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Maize leaf weevil (Tanymecus dilaticollis Gyll) is the most dangerous pest of the maize crop in the south and southeast of Romania. Each year there were attacked one million hectares cultivated with maize were. In case of high pest pressure, weevils can destroy maize plants. After the ban on neonicotinoids, no active ingredients are available in Romania for maize seed treatments to control this pest. This study there were evaluated the effectiveness of three entomopathogenic fungi, Beauveria bassiana (strains BbTd, BbTy), B. pseudobassiana (BpPA), and Metarhizium anisopliae (MaF), for controlling the T. dilaticollis weevils, in the greenhouse conditions, using high pest pressure (4 weevils/plant). It has sowed maize in plastic pots. After the plant's emergence, it added insects collected from the field and it was pulverized solutions with entomopathogenic fungus at each variant. It has assessed phytotoxicity, attack incidence (%), attack intensity on a scale from 1 (plants not attacked) to 9 (plants destroyed), plant heights, and weevils mortality at eight days after infections with entomopathogenic fungi. The conditions of the high pest pressure from the greenhouse it has registered lower weevils mortality. Only in the case of M. anisopliae (MaF) and B. bassiana (BbTy) weevils was mortality higher than 10 %. At all experimental variants from the greenhouse, attack incidence was 100 %, while attack intensity ranged from 8.75 in the control variant to 7.10 in the case of M. anisopliae (MaF) fungus. In this study, there weren’t significant statistical differences between control and treated variants concerning both weevils attack intensity and mortality (p<0.05).

The grey corn weevil, Tanymecus (Episomecus) dilaticollis Gyll., (Curculionidae: Entiminae) is the most destructive pest of maize and sun flower crops in Romania. In this article we report result of evaluation of native strains of entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. (Deuteromicotina: Hyphomycetes) and B. pseudobassiana Rehner et Humber against Tanymecus dilaticollis (Curculionidae: Entiminae) both in laboratory and field. In laboratory assay, two different strains of B. bassiana and one strain of B. pseudobassiana (BbLy) were applied on insects as 1×108 conidia/ml aqueous suspensions. The pure ATCC 74040 commercial strain of B. bassiana and the commercial mycoinsecticide based on this strain (Naturalis) were included in the laboratory assay for comparison. Adult mortalities were recorded daily, 14 days post-exposure. All the fungal strains have been shown to be pathogenic to T. dilaticollis. The B. bassiana strain (BbTd1) and the B. pseudobassiana strain (BbLy) were effective against adults of T. dilaticollis and comparable in percentage of mycosis and virulence to the B. bassiana strain ATCC 74040. The commercial product Naturalis was superior to the tested fungal strains killing the insects within a day. In the field, the strains BbTd1 and BbLy applied as conidia multiplied on barley grains (1×109 /g d.w) in the soil did not affect the T. dilaticollis density in maize crop.

This paper presents a three-year study concerning the effectiveness of the OSR seed treatment with the cyantraniliprole active ingredient in controlling the DBM larvae attack in autumn and four-year monitoring of the DBM flight pattern, using pheromone sticky traps. The experiment and the monitoring were conducted at the experimental field from the National Agricultural Research and Development Institute (NARDI) Fundulea in Southeast Romania. For the field assessments, each OSR sampled plant was photographed in macro mode, and then images were downloaded and magnified on the PC screen to determine the DBM larva attack. The traps were placed in the OSR crop from mid-March till December and checked twice weekly. Data from the field assessment revealed a higher pest attack on OSR plants on 11 November 2020, when the DBM larvae attack degree was 16.26% in the untreated variant and 11.24% in the variant with treated seeds. The results evidenced unusually higher activity for the diamondback moths during November 2019, 2020, and 2022; the beginning of December 2020 and 2021; and mid-December 2022. This is the first report from the Romanian scientific literature concerning higher DBM attacks at OSR plants in autumn and high moth activity during November and December.