EFFECTS OF STRAW AND LEAF MULCHES AND TRICKLE IRRIGATION ON THE ABUNDANCE OF COLORADO POTATO BEETLES (COLEOPTERA, CHRYSOMELIDAE) ON POTATO IN CONNECTICUT

Straw mulch reduced the number of Colorado potato beetle, Leptinotarsa decemlineata (Say), larvae an potato during the first generation, and reduced the proportion of stems that were more than 50% defoliated co mpared to unmulched and unirrigated control plots. Leaf mulch and tric kle irrigation did not affect number of larvae or the proportion of he avily defoliated plants compared to the control. None of the treatment s significantly affected the number of adults per stem until the end o f the first generation and none affected the number of egg masses, so the straw mulch must affect mortality or development of eggs and larva e. Both types of mulch and trickle irrigation increased yield relative to the control, perhaps due to lower soil temperature in a hot, dry y ear.