A novel trap to capture ballooning spiders

An unattended trap was designed to sample and retain spiders dispersing from agricultural grassland and crops. Traps comprised a removable bottle-trap fixed to the top of a vertical metal rod or climbing-stick that spiders climbed during normal pre-ballooning behavior. Bottle-traps caught over eight times more spiders than sticks treated with insect trapping adhesive. Draping sticks with nets increased the effective area of the traps and increased the catch size threefold. On average, 9.1% of spiders were lost from traps during the daytime sampling period. No difference in average rate of loss of spiders from the bottle-traps was observed between night and daylight hours. The bottle-trap design is economical and simple to construct, erect and operate. Continuous sampling also allows multiple traps to be used simultaneously in various locations.