The Entomological Society of NSW

The Entomological Society of NSW

The Entomological Society of NSW

Contents Vol. 28


The Journal of the Entomological Society of New South Wales Inc.



CLIFT, A.D. & MEATS. A. The relation of percentage of positive traps’ to the negative binomial distribution and to progress in the eradication of Bactrocera papayae Drew & Hancock (Diptera: Tephritidae) in northern Queensland ……………………………………… 61

Catches of fruit flies in male lure traps are highly variable, but follow the negative binomial distribution.  The proportion of positive traps is often used as an index of progress in a control or eradication campaign, but care is required in the interpretation of this index.  Part of the problem is that the proportion of positive traps does not seem to be sensitive to changes in mean catch per trap.  The basic characteristics of the distribution explains most of the difficulties.  Firstly, the average catch per fortnight per trap (C/T) must be low, <1, before the proportion of positives (PP) declines below 0.3: the PP drops to 0.1 when C/T drops to 0.1, with both PP and C/T having virtually identical values below 0.1.  Secondly, C/T must be <1 before the proportion of traps with >3 drops below 0.1. In Australia, when B. tryoni is detected within the quarantine zones, most trap catches are within this range.

General and Applied Entomology 28: 61-64

DOMINIAK. B.C., CAGNACCI, M., RAFFERTY, T & BARCHIA, I. Field cage release of sterile Queensland fruit fly (Bactrocera tryoni (Froggatt)) …………………………….. 65

Field cages were trialled as an alternative, low resource method of releasing sterile fruit fly.  For the whole trial, there was an average emergence of 51.77% from cages which included cages of sub-optimal loadings and a recapture rate of sterile males of 0.0677%.  The field cage release system gave acceptable results (74.7% emergence) so long as the depth of pupae did not exceed 9 mm (approximately 0.8 million per cage).  These results compare favourably with the results of other Qfly trials.

General and Applied Entomology 28: 65-71

DOMINIAK, B.C. & WEBSTER. A . Sand bed release of sterile Queensland fruit fly (Bactrocera tryoni (Froggatt))at Young, NSW ……………………………………….. 9

A new release method of sterile fruit flies using an artificial sand bed technique was tested.  Pupae were placed in a sand bed in an orchard to simulate pupal emergence from soil.  Fruit flies escaped successfully from the sand surface as adults without protection from predation.  The emergence rate of pupae was 82.3% and the recapture rate of adults was 0.0404% on a 1 km trapping grid.

General and Applied Entomology 28: 9-11

DOMINIAK, B.C., RAFFERTY, T.D. & BARCHIA, I. An analysis of travellers carrying fruit near Griffith, is SW during Easter 1996 to assess the risk for Queensland fruit fly (Bactrocera tryoni (Froggatt)) …………….. 13

Roadblocks were conducted on the entry side of the Fruit Fly Exclusion Zone near Griffith (NSW) during 5 days covering the Easter 1996 period to determine the rate of fruit carrying by tourist traffic into the Murrumbidgee Irrigation Area (MIA).  A high proportion (80.2%) of the traffic passing the site during the operation was stopped, asked to answer a questionnaire, and inspected for fruit brought into the MIA.  The 1595 completed forms were analysed for trends according to types of travellers, origin and destination of travellers, and fruit carried by travellers.  Travellers from Queensland, and families and retirees were found to be the highest risk groups which carried fruit into the quarantine zone.

General and Applied Entomology 28: 13-19

HANCOCK, D.L., OSBORNE, R. & MCGUIRE, D.J. New hostplant and locality records for Ceratitidinae and Trypetinae in northern Queensland (Diptera: Tephritidae) ………………………….. 21

Hostplant and locality records are provided for two species of Ceratitidinae and 18 species of Trypetinae from northern Queensland.  First Australian host records are provided for Ceratitella unifasciata Hardy, Rabaulia nigrotibia Hering, Trypanocentra nigrithorax Malloch and Philophylla fossata (Fabricius). Australian records of Rabaulia fascifacies Malloch are shown to be misidentifications of R. nigrotibia.

