MATING DISRUPTION OF PINK BOLLWORM, PECTINOPHORA GOSSYPIELLA (SAUNDERS) USING PB ROPE DISPENSERS IN COTTON GROWING AREAS OF PUNJAB, PAKISTAN

Pink bollworm, Pectinophora gossypiella (Saunders), (Lepidoptera: Gelechidae) is considered as a notorious and destructive pest in the world and can reduce cotton yield up to 30% if not managed properly. Insect pest management through mating disruption technique offers practically an ideal approach to combat the pests. In the present study, the efficacy of mating disruption dispensers (PB rope L) for the management of pink bollworm was evaluated and the percent infestation in bolls and leftover bolls was determined in the cotton growing areas of Punjab, Pakistan during 2017. The PB ropes @100 per acre were used for each treated field of approximately 50 acres with a block of 10 acres as a control plot in the same union council of the treated plot. Calculation was made by comparing infestation and cotton yield in treated field with that of control field. The PB rope significantly reduced both the number of males in the sex pheromone traps and cotton bolls damage. Results revealed that PB rope during the first pin square period (45 days after sowing) effectively minimized the damage even in leftover bolls. The yield of treated field was enhanced compared with control field by 31% in 2017. Infestation in leftover bolls was estimated by comparing cotton bolls collected from control field with bolls from the treated field. The results reflected 1.56% damage in control field and 0.30% damage in treated field with a difference of 1.26 (80% reduction in damage in treated plots). Result indicated that PB rope disrupted the pest mating effectively during July to October.

Captures of two leafroller moth species (Lepidoptera: Tortricidae) in traps baited with varying dosages of pheromone lures or commercial mating-disruption dispensers in untreated and pheromone-treated orchard plots

A 2-year study conducted in 0.6-ha apple (Malus domestica Borkh.) blocks examined the effects of treatment with pheromone rope dispensers on captures of the obliquebanded leafroller, Choristoneura rosaceana (Harris, 1841), and the redbanded leafroller, Argyrotaenia velutinana (Walker, 1863), in traps baited with varying dosages of pheromone lures or Isomate®-OBLR/PLR Plus pheromone rope dispensers. In untreated blocks, captures of male A. velutinana were high and did not differ among (i) traps baited with a standard lure loading used to monitor this pest, (ii) lure loadings 10 and 100 times the standard loading, and (iii) traps baited with an Isomate-OBLR/PLR Plus pheromone rope dispenser. In pheromone-treated blocks, captures of A. velutinana in traps were reduced 94%–99% for all loadings tested (up to 1000 times the standard loading). The results for C. rosaceana were different. In untreated blocks in 2002, traps baited with 10 or 30 standard lures captured significantly more C. rosaceana than traps baited with a single standard lure; however, in 2003, traps baited with the standard lure loading captured significantly more moths than traps baited with 100 and 1000 times the standard loading. Also, traps baited with Isomate-OBLR/PLR Plus pheromone rope dispensers captured significantly fewer C. rosaceana than traps with standard lures in untreated blocks. In pheromone-treated blocks, traps baited with standard monitoring lures and lures with higher loadings (10 and 1000 times the standard) captured equivalent numbers of C. rosaceana; the capture of moths was reduced by only 50%–71%. We conclude that Isomate-OBLR/PLR Plus pheromone rope dispensers deployed in Michigan, United States of America, are effective in disrupting orientation of A. velutinana; however, they are not very effective for C. rosaceana. In addition, increasing lure loading above that of 1× monitoring lures (rubber septa or membrane type) does not appear to reliably increase the effectiveness of monitoring of males of either leafroller species in orchards where pheromone ropes are deployed at recommended densities.

Evaluation of Shin-Etsu twist-tie rope dispensers by the mating table technique for disrupting mating of the cotton bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae), and the pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae)

Different Shin-Etsu twist-tie rope formulations, containing either the cotton bollworm, Helicoverpa armigera (Hübner) pheromone or pink bollworm, Pectinophora gossypiella (Saunders) pheromone, or both, in the same rope, were tested in Israel for mating disruption. The success of mating disruption was evaluated by the mating table technique, comparing the percentage of mating of virgin sentinel females in pheromone-treated and control plots. Two variants of this technique were evaluated, one with two mating tables per plot, each containing five to seven females, and the other with six to eight mating tables per plot, with only one female per table. The latter method was more sensitive than the former, particularly at low population densities. Two tests were conducted in 1995 in order to compare a blend of five components of H. armigera pheromone with a blend of two components for mating disruption. The application consisted of 2000 ropes/ha, each with 80 mg pheromone. Evaluation by the two mating table methods showed clearly that the formulation containing two components was superior to the five-component blend for mating disruption, suppressing mating almost completely for 49 days. A new combined formulation, HPROPE, containing 175 mg of the H. armigera two component blend and 65 mg of P. gossypiella pheromone was tested in 1996 for mating disruption of both pests. Application of 625 ropes/ha caused a high level of suppression of mating of H. armigera females for at least 94 days and that of P. gossypiella females for 161 days. The pheromone release rates were c. 625 mg/day/ha for H. armigera and 162 mg/day/ha for P. gossypiella. A ‘long-life’ formulation of P. gossypiella pheromone, PBW rope LR, applied at 125 ropes/ha releasing 137 mg/day/ha achieved complete suppression of mating over 75 days. This release rate of P. gossypiella pheromone was much lower than that currently used in Israel (275 mg/day/ha). The present study indicates that mating of females of two moth pests with different pheromones can be disrupted by one combined formulation.

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

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.