The cotton bollworm, Heliothis armigera Hubner, is the most serious pest of cotton in Thailand. A programme of screening chemicals for this insect in the field has been conducted since 1965 to discover the most effective insecticides and to establish a control strategy. This report gives a brief account of the history of insecticide use, beginning with endrin plus DDT, and toxaphene plus DDT during 1966-1983. Details of recent findings include some organophosphate compounds, one carbamate compound, one organic hydrocarbon, many synthetic pyrethroid compounds and some interesting insecticide tank mixtures. Insect resistance to the synthetic pyrethroids and some side-effects of certain insecticides are also discussed in the text. Alternate sprays between 2 different groups of chemical compounds is proposed for as one control measure.

Three species of pest mites are found in cotton in NSW and Qld: the two spotted mite, Tetranychus urticae, the bean mite, T. ludenli, and the strawberry mite, T. lambi. Of these T. urticae is the major pest, and has a level of resistance to the two organo-phosphate miticides currently used in cotton. Most growers apply between 1-3 expensive sprays ($20 - $40/ha) specifically to control mites each season. Mites can often be found in seedling cotton, but as the cotton undergoes a phase of rapid growth in November and December mites usually become scarce until mid-late January when mite numbers again increase.

Currently our district relies on weather data from St. George Queensland (4487), which is 95kms north of our town, Mungindi in New South Wales (110kms away) or alternatively Walgett, which is 205kms from our district. We have irrigated cotton growers in the district who rely on this information to make critical business decisions. Often the data from St. George, Mungindi or Walgett is not indicative of our district weather conditions or local historical data. A local weather station unit would solve this.

The scouting of cotton for eggs and larvae of Heliothis spp is a labour intensive and therefore expensive undertaking. The question arises whether cost savings could be made by using semi-automatic monitoring devices to partially replace crop scouting. This paper describes the advantages and disadvantages of light and pheromone traps and the information they can be expected to give, from experience gained in progressively developing trapping systems over the past eight years.

Early crop protection is a controversial subject in modern pest management. Grower magazines in Australia and the U.S. carry articles expressing firm opinions both for and against. Australian cotton growers remain divided on the issue. Two opposite philosophies have developed: the early strategists and the plant compensationists. Who should growers believe? What are the facts?

This travel was undertaken to participate in the CRDC one day forum on 'Soil Constraints' held at Moree on the 14th July.

The development and release of SIOKRA, the new okra-leaf variety, has created considerable interest with respect to pest management. The altered leaf shape of this cultivar, which results in a more open canopy, has led many growers to expect differences in its attractiveness to Heliothis in particular, and to other insect pests in general. Indeed, many growers and consultants have commented on the apparent reduction in Heliothis and in the number of sprays applied to SIOKRA crops. The SIRATAC database confirms this trend.

Heliothis spp. have two main attributes which give rise to their pest status and make them difficult to manage (see Fitt this volume). Firstly both species exploit a wide range of host plants in addition to cotton, including most crops (eg. sorghum, sunflower, maize, and many others), and many weeds. Many of these hosts are extremely important in the seasonal dynamics of Heliothis populations and past research has identified the sequence in which they are used from spring through to autumn. These hosts represent the source of many of the moths which colonise cotton crops, but at present we have no way of estimating the relative importance of intercrop movement in the dynamics of Heliothis on cotton or the contributions of different crops to the local population. The second important attribute is that Heliothis moths are highly mobile.

Attendance and presentation of a scientific research paper at the joint conference of American Societies of Agronomy, Soil Science and Crop Science at Phoenix, Arizona, USA (https://www.acsmeetings.org). Additionally, meetings with University of Arizona and USDA-ARS staff (Maricopa Research Centre) conducting research on alternative sources of irrigation water and cotton farming systems in saline and sodic soils and then on return, updating University of Southern Queensland(USQ) researchers on current research on using wastewater for irrigation.

The travel undertaken consisted of (a) Pre-conference tours on regional pedology (4-5 November 2016) and irrigated cropping systems of central Arizona (6 November 2016). (b) Attend and present paper at the international joint conference of the American Societies of Agronomy, Soil Science and Crop science. Approximately 4000 oral and poster papers were presented at the conference which was attended by around 6000 delegates. (c) Visit Arid Lands Research Centre of the University of Arizona and the USDA Agricultural Research Service. I was hosted by Dr. Clinton Williams, soil scientist at the centre. Dr. Williams’ research focusses on issues related to saline water and effluent irrigation. (d) Visit to University of Southern Queensland for discussions with Dr. Jon Bennet and Aditiya Dang.

The resulting outcomes from Dr Hullagale's participation were lengthy

(1) Exposure of my research results to an international audience (number of attendees at this conference usually exceeds 4000). The feedback received will enhance formulation of future research activities.

(2) Interaction and discussions with soil scientists and agronomists working on alternative irrigation water sources and irrigated cotton farming systems in saline/sodic soils of semi-arid and arid zones will facilitate future collaborations.

The above topics are highly relevant to Australian cotton farming systems. The reduced availability of irrigation water due to drought and legislation, and its increasing cost suggests that alternative sources of water, its management and impact on soil quality will be of increasing importance in the future. Sodicity is common, and transient salinity during drought years is not uncommon in Australian cotton soils.

(3) Current USQ project on wastewater irrigation refined in the light of recent US research on wastewater irrigation.

Of the five species of Heliothis in Australia, only two, Heliothis armigera and H. punctigera are major economic pests. They are clearly the major pests of cotton in all production areas. My comments in this paper refer only to these two pest species.