How to send the value of a combo box to the database

Question

Man ComboBox brings the ID Primário table Produto to be registered in a new table that is the Pacotes.

So far so good, the problem is that if I select another record on ComboBox it saves as if it were the first record of the table Produtos.

Then I needed a help how to send the ID_Produto second record.

I will put the code of the save button that makes the function of sending the data to the database (remembering that I am using Mysql), remembering that the cbxPeca in the code is mine ComboBox:

private void btnSalvar_Click(object sender, EventArgs e)
{
    try
    {
        Selecionarproduto();
        conectar.Open();

        int DataEntrada = Convert.ToInt32(txtEntrada.Text);
        int DataSaida = Convert.ToInt32(txtSaida.Text);

        //MessageBox.Show("Conectado");

        MySqlCommand Inserir = new MySqlCommand();
        Inserir.Connection = conectar;
        Inserir.CommandText = Inserir.CommandText = "INSERT INTO Pacote (ID_Produto, Nome, Quantidade, Data_entrada, Data_saida ) VALUES ("
                                +cbxPeca.SelectedValue.ToString() + ", '" + txtNome.Text + "', '"
                                + txtQuantidade.Text + "', '" + DataEntrada + "', '"
                                + DataSaida +"'); ";

        Inserir.ExecuteNonQuery();
        conectar.Close();
        MessageBox.Show("Cadastro Realizado!", "Concluido",
          MessageBoxButtons.OK,
          MessageBoxIcon.Information);
        selecionarCategoria();
    }
    catch (SqlException)
    {
        MessageBox.Show("Falha na conexao!", "falha",
          MessageBoxButtons.OK,
          MessageBoxIcon.Information);
    }
}

Populating the combo box

private void Selecionarproduto(){

        DataTable dtTabelas = new DataTable();

        MySqlConnection conectar = new MySqlConnection("server=127.0.0.1;database=ProdPacote; Uid=root; pwd=1234;");

        MySqlDataAdapter mySqlDataAdapter = new MySqlDataAdapter("select ID_Produto, nome from Produto", conectar);
        DataSet DS = new DataSet();
        mySqlDataAdapter.Fill(DS);
        cbxPeca.DataSource = DS.Tables[0];
        conectar.Close();
        mySqlDataAdapter.Fill(dtTabelas);

        //cbxPeca.DropDown;

        //carrega as informacoes no combo
        cbxPeca.DataSource = dtTabelas;
        cbxPeca.DisplayMember = "nome";
        cbxPeca.ValueMember = "ID_Produto";
    }