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AbstractMany ground-nesting bees are known contributors to crop pollination, but only a few specialist pollinating species are managed within agricultural systems. On the whole, most species (including the very large genus Lasioglossum) have been ignored for their crop pollination contribution, largely because of their perceived inability to be effective pollinators. Lasioglossumspecies are globally very widespread, including across many different environmental and ecological niches. Scattered reports provide credible evidence that these commonly small bees are effective pollinators across a wide range of crops, particularly as they often nest in close aggregations and may be present in crops in large numbers. Given the frequency and flexibility of this genus as flower visitors of many crops, further research to assess their effectiveness as pollinators deserves much greater focus. This is starting to change as assessments begin highlighting their effectiveness as pollinators of a range of crops. Preliminary attention is now being placed on developing potential management (or at least population-influencing) practices to enhance their use.

ABSTRACTWhite clover (Trifolium repensL.) seed crops require insects for pollination. Apis melliferaLinnaeus, 1758 are normally placed within fields but other insects might also be contributing additional pollination. To understand their potential contribution, we evaluated abundances across fields during peak flower; measured loose body pollen on four bee and two fly species and compared the rate of movement between inflorescences and florets for A. melliferaand B. terrestris(Linnaeus, 1758). A. melliferawere the most abundant verified flower visitor, although B. terrestrisand long-tongued Bombusspecies also visited fields. Other insects recorded included Lasioglossumbees and two hover fly species, but these were considered ineffective pollinators (either low abundances or carried few pollen grains). B. terrestriswere considered a more efficient pollinator than A. melliferamoving faster between florets but were less effective due to low abundances. Many Bombusspp. will forage under weather conditions unfavourable to A. mellifera, therefore, providing complimentary pollination.

Small hive beetles (SHBs), Aethina tumida(Coleoptera: Nitidulidae), are parasites and scavengers of honey bee colonies in their endemic range in sub-Saharan Africa as well as in their new distribution range. Even though flowering plants may in principle also serve as a food for SHBs, evidence so far suggest that this beetle is unlikely to visit flowers. However, field data remain scarce calling for more efforts to investigate the potential of flowers as reservoirs for this pest of social bees. Here, we conducted extensive field surveys of flowering plants in Australia. Despite the very large sample size, not a single adult SHB was found on any of the flowers. This is in line with an earlier field survey. Since SHBs were also absent from fruits in another surveys, it appears as if alternative food sources outside of bee colonies are of minor importance only for SHBs.

Paropsine leaf beetle larvae from the genera Paropsisand Chrysophthartacan cause extensive defoliation to eucalypt stands in Australia and New Zealand. The larvae prefer immature leaves but the late instars (beyond the 2nd) consume most leaf material. With the consumption of all immature foliage and softer shoots, feeding on mature leaves might be necessary to complete larval development. Few studies have examined whether late instar larvae are able to establish on mature leaves, so the ability of 3rd and 4th instar C. bimaculata(Olivier) larvae to establish on mature Eucalyptus regnans(F. Mueller) leaves was tested. Groups of five larvae were placed on individual mature leaves with toughness ranging from 92.1 and 93.5g as measured with a penetrometer. Additional larvae were reared from neonates to pre-pupation under similar laboratory conditions to compare survivorship on the preferred immature leaves. The 3rd and 4th instar larvae did not establish on mature leaves although 10% of the 4th instar larvae developed into pre-pupae. In contrast, 76.7% of the larvae developed from neonates to prepupae on the immature leaves. If these findings were reflected in the field then C. bimaculatalarvae would be restricted to feeding on immature foliage. When C. bimaculatalarval densities are high then trees with the fewest immature leaves will suffer the least defoliation.