Pistachio processionary moth
| Pistachio processionary moth | ||||||||||||
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Pistachio processionary moth caterpillars |
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| Thaumetopoea solitaria | ||||||||||||
| ( Freyer , 1838) |
The pistachio processionary moth ( Thaumetopoea solitaria ) is a butterfly ( moth ) from the tooth moth family (Notodontidae). The animals occur from the southern Balkans eastward to the Middle East and southward to the Levant and colonize dry and hot habitats. Mass occurrences, as with other processionary moth species, are rare, but the species is one of the economically important pests on pistachio cultures.
features
butterfly
The moths reach a wingspan of 20 to 28 millimeters (males) or 25 to 35 millimeters (females). They look very similar to the oak processionary moth ( Thaumetopoea processionea ), in extreme cases it is difficult to differentiate between them. Both sexes of the pistachio processionary moth have white hind wings that are completely lacking a central band. Instead, however, there is a dark hem mark at the anal corner. Similar to the oak processionary moth, the forewings are colored gray and each have a dark transverse band in the discal and post-discal region. However, this drawing is clearly less contrasting than in the similar species. Unlike the similar species, the inner band is closer to the root, is also noticeably more rounded and forms almost a quarter circle. The outer band is only slightly wavy and often curved outward on the inner edge of the wing. The females have less long feathered antennae and a 13 to 14 millimeter long, cylindrically shaped abdomen, which has a gray-black anal bush at the end . The abdomen of the males is 12 to 13 millimeters long and tapers conically towards the rear. At the end of the abdomen, the males wear a tuft of long, light-colored hair.
egg
The eggs are yellow on top and greyish-yellow on the underside. They are hexagonal in shape and measure 0.45 by 0.5 by 0.7 millimeters.
Caterpillar
The caterpillars have to Halperin stinging hairs and can as well as most other types of processionary a caterpillar dermatitis trigger. According to de Freina, however, the caterpillars do not have such stinging hairs. The description follows here Halperin.
After hatching, they are 1.6 to 2 millimeters long and have a 0.4 millimeter wide black head capsule. There is a brightly colored, inverted "Y" on it. At first, the body is only sparsely covered with hair. In the second stage, the caterpillars are 3.5 to 4 millimeters long with a head capsule 0.6 to 0.7 millimeters wide. In the third stage they measure six to seven millimeters, the head capsule is 0.9 to 1 millimeter wide. Her body is now thickly covered with long white hair. On the back of the eighth segment of the abdomen there is a dark bush with stinging hairs. The fourth instar caterpillars are 12 to 16 millimeters long, the head capsule is 1.3 to 1.5 millimeters wide in the males and 1.6 to 1.8 millimeters wide in the females. Dark tufts of hair with stinging hairs appear on the first through eighth abdominal segments, but are only numerous on the eighth segment. The stinging hairs are approximately 0.2 millimeters long. In the fifth and final stage, the caterpillars reach a length of 24 to 30 millimeters. The head capsule is 2.4 to 2.6 millimeters long in the males and 2.7 to 2.9 millimeters in the females. Her body is black on the back, greenish on the belly and gray in between. The entire body is covered with long gray hairs, the stinging hairs on the first to the eighth abdominal segment are numerous at this stage. By the end of development, the hairs of the caterpillars become a little shorter and darker.
Doll
The pupa is 8 to 12 millimeters long and is located in a cocoon , which is about 15 millimeters long in males and 18 millimeters in females. It is robustly built and waterproof. It is covered with soil on the outside and the hair of the caterpillar on the inside.
Occurrence and habitat
The animals occur on the southern edge of the central Palearctic from Macedonia via Asia Minor and Cyprus to Syria , Palestine , Iraq and Iran . Dry and hot habitats such as karst areas are settled. The species is common, but is only found locally.
Way of life
The moths fly from August to September. Pairing takes place between 9:00 p.m. and 12:00 p.m. local time and takes at least 15 minutes. Immediately afterwards, the female begins to lay eggs.
The caterpillars feed mainly on pistachio leaves . In Israel it is found mainly on Pistacia terebinthus subsp. palaestina and Atlantic pistachio ( Pistacia atlantica ), less often with pistachio ( Pistacia vera ) and very rarely with mastic ( Pistacia lentiscus ) and Brazilian pepper tree ( Schinus terebinthifolius ). Otherwise they feed on Mediterranean cypress ( Cupressus sempervirens ) and ash ( Fraxinus ). The first instar caterpillars feed on the leaf margin; in the second stage, the entire leaf except the midrib and, from the third stage, the entire leaf is eaten. In the fourth and fifth stages, if there is a shortage of food, the petioles are also eaten.
development
The females lay their entire eggs in a single, flat, single-layer, hexagonal and symmetrical clutch. This is on average 16 to 20 millimeters long and 6 to 7 millimeters wide and consists of 7 to 8 rows of eggs. The number of eggs in Israel varied significantly between 80 and 196 pieces, and the average there also fluctuated significantly from year to year, between 169 in 1977/78 and 146 in 1978/79. The clutch is placed on the shady side of thin, 3 to 12 millimeter thick branches. After being deposited, it is covered with the gray hairs of the anal bush, which means that it is well camouflaged on the bark of the food plants.
