As this weevil also feeds above ground, it is better suited to areas of low grazing pressure. The flea beetle is a small shiny black beetle, mm long. It is so named because it has large hind legs that are adapted for jumping like fleas. The flea beetle has only one generation per year.
The adult beetles become active from late autumn May to late winter August after heavy rains stimulate Paterson's curse germination. Female beetles become sexually mature after feeding on Paterson's curse for weeks, and lay eggs directly on the taproot of the rosettes. Eggs production can last from May to November, with each female producing on average eggs. The eggs hatch in weeks with larvae feeding and mining into the taproot and secondary roots.
They are protected from grazing livestock and can reduce plant growth. It takes larvae to destroy the root and continue feeding into the crown the growth point of the weed killing rosettes cm in diameter. Once feeding is complete, larvae leave the root and pupate in the soil up to 20cm below the ground surface. Over summer the pupae turn into adults and remain below ground until the winter rains stimulate them to emerge from the ground and start a new generation.
The ability of the flea beetle to remain dormant below ground until winter makes it ideally suited to regions with hot dry summers and late autumn breaks. Flea beetles have been successful in heavily grazed paddocks because the insect spends most of its life below ground, protected from grazing stock. The pollen beetle is a small, black beetle. Larvae are cream with a black head and grow up to mm long. Larvae feed inside the flower bud and on the developing green seed.
This beetle becomes active in early spring when Paterson's curse rosettes start to bolt and flower. Adults can be seen congregating on the first flowering plants feeding on the unopened flower buds. After a week of feeding, the females become sexually mature and lay on average eggs, between the unopened buds of the Paterson's curse. Larvae hatch from the eggs and mine into the flower bud where they feed on the pollen and ovules female parts of the flower , destroying the bud and preventing it from setting seed.
Larvae then move between flowers feeding on the immature green seeds preventing them from forming viable hard seeds. When larvae complete feeding, they drop from the flowering plant and pupate in the soil. After weeks new adults emerge from the soil and can feed on the buds and immature green seed until the end of flowering. The lifecycle of the pollen beetles enables it to attack the first flowers to the last seed produced by Paterson's curse. Green vegetable bug. Mediterranean snails.
Banana skipper. Breadfruit mealybug. Paterson's curse. Bridal creeper. Bitou bush. Water hyacinth. Conservation Biocontrol. Plague locusts. And yes, the bags are both being reused and repurposed as we speak. Skip to Content. Removing Paterson's Curse. Over the years a combination of hand-weeding and chemical spraying has taken place, and this August the war continued with a small but mighty army.
They come in through the ports, and are let loose wherever there is a town, or village, or homestead to which goods are sent. Once escaped, they travel especially along the wastes by roadsides, and stock routes and railways.
The roads leading out of Adelaide contain many of these vagabond plants that are on the march. A ragged, untidy-looking fellow redeemed by beautiful flowers of pale cornflower blue is the succory, or chicory Cichorium intybus. The flowers as large as those of sow thistles, evidently belong to the same order of composite plants.
They sit close down singly or in pairs on the stems and branches in a way that adds to the ungainly impression of the whole. It is like a man's head right down between his shoulders without the intervention of a neck! We need not spend long over the part of the plant which is above ground. Just notice how tough and almost woody is the stem by comparison with the green, hollow sow thistle; but the latter is an annual, whereas succory possesses a perennial stock.
Most of the leaves of succory are in a rosette at the root, with deep, pointed lobes and coarse teeth. The salad endive is perhaps only a cultivated variety of them. The long stout taproot is fleshy and brittle, but with a little trouble we can get it up entire.
This root is the principal adulterant of coffee. Many people prefer the mixture. All that is necessary is to roast the root and grind it; so, if you like to make an amateur experiment, there is plenty of raw material along, the suburban roads.
Cheap though it is, this adulterant is itself adulterated with things still cheaper — dock roots, for instance, which are similar in form. Wandering along the wastes together with succory are two other composites already mentioned as garden weeds. Once or twice, I noticed striking examples of the red tinted form of sow thistle. There is another variety Sonchus asper of which I should like to hear locally. Its leaves are usually darker, with crisped and more closely toothed margins, and the stem clasping ears are more rounded and prickly instead of being prolonged into a point.
But a seeding piece should be obtained, if possible, as the final determination rests on a minute difference in the fruits. Then there is bristly ox tongue again. Two further points must be noted. Besides the green bracts that closely embrace the flowers, there is a second whorl of fewer but much broader ones below.
