Influence of Bacillus thuringiensis application timing on population dynamics of gypsy moth in Mediterranean cork oak forests

2019 ◽  
Vol 76 (3) ◽  
pp. 1103-1111
Author(s):  
Roberto Mannu ◽  
Arturo Cocco ◽  
Pietro Luciano ◽  
Andrea Lentini
Keyword(s):  
Population Dynamics ◽  
Bacillus Thuringiensis ◽  
Gypsy Moth ◽  
Cork Oak ◽  
Oak Forests ◽  
Application Timing

scholarly journals Comparative Efficacy Trials with Two Different Bacillus thuringiensis Serovar kurstaki Strains against Gypsy Moth in Mediterranean Cork Oak Forests

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 602
Author(s):  
Maurizio Olivieri ◽  
Roberto Mannu ◽  
Luca Ruiu ◽  
Pino A. Ruiu ◽  
Andrea Lentini
Keyword(s):  
Bacillus Thuringiensis ◽  
Gypsy Moth ◽  
Untreated Control ◽  
Larval Density ◽  
Resistance Management ◽  
Cost Savings ◽  
Cork Oak ◽  
Oak Forests ◽  
Density Reduction ◽  
Untreated Check

The efficacy of two formulations (Foray® 76B AVIO and Rapax® AS AIR) containing different Bacillus thuringiensis kurstaki (Btk) strains (ABTS-351 and EG-2348, respectively) was evaluated against Lymantria dispar larval populations in cork oak forests in Sardinia (Italy), in 2018 and 2019. The experimental design involved the following treatments: (I) untreated control; (II) Foray® 76B at the dose of 2.0 L/ha; (III) Foray® 76B at the dose of 2.5 L/ha; (IV) Rapax® AS AIR at the dose of 2.0 L/ha. Aerial applications were carried out using a helicopter equipped with four electronic rotary atomizers adjusted to sprinkle 160 micron-sized drops. Btk efficacy was evaluated by assessing the larval density reduction 7, 14, and 21 days after the application in each experimental plot in comparison with an untreated check. In addition to field surveys, the mortality of second and third instar larval samples, randomly collected from each plot after treatment and fed with foliage from the same plot, was determined in the laboratory. All Btk treatments were similarly effective, and no differences in larval density reduction among Btk strains and doses were found in either year. Twenty-one days after application, the average larval density reduction in the field was approximately 70% in all treated plots in 2018, whereas in 2019 it reached 80% only in areas treated with Foray 76B at 2.5 L/ha. Laboratory observations showed that all Btk-based products were effective against gypsy moth larvae, with significant differences in mortality between untreated control and the different Btk treatments. Our results shed light on the possibility of alternating different Btk strains for resistance management purposes and of applying lower doses than labeled, in order to achieve cost savings for product shipment and distribution and to reduce the environmental impact.

scholarly journals Gypsy Moth Management with LdMNPV Baculovirus in Cork Oak Forest

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 495
Author(s):  
Luca Ruiu ◽  
Roberto Mannu ◽  
Maurizio Olivieri ◽  
Andrea Lentini
Keyword(s):  
Population Dynamics ◽  
Gypsy Moth ◽  
Block Design ◽  
Larval Mortality ◽  
Larval Density ◽  
Management Program ◽  
Cork Oak ◽  
Forest Protection ◽  
Randomized Block Design ◽  
Species Specific

(1) Research Highlights: Applications of a species-specific baculovirus is a promising method to control the gypsy moth and regulate its population dynamics in forest ecosystems. (2) Background and Objectives: Cork oak protection against the Lepidopteran defoliator Lymantria dispar requires an appropriate forest ecosystem management program, involving the application of eco-sustainable microbial products during population outbreaks. The species-specific multicapsid nucleopolyhedrovirus (LdMNPV), agent of natural epizootics in gypsy moth populations, represents an option that was investigated in a multi-year field study, involving viral applications either from the ground or by aerial treatment. (3) Materials and Methods: Efficacy trials against L. dispar populations were conducted in 2018 and 2019 in Sardinia, according to a randomized block design. Each year, two trials were conducted, applying a baculovirus commercial formulation with an atomizer from the ground and assessing the effects of different doses and application timing, respectively. An aerial application trial distributing LdMNPV at ultra-low volumes (2 L/ha) was also conducted in 2019 to assess the virus efficacy at a larger field scale. (4) Results: In both years, a significant increase in larval mortality was detected in plots treated with higher viral occlusion body (OB) doses and with an earlier application targeting younger larvae, in comparison with untreated controls. Due to an observed retrogradation phase of the target pest in 2019, no significant differences in larval density between areas treated from a helicopter and control were detected, but in the few weeks following application, a meaningful vitality decrease in larval samples from treated plots was observed. (5) Conclusions: Based on the results of this study, the use of LdMNPV in forest protection programs against gypsy moth can be worth consideration in multi-year integrated program strategies to modulate population dynamics.

Forecasting infestation byCoraebus undatus(Coleoptera, Buprestidae) in cork oak forests

2012 ◽  
Vol 58 (3) ◽  
pp. 275-280 ◽  
Author(s):  
A. Gallardo ◽  
A. Jiménez ◽  
C.A. Antonietty ◽  
M. Villagrán ◽  
M.E. Ocete ◽  
...  
Keyword(s):  
Cork Oak ◽  
Oak Forests

scholarly journals Population dynamics of pre-imaginal stages of olive fruit fly Bactrocera oleae Gmel. (Diptera, Tephritidae) in the region of Bar (Montenegro)

2013 ◽  
Vol 28 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Tatjana Perovic ◽  
Snjezana Hrncic
Keyword(s):  
Population Dynamics ◽  
Developmental Stages ◽  
Fruit Fly ◽  
Bactrocera Oleae ◽  
Yield Reduction ◽  
Olive Fruit Fly ◽  
Application Timing ◽  
Olive Fruit ◽  
Fruit Drop

Olive fruit fly is the most harmful pest of olive fruits and important for oil production. Damage involves yield reduction as a consequence of premature fruit drop, but also a reduced quality of olive oil and olive products. There is little available data regarding the biology of Bactrocera oleae in Montenegro. Knowledge of the pest life cycle and development would improve optimization of insecticide application timing and protection of fruits, and reduce adverse effects on the environment. Investigation was conducted on the Zutica variety in an olive grove located in Bar during a three-year period. Population dynamics of the pre-imaginal stages and level of fruit infestation were monitored from mid-July until the end of October. The results of this three-year investigation showed that the beginning of infestation was always at the end of July. It was also found that, depending on environmental conditions, the level of infestation was low until the end of August. In September and October it multiplied, and reached maximum by the end of October. Regarding infestation structure, eggs and first instar larvae were the dominant developmental stages of the pest until the middle of September. From mid-September until mid-October all developmental stages (eggs, larvae, pupae) were equally present in infested fruits. Pupae, cocoons and abandoned galleries prevailed until the harvest.

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