The caterpillars hatch after a diapause of 143 days on average, usually at the time when the pistachio plants start to sprout, but sometimes a little earlier. This is the case in February or March. They need an average of 52 days to pupate, whereby higher temperatures strongly favor their growth and late hatching caterpillars can be fully grown after around 31 days. During the day, the caterpillars are sometimes found huddled together in a clump at the base of the food plants, especially during the moulting phase. You don't spin a web. Food intake takes place at different times, but mostly in the evening. A few hours after eating, they gather on a branch in order to devote themselves to eating again after a few more hours. They also eat in groups, but they can also split up into individual smaller groups, each of which then selects its own branch. Sometimes there are two to three caterpillars on a leaf when eating. The caterpillars look for a new resting place on the plants every day. When it rains, they hide in dry places on branches, during the hot hours of the day they can be found on the branches, with the caterpillars lifting the front or back of the body from the branch. In the event of a disturbance, adult caterpillars can be individually dropped from the plant and hide on or in the ground. As is usual with processionary moths, at the end of their development they go in a common procession in search of a suitable place to pupate. The procession is occasionally divided into smaller groups, but can also join other groups and then consist of several hundred individuals. The caterpillars pupate in the ground, initially hiding in the top soil layer for a few days and only then digging into the loose soil. The cocoon is spun at a depth of about three to four centimeters. The pupil rest in the ground averages 170 days. It is not uncommon for the pupae to linger for a year or two before the moths hatch.
Specialized enemies
Several parasitoids are known, of which the caterpillar fly Drino imberbis is most frequently found in the pistachio processionary moth, at least in Israel, and attacks up to 10.1% of the pupae .
Economic importance and control
As a common species, the pistachio processionary moth is one of the economically important pests of pistachio cultures, although the species also eats other types of pistachio and plants of other genera in addition to cultivated pistachios. The caterpillars damage the pistachio buds at an early stage, which means that fewer shoots are formed. The leaves are eaten by the remaining shoots, so that young plants in particular can be defoliated completely in the event of severe infestation. This affects both the growth of the plants and the yield. Essentially, Thaumetopoea solitaria is currently being fought with insecticides such as those based on dimethoates , azinphosmethyl and diflubenzuron . However, combating with these substances is ecologically problematic, which is why alternatives are being sought. A method, even if it is not very effective, is to remove the clutches from the plants by hand. In a study it was also shown that an extract from real hops ( Humulus lupulus ) is effective in controlling the species, but further studies on the effects on the environment, in particular on other insects, are necessary.
The bacterium Bacillus thuringiensis var. Kurstaki is being researched as a biological control method, which can be used very effectively against the butterfly species in the laboratory if the leaves are completely wetted. However, since such an area-wide application in the culture is difficult and also environmental wine flows have negative effects on the bacterium, a high dosage is necessary. Since the bacterium has already been used successfully against the pine processionary moth ( Thaumetopoea pityocampa ), further research into this control method appears promising.
supporting documents
Individual evidence
- ↑ a b c d e f g h i j k l m n J. Halperin: Thaumetopoea solitaria Freyer (Lepidoptera: Thaumetopoeidae) in Israel. Phytoparasitica Volume 11, Number 2, June 1983: pp. 71-82
- ↑ a b c Mehmet Kubilay Er, Serpil Karadağ, Cafer Mart: Effectiveness of Bacillus thuringiensis var.kurstaki on Thaumetopoea solitaria Frey (Lepidoptera: Thaumetopoeidae) Larvae in Laboratory Conditions. Turkish Journal of Agriculture and Forestry, Volume 31, 2007, pp. 255-261.
- ↑ a b c d e f Josef J. de Freina, Thomas J. Witt: Noctuoidea, Sphingoidea, Geometroidea, Bombycoidea . In: The Bombyces and Sphinges of the Western Palaearctic . 1st edition. tape 1 . EFW Edition Research & Science, Munich 1987, ISBN 3-926285-00-1 , p. 288 f .
- ↑ Mehmet Kubilay Er, Ayhan Gökçe, Mark Edward Whalon: Contact and ingestion toxicities of plant extracts to Thaumetopoea solitaria Frey. (Lepidoptera: Thaumetopoeidae). Journal of Pest Science, Volume 82, Number 1, pp. 95-99.
literature
- Josef J. de Freina, Thomas J. Witt: Noctuoidea, Sphingoidea, Geometroidea, Bombycoidea . In: The Bombyces and Sphinges of the Western Palaearctic . 1st edition. tape 1 . EFW Edition Research & Science, Munich 1987, ISBN 3-926285-00-1 .
Web links
- Moths and Butterflies of Europe and North Africa (English)
- Thaumetopoea solitaria in Fauna Europaea