General and Applied Entomology 28: 21-27

JESSUP, A.J., DALTON, S.P. & SLOGGET, R.F. Determination of host status of table grapes to Queensland fruit fly. Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), for export to New Zealand ……….. 73

Laboratory experiments were carried out according to a New Zealand Standard to test the host status of ‘Flame Seedless’, ‘Thompson’s Seedless’, ‘Menindee Seedless’, ‘Red Globe’, ‘Calmeria’ and ‘Red Emperor’ table grapes to Queensland fruit fly, Bactrocem tryoni, Froggatt.  Under the conditions prescribed by the Standard these table grape cultivars were able to support development of B. tryoni to the adult stage.  Table grapes of these cultivars cannot be exported to New Zealand from Australian regions where B. tryoni is endemic, has become established or, having been trapped, has enforced a ‘fruit fly outbreak’ restriction unless an approved quarantine treatment has been applied.

General and Applied Entomology 28: 73-75

JESSUP, A.J. & WALSH, C.J. Sex-ratios of non-diapausal and diapausal laboratory-reared Diachasmimorpha tryoni (Cameron) (Hymenoptera: Braconidae) — a larval parasitoid of Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) ……………………….. 77

A small proportion from each cohort of the wasp, Diachasmimorpha tryoni, a larval parasitoid of the Queensland fruit fly, Bactrocera tryoni, entered diapause under constant laboratory conditions of 12:1:10:1 hours light:dusk:dark:dawn, 26°C and 60% relative humidity.  Wasps in diapause commenced adult eclosion some two to nine weeks after the peak eclosion of non-diapausing wasps, and continued eclosion in small numbers for several months after that.  The sex ratio of laboratory-reared non-diapausing wasps was about 1 male:2 female, whereas that for diapausal wasps was about 1 male:9 female.

General and Applied Entomology 28: 77-80

LLOYD, A., LEACH, P. & KOPITTKE, R. Effects of exposure on chemical content and efficacy of male annihilation blocks used in the eradication of Bactrocera papayae in north Queensland …………………. 1

A program to eradicate the introduced pest fruit fly species Bactrocera papayae Drew and Hancock (papaya fruit fly) from north Queensland commenced in October 1995.  The primary eradication strategy employed was male annihilation using fibre-board (‘Cane-ite’) blocks (5x5x1.3 cm) impregnated with approximately 18 mL of a 3:1 mixture of male lure (methyl eugenol) and toxicant (maldison ULV).  Studies were undertaken to determine the effects of short and long term exposure on the chemical content and efficacy (attraction and toxicity) of these blocks.  As the numbers of B. papayae in the eradication area were very low, the efficacy of blocks was determined by their ability to attract and kill the endemic non-pest species Bactrocera cacuminata (Hering) which also responds to methyl eugenol.  Results showed that the loss of methyl eugenol and of efficacy followed similar exponential curves over a 52 week exposure period.  After eight weeks exposure the efficacy of blocks was reduced by 50% in comparison to a new block and the methyl eugenol content was reduced by 73%.  The maldison content of blocks did not change significantly over a 28 week period, although some small loss of maldison occurred after prolonged exposure up to 52 weeks.  Blocks up to 52 weeks old continued to attract and kill up to 5% of the number of flies caught by new blocks.  The significance of these findings with respect to eradication treatments for papaya fruit fly is discussed.

General and Applied Entomology 28: 1-8

MEATS, A. Predicting or interpreting trap catches resulting from natural propagules or releases of sterile fruit flies. An actuarial and dispersal model tested with data on Bactrocera tryoni .……………………. 29

As with many insects, a batch of released (or naturally emerging) flies declines in density with time at the point of origin and declines in density at any time with distance from the origin.  A generic model is presented that can be adapted for a variety of species and is tested with data on the Queensland fruit fly, Bactrocera tryoni (Froggatt).  It requires prior estimation of parameters that are readily obtained for fruit flies and predicts proportions captured or recaptured in terms of catch per trap at any distance.  It is therefore applicable to any number and disposition of traps of any type.  The model is sensitive to variations in mortality rates and development times.  The example with sterile and fertile B. tryoni shows how this feature can be used to assess the quality of released sterile flies.

General and Applied Entomology 28: 29-38

MEATS, A. A quality assurance measure for field survival rates of released sterile flies based on recapture rates ……………………………… 39

The quality of released sterile male insects used for population control with the sterile insect technique (SIT) is related to their ability to survive to mating age and to their subsequent rates of survival and mating competitiveness.  The latter is usually expressed as a proportion, denoted here as CM, being the overall mating success of the average sterile male relative to that of a wild male in encounters with wild females.  If survival to mating is expressed with an analogous term CS, this would be ‘survival competitiveness’ and the product CSCM would be a measure of the total field competitiveness of released flies CR.

