Bernard Jackman believes the departure of Jared Payne has played a big part in Ulster's dreadful mid-season form which has seen them lose five of their last six games in all competitions.Dan McFarland's side have been in free-fall since the start of December when they surrendered a 22-3 lead against Leinster to lose 38-29 at the RDS, with further defeats to Sale Sharks, La Rochelle, Munster and Benetton, the only win in that time being a nervous 22-20 victory at Connacht, in which the hosts missed a conversion to secure a draw with the final play of the game.Saturday's defeat to Benetton was just their second ever defeat to the Italian side, and while Marco Bortolami's side needed a late penalty to secure the win, they had been ahead of Ulster for much of the game in Treviso.With an average of 29 points conceded per game across the last six fixtures in all competitions, the province's good defensive efforts earlier in the season appear to be coming unstuck.Notably there was a change in defensive coach in the off-season, with Jared Payne departing after four years in the role to join Clermont, with another former Ulster player - Jonny Bell - coming in to replace him.And Jackman says Payne's absence is being felt this season."Speaking to some players who have worked under him [Payne], they're missing him badly," Jackman told the RTÉ Rugby podcast."The problem is that because they're defensively porous, they've become incredibly reliant on their lineout maul, which is a weapon, but when they come up against teams like Sale, La Rochelle or Leinster, it's nowhere near as useful as it is against some of the smaller sides."Their attacking game has fallen away, and when we look back at Ulster in the last couple of years under