Incidence and abundance of bees and wasps in centipedegrass lawns in Georgia

Authors: JOSEPH, SHIMAT - University Of Georgia; Harris-Shultz, Karen; JESPERSEN, DAVID - University Of Georgia; VERMEER, BRIAN - University Of Georgia; JULIAN, CALEB - University Of Georgia

Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/25/2020
Publication Date: 10/30/2020
Citation: Joseph, S.V., Harris-Shultz, K.R., Jespersen, D., Vermeer, B., Julian, C. 2020. Incidence and abundance of bees and wasps in centipedegrass lawns in Georgia. Journal of Entomological Science. 55(4):547-559. https://doi.org/10.18474/0749-8004-55.4.547.
DOI: https://doi.org/10.18474/0749-8004-55.4.547

Interpretive Summary: In the U.S., turfgrasses are a major component of the landscape covering over 160,000 km2. Centipedegrass is a warm-season turfgrass that is often grown in the southeastern U.S. Recently honeybees were documented collecting pollen from the inflorescences of centipedegrass. With the decline of pollinators in abundance and diversity worldwide, we sought to survey the activity of bees in centipedegrass lawns in central and southern Georgia using nine lawns. 173 bees were collected from centipedegrass lawns of which 79% were Lasioglossum spp. (sweat bees), 7% were Halictus spp., and 4% were Melissodes (long-horned bees). Other bees collected were Augochlorella spp. (sweat bees), Agapostemoa spp. (metallic green sweat bees), Bombus spp. (bumble bees), Megachile (leafcutter bees), Apis, Peponapis (squash bees), Ceratina (small carpenter bees), Ptilothrix, Svastra (long-horned bees), and Nomia spp (sweat bees). Thus, our data shows that a diverse genera of bees are residing in or in close proximity to lawns and foraging in and around the lawns seeking floral resources. With the knowledge that a large number of bees are present in centipedegrass lawns, homeowners and landscape managers should apply insecticides conservatively as certain insecticides are toxic to foraging bees in lawns.

Technical Abstract: Bees and wasps are important groups of beneficial insects that provide essential ecosystem services to urban and suburban landscapes. Since there is limited information on the occurrence, abundance and diversity of bees on lawns in the southeastern U.S., we surveyed activity of bees on nine centipedegrass lawns in central and southern Georgia in 2019. Lawns selected in this study had no prior exposure to insecticides. In each lawn, a 3.048 × 3.048 m2 area was marked and not mowed but the remainder of the lawn area was mowed. Three pans: one each of yellow, blue and red color were deployed in non-mowed and mowed areas of each lawn. When each centipedegrass lawn reached anthesis, pans were filled with soapy water and the contents were emptied after 3 d. Each lawn site was sampled 3-5 times. Of 173 total bees collected from centipedegrass lawns, 79.2% were Lasioglossum spp. followed by 6.9% Halictus, and 4% Melissodes. Only four Bombus spp. was collected from the lawns. Other bees collected were Augochlorella spp., Agapostemoa spp., Megachile, Apis, Peponapis, Ceratina, Ptilothrix, Svastra, and Nomia spp. Most of the Lasioglossum spp. were collected in August (48.6%) and September (26.6%). Lasioglossum spp. were sampled from all centipedegrass lawns; however, Halictus spp. and Melissodes spp. were collected only from one lawn in South Georgia. Bee captures were similar regardless of mowed and non-mowed centipedegrass lawn. Most of the bees were collected in blue and yellow pans whereas, wasps were mostly captured from yellow colored pans.