General and Applied Entomology 28: 39-46

MEATS, A. The power of trapping grids for detecting and estimating the size of invading propagules of the Queensland fruit fly and risks of subsequent infestation ……………………. 47

A method is given for interpreting the trapping rates of cuelure traps. This is related to the catching power of grids of different sizes and densities. Results depend on where it is assumed that the invading propagule arose on the grid (at a trap site or between traps). Thus methods for highest and lowest estimates are given. The magnitude of the difference between the two gets larger the larger the grid spacing so that catches on grids of 5 and 10 km spacing are essentially uninterpretable. Using the highest estimates for grids of 0.4 and 1 km spacing, a method is given for assessing the risk of a continuing infestation from the number of flies caught. The assessments are based on our knowledge of the minimum density required for breeding. These estimates are compared with those assumed by the existing code of practice.

General and Applied Entomology 28: 47-55

MEATS, A. Cartesian methods of locating spot infestations of the papaya fruit fly Bactrocera papaya Drew and Hancock within the trapping grid at Mareeba, Queensland, Australia …. 57

It is possible to use simple Cartesian methods to estimate the location of the source of flies caught on a grid of traps.  If the epicentre is a true source then the catch per trap should fall from the epicentre according to a dispersal model.  A method is given for estimating significant deviations from the predictions of the model so that it is possible to decide whether there is a single source or several sources for the flies caught with a small cluster of traps on a larger grid.  Examples from the Mareeba grid are given, showing simple and complex patterns of trap catches arising from locally single and locally multiple breeding sources respectively.

General and Applied Entomology 28: 57-60


BISHOP A.L.., MCKENZIE.. H ., BARCHIA. I. & HARRIS, A.M. Occurrence and effect of temperature regimes on four species of fly (Diptera) found with Culicoides brevitarsis Kieffer (Ceratopogonidae) in bovine dung …………………………………… 93

The seasonal occurrence and the effects of temperature regimes on development, survival and emergence are given for Psychoda sp. (Psychodidae), Australosepsis niveipennis (Becker) (Sepsidae), Leptocera mirabilis (Collin) (Sphaeroceridae) and Pyrellia tasmaniae Macquart (Muscidae) breeding in bovine dung in the Hunter Valley, NSW.  The data were then used to consider the possible interaction between these species and arbovirus vector, Culicoides brevitarsis, at the southern limits of its distribution.  Like C. brevitarsis, P. tasmaniae was largely absent from dung in winter.  The other species were present continuously.  A. niveipennis and P. tasmaniae increased in number from spring to autumn.  Psychoda sp. and L. mirabilis were limited to peaks in spring and autumn.  The occurrences of A. niveipennis, Psychoda sp. and L mirabilis were each related to average monthly temperature.  No occurrence of the four species was related to rainfall.  Each species was present when C. brevitarsis re-establishes in the study area each season.  All except Psychoda sp. developed in a temperature range (17°C to 36°C) similar to that of C. brevitarsis.  Psychoda sp. was active at 15°C but was inactive above 32°C.  Development times for each species decreased as temperatures increased.  These were different between species and these differences were maintained over the temperature range tested.  Some development of juveniles occurred below temperatures inhibiting adult emergence which could be induced by raising the temperature above 17°C.  Despite close similarities in time, space and responses to temperature, the fly fauna endemic in fresh dung was not considered as important to the re-establishment, growth and survival of C. brevitarsis.

General and Applied Entomology 28: 93-99

BROWN, G.R. The generic status of Catocheilus Guérin and Hemithynnus Ashmead (Hymenoptera: Tiphiidae: Thynnini) …………………………………. 89

Hemithynnus Ashmead is synonymised with Catocheilus Guerin and a diagnosis is given.  Included species are listed. H. libes Montet is synonymised with C. cognatus (Smith), and Lestricothynnus hegias Montet with C. perplexus (Smith).

