWARD ISLAND

1994 ◽  
Vol 126 (4) ◽  
pp. 961-969 ◽  
Author(s):  
Andrew P. Dornan ◽  
Jeff G. Stewart ◽  
Mark K. Sears
Keyword(s):  
Trichoplusia Ni ◽  
Prince Edward Island ◽  
Pieris Rapae ◽  
Diamondback Moth ◽  
Management Strategies ◽  
Abundant Species ◽  
Cabbage Looper ◽  
Equivalent Model ◽  
Brussels Sprouts ◽  
High Yields

AbstractAn investigation into the use of thresholds based on Cabbage Looper Equivalents (CLE) was conducted on Brussels sprouts, Brassica oleracea var. gemmifera (L.), cv. Valiant, grown in Prince Edward Island in 1991 and 1992. The CLE model was used to equate foliage consumption by larvae of the imported cabbageworm, Pieris rapae (L.), the diamondback moth, Plutella xylostella (L.), and the cabbage looper, Trichoplusia ni (Hübner). Management strategies included the following: (1) an untreated check; applications of insecticides after thresholds of (2) 1.0 CLE; (3) 0.50 CLE; or (4) 0.25 CLE per plant were exceeded; (5) bi-weekly applications of insecticides; and (6) applications of insecticides according to the grower’s spray schedule.In 1991, the imported cabbageworm was the most abundant species in the complex attacking the crop and high yields were obtained in all treatments. However, in 1992, the diamondback moth was the principal species and significantly reduced marketable yields in all treatments. Use of CLE as a model for threshold determination in the crop of Brussels sprouts underestimated the potential of the diamondback moth for damage and resulted in improper timing of applications of insecticide for adequate control of the diamondback moth.

A Long-Term Survey of Parasitoid Species Composition and Parasitism of Trichoplusia ni (Lepidoptera: Noctuidae), Plutella xylostella (Lepidoptera: Plutellidae), and Pieris rapae (Lepidoptera: Pieridae) in Minnesota Cabbage

2005 ◽  
Vol 40 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Suzanne J. Wold-Burkness ◽  
W. D. Hutchison ◽  
Jana C. Lee ◽  
R. L. Hines ◽  
P. C. Bolin ◽  
...  
Keyword(s):  
Species Composition ◽  
Plutella Xylostella ◽  
Trichoplusia Ni ◽  
Pieris Rapae ◽  
Diamondback Moth ◽  
Species Abundance ◽  
Cabbage Looper ◽  
Cotesia Glomerata ◽  
Pest Species ◽  
Pupal Parasitoids

Field studies were conducted near Rosemount, MN, during the years 1991–1994, 1996–1997, and 1999–2003, to assess the diversity of and parasitism by larval and pupal parasitoids of cabbage looper, Trichoplusia ni (Hübner), imported cabbageworm, Pieris rapae (L.), and diamondback moth, Plutella xylostella (L.). Species composition, parasitism rate, and species abundance (Hill's N1) were determined for each pest species. Voria ruralis (Fallen), Copidosoma floridanum (Ashmead), and Compsilura concinnata (Meigen) were the dominant parasitoids of T. ni; Phryxe pecosensis (Townsend), Cotesia glomerata (L.), and Pteromalus puparum (L.) are the dominant parasitoids of P. rapae; and Diadegma insulare (Cresson) is the dominant parasitoid of P. xylostella. In addition, the first records of the introduced parasitoid, C. concinnata, parasitizing T. ni and P. rapae, and Cotesia rubecula (Marshall) parasitizing P. rapae are documented for Minnesota.

Mating Disruption of Diamondback Moth (Lepidoptera: Plutellidae) and Cabbage Looper (Lepidoptera: Noctuidae) in Cabbage Using a Blend of Pheromones Emitted from the Same Dispenser1

1997 ◽  
Vol 32 (2) ◽  
pp. 120-137 ◽  
Author(s):  
E. R. Mitchell ◽  
G. Y. Hu ◽  
J. Okine ◽  
J. R. McLaughlin
Keyword(s):  
Trichoplusia Ni ◽  
Mating Disruption ◽  
Diamondback Moth ◽  
Cabbage Looper ◽  
Control Field ◽  
Economic Action ◽  
Action Threshold ◽  
Larval Count ◽  
Rope Dispensers ◽  
Lepidoptera Noctuidae

