Bee pollinators

By Anne-Marie Steyn, Msc. Environmental Water Management

The impending neonicotinoid ban in the EU, and its potential impact on farmers and pollinators, leads us to the question: How does pesticide use affect pollinators here in Kenya?

Pesticide use

Subsistence maize farmers, the majority, use very little fertiliser, let alone insecticides, except for situations such as the current FAW outbreak, and potatoes, the second largest crop, usually require only fungicides.

However, in higher value cash crops and export crops such as coffee, beans, tomatoes and various fruit crops, insecticide use can be high. Recent press coverage has shown residue levels on local produce such as tomatoes to be above international health authority levels.

Indeed, the majority of small holder farmers, though aware of the various risks of using pesticides, do not follow label instructions, and apply pesticides without due care or concern for PPE, application timings, pre harvest intervals, or pollinator activity. Observing such practices greatly reduce the risk of pesticide residues in crops.

pesticide residue level

Recent press coverage has shown residue levels on local produce such as tomatoes to be above international health authority levels

There is general consensus that the amount of insecticides being used in East Africa is increasing, and with this, the impact of those chemicals on local fauna.

There are over 40 neonicotinoid products registered in Kenya for use on crops ranging from coffee to tobacco, wheat and roses. African honey bees have been shown to be more sensitive to neonicotinoids than European honeybees.

Around a third of the pesticides approved for use in Kenya by PCPB are not approved in Europe because of their impact on human or environmental health. Pesticide labels show toxicity for humans but rarely LD50 for insects or pollinators – and with the low awareness about pollinators, and poor pesticide handling, it is unlikely that even label changes would cause pollinator related changes at the small scale farmer level.

However, there have been widespread and fairly rapid impacts in chemical use among export growers, as top down directives directly impact the pocket of the grower. Revision of MRL levels trickles down to a reduction in the use of chemicals and improvements in the handling of pesticides on crops by farmers involved in those value chains.

Thus, the neonicotinoid ban in Europe is likely to lead to similar knock on effect on neonicotinoid use in Kenya, which, though likely only restricted to export growers, is sure to have some beneficial impact on the country’s pollinators. Should the PCPB decide to follow EU’s suit and ban this class of chemical for outdoor agriculture, it might spur a shift toward, where possible, more biological pest control options.

Indigenous Pollinators and their crops

Pollinators in Kenya include the various types of bees, flies, butterflies, birds and bats. Some of the important cash crops are dependent upon pollinators including the Cucurbitaceae, Eggplant, Passionfruit, mango and so on.

It is well known that papaya plantations in wilder areas produce more, better quality fruit, due to the abundance of pollinators (Hawkmoths) and the reduced distances between habitat and plantation. Many coffee varieties can self-pollinate, but need pollinators for higher yielding and better quality crops. The Robusta variety depends on pollinators.

Crop pollination

Pollinators in Kenya include the various types of bees, flies, butterflies, birds and bats. Some of the important cash crops are dependent upon pollinators including the Cucurbitaceae, Eggplant, Passionfruit, mango and so on.

Crops such as eggplant and tomato are buzz pollinated, so it is important that there are places nearby for pollinators to get nectar, too – such as blocks of bush or forest. Furthermore, pollinators travel long distances, so community level pollinator awareness is required – especially for smaller scale farms.

The Environmental Management and Coordination Act provides an opportunity for communities to conserve areas which provide services such as pollinator habitat for their crops e.g. coffee farmers could apply for protection of forest segments as habitat for pollinators. It is well known that large scale monocultures are linked to poor pollinator populations, and intensive land use has been shown to decrease the number of pollinator species (though the latter does increase the number of individuals).

The use of commercial bee colonies for crops is virtually non-existent here, so wild populations of pollinators are of vital importance  to the country’s main GDP earner. Despite this, here is no Red List for pollinators in Kenya and the data on the status of pollinator populations in agricultural areas are few and far between

The impact of pesticide use on pollinators

Lack of awareness amongst farmers about what their crop’s pollinators look like leads to pollinators being mistaken for pests – e.g. spraying what they think are beetles, but are actually pollinating carpenter bees in passionfruit, and thus getting a crop failure.

There is a high incidence of blanket spraying – where farmers are routinely spraying their crops with various chemicals, but are unaware of why they do this and what they are targeting. Furthermore, improper spray timing means that many are spraying when pollinators are foraging – i.e. early morning and late evening, and spraying at flowering which is counterproductive.

Crop Spraying

Lack of awareness amongst farmers about what their crop’s pollinators look like leads to pollinators being mistaken for pests

 

Spray drift and poor disposal of pesticides means that adjacent wild areas, such as hedgerows, are also affected and therefore poor refuges for pollinators.

Unfortunately, misuse of pesticides in pollinator-dependent crops leads to a decline in crop yield, which is most commonly seen in high value fruit crops. Small studies have shown that conservation of hedgerows and nearby bush or forest blocks as pollinator refuges can contribute to increases in yields of these crops. Coupled with IPM pest management techniques, farmers can see an increase in crop health and productivity at the same time as they reduce their reliance on toxic pesticides.

Change

There are a number of changes that may be made forcibly, through export buyers demanding similar standards for products as are required by the destination country. There are also a number of changes that need to be made at a local level, driven by a need to conserve and improve environmental health and also the health of the farming community. These are summarised below:

Education and training on pesticide use:

  • Spray timing
  • Correct concentrations and toxicity levels (LD50s)
  • Local food safety standard enforcement with regards to pesticide residues
  • Reactive rather than blanket application (which can cause resistance)
  • Integrate or switch to biological control options
  • Educate extension workers – both public and commercial – who rarely recommend biological control methods for pests.
  • A caveat: though the majority of farmers can report a first hand toxicity event for themselves, a neighbour or local insect populations, they do not translate this risk into change of practice.
  • Not spraying hedgerows, fallow areas or other pollinator refuges
  • Improved pesticide disposal – which is frequently implicated in large mortality events of pollinators

Education and awareness of pollinators for each crop and diversity:

  • Pollinator identification by crop
  • Pollinator surveys and status
  • Pollinator diversity vs number of individuals
  • Conservation of wild areas for pollinator habitats – hedgerows, riparian areas, fallow land – at landscape scale

That just leaves the glaring question, who will bring about the changes?

Till next time,

Anne-Marie,

About Anne-Marie

anne-marie-steyn

 

Anne-Marie is a Water, Agriculture & Development Consultant working mainly in East Africa. Her specialty is in Water & Land Management, Crop Production, Dairy Farming, Wetland Conservation, Communications & Development.