Bemisia tabaci biotype B is a significant pest of agriculture world-wide. It was first detected in Australia in 1994. Assessments of the potential of parasitoids already present in Australia to control this pest indicated that two species of Eretmocerus and 11 species of Encarsia were present, but they did not exert sufficient control with a combined average of 5.0+/-0.3% apparent parasitism of 4th instars. Further, only 25% of samples containing biotype B had parasitised individuals present. The surveys also identified that fewer B biotype were being parasitised compared with the Australian indigenous biotype. Overall, Er. mundus was the most abundant parasitoid prior to the introduction. Previous research indicated that Er. hayati offered the best prospects for Australia and, in October 2004, the first releases were made. Since then, levels of apparent parasitism have averaged 29.3+/-0.1% of 4th instars with only 24% of collections having no parasitism present. Eretmocerus hayati contributed 85% of the overall apparent parasitism. In addition, host plants of the whitefly with low or no parasitism prior to the release have had an order of magnitude increase in levels of parasitism. This study covers the establishment of the case to introduce Er. hayati and the post-release establishment period November 2004-March 2008.

The reproductive condition and mating status of female Helicoverpa armigera (Hübner), H. punctigera (Wallengren) and the mating status of the armywormMythimna convecta (Walker), trapped in tower-mounted light traps were studied over a four and a half year period, from November 1985 to December 1989. The traps were mounted on towers (40 and 50 m high) in two geographically distinct sites, one located at Point Lookout and the other at Mt Dowe both in north-eastern New South Wales, Australia. At the Point Lookout site, 132 females of H. armigera and 366 of H. punctigera were examined and of those, 88.7% and 89.9% were unmated and immature, respectively. Most of the remaining females of both species were mature and mated. Of the matedH. armigerafemales, 78.6% carried only a single spermatophore, the remainder having either two or three spermatophores. Most of the matedH. punctigerafemales (97.1%) carried only a single spermatophore and the remainder had no more than two. Females ofM. convectawere predominantly (97.1%) unmated. At the Mt Dowe siteH. punctigeraadults were predominant and all 44 females of this species examined were unmated and non-gravid. Pre-reproductive flight byHelicoverpaspp. andM. convectais considered as an important component of the life-history strategies of these insects. Flexibility in the timing and spacing of reproductive effort is seen as enabling colonization of heterogeneous environments.

Catches of moths in tower-mounted light traps in northern New South Wales were analysed in relation to local and synoptic weather. Catches were correlated with windspeed, relative humidity and possibly rainfall. No correlations were obtained with temperature or moon phase. Catches were more likely to occur when winds were from the east, and were associated with wind shifts. There was a significant association with the passage of depressions or troughs, but not cold fronts. The traps were considered to be poor indicators of migration associated with fronts, because these were accompanied by high winds in which trap efficiency was reduced. Stepwise multiple regressions using temperature, relative humidity, rainfall and windspeed accounted for only about 25% of the variance, much lower than in comparable studies with ground level light traps. These results are thought to indicate that the trap catches were reflecting long-distance migration, which was usually associated with disturbed weather. Back tracking with upper wind data was used to define probable sources of moths. In the spring and early summer, these sources were predominantly to the north and west of the traps, in semi-arid pastoral and subhumid cropping zones. In the late summer and autumn they were predominantly to the south and east, in the humid pastoral and forest zone. These results are discussed in relation to the migratory strategies of several important agricultural pest species.