Experiments were conducted in commercial plantings of cabbage in spring 1994 and 1995 to evaluate the efficacy of a blend of pheromones for diamondback moth, Plutella xylostella (Linnaeus), and cabbage looper, Trichoplusia ni (Hübner), for disrupting mating when dispensed simultaneously from Yoto-con-S® ‘rope’ dispensers (Shin-Etsu Chemical Co., Ltd., Tokyo, Japan). A 12.1-ha cabbage field was treated with pheromone in 1994 using a blend of (Z)-11-hexadecenal, (Z)-11-hexadecen-l-ol acetate, and (Z)-11-hexadecanol in a 49:50:1 ratio for diamondback moth and (Z)-7-dodecen-l-ol acetate and (Z)-7-dodecen-l-ol in a 98:2 ratio for cabbage looper. The test was repeated in 1995 using a 10.1-ha cabbage field. In 1995, 24.6 ha of cabbage also were treated with a blend of diamondback moth-only pheromone: (Z)-11-hexadecenal and (Z)-11-hexadecen-l-ol acetate in a 50:50 ratio. All pheromone treatments were applied at the rate of 1,000 m rope per ha within 2 wk after the cabbage was planted. Captures of diamondback moth and cabbage looper males in traps baited with synthetic pheromones and mating by laboratory-reared sentinel females in pheromone-treated fields were significantly reduced for 7 to 9 wk post-treatment relative to control areas. Larval infestation data on cabbage were insufficient to establish the effect, if any, of the diamondback moth/cabbage looper combination pheromone treatment on cabbage looper control. In 1995, the diamondback moth pheromone only and the diamondback moth/cabbage looper combination pheromone effectively suppressed diamondback moth larval numbers below the composite economic action threshold of 0.3 larva per cabbage plant for approximately 60 days. A single application of pesticide quickly reduced the diamondback moth larval count below the action threshold in the pheromone-treated cabbage, and no further pesticide applications were required. The correspondent control field was sprayed 7 times with pesticides for control of diamondback moth.

Abundance and Relative Importance of Caterpillars Attacking Cabbage in Eastern Ontario

1955 ◽  
Vol 87 (9) ◽  
pp. 400-406 ◽  
Author(s):  
D. G. Harcourt ◽  
R. H. Backs ◽  
L. M. Cass
Keyword(s):  
Trichoplusia Ni ◽  
Pieris Rapae ◽  
Diamondback Moth ◽  
Economic Importance ◽  
The Other ◽  
Cabbage Looper ◽  
Relative Importance ◽  
Four Seasons ◽  
Large Numbers ◽  
Eastern Ontario

Cabbage and related crops are attacked every year throughout Ontario by caterpillars of three species, namely, the imported cabbageworm, Pieris rapae (L.), the diamondback moth, Plutella maculipennis (Curt.), and the cabbage looper, Trichoplusia ni (Hbn.). The imported cabbageworm is generally regarded as the most abundant of the three species and is reported as doing damage of considerable economic importance each year. The cabbage looper does not occur in large numbers until late in the season, but in most years it is believed to be second only in importance to the imported cabbageworm. The diamondback moth is generally considered to be much less important than the other two species (Caesar, 19i8). As previously reported (Matthewman et al., 1952), these beliefs were not borne our by observations of field populations at Ottawa in 1950. Whereas populations of the cabbage looper were strikingly low, those of the diamondback moth were much higher than the literature indicated. This paper is a summary of four seasons' experiments, 1951-1954, undertaken to assess the abundance and relative importance of the three species in eastern Ontario.

scholarly journals Seasonal occurrence of three Lepidoptera on broccoli and effectiveness of planting date as a pest management tool in southeastern New Brunswick

2005 ◽  
Vol 79 (3) ◽  
pp. 129-137 ◽  
Author(s):  
P.M. Maltais ◽  
J.R. Nuckkle ◽  
P.V. LeBlanc
Keyword(s):  
New Brunswick ◽  
Pest Management ◽  
Trichoplusia Ni ◽  
Pieris Rapae ◽  
Diamondback Moth ◽  
Planting Date ◽  
Cabbage Looper ◽  
Management Tool ◽  
Larval Population ◽  
Lepidoptera Noctuidae

