Natural enemies of the convergent lady beetle, Hippodamia convergens Guérin-Méneville: Their inadvertent importation and potential significance for augmentative biological control

Microsporidia Biological Control Agents and Pathogens of Beneficial Insects

“…hippodamiae was detected in individuals from 13 to 22 shipments of adult H. convergens from three commercial insectaries. Although the prevalence of T. hippodamiae in commercially available beetles is low (0.9%; range 0-3%), H. convergens are sold and released in large numbers, and it is likely that thousands of these beetles are infected with microsporidia (Bjørnson 2008).…”

“…hippodamiae prolongs the development of H. convergens larvae and reduces the fecundity and survival of adults. The pathogen is transmitted horizontally with 100% efficiency among H. convergens cohorts and other coccinellids when microsporidia-infected H. convergens eggs are cannibalized (Saito & Bjørnson 2006, 2008Joudrey & Bjørnson 2007). Under laboratory conditions, T. hippodamiae infects several coccinellids, including Adalia bipunctata (the two-spotted lady beetle), Coccinella septempunctata (seven-spotted lady beetle), C. trifasciata perplexa (three-banded lady beetle), and Harmonia axyridis (multicolored Asian lady beetle).…”

“…Under laboratory conditions, T. hippodamiae infects several coccinellids, including Adalia bipunctata (the two-spotted lady beetle), Coccinella septempunctata (seven-spotted lady beetle), C. trifasciata perplexa (three-banded lady beetle), and Harmonia axyridis (multicolored Asian lady beetle). For all of these beetle species, the development of T. hippodamiaeinfected larvae is prolonged when compared to uninfected larvae, but the pathogen has no effect on larval mortality (Saito & Bjørnson 2006, 2008.…”

Natural enemies of the Coccinellidae: Parasites, pathogens, and parasitoids

“…Coccinellid mortality resulting from B. bassiana infection does occur naturally but has not clearly been shown to regulate populations. Fungi other than B. bassiana are also reported from Coccinellidae (Bjørnson, 2008). found overwintering populations of C. septempunctata in Poland also infected by Paecilomyces farinosus (Holm & Gray), Verticillium lecanii (Zimmerman), and Cephalosporium sp.…”

“…They are extracellular and are found in the digestive tracts and body cavities of hosts (Tanada and Kaya, 1993). Bjørnson (2008) reported that 0.2% of winter-collected H. convergens purchased from commercial suppliers were infected with eugregarines. Three different-sized eugregarines were collected, but none were identified.…”