SPIDERS AND THEIR PREY IN MASSACHUSETTS CRANBERRY BOGS

Spiders from a total of 24 genera and eight families that possessed pr ey were collected using direct observation and sweep sampling during a survey of seven stands of wild (four sites) and abandoned (three site s) cranberry bogs in Massachusetts. Over all sites, 7009 spiders were inspected and 2.7% of all individuals possessed prey. At the wild bogs , Lycosidae and Araneidae were most commonly collected and at the aban doned bogs, Oxyopidae and Tetragnathidae were most common. A total of 11 orders of prey was observed and small Diptera (39.4% of total) (par ticularly Chironimidae), Collembola (18.6%), Homoptera (11.7%) (partic ularly Cicadellidae), and small Hymenoptera (9%) were the most common prey items. For all sites, three species of spider [Pardosa saxatilis Hentz (Lycosidae), Oxyopes salticus Hentz (Oxyopidae), and Tetragnatha laboriosa Hentz (Tetragnathidae)] represented 58% (109/ 188) of all s pecimens collected with prey. Sixty-seven percent of the prey recovere d from P. saxatilis were Diptera or Collembola; another 20% were ident ified as Homoptera and Araneae. Collembola (35%) and Diptera (24%) wer e the dominant prey captured by O. salticus, and no predation on spide rs by this species was observed. The majority of T. laboriosa with pre y possessed chironomids (63%) or homopterans (17%). Dvac(R) samples of vegetation, taken during the study to determine levels of the total p otential prey, showed that the most abundant orders were Collembola, D iptera, and Araneae and Hymenoptera and that the number and type of pr ey taken by spiders fluctuated with the relative abundance of potentia l prey.