Studies on the strains of Trichogramma evanescens Westwood (Hym., Trichogrammatidae) collected from different hosts in Northern Maldova

Abstract

Biological and morphological characteristics together with electrophoretic patterns were compared for five strains of Triclzogramma ecanescens W., collected from the eggs of Mamestra brassicae L., Ostrinia nuhilulis Hb. and Agrotis segetum Schiff. in northern Maldova. Significant differences were observed in the biological characteristics including the proportion of female progeny, developmental period, longevity and fecundity. The strains also differed in the ratio of antenna1 hair length to the maximum width of flagellum in males. Patterns of esterase systems indicated that the strains differed in the mobility and intensity of esterase bands. All the strains had a strong preference for the host from which they were collected in the field. Crossing of the strains indicated that one strain was reproductively isolated. The results have application in selecting the strategy for establishing initial colony in mass rearing of parasitoids and for research on Trichogramma ecology and evolution.

Comparative biology and life tables of Trichogramma evanescens and T. cacoeciae with Ephestia elutella as host at four constant temperatures

“…Following host acceptance, the parasitising female starts oviposition, and this step is strongly depending on temperature. The range of parasitised eggs of S. cerealella at 27 • C was 17.4 and 25.5 with five strains from Moldavia (Ram et al, 1995). The temperature dependence of parasitism of T. cacoeciae was found to be similar compared with those species.…”

Performance of two Trichogramma brassicae strains under greenhouse and field conditions for biocontrol of the silver Y moth in spinach cultures

“…Furthermore food availability in the habitat aVects survival and parasitization rates (Zhang et al 2004;Romeis et al 2005) and diVerent strains of the same species may show distinct host preferences (Van Dijken et al 1986;Ram et al 1995). Therefore Smith (1996) and Wührer (1996) propose that the four main factors, i.e.…”

Field evaluation of the egg parasitoid, Trichogramma evanescens West. against the olive moth Prays oleae (Bern.) in Egypt

“…TE parasitoid was extensively used in inundative releases against a number of lepidopterous pests of several crops (e.g., corn, rice, sugarcane, cotton, fruit trees, grape, etc.) (Ram et al 1995;El-Wakeil et al 2008), but had not been observed in olive groves. Releases of TE wasps were carried out in an olive farm that represent a young and large intensively managed plantations under arid weather condition and TE free.…”

“…These species/strains had not been collected from olive groves, but some of them were successfully used in other crop systems. TE wasps are known to attack a wide variety of field crop moths (Abbas et al 1987;Ram et al 1995;Bayram and Kornosor 1999;Herz et al 2005). TE parasitoid was extensively used in inundative releases against a number of lepidopterous pests of several crops (e.g., corn, rice, sugarcane, cotton, fruit trees, grape, etc.)…”