REARING OF FIELD COLLECTED LARVAE OF THE MAHOGANY SHOOT BORER, Hypsipyla robusta (MOORE) ON AN ARTIFICIAL DIET A PRELIMINARY STUDY

Hypsipyla robusta (Morre) (Lepidoptera: Pyralidae) is an important pest of mahogany,Swietenia macrophylla (King) in Sri Lanka and world over. Larval attack at an earlystage of growth, leads to branching which reduces the quality and value of timber,significantly. Work is in progress to study the effect of shade on the growth anddevelopment of mahogany and attack by the shoot borer. This paper presents aspects ofdevelopment of shoot borer larvae reared on an artificial diet, as well as field informationrelated to damage and parasitism. Larvae collected from two field sites at fortnightintervals were reared in the laboratory on an artificial diet at 27-32° C. Development offield collected larvae were followed until the emergence of adults, during which duration ofthe developmental stages, adult sex ratio, parasitism level and mortality were recorded.Measurement of head capsule widths of larvae collected and their location on the shoot,was also made. A total of 774 larvae were collected and reared during the study, out ofwhich 120 Hypsipyla adults emerged giving a male: female sex ratio of 1:8. Nearly 40%of the field collected larvae were parasitized by Cotesia app. (Hymenoptera: Braconidae).Head capsule measurements indicated five larval instars that were found to infest differentparts of the growing shoot. Duration of development of larvae differed depending onwhether they were parasitized or not. Several problems encountered during rearing arediscussed

EFFECT OF SHADE ON LlMONOID AND NITROGEN COMPOSITION IN SHOOTS OF Swietenia macrophlla.(KING)

The main factor limiting cultivation of mahogany, Swletenia macrophylla King(Meliaceae), in plantations is damage by shoot borers (Hypsloyla spp.). Shade hasbeen repeatedly cited as reducing shoot borer attack but the responsiblemechanisms have not been determined by experimentation. Shade may altereither secondary compounds such as limonoids or nitrogen concentrations or bothin the plants making them unsuitable for insect survival and development.Previous studies have not examined whether shade influences Iimonoid andnitrogen content of S.marcrophylla and thereby alter shoot-borer attack.Therefore, these studies were designed to identify the variation in incidence ofshoot borer attack under three levels of shade treatments in the field conditionsand the variation in plant chemistry of Ssmarcrophylla shoots grown under threedifferent artificial shade treatments. The hypotheses tested were under high lightavailability (i) incidence of shoot borer attack increases (ii) the concentration oflimonoids present in the shoots of S. macrophylla decreases ind(iii) total nitrogencontent of shoots increases.This study was done from 1997-99 in Sri Lanka and UK. Attack by the shootborer was assessed 54 weeks after planting. The Limonoid content wasinvestigated by Thin Layer Chromatography (TLC) and the total nitrogen byKjeldhl method using freeze-dried ppowdered shoots. The incidence of shootborer attack was significantly higher under low shaade (dJ.=2, F=8.6, p=O.0003).The intensity of the green-blue fluerescence under UV seen in the TLC plates wasgreater using the extracts from the high shade treatment compared to that from thelow shade treatment. The total nitgrogent content was satistically lower in thehigh shade (1.l14± 0.22%, n=33) compared to that in full light (1.36± 0.22%;n=31). These results suggest that light environment may have a significant effecton the concentrations of limonoids and nitrogen in S.macrophylla which in turninfluences the shoot borer attack.The study forms part of a larger project on 'Silvicultural prescription formahogany plantation establishment; Research grant funded by DFlD, UK isgreatfullyacknowledged.

New research on the impact and control of Rutherglen bug in sorghum

RGB will reduce seed set in sorghum when present during flowering at densities in excess of 50 bugs per panicle (head). There is some compensation for this reduction in seed set. If RGB are present in sorghum through milky and soft-dough stages, they will feed directly on grain, impacting on seed size and quality. Feeding wounds will allow entry by bacteria and fungi, further discolouring and deteriorating the grain. From physiological maturity onwards, it is unlikely that RGB cause any impact on grain, but further research on this stage of infestation is ongoing. Alphacypermethrin and deltamethrin are the only effective options for controlling high densities of RGB in sorghum. Good coverage is critical to achieving good control. DPI&F is conducting research on control options, including biopesticides (fungal pathogens), that are effective against RGB without disrupting sorghum IPM

A scoping study of IPM compatible options for the management of key vegetable sucking pests: Final report (Project Number: VG06094)

