Coconut Rhinoceros Beetle on Guam – an update

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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

Cassava virus resistance breakthrough for Africa

Cassava roots
Cassava is a staple food for millions but is susceptible to viruses that make it unpalatable © Seth Anderson (CC BY SA license)

One of the worst diseases of the tuber crop, cassava, in sub-Saharan Africa is Cassava brown streak disease (CBSD). Since its resurgence in East Africa in recent years, it is now spreading to Central and Western Africa. The other major disease of cassava in this region, Cassava mosaic disease (CMD), can also cause widespread damage to the crop, however there already CMD-resistant varieties of cassava available. Until now, very little natural resistance to CBSD has been found. Plant scientists at the Swiss Federal Institute of Technology (ETH) Zurich have combined natural resistance to CMD with modifications of the cassava genome to develop a variety of cassava resistant to both CBSD and CMD that can be grown in Africa. As cassava is a staple food to millions of people, this new variety has the potential to halt the spread of the disease and prevent famine from crop losses. Continue reading

Does rust-free rice hold the secret?

All cereals, except rice, are susceptible to rust. Wheat, maize, barley, millet, triticale, and oats all get rust. The spores of rust fungi land on a host plant, germinate, and grow toward a stomatal pore on the leaf surface to initiate infection. Rust infections produce red or yellow pustulating spores that give infected plants a “rusty” look. In susceptible plants, rust cuts off the plants’ ability to photosynthesise nutrients in their leaves and transport nutrients in their stems, causing stems to weaken and plants to fall over, making what little yield there is nearly impossible to harvest.

Rice, the “stainless steel” among cereal grasses, has long intrigued plant breeders and plant pathologists. For decades scientists have believed that, by discovering the genes that make rice immune to rusts, they might be able to introduce these genes into other cereal grains such as wheat and maize.

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Hessian fly heading for the sack

Wheat crops suffer millions of dollars’ worth of damage each year due to the hessian fly, Mayetiola destructor. The most effective control method is genetic resistance, when wheat resistance genes cause death of the attacking larvae by activating a defense response against avirulent hessian flies. Unfortunately this has led to flies that can overcome resistant wheat and the need for regular evaluations of field collections of this pest.

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