These outer bracts are usually five in number, but a look out should be kept for specimens with four, only. The second point concerns its name. Even scientific names are sometimes interesting, and the ox tongue is called Helminthia echioides, or the Echium-like Helminthia, because its foliage, and especially the short heartshaped stem leaves, so closely resembles that of the Echium which is growing alongside of it. Looking at the handsome purple-blue flowers of the plantain-leaved viper's bugloss Echium plantagineum you would say the title given to it above is as unkind to the plant as it is to Paterson.
But handsome is that handsome does, and although the young leaves afford good fodder, the viper's bugloss soon becomes much too rough for stock, and, while useless itself, kills the grass beneath it.
There are various ways of achieving fame, and when the Patersons on their small farm near Albury introduced this pretty 'blue weed' as a garden flower 30 years ago they little imagined their name would be associated through it with one of the worst weed-pests in the district. The likeness to bristly ox tongue suggested in the scientific name is also recalled in the popular designation, for bugloss, derived from two Greek words, signifies nothing more than 'ox tongue.
But the plants have no botanical affinity, and their flowers are utterly unlike. Five years ago Mr. If that means that it is as yet unknown in the fertile plains, the sooner its outward march from Adelaide is checked the better. It has already got loose in the southern suburbs; and, although high cultivation may keep it from the fields in the immediate neighbourhood, the plant will soon be on the tramp 'out back,' where it will quickly get beyond control. Experience shows that these weeds travel along the unwatched roads, As the worst and most extensive experiences of viper's bugloss nave been in New South Wales, the pamphlet on the subject published in by Mr.
Maiden is worth attentive perusal. From various reports quoted there I take two sentences only, of ugly importance. Wherever the plant gets a fair hold it completely smothcrs the grass. Although not at present in flower, the holy or milk thistle is so exclusively cultivated for the beauty of its foliage, that it calls for description on sight of its leaves alone. Moreover, it is yet one more composite on our list, and a prickly one to boot.
But the prickles are merely the spinous margins of the lobes. The surface of the leaf is a deep, shining green, reticulated with beautiful milk-white veins.
You would think that a gardener who sowed thistles, instead of grubbing them up, was cursing the ground already cursed enough for his sake. But holy thistle is an annual, or at most, a biennial, flowering only once from the same stock. It is, therefore, easily controlled, and the landscape gardener can safely avail himself of its handsomely marbled foliage. It remains to be seen whether it will behave as well now that it has, so to speak, shouldered its swag, and started off down the street on its own, for the holy thistle is no uncommon eight by the suburban roadside.
Although from an agricultural point of view, we found sow thistle to be one of the few useful plants of a comparatively useless order, another composite— the star thistle Centaurea calcitrapa has the distinction of being one of the very worst weeds in Australia. Unfortunately, it is common on wastes, and along roadsides in and near Adelaide, and the only check on its multiplication seems to be the flocks of small birds that feast on its seeds. No grazing animals help to keep it down; for, not only is the foliage prickly, but the small thistle-like heads of purple flowers are defended by, long, stout spines, terminating the involucral bracts, and standing out in all directions at right angles from the flower heads.
Star thistle does not appear in isolated specimens like sow thistle and holy thistle, but usually forms thick patches or colonies. The difference is due to the fact that the two latter plants have a feathery pappus by which the ripe seeds of a single plant are wafted over a wide area by the wind.
Star thistle seeds have no such equipment, and fall near at hand round the parent plant. Nevertheless, they are transported to long distances by roads and stock routes in a very effective manner. If you force your way through a ripening dump of star thistle, several whole heads are almost certain to break off, and stick into your clothing by their sharp spines. Travelling stock similarly catch the heads in their coats; and, if they are sheep, their wool is also caught by the plant, and matted and torn.
I wish we could describe it as a rare annual or biennial, such as it is in the British flora but it is very common round Adelaide, and apparently quite unchecked on waste lands. Its effectiveness in tearing the wool of sheep is increased by the spines on the its involucre having two small prickles at their base, so that they are as difficult to withdraw when once buried in the fleece as a whale harpoon or a barbed arrow from the wound.
It is strange to find this plant so flourishing along the public roads, in view of the South Australian Act passed as long ago as , and directed against star thistles, though apparently meant at the time for a yellow species. I believe that almost exhausts the list of composites— good, bad, and indifferent flowering just now along our roadsides for, with the sole exception of Paterson's curse, all the plants described in this paper belong to that vast order.
But an addition, a cultivated marigold Calendula officinalis has made its escape in some parts. I found a stray plant of it by the road up Glen Osmond at ft.
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