Population Dynamics of Pre-Imaginal Stages of Olive Fruit Fly Bactrocera oleae Gmel. (Diptera, Tephritidae) in the Region of Bar (Montenegro)

Abstract

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 Žutica 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.

Najveće štete u proizvodnji maslina i maslinovog ulja pričinjava muva masline. Štete se ogledaju u smanjenju prinosa usljed prijevremenog otpadanja ploda, ali i u smanjenju kvaliteta maslinovog ulja i proizvoda od masline. O biologiji Bactrocera oleae u Crnoj Gori malo je podataka. Saznanja o razvojnom ciklusu ove štetočine doprinijela bi optimizaciji vremena primjene insekticida a time i boljoj zaštiti ploda, te smanjenju štetnih efekta na životnu sredinu. Istraživanja su sprovedena u zasadu masline sorte žutica u Baru, u trogodišnjem periodu. Dinamika populacije predimaginalnih stadijuma i nivo infestacije ploda praćeni su od početka jula do kraja oktobra. Početak infestacije u sve tri godine istraživanja konstatovan je krajem jula. Do kraja avgusta, zavisno od uslova sredine, infestacija je niska. U septembru i oktobru višestruko se povećava i najveća je krajem oktobra. U strukturi infestacije do sredine septembra dominiraju jaja i larve (L1). Od sredine septembra do sredine oktobra prisustvo svih razvojnih stadijuma (jaje, larva, lutka) štetočine u plodovima je ujednačeno, nakon čega preovladavaju lutke, lutkine košuljice i napuštene galerije.