Studies carried out to identify which pollinators visit which fruit crop flowers and how frequently.
With more efficient fruit pollination potentially raising productivity by 16 per cent, growers should be aware of creatures that pollinate their crops and how to encourage them, East Malling Research entomologist Dr Michelle Fountain told the recent Agrovista fruit technical seminar in Herefordshire.
“We are trying to grow more intensively, with more flowers per hectare, while expecting pollinators to do the same job,” she said.
Fountain and colleagues carried out studies of apple, pear and blackcurrant to see how many visits are made to each flower and by which insects. In all, 23 species visited apples, with bumblebees, honeybees and solitary bees in equal proportion.
“Solitary bees can’t travel as far so may not get into the middle of large orchards,” she said. As a pollinator, Andrena is the most significant genus of solitary bees and all UK species nest in bare soil – ideally sandy, south-facing banks, she added.
Blossoming earlier in cooler temperatures, pears attracted lower pollinator diversity but similar Andrena species, said Fountain. “You might want to supplement pollination with honeybees as they really like pear.”
Blackcurrants attracted a similar species diversity to pear but with honeybees playing a relatively unimportant part. Bumblebees, however, “did a really good job”.
“Building up a diverse range of pollinators gives you a more resilient crop”, Fountain advised. This includes providing forage by sowing appropriate perennial seed mixes because “you don’t want to have to start over each year”, she added.
Overlooked allies – Earwigs predate pests
Earwigs were thought to be a pest of apples because they are often found in holes created by other pests, Dr Michelle Fountain told the seminar.
“In fact, they are voracious nocturnal predators of pests,” and are even capable of breaching ants’ “aphid farms”.
Farm-scale trials showed that Chorpyrifos “killed everything”, as did Thiacloprid (Calypso) but more slowly, while others were found to be non-lethal to earwigs but slowed the insects’ growth. “You could replace Thiacloprid with Gazelle,” she suggested.