Calligrapha suturalis, commonly known as the ragweed leaf beetle, is a species of leaf beetle belonging to the family Chrysomelidae, in the subgenus Zygogramma, which was formerly a genus.[1] Native to North America, it has been introduced into Russia and China for the biological pest control of ragweed.
Description
Ragweed leaf beetle
This leaf beetle is small with a brown head and pronotum, and yellow elytra marked with two wide margins of brown on each wing; one in the middle and one at the suture.
It was introduced into Russia in 1978 in an attempt to control invasive Ambrosia artemisiifolia (common ragweed).[2] About 1500 individuals were originally released, eliminating ragweed at the experimental control site by 1983. The success of C. suturalis in Russia led to a population explosion with densities of up to 100,000,000 adults per square kilometre recorded subsequently.[3]
It was introduced to China as a biological pest control for ragweed in 1987.[4]
Overwintering adults began feeding in late April or early May of the following year, having emerged when ragweed seedlings were only 2–5 cm tall.[6] Larvae of the first or spring generation began feeding in mid-May or early June and most reached maturity by early July.[6] Larvae of the second or late summer generation were evident during the first two weeks of August.[6]
No complex courtship behavioural patterns have been observed in C. suturalis; copulation most commonly takes place during the late morning or early evening and lasts from a few minutes to well over an hour.[6] Females lay between 145 and 563 eggs, over a period of 22–42 days.[6] Eggs are deposited in clusters of two or three on the underside of young ragweed leaves, usually near the leaf tip.[6]
Investigations in the USA showed that C. suturalis had 2 generations a year,[6] but field investigations in China have shown that the beetle species could have up to 3 generations a year in that populations.[4] At 26±1 °C, the average lifespan of the adult female and male was 82.5 and 67.8 days respectively.[4] The mated females began laying eggs two weeks after emergence. Each female lays an average of 394 eggs.[4]
References
^ abShawn M. Clark, Hume B. Douglas, Daniel J. Cavan (2024) Notes on Calligrapha Chevrolat (subgenus Zygogramma Chevrolat) and Tritaenia Motschulsky (Coleoptera: Chrysomelidae: Chrysomelinae). The Coleopterists Bulletin 78(2): 281-295.
^Kovalev, O.V.; Reznik, S.Ya.; Cherkashin, V.N. (1983). "Specific features of the methods of using Zygogramma Chevr. (Coleoptera, Chrysomelidae) in biological control of ragweeds (Ambrosia artemisiifolia L., A. psilostachya D.C.)". Entomologicheskoe Obozrenije (in Russian). 62: 402–408.
^ abcdefgPiper, Gary, L. (1975). "The biology and immature stages of Zygogramma suturalis (Fabricius) (Coleoptera: Chrysomelidae)". The Ohio Journal of Science. 75 (1): 19–24. hdl:1811/22261.{{cite journal}}: CS1 maint: multiple names: authors list (link)
