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

Abstract

Pasture production losses caused by natural infestations of black field cricket (Teleogryllus com modus Walker) were quantified on dairy pasture on clay or clay loam soils in Northland. In 1980 and 1981, summer and autumn rainfall was above normal and cricket densities were too low (2-5/m2) to influence pasture production. In the dry 1979, 1982, and 1983 years, cricket populations were moderate (8-22/m2) and significantly affected pasture production. Responses from baiting crickets ranged from 0.4 to 1.3 kg dry matter (DM) ha-1 cricket-day-l m-2. A loss of 0.8 kg DM ha-1 cricketday-l m-2 would mean that a field population of 20 crickets/m 2 could cause a pasture loss of 1600 kg DM/ha. Pasture loss from cricket attack occurred primarily during February-April when growth was severely restricted because of low soil moisture.

Sampling black field cricket (Teleogryllus commodus) eggs

“…These investigations were carried out in conjunction with other studies investigating cricket damage and control which were undertaken on numerous sites throughout the North Auckland peninsula from 1978 to 1983 (Blank et al 1984(Blank et al , 1985(Blank et al , 1986. Sites most frequently used were on Kaipara clay soil in the Dargaville -Ruawai area; Whareora, Mata, Waipu, Pakotai, Whakapara clay soils in the Whangarei area; and Kaitaia, Rangiuru, Oponga, Okaka clay soils in the Kaitaia -Mangonui area.…”

“…Sites most frequently used were on Kaipara clay soil in the Dargaville -Ruawai area; Whareora, Mata, Waipu, Pakotai, Whakapara clay soils in the Whangarei area; and Kaitaia, Rangiuru, Oponga, Okaka clay soils in the Kaitaia -Mangonui area. These soil types are examples of the gley, yellow-brown earth, brown granular loam, and clay soils which occupy about 80% of the North Auckland peninsula and are susceptible to cricket attack (Blank 1985). Sites were variable in size, ranging from 0.5 ha paddocks on dairy farms to 5 ha areas on sheep and beef farms.…”

“…These nymphs pass through eight moults before becoming adults in February -March. The large nymphs and adults consume over half their bodyweight of herbage per day and can cause considerable pasture loss and damage (Blank & Olson 1981;Blank et al 1985). Eggs are laid in moist soil in autumn and the adult crickets then die of old age.…”

Black field cricket (Teleogryllus commodus) oviposition and egg survival

“…Cricket density and the proportion of adult crickets present were determined using 12 pitfall traps per paddock from 1979 to 1981 and four flushing counts in 1982 (Blank et al 1985). The numbers of mature eggs present in the oviducts of adult females were determined by dissecting 10 females from each density assessment.…”

“…The black field cricket is an important pasture pest, particularly in dry years, in northern regions of New Zealand (Blank et al 1985). The first instar nymphs hatch from the overwintering egg stage, usually during October -December, and pass through eight moults before becoming adults in summer or autumn.…”