On page 188, the first sentence of paragraph 6 should read as “Seneciobium americanum was described from eight winged females caught in yellow water traps in Malargüe (Mendoza).”

Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a serious pest of greenhouse vegetable and ornamental crops across Canada (Broadbent et al. 1987). Upon completing larval development, F. occidentalis either pupates on their host plant or drops to the ground before pupation occurs (Lewis 1973). Because several soil-dwellers prey on or infect F. occidentalis pupae (Gillespie and Quiring 1990; Helyer et al. 1995), assessing the proportion of individuals that pupate on the ground is of critical importance for developing pest management strategies. The present study provides the first quantitative assessment of the pupation behaviour of F. occidentalis.

The 2-year-cycle spruce budworm, Choristoneura biennis Free. (Lepidoptera: Tortricidae), causes defoliation of spruce – subalpine fir forests in British Columbia, Canada. Historical and newly obtained data were used to develop a linear regression relating percent defoliation in the 2nd feeding year of the life cycle to the percentage of shoots damaged in the previous, 1st feeding year of the life cycle. The resulting regression was tested with independent data and correctly predicted (95% prediction intervals) defoliation in 14 of 15 stands. Patterns of defoliation were similar on white spruce, Picea glauca (Moench) Voss (Pinaceae), and subalpine fir, Abies lasiocarpa (Hook.) Nutt. (Pinaceae), and hence the regression can be used for either mixed or pure stands of either species.

The native balsam fir sawfly, Neodiprion abietis (Harris) (Hymenoptera: Diprionidae), occurs throughout Canada, Alaska, and the northern United States of America (Rose et al. 1994; Drooz 1985). This sawfly was originally described as Lophyrus abietis (Hymenoptera: Diprionidae) (Harris 1841), then transferred to the genus Diprion (Hymenoptera: Diprionidae) (MacGillivray 1916). Rohwer (1918) established the genus Neodiprion for Nearctic species of the genera Lophyrus and Diprion. Based on differences in size, color, and female genitalic characters between adults reared from the genera Abies, Picea, Pseudotsuga, and Tsuga (Pinaceae), Ross (1955) considered N. abietis as a complex. After a thorough morphological and physiological study, Knerer and Atwood (1972) concluded that there were five strains of N. abietis in North America: one western and four eastern.

In 2002, we evaluated the performance of imidacloprid-treated spheres topped by newly developed, rodent-protected, sugar/paraffin discs (that released sugar as needed, feeding stimulant onto the sphere surface) against apple maggot flies, Rhagoletis pomonella (Walsh). Commercial orchard plots (30 m × 30 m) surrounded by odor-baited, imidacloprid-treated, plastic spheres topped by 150-g discs (not replaced during the 12-week period of deployment) received no more immigrant adults or fruit injury than plots surrounded by odor-baited, imidacloprid-treated, wooden spheres topped by 50-g discs (replaced after 6 weeks), plots surrounded by odor-baited sticky-coated spheres, or plots sprayed two or three times with insecticide to control this insect. Approximately half of all apple maggot flies placed on imidacloprid-treated spheres not receiving additional sugar following retrieval from the plots died following exposure to spheres in the laboratory, irrespective of field-exposure duration (6, 9, or 12 weeks). Nearly all flies died when placed on orchard-exposed spheres that did receive additional sugar following retrieval. Future studies will aim at refining disc construction to ensure that all apple maggot flies alighting on imidacloprid-treated spheres will encounter feeding stimulant and be killed.

The timing of acaracide treatments for control of low-level populations of Varroa destructor Anderson et Trueman has implications for colony performance of honey bees, Apis mellifera L. (Hymenoptera: Apidae). Replicated colonies with low levels of V. destructor were left untreated, exposed to fluvalinate at each of two doses for 42 days, or exposed to three applications of formic acid, with the four treatments applied in either spring or fall. Varroa destructor densities were measured by alcohol wash and drop boards, and both gave similar estimates. Over the course of one season, the mean abundance of V. destructor increased from 0.002 to 0.11 mites per bee. Extended broodless periods during winter reduced the mean abundance of V. destructor by 28%, but mite mortality over winter was not high enough to prevent the need for treatment the following year. Apistan® was more effective than formic acid in both spring and fall treatments. Doses of one or two strips of Apistan® per colony were equally effective in spring or fall treatments. The mean abundance of V. destructor remained low throughout the season following spring treatment with either dose of Apistan®. Fall formic-acid treatments were more effective than spring treatments. Fluvalinate residues in samples of honey and wax collected from brood chambers and from honey supers were slightly higher in colonies treated with two strips of Apistan® than with one strip, but no detectible residue was found in extracted honey from 4500 commercial colonies treated in spring with Apistan® one strip per brood chamber for single or double storey hives. The levels of V. destructor in this study did not affect honey production or colony survival over winter.