Clone and Validate cloned fields
HTML
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.11.1/jquery.validate.min.js"></script>
<form method="post">
<div class="wrapper">
<div class="toclone">
<select name="list">
<option>selecione...</option>
<option>opção 1</option>
<option>opção 2</option>
<option>opção 3</option>
<option>opção 4</option>
</select>
<input type="text" name="produtos[qtd][]">
<button type="button" id="add">+</button>
<button type="button" id="remove">-</button>
</div>
</div>
<input type="submit">
</form>
CSS
label.error {
color: red;
font-size: 10px;
font-family: arial;
}