Ophraella communa
| Ophraella communa | ||||||||||||
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Imago and larva of Ophraella communa on ragweed ( Ambrosia artemisiifolia ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Ophraella communa | ||||||||||||
| LeSage , 1986 |
Ophraella communa is a beetle fromthe leaf beetle family (Chrysomelidae). The species originally distributed in North America was introduced in Europe and Asia. The beetle species feeds on only a few types of plants ( oligophag ), in particular on ragweed ( Ambrosia artemisiifolia ).
features
The beetles are 3.4 to 4.1 millimeters long and 1.8 to 2.1 millimeters wide (males) and 3.9 to 4.3 millimeters long and 2.0 to 2.4 millimeters wide (females). Her head is yellowish and has a large black spot on the back. It is roughly dotted and with thick flowers. The antennae are dark brown, with the first five segments ventrally yellowish in color. The pronotum is yellowish and has three black or dark brown spots that often merge with one another. The pronotum is roughly punctured, the distance between the individual pits being less than the diameter of a single pit. The pronotum is also densely fluffed, with the fluff often covering the puncture. It is about twice as wide as it is long.
The wing covers (elytra) carry, as in all species of the genus Ophraella dark longitudinal bands. No such band is formed along the wing cover seam . An uninterrupted band runs parallel on both sides of the seam. Characteristic of the species is an additional band that runs about half the length of the wing and often merges at its tip with the band on the side of the wing seam. The discal bands are slightly curved and extend over a third to five sixths of the length of the wing. The submarginal ligaments are broad and also fused at their tips with the ligaments on the side of the wing seam. There are also pale colored individuals showing a similar pattern, but which is brownish and much lighter in color. The wings are densely fluffed, with numerous, long, close-fitting hairs and a few upright hairs at their tips. The wings are about three times as long as they are wide. The species can also be distinguished from the rest of its genus by its dense plumage and its food plant.
Occurrence and habitat
The natural range of Ophraella communa was limited to North America, where the species occurs from Mexico to the Canadian prairie provinces. It is more common in eastern North America, with the pale colored form occurring primarily in the arid areas east of the Rocky Mountains. In northern North America, adult beetles can be seen in August and September. For some years now the species has been spreading rapidly as a neozoon in Europe (southern Switzerland and northern Italy) and East Asia (China and, since 1996, Japan) after being unconsciously spread by humans.
Ophraella communa needs temperatures between 20 and 32 ° C during the development period to survive, with the optimum between 25 and 28 ° C.
Way of life
All stages of the species live on their food plants. The eggs are laid in groups on the underside of young leaves of the food plants, with the females secreting a secretion through the mouth before laying them, with which the eggs are glued to the leaves. The females create several such clutches, whereby a maximum of 18 pieces, one per day, can be created. Females achieve the highest egg-laying rate at 28 ° C (with an average of 2712 eggs). Seen from the side, the eggs are pear-shaped and have a hexagonal microsculpture. They are initially yellow and quickly change color to orange. The larvae often eat the young leaves down to the veins , the adults eat the entire leaves. You can defoliate your host plants completely. Before pupation, the beetles form loose cocoons on a leaf tip from initially tough, rapidly hardening secretion. The puppet rest lasts one to two weeks. At 32 ° C, the generation sequence is particularly short with 24 to 25 days, at lower temperatures (20 ° C) it is particularly long with over 79 days.
After hatching, the adults initially remain on their host plants. The flight activity is limited in the first days after hatching and only fully developed from the fourth day in daylight, but remains low at night. Because of their activity, the beetles could migrate up to 25 km within a day . Late in the year, the beetles hide in the leaves for the winter.
Biological weed control
The species was able to contain an undesirable neophyte in Europe as well as in China, the sagebrush ragweed ( Ambrosia artemisiifolia ), a plant species native to North America and invasive in Europe . It is being investigated whether the beetles are suitable for the control and containment of the allergy-causing mugwort ragweed in accordance with biological pest control. The impact on other plant species is discussed.
Individual evidence
- ↑ a b c d e f g h Laurent LeSage: A taxonomic monograph of the Nearctic galerucine genus Ophraella Wilcox (Coleoptera: Chrysomelidae). In: Memoirs of the Entomological Society of Canada , Volume 133, 1986, pp. 3-75. doi : 10.4039 / entm118133fv .
- ↑ a b c R. P. Webster, L. LeSage, I. Demerchant: New Coleoptera records from New Brunswick, Canada: Megalopodidae and Chrysomelidae. In: Zookeys , Volume 179, 2012, 321-348. doi : 10.3897 / zookeys.179.2625
- ^ NM Downie, RH Arnett: The Beetles of Northeastern North America. Vol. 1 and 2. The Sandhill Crane Press, Gainesville, FL. 1996.
- ↑ a b c d e f Zhong-Shi Zhou, Jian-Ying Guo, Hong-Song Chen, Fang-Hao Wan: Effects of temperature on survival, development, longevity, and fecundity of Ophraella communa (Coleoptera: Chrysomelidae), a potential biological control agent against Ambrosia artemisiifolia (Asterales: Asteraceae). In: Environmental Entomology , Vol. 39, No. 3, June 2010, pp. 1021-1027. doi : 10.1603 / EN09176 .
- ↑ a b c H. Müller-Schärer, STE Lommen, M. Rossinelli, M. Bonini, M. Boriani, G. Bosio, U. Schaffner: Ophraella communa, the ragweed leaf beetle, has successfully landed in Europe: fortunate coincidence or threat? January 25, 2014 doi : 10.1111 / wre.12072
- ↑ a b Zhenjun Cao, Hongyuan Wang, Ling Meng, Baoping Li: Risk to nontarget plants from Ophraella communa (Coleoptera: Chrysomelidae), a potential biological control agent of alien invasive weed Ambrosia artemisiifolia (Asteraceae) in China. In: Applied Entomology and Zoology , Vol. 46, No. 3, pp. 375-381. doi : 10.1007 / s13355-011-0048-8 .
- ↑ a b Koichi Tanaka, Takehiko Yamanaka: Factors affecting flight activity of Ophraella communa (Coleoptera: Chrysomelidae), an exotic insect in Japan. In: Environmental Entomology , Vol. 38, No. 1, 2009, pp. 235-241. doi : 10.1603 / 022.038.0129 .
Web links
- Ophraella communa in the Integrated Taxonomic Information System (ITIS)
- Ophraella communa at the National Center for Biotechnology Information (NCBI)