Calligrapha suturalis
Species of beetle
From Wikipedia, the free encyclopedia
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.
| Calligrapha suturalis | |
|---|---|
| |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Suborder: | Polyphaga |
| Infraorder: | Cucujiformia |
| Family: | Chrysomelidae |
| Subfamily: | Chrysomelinae |
| Tribe: | Chrysomelini |
| Genus: | Calligrapha |
| Species: | C. suturalis |
| Binomial name | |
| Calligrapha suturalis (Fabricius, 1775) | |
Description
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.
Distribution
C. suturalis is native to Canada and the USA.[1]
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]
Life cycle and habitat
Adults and larvae feed on Ambrosia artemisiifolia (common ragweed), A. psilostachya, and A. trifida.[5]
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]