Platyptilia carduidactyla
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Platyptilia carduidactyla |
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| Platyptilia carduidactyla | ||||||||||||
| ( Riley , 1869) |
Platyptilia carduidactyla is a butterfly ( moth ) from the family of pterophoridae (Pterophoridae).
features
The species is characterized by the slimmer structure of the valves in the male genitalia and the strongly curved attachment point between the ductus bursae and the bursa copulatrix in the female genitalia. Depending on the intensity of the coloration, the appearance of the moths can vary in both sexes, ranging from ocher to dark brown.
The male moths reach a wingspan of 22 to 24 millimeters. The head is scaled rust-red in several layers . At the front of the head is a small tuft of hair half the size of the diameter of the eye. The palps are slender and one and a half times the diameter of the eyes. The antennae are slightly gray-white and gray-brown ringed and ciliate briefly. The thorax and the scales on the wing joint of the mesothorax are pale to very rusty brown in color. The mesothorax is dark brown and distally pale brown to brown and has a few small lateral scale processes. The hind legs are ocher-colored and ringed brown, the brown sections are in front of the spurs. The proximal pair of spurs is unequal in length, with the outer spurs being shorter. The spurs of the distal pair are of equal length.
The pale rust-brown forewings are split in the last quarter and provided with a dark brown mark. This consists of a weak line near the base of the wing's outer edge and a small triangular spot on the costalader between the base of the wing and the base of the wing incision. This triangular spot has a pale border on the distal side. The coloration of both forewing lobes gradually darkens towards the outer edge of the wing. The subterminal line is white and indistinct. The fringes are white and have a black line on the outer edge. There are three small scale teeth on the outer edge of the wing. The lead R1 of the front wing is present. The underside of the wing is brown, on the outer edge of the Costa triangle there is a yellowish-white point and a yellowish-white subterminal line.
The hind wings are pale brown-gray and have gray fringes. At the tip of the first and second wing lobes, a dark line runs through the fringes. On the outer edge of the third lobe there is a so-called scaly tooth in the middle, which gradually narrows distally. There are individual dark scales between the scalloped tooth and the base of the wing. The underside of the wing is rust-brown to gray-brown.
The freshly laid eggs are initially light greenish-yellow and turn orange-yellow over time. They are translucent and about 0.5 millimeters in size.
The newly hatched caterpillars are about a millimeter long and pale yellow in color. Four to five caterpillar stages are passed through, whereby the caterpillars are similar in color and drawing between the first and last stage, they only differ in size. Those of the last stage reach a length of about 1.5 centimeters. They are cream-colored and when fully ripe they are yellowish to pinkish-red in color.
Similar species
- Platyptilia percnodactyla ( Walsingham , 1880) has wider fore wings, a less pronounced scaly tooth on the outer edge of the third lobes of the hind wing, the scalp hair is longer, the aedeagus of the male genitals is longer, in the female genitals the ductus bursae is shorter and the signa longer .
distribution
Platyptilia carduidactyla is native to the Nearctic in the United States and Canada and in the southern Pacific in New Zealand .
Way of life
The females lay up to 245 eggs on the underside of the leaves, and the eggs are occasionally found on flower stalks. On vegetative shoots, the caterpillars often feed on the surface of the leaves and only drill into the petiole after the first moult. Other young caterpillars dig into the leaf veins immediately after hatching and move in the direction of the petiole while eating. These specimens go through the entire larval stage within the leaf. The situation is different with caterpillars whose eggs were laid on leaves near buds or directly on buds. They migrate to the bud and mine in the outer bracts. With each further moult, the feeding activity shifts further into the center of the bud. The caterpillars feed polyphagous and were found on various types of thistle ( Cirsium ) such as the common thistle ( Cirsium vulgare ), Cirsium edule , Cirsium occidentale , Cirsium quercetorum , Cirsium discolor , Cirsium undulatum , the field thistle american ( Cirsium arvenseum ) , Cirsium horridulum , Cirsium nuttallii and artichoke species ( Cynara ) such as Cynara scolymus and Cynara cardunculus as well as on the Malta knapweed ( Centaurea melitensis ) and on the milk thistle ( Silybum marianum ).
