Yield of southern highbush blueberry (Vaccinium corymbosum) using the fly Calliphora albifrontalis (Diptera: Calliphoridae) as a pollinator

Abstract

Southern highbush blueberry plants (Vaccinium corymbosum hybrid) from a commercial blueberry farm were placed in quarantine glasshouses and either exposed to adults of the western golden-haired blowfly Calliphora albifrontalis (Malloch) or no insects at all over a 21-week period. Laboratory reared C. albifrontalis were regularly released into one house to maintain a population of 1000-1500 flies. Flies could only obtain sugar from the plant flowers, and there was sufficient water from the leachate fraction draining out of each bagged plant. Berries were harvested at least twice weekly from the bushes over 21 weeks (46 harvest dates), and yield (both total berry weight and numbers) recorded. Temperature and humidity were very similar between the glasshouses, and plants were irrigated daily with 2.5-4 L/plant as per the producer's recommendations. Adult C. albifrontalis required at least 1.5 flowers/fly to survive. Both more berries (17.14 kg from 9108 berries vs. 10.43 kg from 6379 berries) and larger berries (1.88 vs. 1.63 g/berry) were produced by the bushes with adult C. albifrontalis present. Mature berries are ready to pick ≈10 weeks after flower opening. This study showed that yield between the two treatments began to differ 11 weeks after the flies were first released. Berry yield remained higher in the house with flies (11.29 kg from 6177 berries at 1.83 g/berry) compared with those plants without flies (4.98 kg from 3427 berries at 1.45 g/berry. Berry size was positively correlated with seed numbers. This is the first demonstration under controlled conditions of the ability of an Australian calliphorid blowfly to pollinate and increase yield of commercial blueberry bushes.

Blow flies (Diptera: Calliphoridae) ability to pollinate Hass avocado trees within paired tree enclosures

“…Calliphora albifrontalis was previously shown to be an effective pollinator of blueberries in a glasshouse study, where both more berries and bigger berries were produced from bushes with this fly present during flowering compared with bushes without any insect pollinator (Cook, Deyl, et al, 2020). However, C. albifrontalis was not an effective pollinator of Hass avocados in this study as there was not significantly more fruit set when compared with trees where insects were excluded.…”

Pollen associated with a Texas population of blow flies‐(Diptera: Calliphoridae) highlights underappreciated aspects of their biology

“…First, while they are already known to be pollinators, the full potential of blow flies and other dipterans may be underappreciated and could be exploited in some instances to enhance pollination efforts (Cusser et al, 2021; Moophayak & Meeinkuirt, 2017; Taka & Yee, 2023). Despite not being as efficient as bees on a per‐visit basis (Howlett et al, 2017), the frequency of fly visits may contribute significantly to pollination services of many plants (Cook et al, 2023; Kearns & Inouye, 1994; Zheng et al, 2011). One known example of such a strategy can be found in the use of mutton hung from trees to draw carrion flies to pollinate mango (Cook et al, 2020).…”

Observations of nectarivorous birds and potential biological control agents in berry orchards

“…also pollinate blueberry flowers, but they are not present on mainland Australia, only on the island state of Tasmania (Kingston et al, 2002). In addition to bees, flies have also been recorded as blueberry pollinators (Cook, Deyl, et al, 2020; Cook, Voss, et al, 2020). A large number of flies, however, are not often seen visiting blueberry flowers under field conditions (Goodman & Clayton‐Greene, 1988; Kendall et al, 2020).…”