A synthetic blend of the aggregation pheromone [(3R,4S,1'E)-3,4-bis(1'-butenyl)tetrahydro-2-furanol, linalool, farnesol, and nerolidol] of the spined citrus bug,Biprorulus bibax, and the pentatomid defense chemical, (E)-2-hexenal, both attracted adultB. bibax to individual trees in citrus orchards. Lemon trees containing single glass vials with aggregation pheromone or (E)-2-hexenal were colonized by significantly greater numbers of reproductiveB. bibax than unbaited trees. There was no significant difference between the treatments and bug recruitment was not improved by using both treatments.B. bibax did not enter cylinder/funnel traps baited with aggregation pheromone but colonized trees containing the traps. Orange or lemon trees containing aggregation pheromone on orchard perimeters recruited significantly larger populations of emigrating, nonreproductiveB. bibax during fall than untreated trees. Nonreproductive bugs were not attracted to trees containing (E)-2-hexenal. The potential for using these semiochemicals as management tools forB. bibax is discussed.

Cybocephalus aleyrodiphagus sp.n., a predator of Australian citrus whitefly, Orchamoplatus citri (Takahashi), is described from adults and larvae collected from southern New South Wales (where it appears to be the major natural enemy of O. citri) and South Australia. Eggs of C. aleyrodiphagus are laid singly near egg circles of O. citri and larvae feed on eggs, crawlers and nymphs. Adults feed on all immature stages of O. citri. Reproductive, but not non‐reproductive, females contain greater quantities of stearic, oleic and linoleic acid than males indicating the possible presence of a sex pheromone. In southern New South Wales, C. aleyrodiphagus sp.n. overwinters as non‐reproductive adults and produces two adult generations during December‐January and March‐May. the sex ratio is close to 1:1 during October‐December (overwintered adults) but male biased (2.2:1) during January‐July (new generation adults). Trends of abundance for C. aleyrodiphagus correspond well with those for O. citri nymphs/pupae indicating a functional response of the predator to prey, despite disruption by foraging ants.