Biological control of exotic pests in Italy: recent experiences and perspectives¹

Abstract

In Italy, successful application of classical biological control began in the 20th century, when Berlese released the predator Rodolia cardinalis in 1901 and the parasitoid Encarsia berlesei in 1906. Later, the ‘inoculative’ method was applied many times, limiting the misuse of insecticides and therefore achieving very positive effects for both the agricultural economy and environmental protection. When the establishment of new natural enemies failed, some exotic pests continued to damage important crops, sometimes disrupting any possibility of applying Integrated Pest Management (IPM). In other cases, new associations between exotic pests and native natural enemies occurred spontaneously and the importation of new species was not necessary: when no broad‐spectrum plant protection products are applied, some palaearctic parasitoids, such as Diglyphus isaea, naturally control the imported American leafminers Liriomyza trifolii and L. huidobrensis and some native predators (mainly Orius spp.) often control the exotic western flower thrips Frankliniella occidentalis. However, the introduction of natural enemies from the area of origin of the exotic pest is often the only alternative to chemical insecticides. Since its introduction in 1979, the American Flatid, Metcalfa pruinosa, has been spreading annually into new areas of the Mediterranean, causing severe damage to many crops because none of the indigenous natural enemies are sufficiently effective. Therefore, only the introduction of exotic natural enemies, such as the parasitoid Neodryinus typhlocybae, may reduce the outbreaks.

Responses of native egg parasitoids to the invasive seed bug Leptoglossus occidentalis

“…When insect pests are introduced in a new region, new interactions may be created with the indigenous parasitoids; this may contribute to the future control of the invasive populations. This has already been documented for other invasive pests (Godfray et al, 1995;Nicoli, 1997). For the invasive Western Conifer Seed Bug (WCSB), Leptoglossus occidentalis Heidemann (Heteroptera, Coreidae), there is a surprising lack of information available about its natural enemies in its invaded range of Europe.…”

Insecticide Use and the Ecology of Invasive Liriomyza Leafminer Management

“…Many, but not all, of the species are oligophagous so that they may attack the different pest species and native non-pest Liriomyza spp. (Nicoli, 1997). It should be noted that there is evidence of differential parasitism across Liriomyza spp.…”

“…Parasitoids associated with native non-pest Liriomyza spp. have the potential to provide biological control of invasive leafminers because the native hosts serve as reservoirs for parasitoids populations (Chen et al, 2003;Nicoli, 1997;Tran et al, 2006) Often, parasitoids of Liriomyza pest species are introduced along with their alien hosts Tagami et al, 2006). These relationships may then be exploited as a form of unintended classical biological control.…”

Effect of Some Bio- insecticides against Tetranychus urticae Koch

“…Some of the species are known to be of great economic importance as Tetranychus urticae Koch. They cause many indirect damages by transmitting several microorganisms such as viral and fungal pathogens Nicoli (1997) ;Nasser,et al(2002) Vishwanath, and Singh, (2003):. The present works include the efficiency of new control measures of potato spider oregano phosphorus compound, Marshal 25%wp., the two botanical insecticides (Marshal 0.15% & Bemistop 21.1% EC.…”