Investors are queuing up to buy shares in Marston's following a trading update.Food sales from its managed pubs continued to lead growth in the half year to April 3 and the company, which owns the Pitcher & Piano chain, remains on track to meet expectations for the full year.Electrical parts distributor Electrocomponents has seen sales put on a growth spurt in February and March, which should see full year profits come in ahead of expectations. The shares have been jolted higher by the update.Heritage Oil is today's laggard. The oil firm is to dig its Miran West-2 test well in Kurdistan deeper than originally planned after results proved much less productive than the adjacent test well.FTSE 250 - RisersSalamander Energy (SMDR) 286.20p +6.79%Lamprell (LAM) 272.30p +6.16%Connaught (CNT) 283.50p +5.86%Senior (SNR) 112.70p +4.45%Domino Printing (DNO) 402.90p +4.16%Marston's (MARS) 98.10p +3.86%Euromoney Institutional Investor (ERM) 549.50p +3.68%Electrocomponents (ECM) 235.10p +3.61%TalkTalk Telecom Group (TALK) 141.70p +3.51%Stobart Group Ltd. (STOB) 156.50p +3.51%FTSE 250 - FallersHeritage Oil (HOIL) 529.00p -8.95%Computacenter (CCC) 302.30p -3.66%Soco International (SIA) 1,722.00p -3.26%Aquarius Platinum Ltd. (AQP) 444.40p -2.97%Ferrexpo (FXPO) 376.70p -2.91%Telecity Group (TCY) 441.30p -2.58%Arriva (ARI) 713.50p -2.39%JD Wetherspoon (JDW) 507.00p -2.31%Murray International Trust (MYI) 871.00p -2.24%Xchanging (XCH) 196.50p -2.19%