Sampling black field cricket (Teleogryllus commodus) eggs

Abstract

Black field cricket, Teleogryllus

Pasture production losses from black field cricket (Teleogryllus commodus) attack

“…Thirty-seven of the paddocks used were located on 6 farms in the Dargaville-Ruawai area on the estuarine flats of Kaipara clay soil. Three additional paddocks, near Whareora on a Whareora clay loam, were studied in 1980. In 1981, an additional 6 paddocks were studied at Titoki on a Pakotai clay soil.…”

“…For pasture production measurements, cages were placed over pasture which had been trimmed to a height of 20 mm with a lawnmower. After 4-8 weeks, the pasture, which was protected from stock by the cages, was harvested to ground level within a 0.715 X 0.466 m quadrat (0.3332 m2) using a The 1981The , 1982The , and 1983 pasture measurements estimated the amount of residual by cutting trimmed pasture alongside the cage to ground level. This residual was then subtracted from the production cut to obtain an estimate of pasture production.…”

“…The 1979 and 1980 cuts were adjusted for residue determinations using estimates of trimmed pasture obtained in the 1982the and 1983the seasons. In 1979the , 1980the , and 1981, pasture cages were set up between 11 and 17 December and the first cut taken during 9-18 January. In 1982 and 1983, pasture cages were set up during 23-26 November and the first cut taken during 6-13 January.…”

“…Pasture production cuts usually stopped at the end of June or the beginning of July although, at some sites, cuts were continued for another 2 months. A sample of herbage taken from within the cages was dissected into pasture species in January, March, and May 1979, 1980, and 1981. In the 1982and 1983 trials, a sample of herbage was dissected into species at each pasture cut.…”

“…The quantification of damage caused by crickets is an essential prerequisite to determining the need to apply control measures. Preliminary quantitification of pasture loss involved confining crickets in cages over a Poa spp.-ryegrass-white clover pasture (Blank & Olson 1981) on a Northland clay soil. In those trials, low densities of 5 crickets/m 2 caused estimated pasture losses of 1.8 kg dry matter (DM)/ha per day (a grazing pressure equivalent to about 1.5 ewes/ha per day), and high density populations of 60 crickets/m 2 caused losses of 25 kg DM/ha per day (equivalent to 21 ewes/ha per day), or a total seasonal pasture loss of 2920 kg DM/ha.…”