Can insect body pollen counts be used to estimate pollen deposition on pak choi stigmas

Abstract

Measuring pollen deposition onto stigmas by insects is one technique used to assess pollinator effectiveness but it can be unpredictable and timeconsuming as insects must visit test flowers This study examined whether a measurement of pollen grains from flowervisiting insects could be used to predict pollen deposited on stigmas Individuals were collected from four bee and six fly species as they visited pak choi flowers in commercial and trial seed fields to assess their body pollen Pollen was removed from insects by pressing their bodies (excluding activelycollected pollen on bees hind legs) with a cube of gelatinefuchsin In this study there appears to be a strong correlation between mean estimated pollen counts for each insect species and previously published data recording mean number of pollen grains deposited on stigmas for the same species Therefore the measurement of pollen grains directly from flowervisiting insects shows potential as a quicker and easier technique to assess pollinator effectiveness as insects can be directly collected from flowers

Global warming and plant–pollinator mismatches

“…The overall size matching will also determine the efficiency of pollen transfer: smaller pollinators (with on average shorter tongues) can have lower pollination efficiency (e.g. [59] but see [60]) through reduced pollen delivery, therefore, having a lower single-visit pollen deposition rate and seed set while large-or middle-sized species are, most of the time, more likely to have greater contact with anthers and stigma and therefore have a greater pollination efficiency [61]. Most of the studies have focused on pollen deposition and the pattern is largely constant.…”

“…Indeed, many other morphological features from both partners are driving pollination efficiency, notably hair characteristics (e.g. size and density) [58,59] which can also be impacted by temperatures during development [60]. Overall, morphological mismatches between plants and pollinators are most likely to occur within plant species displaying specialised flower morphologies as their morphological fit with pollinators is most restricted [51].…”

Native and introduced bee abundances on carrot seed crops in New Zealand

“…Although there are currently only 41 described introduced and native bee species in New Zealand (Donovan 2007), some of these may play an important role in crop pollination (Rader et al 2009;Davidson et al 2010;Howlett et al 2011;Rader et al 2012;Howlett et al 2013). There is a lack of published data on the abundance of both honey bee and other wild bee species between and within commercial hybrid carrot seed crops in New Zealand, information that is required to begin assessing their effectiveness as pollinators.…”

Are insect flower visitor assemblages distinguishable between Brassica napus and B. rapa?

“…In New Zealand, many crop species share a number of verified or potential pollinating species demonstrating their possible flexibility in multi-crop systems. At least four bee species and six fly species are pollinators of B. rapa (Rader et al 2009;Howlett et al 2011) and some of these have also been shown to pollinate a range of other crops including onion Allium cepa L. (Howlett et al 2017a); kiwifruit Actinidia.deliciosa (A.Chev.) C.F.Liang & A.R.Ferguson (Stavert et al 2016) and avocado Persea americana Mill.…”