Biological control of gypsy moth (Lymantria dispar) by the entomopathogenic fungus Entomophaga maimaiga in Bulgaria in 2021

By

Georgiev, Georgi
Mirchev, Plamen
Georgieva, Margarita
Kechev, Mihail
Belilov, Sevdalin
Matova, Maria
Petrova, Vyara
Mateva, Petya
Kirilova, Maria
Mutafchiiski, Ilian

Type

Article

Date of Publication

2021-12-14

Original Publication

Silva Balcanica

Volume

22

Series / Issue

Issue: 3

Pages

17--27

Subjects

Biological control , Entomophaga maimaiga , Lymantria dispar , release

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Forest Research Institute - Bulgarian Academy of Sciences (FRI-BAS) [2001]-

Identifiers

DOI: https://doi.org/10.3897/silvabalcanica.22.e78600

 

Abstract

In 2021, biological control programme against gipsy moth (Lymantria dispar) populations was carried out by introduction of the entomopathogenic fungus Entomophaga maimaiga on the territory of four State Forest Enterprises: Municipal Enterprise (ME) ‘Management of Municipal Forests, Agriculture and Forestry’, Nessebar; State Game Enterprises (SGE) Nessebar and Balchik; State Forestry (SF) Vidin. The pathogen was introduced during the period 15-26.03.2021 in 34 localities - five in ME Nessebar, eight in SGE Nessebar, ten in SGE Balchik and eleven in SF Vidin. The average number of gypsy moth population density in the locations of introduction was relatively high, ranging between 0.4-15.9 egg mass/tree in the area of ​​SGE Balchik and 11.9-65.0 egg mass/tree in the area of ​​ME Nessebar. The average mortality of young gypsy moth caterpillars (first-third instar) due to E. maimaiga varied between 2.6% (SGE Balchik) and 13.0% (SF Vidin), and of caterpillars in later fourth-sixth instar - between 20.7% (SF Vidin) and 52.4% (ME Nessebar). The overall mortality of the gipsy moth caterpillars due to E. maimaiga was lowest in the region of SGE Balchik (26.1%), followed by SF Vidin (33.7%), SGE Nessebar (48.5%) and ME Nessebar (55.9%). As a result of the introduction, gipsy moth severe outbreaks in the region of Nessebar was significantly suppressed. The high number of E. maimaiga resting spores persists in the surface layers of the soil in the other two areas (Vidin and Balchik) has the potential to suppress L. dispar attacks in next years.