For many low-income farmers, commercial pesticides are too costly to use. Seemingly, the next best option for many is to turn to homemade botanical insecticides using local sources. But how reliable are these resources, and are they safe to recommend?
A CABI-authored paper published in Agronomy for Sustainable Development reviews the efficacy of some of the most commonly used homemade botanicals in controlling insect pests. This paper specifically focuses on previous studies that tested homemade preparations under “realistic local field or storage conditions”, as there has been no previous in-depth review on this particular topic.
A new study has brought to light how native bat species in Madagascar are playing an important role in the control of agricultural crop pests. If more attention and information was brought to this, zoologists from the University of Cambridge believe that bats could reduce the financial strain on farmers for chemical pesticide use as well as the need to convert forests into fields. Continue reading →
An adult male coconut rhinoceros beetle. Emmy Engasser, Hawaiian Scarab ID, USDA APHIS ITP, Bugwood.org
10 years ago the Coconut Rhinoceros beetle (CRB) was first discovered on the western Pacific island of Guam. Since then, these shoe-shine black, miniature invaders have spread to all parts of the island and are laying waste to the local coconut and oil palm population. The economy, culture and ecology of Guam and other Pacific islands are intrinsically linked to the native palm species such that the rhino beetle poses a major threat. The indigenous peoples of Guam have a long history of weaving palm fronds, an artistry that is now at risk due to the rhino beetle. These trees are a symbol of tropic paradise, a motif that drives Guam’s primary industry; tourism. Continue reading →
A facility has been launched in Kenya to aid commercial production of a protein bait to control fruit flies in Sub-Saharan Africa. The US$250,000 facility, which resulted from public-private partnership involving the International Centre of Insect Physiology and Ecology (icipe) and Kenya Biologics Ltd, will enable smallholders control fruit flies that devastate their fruits and vegetables.
A recent study carried out in Costa Rica found that insectivorous birds such as the Yellow Warbler help to reduce infestations of the Coffee Berry Borer Beetle on coffee plantations by 50%. This free pest control service is estimated to save a medium sized coffee farm up to $9,400 per year. The study carried out by biologists from Stanford University could provide incentive for biodiversity conservation and enhancement of ecosystem services and also offer hope to coffee farmers devastated by the beetle.
A new protein discovered in the venom of Australian tarantulas can also kill insect pests that consume the venom orally. The protein known as orally active insecticidal peptide-1 (OAIP-1) was found to be highly toxic to insects that consumed it, with a similar efficacy to the neonicotinoid insecticide imidacloprid. In particular, the protein was found to be highly toxic to the cotton bollworm, Helicoverpa zea.
Many spider species have evolved insecticidal toxins in their venom, which they inject into the prey through their fangs. Consequently it has often been presumed that the venom would not be toxic when ingested orally by insects pests, and therefore would not be suitable for use as an insecticide. Conversely, the scientists in this study discovered it is possible to isolate spider venom peptides with high levels of oral insecticidal activity. The team used the venom from Selenotypus plumipes which is a large tarantula native to Australia which despite its large size is not harmful to humans.
Transgenic Bt crops have been grown around the world since the 1990s and have contributed to increased yields by controlling agricultural pests. Due to the importance of this technology, there has been continuous study into the development of resistance to Bt crops and how best to avoid this happening. A recent investigation into the rapid spread of Bt resistance in South Africa has revealed one of the more surprising discoveries to date, that the maize stalk borer (Busseola fusca) has evolved Bt maize resistance inherited as a dominant trait for the first time. This has significant impacts on the management of Bt crops, as current methods for sustaining susceptibility rely on the recessive inheritance of Bt resistance.