Seasonal variations in abundance of three lepidopterous pests, the diamondback moth, Plutella xylostella [Lepidoptera : Plutellidae], the imported cabbageworm, Pieris rapae [Lepidoptera : Pieridae], and the cabbage looper, Trichoplusia ni [Lepidoptera : Noctuidae], were monitored over two years in broccoli plantings (Brassica oleracea var. italica) in southeastern New Brunswick. Four population peaks of imported cabbageworm were seen in 1990 and 1991 with 92 and 99% of the total larval population, respectively, being recorded during the latter part of the season, after 23 July. Four population peaks were also recorded for the diamondback moth in 1990 and 1991 with 81 and 97%, respectively, of the population being recorded after 23 July. Populations of cabbage looper appeared later in the season and because of low numbers were more difficult to assess. Using cabbage looper equivalents (CLE), the effectiveness of planting date as a pest management tool was also studied. Early crops have lower mean CLE per plant

Timing of DDT Applications for Control of Caterpillars on Cabbage

1952 ◽  
Vol 84 (11) ◽  
pp. 346-352 ◽  
Author(s):  
W. G. Matthewman ◽  
D. G. Harcourt ◽  
J. P. Perron
Keyword(s):  
Trichoplusia Ni ◽  
Pieris Rapae ◽  
Diamondback Moth ◽  
Cabbage Looper ◽  
Severe Damage ◽  
Four Seasons

Three species of caterpillars commonly attack cabbage at Ottawa, namely, the imported cabbageworm, Pieris rapae (L.), the larva of the diamondback moth, Plutella maculipennis (Curt.) and the cabbage looper, Trichoplusia ni (Hbn.). All three species are readily controlled with DDT sprays or dusts but the timing of the applications is imporrant. Growers sometimes begin dusting or spraying too early, wasting one or more applications, or they delay the first application until mid-August, when severe damage has already occurred. This paper is a report on four seasons' experiments at Ottawa, 1947 to 1950, to determine the number and timing of applications of DDT required for control of caterpillars on late cabbage.

FALL BROCCOLI PESTS AND THEIR PARASITES IN VIRGINIA

1989 ◽  
Vol 24 (2) ◽  
pp. 258-265 ◽  
Author(s):  
Loke-Tuck Kok ◽  
Thomas J. McAvoy
Keyword(s):  
Plutella Xylostella ◽  
Trichoplusia Ni ◽  
Pieris Rapae ◽  
Diamondback Moth ◽  
Heliothis Zea ◽  
The Other ◽  
Cotesia Marginiventris ◽  
South Central

The major pests of fall broccoli in south-central Virginia between 1985/87 were Trichoplusia ni (Hübner), Hellula rogatalis (Hulst), Plutella xylostella (L.), and Heliothis zea (Boddie); minor pests included Pieris rapae (L.), Evergestis rimosalis (Gueneé), Spodoptera ornithogalli (Gueneé), Pieris protodice Boisduval and LaConte and Plathypena scabra F. Seven species of parasites were recovered, the most abundant being Diadegma insularis (Cresson) which parasitized up to 37% of the diamondback moth larvae and Cotesia marginiventris (Cresson) which parasitized up to 20% of the corn earworms. The other parasites were found in very low numbers.

Biology of the Diamondback Moth, Plutella maculipennis (Curt.) (Lepidoptera: Plutellidae), in Eastern Ontario III. Natural Enemies

1960 ◽  
Vol 92 (6) ◽  
pp. 419-428 ◽  
Author(s):  
D. G. Harcourt
Keyword(s):  
Environmental Factors ◽  
Relative Abundance ◽  
Natural Enemies ◽  
Trichoplusia Ni ◽  
Pieris Rapae ◽  
Diamondback Moth ◽  
Cabbage Looper ◽  
Eastern Ontario

The diamondback moth, Plutella maculipennis (Curt.), is a sporadic pest of cruciferous crops throughout Canada. It is normally held in check by a multiplicity of environmental factors, chiefly biotic; however, serious outbreaks do occur (MacNay, 1948, 1953, 1957, 1959). In eastern Ontario it has been extremely numerous since late 1951, and during the present study, 1952 – 1956, it was more abundant than the imported cabbageworm, Pieris rapae (L.), or the cabbage looper, Trichoplusia ni (Hbn.) . Two earlier papers (Harcourt, 1956, 1957) presented the history, distribution, and synonymy of the insect, giving general descriptions of the stages and many aspects of its biology in eastern Ontario. This article gives the relative abundance of its parasites and predators, and discusses certain population relationships.

