Discovery of two non-native mealybugs in Germany: Conicosoma gracile and Puto barberi (Hemiptera: Pseudococcidae, Putoidae)

Abstract Scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) are obligate phytophagous insects that often become pests on ornamental plants, particularly indoors. Due to their purpose, botanical gardens require the constant exchange of plant material to maintain and enhance their living collections. Exotic scale insects are frequently introduced into Europe via this pathway, potentially threatening local flora and fauna. As part of a larger sampling effort in several German botanical gardens, two non-Palaearctic mealybugs were identified in the Botanical Garden of the University of Hamburg, namely Conicosoma gracile De Lotto, 1971 (Pseudococcidae) and Puto barberi (Cockerell, 1895) (Putoidae). Conicosoma gracile is an Afrotropical species restricted to South Africa; it is well adapted to indoor conditions and is regarded as a pest of Aizoaceae in the Hamburg Botanical Garden. In contrast, P. barberi is a Neotropical species, distributed across the Caribbean and Central America, with populations and damage on its host plants currently remaining low. Photographs of each species in situ are provided, along with microphotographs illustrating diagnostic characters. A discussion of their introduction, biological traits, and potential implications for local flora and fauna is also included. With these two new records, the diversity of Pseudococcidae in Germany increases to 59 species, and that of Putoidae to three species, underscoring the role of botanical gardens as entry points for non-native scale insects.