Pyralis farinalis
Mehlzünsler ( Pyralis farinalis )
The Mehlzünsler ( Pyralis farinalis ) is a butterfly of the family of European corn borer ( Pyralidae ), which occurs as a stored product pest in appearance and one of the classic food moths.
Features
The moths reach a wingspan of 18-30 mm (27 mm or 8-14 mm forewing length). The front wing is divided by two whitish cross lines in three, usually very characteristic colored fields: in a purple -brown to dark brown root field, in an ocher-colored midfield emanating from the outer transverse line darker areas, and a mostly purple -brown to dark brown Saumfeld, often lightened partially light brown or brighter Überstäubung. The inner cross- line is curved outwardly, the sheet often is easily broken in the middle. In contrast, the outer transverse line at center shows strong and broad bulge. It is reinforced in Kostal's edge, where it forms a quasi- convex inward arc spot. The inner transverse line may be at Kostal margin somewhat thickened. The transverse lines are mostly entire, only the bulge of the outer transverse line may be slightly denticulate at the bottom of the bay. Between the inner and outer transverse line usually several small white spots are developed in Kostal's edge.
The hind wings are whitish to gray with two lighter curved transverse lines.
The head is yellowish, purple-brown thorax and the abdomen alternately violet red and yellow. The antennae are finely ciliate in males, the antennae of female simple and thready.
The egg is elongate oval and gray colored white. It measures 0.52 ± 0.03 x 0.37 ± 0.02 mm. The surface shows a pronounced irregular network pattern. The raised boundaries of the fields are strongly folded.
The caterpillars are whitish gray, have a yellowish- brown neck shield and a dark-brown to reddish-brown head with only four ocelli. Adults bead is 20 to 25 mm
The pupa is yellowish brown with a reddish-brown abdomen. On the cremaster sit six hook-shaped bristles.
Geographical distribution and habitat
The Mehlzünsler is spread by human procrastination almost worldwide. The original distribution area can no longer be determined.
The Mehlzünsler comes almost exclusively synanthropic before, ie near the man and his habitation, especially of course in mills, bakeries and cereal stores, but also in households and in animal stalls where feed is stored. The larvae prefer a more moist and warm environment.
Way of life
Pyralis farinalis is usually one or two generations per year; occasionally takes the development two years. Under very favorable conditions ( warm and humid conditions) but continuously formed generations; up to five generations per year are possible. The moths usually fly from June to August. They are crepuscular and nocturnal and come to artificial light sources. Also on sugary baits they are being watched. The moths rest during the day with slightly splayed wings and upwardly curved abdomen on dark walls and can hardly be startled. If the moths are disturbed, they fly on little, but quickly run into a new dark hiding place. The females lay 200 to 500 eggs in small clusters from near the later tracked food. The Eiraupen hatch after 3-5 days. The caterpillars eat mostly grains and grain products, but also dried parts of plants such as clover (Trifolium ) and alfalfa ( Mendicago ). Even excrement and dead animal substances are eaten. It has been speculated that the larvae also feed on fungi. They are also found in totally moldy food. They often form tubes in the food web, which are glued with food residues. The food particles are spun curd -like. Due to the very flexible generation result, the caterpillars can therefore appear all year round. There shall be five larval stages. The development time from hatching to verpuppungsreifen larva is under favorable circumstances, only 42 to 56 days. Pupation takes place in a silken cocoon, which is covered with food particles.
Under optimal growth conditions ( 24 ± 2 ° C and 50 ± 5 % relative humidity) resulted in a mean generation time of about 70 to 76 days ( males usually hatch earlier than the females ). The moths live about 10 days, the males usually have a few days to live longer than females. The females laid on average from 235 eggs. The average development time of the eggs was 9 days.
System
The taxon was described in 1758 by Carolus Linnaeus first time scientifically. It is the type species of the genus Pyralis Linnaeus, 1758. Linnaeus gave no locality. The holotype is preserved in the collection of the Linnean Society in London.
Harmful effect
The Mehlzünsler is quite generally considered to storage pests of grains, grain products, flour and flour products. However, compared for example with the Indian meal moth ( Plodia interpunctelella ) he is only of secondary importance.