General and Applied Entomology 28: 89-92

INGRAM, B.F. Possible alternative host plants for some major pod sucking bug pests of pulse crops in the south Burnett region of Queensland. ………………………….. 101

The alydids Riptortus serripes (Fabricius) and Mirperus scutellaris Dallas (Hemiptera: Alydidae), and the pentatomids Piezodorus hybneri (Gmelin), Dictyotus caenosus and Plautia affiinis Dallas (Hemiptera: Pentatomidae), feed on the pods of pulse crops in Australia.  Farmers currently control these bugs with insecticides.  Alternative plant hosts could potentially be used as pest monitoring tools or in an integrated pest management approach as trap crops.  Consequently, a survey of the possible alternative host plants of these bugs was carried out in southeast Queensland between 1992 and 1995.  Additional information was obtained by searching host plant records compiled by the Queensland Department of Primary Industries, and from records in the literature.  In the South Burnett, R. serripes was found only on legumes, especially Sesbania cannabina, and only in autumn which suggests it is an immigrant species.  M. scutellaris, P. hybneri, and P. affinis were taken on many common weeds found by roadsides and in farmers’ fields.  In most cases these bugs were found only on plants that were fruiting.  The data were insufficient to make conclusions about D. caenosus.  The survey was conducted during a period of prolonged drought so the abundance of possible host plants in non-cultivated areas, which is largely determined by rainfall, was reduced.  Also the numbers of bugs taken were low on both cultivated and non-cultivated plants.  Many possible alternative host plants were found but few appeared to be powerful attractants.  Low numbers of bugs in the ‘wild’ host plants correlated with low numbers in cultivated crops.  The opportunity to compare large populations in ‘wild’ host plants with populations in cultivated crops never arose, because of the drought.  The main possible alternative hosts of Riptortus serripes were ‘Senna’ trees and Sesbania cannabina and these have a very restricted distribution in the South Burnett.  S. cannabina was frequently observed to host two other pests of cultivated grain legume and pulse crops viz. Maruca vitrata (Fabricius) (Lepidoptera: Pyralidae) and Zygrita diva (Coleoptera: Cerambycidae).  Removal of ‘Senna’ trees and S. cannabina should result in big reductions of populations of those three insect species.  Macroptilium atropurpureum (siratro), M. lathyroides (phasey bean) and Medicago saliva (lucerne) appeared to be attractive to R. serripes, M. scutellaris and P. hybneri and could be evaluated as potential trap crops or as pest population monitoring tools.

General and Applied Entomology 28: 101-108

MACDONALD. J.A. & ELDER, J.K. Laboratory Bioassay: Pyrgo Beetle, Pyrgoides tigrina Chapius ………. 84

The toxicity of Novodor BTT to P. tigrina larvae was studied.

General and Applied Entomology 28: 84

SMITHERS, C.N. The Mesopsocidae (Insecta: Psocoptera) of Australia ………. 85

Species of Mesopsocidae appear to be very uncommon in Australia.  Three species are now known, all in the genus Mesopsocopsis Badonnel and Lienhard, two of which, M. occidentale sp. n. and M. setosa sp. n., are described in this paper.  A key to the males of the three species is given.  Females of Mesopsocopsis have not yet been found. All species are from low rainfall areas in South or Western Australia.

General and Applied Entomology 28: 85-88

THWAITE, W.G. & CAMPBELL, J.E. Leaf bronzing in Nashi and European Pear in relation to populations of Tetranychus urticae Koch (Acarina: Tetranychidae) ……….. 81

The link between Tetranychus urticae infestation and leaf bronzing in European pears is already known but no information exists for nashi (Asian pear).  Twenty-two cultivars of both nashi and European pears in an experimental orchard at Orange NSW were rated for overall foliage bronzing.  Six varieties of each type were selected, leaf samples taken and the number of active stages of T. urticae determined.  Each leaf in the sample was rated for bronzing or scorch.  A mite tolerance score was calculated for each variety based on the leaf samples. European pear as a group was less tolerant of mite infestation than nashi.  The order of tolerance (most to least) for European pear was: Williams’ Bon Chretien, Beurre Bosc, Packham’ s Triumph, Doyenne du Cornice, Mock’s Red Williams’ and Corella.  For nashi it was: Shinsui, Kosui, Nijisseiki, Tsu Li, Ya Li and Hosui.

General and Applied Entomology 28: 81-83

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