scholarly journals Factors Affecting Disruption of Navel Orangeworm (Lepidoptera: Pyralidae) Using Aerosol Dispensers

2020 ◽  
Vol 113 (3) ◽  
pp. 1290-1298 ◽  
Author(s):  
Charles S Burks ◽  
Donald R Thomson
Keyword(s):  
Sexual Activity ◽  
Mating Disruption ◽  
Sexual Communication ◽  
Profile Analysis ◽  
Crop Protection ◽  
Spatial Density ◽  
Pheromone Traps ◽  
Sharp Drop ◽  
Navel Orangeworm ◽  
Factors Affecting

Abstract Mating disruption is used to help manage the navel orangeworm on approximately 200,000 ha of tree nut crops. Aerosol dispensers are the most common formulation, and all formulations use an incomplete pheromone blend consisting solely of (Z11,Z13)-hexadecadienal. Profile analysis (examination of capture and males in pheromone traps as a function of spatial density of dispensers) demonstrated a sharp drop of males captured with a very low density of dispensers, and then an approximately linear relationship between 90 and approaching 100% suppression. This near-linear portion of the profile includes both dispenser densities in which crop protection has been demonstrated, and densities in which it is unlikely. Suppression of males in pheromone traps was lost the next night after dispensers were removed, suggesting that the active ingredient was not persistent in the orchard environment. During most of the summer preharvest period, turning the dispensers off 1 or 2 h before the end of the predawn period of sexual activity provides the same amount of suppression of sexual communication as emission throughout the period of sexual activity. This suggests that encountering the pheromone from the mating disruption dispensers had a persistent effect on males. During the autumn postharvest period, only emission prior to midnight suppressed communication on nights on which the temperature fell below 19°C by midnight. These findings and the analysis will help manufacturers refine their offerings for mating disruption for this important California pest, and buyers of mating disruption to assess cost-effectiveness of competing offerings.

scholarly journals Use of mating disruption for control of New Zealand leafrollers in apple orchards

2011 ◽  
Vol 64 ◽  
pp. 215-221 ◽  
Author(s):  
J.T.S. Walker ◽  
D.J. Rogers ◽  
P.L. Lo ◽  
D.M. Suckling ◽  
A.M. El-Sayed ◽  
...  
Keyword(s):  
New Zealand ◽  
Mating Disruption ◽  
Virgin Female ◽  
Pheromone Traps ◽  
Apple Orchards ◽  
Pheromone Trapping ◽  
Fruit Damage ◽  
Lightbrown Apple Moth ◽  
Pheromone Dispensers ◽  
Pheromone Blend

Leafrollers are important pests of apples and infested fruit can result in rejection of export consignments Leafroller mating disruption using a pheromone blend with activity against three species was examined in 12 Hawkes Bay orchards over two seasons (200910 and 201011) Pheromone dispensers (600/ha) and a single insecticide were applied to trees in early November and subsequent insecticide use was based on leafroller pheromone trapping and thresholds The pheromone blend substantially suppressed mating of virgin female lightbrown apple moth in treated orchards and reduced male catch in pheromone traps by up to 98 compared with the season prior to implementation Insecticide use for leafroller control decreased accordingly from 2127 insecticides per block in 2008/09 to 1018 in 2010/11 Leafroller control using mating disruption was acceptable fruit damage varied from 03 to 016 and no leafroller larvae were found on fruit in both field assessments and phytosanitary inspections of packed cartons

Growth, survival and activity patterns of recently metamorphosed Bufo marinus

1993 ◽  
Vol 20 (1) ◽  
pp. 1 ◽  
Author(s):  
MP Cohen ◽  
RA Alford
Keyword(s):  
Profile Analysis ◽  
Activity Patterns ◽  
Survival Rates ◽  
Larval Habitat ◽  
Bufo Marinus ◽  
Daily Maximum ◽  
Growth And Survival ◽  
Factors Affecting ◽  
The Mean ◽  
Stage 1

We examined factors affecting the growth and survival of postmetamorphic Bufo marinus using sampling and experiments. Bufo metamorphs, defined as newly emerged terrestrial toads of 9-29mm snout-ischium length (SIL), were classified into four stages on the basis of colour and size. Stage 1 were uniformly black and about 9-12 mm SIL, stage 2 were mottled with orange spots and about 12-16mm SL, stage 3 had a white mid-dorsal line and were about 16-25mm SIL, and stage 4 had enlarged parotoid glands and were about 25-29 mm SIL. We determined the density of each stage at three distances (0-1, 2-3, 4-5m) from their larval habitat using 1 x 1-m quadrat samples. The mean densities of all metamorphs within 1 m of water were 2.6m-2 and 2.1m-2 for the wet and early dry seasons, respectively. The mean densities of all metamorphs during both seasons at 2-3m and 4-5m from water were 0.8m-2 and 0.6m-2, respectively. Stage 2 metamorphs were most common in samples. Most stage 1 metamorphs occurred within 1m of the water in both seasons (98% wet; 95% dry). Increasing percentages of stage 2, 3 and 4 metamorphs occurred in samples 2-3 and 4-5m from water (38, 49 and 80%, respectively, averaged over both seasons). Three experiments examined the response of metamorph growth and survival rates to density in open-topped flyscreen enclosures. Stage 1 or 2 metamorphs were established at initial densities of 3.3, 6.7 and 16.7m-2. Metamorphs in the lower-density enclosures grew more rapidly than metamorphs in the higher-density enclosures. A profile analysis showed that daily survival rate was not densitydependent. Correlation analyses showed that daily metamorph survival was influenced by daily maximum and minimum temperatures. Metamorphs at lower densities attain juvenile size (30mm) more rapidly; because they survive at the same daily rates as metamorphs at higher densities they experience lower cumulative mortality as metamorphs.

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