Black Field Cricket Teleogryllus Commodus Research Articles

A method for paraffin sectioning and identification of indoleamines in the brain of insects with a sclerotized cuticle

Sectioning of insects with sclerotized cuticles for histological examination can be challenging and often involves double-embedding, chemical dissolution of the cuticle or long periods of sample preparation. Furthermore, exposure of the tissue to harsh chemical treatments potentially interferes with antibody binding and thus chemical dissolution of the cuticle is undesirable for performing fluorescence immunohistochemistry (IHC). A method for obtaining paraffin sections of compound eye and neural tissue from the Australian black field cricket Teleogryllus commodus, an Orthopteran insect with a sclerotized cuticle, without the need for double embedding and with minimal pre-embedding processing is presented here. This method produced sections with minimal tissue curling or lifting in the tissues of interest. Fluorescence IHC labelling of melatonin and serotonin, comprehensively demonstrating their distribution in the compound eye and the optic lobe of the Orthopteran brain, was also performed. This method provides a framework for sectioning insect tissues with sclerotized cuticles and for IHC labelling of indoleamine compounds in the brain of Orthopteran insects.

Selective Enrichment and Sequencing of Whole Mitochondrial Genomes in the Presence of Nuclear Encoded Mitochondrial Pseudogenes (Numts)

Numts are an integral component of many eukaryote genomes offering a snapshot of the evolutionary process that led from the incorporation of an α-proteobacterium into a larger eukaryotic cell some 1.8 billion years ago. Although numt sequence can be harnessed as molecular marker, these sequences often remain unidentified and are mistaken for genuine mtDNA leading to erroneous interpretation of mtDNA data sets. It is therefore indispensable that during the process of amplifying and sequencing mitochondrial genes, preventive measures are taken to ensure the exclusion of numts to guarantee the recovery of genuine mtDNA. This applies to mtDNA analyses in general but especially to studies where mtDNAs are sequenced de novo as the launch pad for subsequent mtDNA-based research. By using a combination of dilution series and nested rolling circle amplification (RCA), we present a novel strategy to selectively amplify mtDNA and exclude the amplification of numt sequence. We have successfully applied this strategy to de novo sequence the mtDNA of the Black Field Cricket Teleogryllus commodus, a species known to contain numts. Aligning our assembled sequence to the reference genome of Teleogryllus emma (GenBank EU557269.1) led to the identification of a numt sequence in the reference sequence. This unexpected result further highlights the need of a reliable and accessible strategy to eliminate this source of error.

Effects of protease inhibitors and dietary protein level on the black field cricket Teleogryllus commodus

AbstractGrowth and survival responses were determined for black field crickets Teleogryllus commodus (Walker) (Orthoptera: Gryllidae) on artificial diets containing a range of levels of dietary protein, and protease inhibitors (PI's) at 0.33% (weight volume, w:v). The effect on cricket gut enzyme activities of adding PI's to a high protein diet was measured. All PI's which had in vitro binding activity against either trypsin or elastase (the two major cricket gut endopeptidases) reduced growth, but those which bound to both enzymes had the greatest effect. None of the PI's acted as a source of nutritional protein. Cricket growth rate increased with the addition of casein up to 3% w:v, but not with a similar addition of wheatgerm. The impact of PI's on growth was greatest on a 1.5% casein diet. On a high protein (3% casein) diet, the gut activity of trypsin was increased by potato proteinase inhibitors 1 and 2 while the activity of elastase and leucine amino peptidase were increased by soybean trypsin inhibitor and potato proteinase inhibitor 2. Increasing dietary casein up to 3.3% improved cricket survival. The potential of PI's as plant resistance factors against crickets was confirmed.

Seasonal patterns of pasture seed loss to black field crickets (Teleogryllus commodus) and other invertebrates

Abstract Daily seed loss from lines of 17 different pasture seed types laid on a hill site was measured at monthly intervals from January to May 1978, and daily loss offour pasture seed types was measured at monthly intervals from October 1978 until December 1979 on an estuarine flatland site and on a second hill site. The black field cricket Teleogryllus commodus (Walker) (Orthoptera: Gryllidae) was the most important invertebrate seed eater and was responsible for the high seed loss found between January and April, which reached a maximum of almost 100% in March at all three Northland sites. There was a significant correlation between seasonal seed loss and cricket pitfall trap catches. At one site seed loss was reduced by 93% in an area baited to exclude crickets. Field slugs (Deroceras (Agriolimax) reticulatum (Muller) and D. panormitanum (Lessona & Pollonera) (Stylommatophora: Limacidae)) caused low levels oflegume seed loss over the winter and early spring. Some minor seed loss was attributed to earthworms Allolobophora caliginosa (Savigny) and Lumbricus rubellus (Hoffmeister) (Opisthopora: Lumbricidae). The significance of the impact of crickets is discussed in relation to pasture damage.

Black field cricket (Teleogryllus commodus) food preferences between sixteen pasture species

Abstract The consumption of plant species as 15-day-old foliage, 48-day-old foliage, seedlings, or seed by nymphal and adult black field crickets Teleogryllus commodus (Walker) (Orthoptera:Gryllidae) was used to determine preference rankings using a balanced lattice design. Crickets discriminated between the various food items; the choice between the plant species was due to a definite preference. A high preference was shown for the main common pasture species of New Zealand improved pasture, particularly perennial ryegrass and white clover. The least favoured plant species, paspalum, phalaris and lotus major, are worth further investigation for persistence and productivity under black field cricket attack.