Light traps were operated between September and April for five years on towers on mountain tops at two locations in northern New South Wales, Australia. The traps were designed so that their lights could only be seen from above, and therefore only insects engaged in high altitude flight, presumed to be migrants, were captured. The catch consisted mostly of Noctuidae and Sphingidae. Sweep netting failed to reveal local breeding, and for many species there were few host plants close to the traps. A total of 51,580 moths were trapped at Point Lookout and 10,223 at Mt Dowe. Sphingids, mostly Hippotion scrofa (Boisduval), comprised 26.9% of the catch at Point Lookout, but only 2.6% at Mt Dowe, and there were more species of noctuids at Point Lookout (44) than at Mt Dowe (15). The most common noctuid species were Agrotis infiisa (Boisduval), Mythimna convecta (Walker), Helicoverpa punctigera (Wallengren), H. armigera (Hiibner), Dasygaster nephelistis Hampson and A. munda Walker.Known or suspected migrants comprised 94.6% of the catch at Point Lookout and 99.9% at Mt Dowe. However, there were at least 24 species not previously suspected as migrants. The seasonal distribution of catches varied between sites and years. Some species showed peaks in both spring and autumn in some years, but only in spring in other years. Many of the less common species were caught only in summer and autumn. Large catches were usually obtained overs short periods (1-2 nights), separated by long periods when catches were very low. These large catches, which were thought to represent major migrations, accounted for 76% of the catch in 3% of the trapping period at Point Lookout, and 87% of the catch in 2% of the trapping period at Mt Dowe.

In this study, we investigated patterns of egg production and inclusion of bacterial endosymbionts in the whiteßy Bemisia aff. gigantea Martin, a species native to lowland tropical rain forests of North Queensland, Australia. Development of the female reproductive system of B. aff. gigantea becomes evident in fourth instar/pharate adults, with extensive accumulation of mature (chorionated) eggs occurring 1Ð2 d before adult eclosion. Evidence from light and electron microscopy indicates that bacteriocytes (specialized cells containing bacterial endosymbionts) appear scattered through the abdominal region in close association with the developing eggs. In pharate adults, bacteriocytes seem to enter developing eggs basally through the pedicel, and after oviposition they move distally from the pedicel as the embryo matures. In addition, developing ova without bacteriocytes were evident in 3-d-old females, indicating that oogenesis and bacteriocyte inclusion is an ongoing process.RÉ SUMÉ Dans cette é tude, nous nous inté ressons à la production dÕÏufs et à lÕinclusion de bacté ries endosymbiotiques de la mouche blanche Bemisia aff. gigantea Martin, une espè ce originaire des plaines des forê ts tropicales du nord-est de lÕAustralie. Le dé veloppement du systè me reproducteur femelle de B. aff. gigantea appraõt au stade adulte pharate, avec une importante accumulation dÕÏufs matures se dé roulant 1 à 2 jours avant lÕé mergence de lÕadulte. Des observations aux microscopes optique et é lectronique montrent que les bacté riocytes (cellules spé cialisé es contenant les bacté ries endosymbiotiques) sont dispersé s dans la ré gion abdominale en relation é troite avec les Ïufs en dé veloppement. Au quatriè me stade larvaire et au stade adulte, les bacté riocytes pé nè trent dans les Ïufs en dé veloppement par la base, au niveau du pé dicelle. Aprè s lÕoviposition, ils sÕé loignent du pé dicelle au fur et à mesure que les embryons se dé veloppent. De plus, des Ïufs en dé veloppement sans bacté riocytes sont pré sents chez des femelles de three jours, indiquant que lÕoogé né sis et lÕinclusion de bacté riocytes sont des phé nomè nes continus. KEY WORDS Bemisia aff. gigantea, egg maturation, pharate adults, endosymbionts, bacteriocytesMuch of our understanding of whiteßy biology and ecology is based on a restricted number of species that occur as pests of horticulture and agriculture (Gerling 1990, Byrne and Bellows 1991, De Barro 1995. Life history traits contributing to the pest status of these species often include extreme polyphagy of primarily herbaceous plants, high dispersive and/or invasive potential, high reproductive output, and ability to transmit plant viruses. Such species are typiÞed by the cosmopolitan whiteßy Bemisia tabaci (Gennadius) with its numerous biotypes, and the greenhouse whiteßy Trialeurodes vaporariorum (Westwood). The life history traits displayed by these pest species are, however, not necessarily representative of the wider Aleyrodidae. Most Aleyrodidae are largely innocuous inhabitants o...