Euwallacea spp. (Coleoptera: Scolytidae) are polyphagous globally distributed invasive ambrosia beetles. One of the species was recently detected attacking Ricinus communis growing in Coffea canephora gardens in Uganda. This study was undertaken to: (a) determine the distribution, incidence, and relative abundance of Euwallacea sp. on R. communis in Uganda; (b) determine the influence of the presence of C. canephora on the incidence and abundance of Euwallacea sp. on R. communis; and (c) identify ambrosia fungus of Euwallacea sp. on R. communis. Five C. canephora farms with R. communis and five others with R. communis but without C. canephora were sampled in each of the six districts surveyed. Incidence of Euwallacea sp. on R. communis was measured, by inspecting the host trees in each farm for the presence or absence of the pest. Abundance of Euwallacea sp. on R. communis was estimated, by counting holes of Euwallacea sp. at the lower 1.7 m of R. communis stems. A fungus was isolated from galleries of Euwallacea sp. on R. communis and identified. Results show that Euwallacea sp. was present on R. communis in all districts surveyed, with 30–70% of the farms infested in each district and 5–28 holes of Euwallacea sp. found on each sampled stem of R. communis. Coffea canephora appeared to facilitate the infestation of R. communis by Euwallacea sp., although it did not seem to influence the multiplication of the insect inside the host. Cunninghamella echinulata appeared to be the ambrosia fungus associated with Euwallacea sp. Therefore, Euwallacea sp. is a threat to many economically important plants in Uganda that are known to be hosts of this pest.

The aim of this study was to verify the occurrence of the coffee berry borer, Hypothenemus hampei (Ferrari), and to evaluate the population fluctuation of the pest in the Brazilian Cerrado (Federal District). The study was conducted, between November 2014 and October 2015, at Embrapa Cerrados (Planaltina/DF, Brazil) in an irrigated conilon coffee production area. In November 2014, 120 samples (ten berries/sample) were collected from berries that had fallen on the ground from the previous harvest. Between November 2014 and October 2015, insects were collected weekly, using traps (polyethylene terephthalate bottles) baited with ethyl alcohol (98 GL), ethyl alcohol (98 GL) with coffee powder, or molasses. Between January and July 2015, samples were collected fortnightly from 92 plants (12 berries per plant). All samples were evaluated for the presence of adult coffee berry borers. Samples from the previous harvest had an attack incidence of 72.4%. The baited traps captured 4062 H. hampei adults, and showed no statistical difference in capture efficiency among the baits. Pest population peaked in the dry season, with the largest percentage of captured adults occurring in July (31.0%). An average of 18.6% of the collected berries was attacked by the borer and the highest percentage incidence was recorded in July (33.2%). Our results suggest that the coffee berry borer, if not properly managed, could constitute a limiting factor for conilon coffee production in the Brazilian Cerrado.