U.K. expert finds fertile field of grain pests

Press, 22 June 1984, Page 24

U.K. expert finds fertile field of grain pests

Searching for tiny insects among millions of cereal grains has kept an English entomologist, Dr Patrick Cox, busy during a yearlong visit to New Zealand.

Dr Cox has hunted moths, beetles and mites in many South Island grain and seed stores and flour mills and some in the North Island.

His study has shown that most grain storage premises are contaminated by insects. Dr Cox is a senior scientific officer at the Slough laboratory near London, one of four laboratories of the United Kingdom Agricultural Development and Advisory Service. He is spending a year in New Zealand on exchange, working at the M.A.F.’s Plant Health Station at Lincoln.

Dr Cox specialises in insect pests of stored grains, and is one of 100 people at the Slough laboratory work-

ing on grain storage pest problems. Dr Cox has concentrated on storage moths while in New Zealand because Ittle was known about them.

Because insects were small, they could hide easily and were often inconspicuous, said Dr Cox. The main species of insects which contaminate stored grain are fairly common in temperate countries, including New Zealand and the United Kingdon. However, Dr Cox’s work in New Zealand has turned up the presence of a native moth, Archyala terranea, in three stores. The moth is

fairly common in the South Island, often observed near farm buildings and houses. But it had never before been associated with stored grain or cereal products, said Dr Cox. The moth’s presence in grain stores could indicate that it was developing into

a minor pest or scavenger of stored grain. It was discovered on grain residues and damp grain. The Mediterranean flour moth was the most common

type of moth infesting flour mills, said Dr Cox. The caterpillars secrete silk which forms a webbing, clogging milling machinery. The Mediterranean moth was the most important pest in the United Kingdom’s flour mills and it had been in New Zealand since the turn of the century. It became a major pest in the 1850 s and 1860 s when mills started using heat.

Most moths are secondary grain pests, which attack grain already damaged, but they are considered primary pests of cereal products, such as flour. Bettles are primary pests because they can tunnel into grains eating the inside and leaving the husks.