Sasajiscymnus tsugae
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Sasajiscymnus tsugae ( Syn .: Pseudoscymnus tsugae ) is a ladybird from the Scymnini tribein the subfamily Coccinellinae . The beetle is originally native to Japan .
features
The Scymnini tribe includes very small ladybugs. Sasajiscymnus tsugae is elongated-oval and reaches a length of only 1.7 millimeters and a width of 1.1 millimeters. The entire body is jet black and hairy on top.
The Sasajiscymnus species differ from the Scymnus species mainly in the shape of their very short antennae . These have only nine antenna elements, Scymnus has eleven antenna elements. The antennae of Sasajiscymnus end with very long bristles. Her legs have only three Tarsen -Glieder.
development
The eggs of Sasajiscymnus tsugae are oval, 0.48 millimeters long and 0.25 millimeters wide. They are reddish-orange in color and have a translucent shell. The eggs are laid individually or in small groups in the cracks of the bark of conifers. The larvae are reddish-brown after hatching, but turn gray over time. During their larval stages, they grow from a length of 1.1 millimeters to 2.7 millimeters. The pupa (fourth larval stage) is reddish-brown and 1.9 millimeters long and 1.1 millimeters wide. After the beetle has stripped off the pupal shell, it is light golden brown in color, but turns black within 24 hours.
Occurrence
The larvae and beetles of Sasajiscymnus tsugae are originally found on the Japanese island of Honshū on the hemlocks Tsuga diversifolia and Tsuga Sieboldii , where they feed on the larvae and adults of the plant louse Adelges tsugae , a relative of the European pine stem louse . For biological control of this aphid on the Canadian hemlock ( Tsuga canadensis ), the beetle is also used in the eastern United States , starting from the states of Connecticut and Virginia .
Lifestyle and diet
The life cycle of Sasajiscymnus tsugae is closely linked to that of its prey, the plant louse Adelges tsugae . Both insect species produce two generations per year in their natural habitat. In spring, the adult ladybirds lay their eggs at exactly the same time as the number of plant lice laid eggs reaches its first peak. The second generation of beetles appears in June, at the same time as that of Adelges tsugae . In summer there is a 14-day break in the development of the plant lice. During this time, the beetles devour the resting stages of their prey.
Under laboratory conditions at constantly higher temperatures, Sasajiscymnus tsugae can also develop three or more generations per year.
Systematics
Sasajiscymnus tsugae belongs within the subfamily Coccinellinae to the tribe Scymnini. The beetle was found in 1992 by Mark S. McClure on the Japanese island of Honshū and first described by him and Hiroyuki Sasaji in 1997 . It was initially included in the genus Pseudoscymnus , newly established by Edward A. Chapin in 1962 . In 2004 Natalia Vandenberg proposed to rename the genus Pseudoscymnus to Sasajiscymnus , since the name Pseudoscymnus was already a synonym for the cartilaginous fish genus Dalatias ( chocolate shark ).
supporting documents
literature
- Hiroyuki Sasaji and Mark S. McClure: Description and distribution of Pseudoscymnus tsugae sp. nov. (Coleoptera: Coccinellidae), an important predator of hemlock woolly adelgid in Japan. In: Annals of the Entomological Society of America. 90, 1997, pp. 563-568.
Individual evidence
- Jump up ↑ Mark S. McClure: Pseudoscymnus tsugae (Coleoptera: Coccinellidae) Biological Control: A Guide to Natural Enemies in North America
- ↑ RS Cowles: Establishing Pseudoscymnus tsugae Sasaji and McClure, for Biological Control of Hemlock Woolly Adelgid, Adelges tsugae Annand. Connecticut Agricultural Experiment Station
- ^ Edward A. Chapin: Pseudoscymnus, a New Genus of Asiatic Scymnini (Coleoptera: Coccinellidae). Psyche: A Journal of Entomology, 69, 1, pp. 50–51, 1962 full text (PDF download, English)
- ↑ Natalia Vandenberg: Homonymy in the Coccinellidae (Coleoptera), Or Something Fishy About Pseudoscymnus Chapin. Proceedings of the Entomological Society of Washington, 106, pp. 483–484, 2004 Abstract ( page no longer available , search in web archives ) Info: The link was automatically marked as broken. Please check the link according to the instructions and then remove this notice. (engl.)