scholarly journals Management of Diamondback Moth (Lepidoptera: Plutellidae) in Cabbage Using Collard as a Trap Crop

HortScience ◽  
2000 ◽  
Vol 35 (5) ◽  
pp. 875-879 ◽  
Author(s):  
E.R. Mitchell ◽  
Guangye Hu ◽  
Denise Johanowicz
Keyword(s):  
Brassica Oleracea ◽  
Natural Enemies ◽  
Trichoplusia Ni ◽  
Diamondback Moth ◽  
Cabbage Looper ◽  
High Concentration ◽  
Trap Crop ◽  
Collard Greens ◽  
Growing Seasons ◽  
Action Threshold

Collard greens (Brassica oleracea var. acephala L.) were planted in the peripheries of cabbage (Brassica oleracea var. capitata L.) fields in the spring growing seasons of 1997 and 1998 to evaluate their effectiveness as a trap crop to manage the diamondback moth (DBM) [Plutella xylostella (L.)]. The numbers of DBM never exceeded the action threshold for application of insecticides in any of the fields that were completely surrounded by collards, but did exceed the action threshold in three of the fields without collards on four sampling dates in 1998. In both years, the numbers of DBM larvae in the collards exceeded the action threshold of 0.3 total larvae/plant in eight of nine fields. Larval counts in cabbage surrounded with collards were not significantly higher than in the conventionally planted cabbage, even though the number of pesticide applications was reduced in the former. The few pesticide applications in fields surrounded by collards probably targeted the cabbage looper [Trichoplusia ni (Hübner)], which was not impeded by the collards from infesting the interior cabbage. There was no significant reduction in marketability, and damage to cabbage was similar to that in fields where collards were planted and in fields where only conventional pesticides were used. The reduced number of pesticide sprays, as well as the high concentration of host larvae in the collards, may help maintain populations of natural enemies of DBM in the agroecosystem. Planting collards in field peripheries is a potentially effective tactic to manage DBM in cabbage.

scholarly journals Management of Diamondback Moth (Lepidoptera: Plutellidae) in Cabbage Using Collard as a Trap Crop

2001 ◽  
Vol 11 (1) ◽  
pp. 150b-151
Author(s):  
E.R. Mitchell ◽  
Guangye Hu ◽  
Denise Johanowicz
Keyword(s):  
Brassica Oleracea ◽  
Natural Enemies ◽  
Trichoplusia Ni ◽  
Diamondback Moth ◽  
Cabbage Looper ◽  
High Concentration ◽  
Trap Crop ◽  
Collard Greens ◽  
Growing Seasons ◽  
Action Threshold

Collard greens (Brassica oleracea var. acephala L.) were planted in the peripheries of cabbage (Brassica oleracea var. capitata L.) fields in the spring growing seasons of 1997 and 1998 to evaluate their effectiveness as a trap crop to manage the diamondback moth (DBM) [Plutella xylostella (L.)]. The numbers of DBM never exceeded the action threshold for application of insecticides in any of thefields that were completely surrounded by collards, but did exceed the action threshold in three of the fields without collards on four sampling dates in 1998. In both years, the numbers of DBM larvae in the collards exceeded the action threshold of 0.3 total larvae/plant in eight of nine fields. Larval counts in cabbage surrounded with collards were not significantly higher than in the conventionally planted cabbage, even though the number of pesticide applications was reduced in the former. The few pesticide applications in fields surrounded by collards probably targeted the cabbage looper [Trichoplusia ni (Hübner)], which was not impeded by the collards from infesting the interior cabbage. There was no significant reduction in marketability, and damage to cabbage was similar to that in fields where collards were planted and in fields where only conventional pesticides were used. The reduced number of pesticide sprays, as well as the high concentration of host larvae in the collards, may help maintain populations of natural enemies of DBM in the agroecosystem. Planting collards in field peripheries is a potentially effective tactic to manage DBM in cabbage.

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