The Simao pine caterpillar (Dendrolimus kikuchii Matsumura) is a genus of pine caterpillars in the family Lepidoptera leafless moths and is one of the main leaf-eating pests of pine trees.
Distribution: Simao pine caterpillar is distributed in Jiangxi, Fujian, Taiwan, Yunnan, Guangdong, Guangxi, Zhejiang, Anhui, Hubei, Hunan, Guizhou, Sichuan, etc., and distributed in the growth area of Southern Anhui Masson Pine Huangshan Pine.
Hosts and hazards: Simao pine caterpillar hosts include Simao pine, Yunnan pine, Huashan pine, masson pine, Huangshan pine (Taiwan pine), Hainan five-needle pine, cedar, money pine, black pine, larch, coastal pine, etc. The larvae feed on pine needles, and when severe, they eat the pine needles in a pine forest, which is like a fire.
Morphological characteristics:
Adult: Male moth body length 22 ~ 41 mm, wingspan of 53 ~ 78 mm, tan to dark brown, forewing base to the outer edge of the parallel arrangement of 4 black brown wavy stripes, sub-outer margin line by 8 nearly circular yellow spots, the middle chamber leukoplakia is obvious, between the white spot and the basal angle there is a large and obvious macula, the body color is darker than the female moth. The female moth is 25 to 46 mm long, with a wingspan of 68 to 121 mm, yellowish brown, no macula near the base of the wing, obvious white spots in the middle chamber, and 4 corrugated stripes.
Egg: nearly round, brown, with 3 yellow ring patterns on the egg shell, 1 small brown dot on each side of the middle stripe, and a white ring outside the dot.
Larvae: Larvae are very similar to Masson pine caterpillars. The first instar larvae are 5 to 6 mm long, the head is orange, the body is red, there is a yellow-green pattern, and the first section of the thorax has two bundles of long hairs, like two horns. 2-4 instar larvae have clearer markings and body color. The 5th instar larvae still have orange-yellow heads, black poisonous tufts on the back of the middle and posterior thoraxes, with a bunch of orange-yellow hairs in between, and two long hairs on each side of the forearm, with a white tip. The body of the older larvae grows and the body color is yellowish brown.
Pupae: oblong oval, initially pale green, later chestnut brown, 32 to 36 mm long, female pupae are larger than male pupae.
Biological characteristics: Simao pine caterpillar overwinters in the understory bushes with 2 to 3 instar larvae every November, begins to feed on the trees in early March of the following year, and pupates on the understory bushes in early May, and the peak period is in mid-May. In early June, adults begin to feather and lay eggs on the twigs or leaves of the understory shrubs. The first generation of larvae is infested from the end of June to July, and the larvae develop for a short time, eat fast, eat a large amount, and often cause serious losses. In early to mid-August, the first generation of larvae cocooned and pupated. The larvae are good at crawling, forming cocoons in the bushes inside and outside the forest, and a few cocoon on the conifers under the young trees. In mid-to-late August, adults feather and lay eggs, eggs are laid on the coniferous leaves, the larvae are initially clustered as pests, mainly feeding at night, and after 6 years of age, the amount of leaf eating is fierce, and they can be eaten day and night. Adults are more likely to be feathered from 18:00 to 22:00 every day, are nocturnal, and have phototropism. The second generation of larvae is infested from September to November, and at the end of November, it overwinters as 4-year-old (a few 5-year-old) larvae. Natural enemies are the same as Pinus massoniana, and the parasitic rate can be 50% in the egg and pupal stages.
Prevention and control methods
Prevention and control of forestry measures: adopt reasonable afforestation density, create mixed forests, timely and reasonable pruning and thinning, preserve mixed irrigation under the forest, and carry out mountain closure and afforestation. The existing artificial pure forests are transformed, and mixed forests are gradually formed, and the characteristics of mixed forests are complex in environment and numerous natural enemies to reduce the occurrence of insect pests.
Biological control: The protection and use of natural enemies, ants, gray magpies, cuckoos and praying mantises, etc., all kinds of parasitic insects (such as red-eyed bees and parasitic wasps), are natural enemies of Simao pine caterpillars and should be protected. The occurrence period can be 0.5 billion to 100 million spores / ml Ofunea crunchus liquid, 100 million to 200 million spores / ml of white zombie water agent, or 500 million spores / ml of ultra-low volume white zombie oil, emulsion, water spray.
Chemical control: In the event of an outbreak, chemical control can be carried out, such as diagonal oil spray, diopyrene oil spray plus diesel dilution 1 to 2 times, 1500 to 2250g per hectare. Ultra-low volume spray of permethrin pesticides, 15 to 30 ml per hectare. 50% octanthion emulsion 1000 times liquid, 50% malathion emulsion 2000 times liquid, 15% insecticidal emulsion 500 times liquid, 90% dichlorvos original drug 3000 times liquid, 50% dichlorvos emulsion 2000 times liquid, spray 4, 5 years before the larvae.