Seasonal biology and associated natural enemies of two Toumeyella spp. in Colorado

Observations were made during 1994 and 1995 on the life history and associated natural enemies of two Toumeyella spp. of soft scale which recently have become established as important pests in several Colorado communities. Observed host plants of the striped pine scale, Toumeyella pini (King), included Pinus sylvestris, Pinus mugo, Pinus edulis and Pinus nigra; observed hosts of the pine tortoise scale, Toumeyella parvicornis (Cockerell), were Pinus contorta and P. sylvestris. Both species were observed to have only a single generation per year. Crawler emergence of T. pini began in Denver on 1 June in 1994 and 21 June in 1995. This was close to that observed with T. parvicornis in Loveland and Greeley, 27 May in 1994 and 21 June in 1995. Crawlers were present for about one month. No parasitoids were recovered from T. pini, but predators of early instar stages included the coccinellids Hippodamia convergens (Guerin-Meneville), Coccinella septempunctata L. and a predatory lampyrid, Lucidota sp. Conversely, an Aphytis sp. aphelinid wasp may be important on populations of P. parvicornis.