BACKGROUND BRIEFING The availability of specific soft option products for other pests such as Lepidoptera species control in vegetables has increased the importance of sucking pests in the modern day pest spectrum. Current vegetable sucking pest management practices are still heavily reliant on older broad spectrum pesticides. These non selective products prevent further adoption of an integrated pest management (IPM) system, and their frequent, multiple crop use pattern has the potential to enhance resistance development in the pest population. A limited number of more recently developed, pest specific or “softer” products for example spinosad (Success®) and pymetrozine (Chess®) are registered in some specific vegetable crops. The management of sucking pests is also complicated by the fact that virus transmission and product contamination are as, if not more important than the physical damage they can cause to vegetable crops. To modernise sucking pest control in the vegetable sector, work in a range of overlapping multifaceted areas needs to occur. A team of entomologist in consultation with crop consultants, growers and specialist reviewers conducted a scoping study of the impact of at least 5 sucking pests commonly found across vegetable crops. Literature reviews, an industry workshop, interstate producer interviews and farm visits were employed to collate information on current best 'fit' management options within an IPM system, relevant to the particular vegetable and potential future management options. Ideas for future research, development, and extension activities highlighted in the workshop process included ; biopesticides, improved beneficial insect management in current cropping systems, monitoring and early warning, improved knowledge of pest ecology, resistance issues, improved soft option products, increased grower awareness and information, extension and publications. Developing and testing fungal biopesticides against sucking pests, managing insecticide resistance and field testing biocontrol agents against thrips were considered the top three topics for further research of 28 topics listed and prioritised by the workshop participants

Working with Invertebrate Pathogens in the Laboratory - Considerations for Improving Non-target Organism Testing

Registration of microbial control agents in Australia must face some of the most rigorous risk assessment regimes in the world. Requirements include not only safety and efficacy data but must satisfying strict legislation on importof non-native organisms.Laboratory bioassays attempt to address these requirements but face challenges in determining the potential harm from and exposure to these biological agents that would be found in field condition. This paper will present examples from the registration and release of microbial control agents, and discuss limits and potentialimprovement of laboratory risk assessment

DAQ00083 - Integration of biopesticides into IPM against sucking pests

Project DAQ540 has shown that pathogenic fungi have significant potential to be used as biopesticides against mirids, green vegetable bug (GVB) and Helicoverpa without impact on natural enemies, particularly to reduce early season pest pressure. Cloned, characterised fungal isolates of at least one fungal biopesticide were supplied to commercial interests and data to support registration and commercial production was analysed and reported. A decision model for mirids was developed and application extended to GVB. Focus groups with up to 12 growers or consultants were conducted near Toowoomba and at least one on-farm trial was carried out in Darling Downs, the Burnett or Central Queensland (QLD)

Biology and management of pest thrips (Thysanoptera: Thripidae) with reference to Australia. Contribution to the report VG 06094: A scoping study of IPM compatible options for the management of key vegetable sucking pests

This paper reviews the biology and distribution of the key thrips species in Australia, and then addresses different issues around thrips management and monitoring. We discuss the practical difficulties in identifying thrips and the lack of valid data on thresholds and damage, and discuss three situations requiring different approaches to management: thrips as disease vectors, economic damage through damage or yield loss, and phytosanitary restrictions on thrips for export or at market. There are also some situations in which control may not be necessary. We address the different management practices for thrips, and discuss options for management and further research in these different circumstances

Final Technical report: New technology for stored grain pest management

Australia depends upon insecticides to meet market demands for insect-free grain, particularly for export. Reliance on only a few products has led to widespread resistance by grain storage beetles such as Tribolium spp and Rhyzopertha dominica: Rhyzopertha is resistant to some degree to almost all registered grain treatments. The few alternative treatments available are expensive and some are not widely accepted by markets. New control options are urgently needed.High levels of mortality in both adults and larvae of Rhyzopertha and Tribolium, and in phosphine-resistant strains, was demonstrated using an ‘attract and kill’ approach based on microbial biopesticides. This approach was more effective and potentially cost effective than direct spray application to insects or to the fabric of buildings. Furthermore, infection wastransmitted at a high rate to untreated adults and larvae, an essential step in an ‘attract and kill’ approach.This project demonstrated that these internationally important pests can be killed by wellknown and characterised biopesticides with widespread commercial manufacture and international registration. An attract and kill approach could provide an effective, selective, low-hazard control for use in resistance management and control of pests in grain storage facilities such as silos and flourmills without direct application to the grain

Mealybugs and Pasture Dieback: Technical note

Mealybugs (soft-bodied scale insects) are sucking pests that attack pastures, cereal crops and turf grass in Australia and around the world. They are typically covered in a soft, waxy coat that gives them a white, ‘mealy’ appearance. This technical note describes common pasture mealybug species and impacts, and provides information to help landholders identify and mitigate against mealybug infestations

Pesticide bans might give us a buzz, but they won’t necessarily save the bees

Impacts of pesticides on pollinators are complex. A simple ban on neonicotinoids may not address the problems, and may have unwanted negative effects as farmers resort to older and more disruptive chemistry like synthetic pyrethroids. We need a substantial shift in pest management away from chemical control and towards biological, transgenic and integrated management strategies