Shortly before pupation, the caterpillars stop eating, leave the feeding place and drop to the ground. The prepupa (mature caterpillar) is very active in the first part of this stage and wanders around in search of a suitable pupation place. It pupates in the litter, whereby dry leaves are preferred.
Flight and caterpillar times
The moths fly in July, in North America the flight time extends from May to September.
Platyptilia carduidactyla forms three to four overlapping generations per year. The individual stages of development require different temperature thresholds for their development. Under the mild climatic conditions on the coast of central California , the very low threshold temperature of the last caterpillar stage of 1.5 degrees Celsius enables generations to develop all year round. At a temperature of around seven degrees Celsius, the development of a generation takes around 19 days.
Economical meaning
The caterpillars of Platyptilia carduidactyla eat all parts of the plant, but the economic damage comes from feeding on the flower buds of the artichoke , which makes them unsightly and can no longer be sold. Plants are occasionally damaged by eating the sprouts, but these often recover. The reproduction and distribution of caterpillars can be influenced in several ways:
- Natural enemies
Various species from the families of caterpillar flies (Tachinidae), such as species from the genus Elfia and Hyalomyodes triangulifer as well as various representatives of the hymenoptera ( Angitia platyptiliae , Gelis spec. , Dibrachys cavus , Epiurus bicoloripes , Phaeogenes spec. , Ploachyneuron , parasitize the caterpillars ) Colpognathus helvus , Microbracon nevadensis , Hyalomyodes triangulifera , Lispidae spec. , Plectops spec. ). The biological control with natural enemies is inefficient, however, as the caterpillars eat inside the plant and are therefore well protected from their enemies.
- Agricultural control
The population dynamics can be decisively interfered with by cutting off the plants five to 7.5 centimeters below the soil, chopping the plant and introducing the plant material into the soil. In this way, the infestation in fields that have been used for several years can be reduced by around 95 percent. Due to the mobility of the moths, the effect of this method on a certain field is only temporary. The stems are pruned from mid-August to mid-June for fields that are intended for harvest in autumn, winter or summer. For the fields to be harvested in summer, it is carried out from August to September. It must be avoided that fields to be harvested in summer are next to fields that have been cut back in summer, since the former represent a reservoir for the moths.
- Biological control
The pheromone- based confusion method is used to specifically prevent the moths from mating. Entomopathogenic nematodes and bacteria such as Steinernema carpocapsae and Bacillus thuringiensis are also used for biological control of the caterpillars.
Systematics
Synonyms
The following synonyms are known from the literature:
- Pterophorus carduidactylus Riley, 1869
- Platyptilia cardui Zeller, 1873
- Platyptilia hesperis Grinnell, 1908
swell
Individual evidence
- ↑ a b c d C. Gielis: Neotropical species of the family Pterophoridae, part I. Zool. Med. Leiden 80 (2006)
- ↑ C. Gielis: Pterophoridae. In: P. Huemer, O. Karsholt, L. Lyneborg (Eds.): Microlepidoptera of Europe 1: 1-222. , Apollo Books 1996, ISBN 87-88757-36-6
- ↑ a b c d C. Gielis: Pterophoroidea & Alucitoidea. In: World Catalog of Insects. Volume 4 , Apollo Books, 2003, ISBN 87-88757-68-4
- ↑ a b c d Artichoke Plume Moth. University of California, accessed September 9, 2008 .
literature
- JK Haworth, RP Puck, J. Weatherston, CC Doane, S. Ajeska: Research and development of a mating disruptant for control of the artichoke plume moth, Platyptilia carduidactyla (Riley) (Lepidoptera: Pterophoridae). Colloq. l'INRA. 1982, 7: 343-35
- MC Birch: 1987. An overview of mating disruption in the artichoke plume moth. Bull. SROP. 1987, 10: 25-26
- JA Klun, KF Haynes, BA Bierl-Leonhardt, MC Birch, JR Plimmer: Sex pheromone of the female artichoke plume moth, Platyptilia carduidactyla. Environ. Entomol. 1981, 10: 763-765
Web links
- University of California A grower managed biorational management program for artichokes on the northern central California coast
- Pherobase Semiochemicals of Platyptilia carduidactyla , the Artichoke plume moth