Are stink bugs beneficial insects or pests? Uncovering the origin of the name "stink ladybug"
General NewsBy Sophie Bennett0 views
Stink bugs, about the size of a woman's fingernail, uniformly dark brown, are called stink bugs, fart bugs, poop bugs, or "stink ladybugs" because they release a foul odor. So are they beneficial insects or pests? According to agricultural records, stink bugs are a general term for a class of insects with abnormally variable wings, with over 30,000 species, of which more than 90% are pests. However, insects also have a beneficial side. Beneficial species include predatory stink bugs that feed on small insects and benefit agriculture, the medicinal jiuxiang bug, the edible guihua cicada, and the field giant water bug and pine algae bug that specifically prey on juvenile fish and harm the aquaculture industry.
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<p style="text-indent:2em;">Most stink bug species are pests. In the cotton region of the Yellow River basin, 3-5 generations occur each year, overwintering as eggs in dead branches and stubble of alfalfa, broad bean, pomegranate, apple, etc., as well as in dead cotton branches and boll shells. They hatch in early to mid-April and emerge as adults in late April. Mid-June to mid-July is the peak damage period. Adults are phototactic, lay more eggs in densely growing cotton fields, and prefer high temperatures and rain. Temperatures of 25°C-30°C and relative humidity above 80% are suitable for egg hatching and reproduction, and cotton fields near alfalfa plots, green manure fields, or with many weeds suffer the most severe damage.</p>
<p style="text-indent:2em;">In the suburbs of Beijing, stink ladybugs mainly harm fruit trees such as pear, peach, and apple, with damage rates generally around 15% to 25%, and fruit damage rates as high as over 70%, turning the fruit into “monkey-head peaches” and “pear lumps” that taste bitter and lose their food value. In urban areas, stink ladybugs harm various landscaping trees and flowers such as willow, elm, mulberry, poplar, pagoda tree, eucommia, paulownia, and pomegranate. They suck the sap of flower buds, petals, leaves, tender leaves, and fruits, greatly reducing the effectiveness of landscaping and beautification.</p>
<p style="text-indent:2em;">To control stink ladybugs, you can concentrate on trapping and killing them when they overwinter; in early spring, take measures such as plugging tree holes and scraping off old bark; at noon in summer, gently shake the tree trunk by hand and promptly kill the stink ladybugs after they fall to the ground; in addition, control should be carried out during the nymph stage of stink ladybugs, because during this period they can only crawl and cannot fly. At present, the use of the stink bug's natural enemy, the stink bug egg parasite wasp, for biological control of stink ladybugs at the forestry biological control center has entered the experimental stage. Field surveys show that the stink bug egg parasite wasp has a high parasitism rate on stink bug eggs, with an average parasitism rate of 47.22% on tea-winged stink bug eggs and 30.56% on pear stink bug eggs, making it a natural nemesis of stink ladybugs.</p>
<p style="text-indent:2em;">The rice stink bug egg parasite wasp parasitizes rice brown stink bug eggs, singly. In a July 1957 survey of rice fields in Hangzhou, Zhejiang, up to 97.1% of rice brown stink bug eggs were parasitized by black egg wasps, of which this species accounted for 94.2% and the rice stink bug small black egg wasp for 2.9%. The sex ratio of this species was 81.54%. According to another survey in Wangcheng, Hunan, of the 67.24% parasitism rate of rice brown stink bug eggs, this species accounted for 41.75% (Zhou Renlian, 1955). Parasitized eggs appear black before emergence and light yellow after emergence. The emergence hole is on the top surface of the egg, irregularly circular, with an uneven cut edge and strip-like debris connected to the rim of the hole. Creamy egg contents remain on both sides inside the egg. Adult wasps mate immediately after emergence, and the time is extremely short, only 3-5 seconds. When laying eggs, they constantly use their antennae to explore above and to the sides of the egg, and always insert eggs from the side. Laying one egg takes about 30 seconds; after laying, they move slightly and then lay eggs on another host. When reared by introducing fresh stink bug eggs, the period from egg laying to emergence is 7 days, with an average of 22 offspring wasps. Adult wasps live 4 days, and if supplied with diluted honey solution, this can be extended to 20-22 days.</p>
Stink bugs, about the size of a woman's fingernail, are blackish-brown all over, and because they release a foul odor, they are called stink bugs, fart bugs, dung bugs, and stink ladies. So are they beneficial insects or pests? According to agricultural records, stink bugs are a general term for a class of insects with abnormally modified wings, totaling more than 30,000 species, of which over 90% are pests. However, insects also have their beneficial side. Beneficial species include predatory stink bugs that prey on small insects and benefit agriculture, the jiuxiang bug used in traditional Chinese medicine, the guihua cicada used as food, and the giant water bug and pine algae bug that specifically prey on young fish and harm the aquaculture industry.
Most stink bug species are pests. In the cotton region of the Yellow River basin, 3-5 generations occur each year, overwintering as eggs in dead branches and stubble of alfalfa, broad bean, pomegranate, apple and others, as well as in dead cotton branches and boll shells. They hatch in early to mid-April and emerge as adults in late April. Mid-June to mid-July is the peak period of damage. Adults are phototactic, lay more eggs in densely growing cotton fields, and prefer high temperatures and heavy rain. A temperature of 25°C-30°C and a relative humidity above 80% are suitable for egg hatching and reproduction, and the damage is most severe in cotton fields near alfalfa plots, green manure fields, or fields with many weeds.
In the suburbs of Beijing, stink ladies mainly harm fruit trees such as pear, peach and apple, with a damage rate generally around 15% to 25%, and a damage rate to fruit as high as over 70%, turning the fruit into “monkey-head peaches” and “pear lumps”, bitter in taste and losing their edible value. In urban areas, stink ladies harm many greening trees and flowers such as willow, elm, mulberry, poplar, pagoda tree, eucommia, paulownia and pomegranate, sucking the sap of flower buds, petals, leaves, tender leaves and fruit, greatly reducing the greening and beautification effect.
To control stink ladies, they can be caught and killed in concentrated efforts when they overwinter; in early spring, measures such as plugging tree holes and scraping off old bark can be taken; at noon in summer, the tree trunk can be gently shaken by hand to kill the stink ladies that fall to the ground in time; in addition, control should be carried out during the nymph stage of the stink ladies, because during this period they can only crawl and cannot fly. At present, the use of the stink bug's natural enemy, the stink bug egg parasitoid wasp, for biological control at the forestry biological control center has entered the experimental stage. Field surveys show that the stink bug egg parasitoid wasp has a relatively high parasitism rate on stink bug eggs, with an average parasitism rate of 47.22% on tea shield bug eggs and an average parasitism rate of 30.56% on pear stink bug eggs, making it a natural nemesis of the stink lady.
The rice stink bug egg parasitoid wasp parasitizes the eggs of the rice brown stink bug, as a solitary parasitoid. In a survey of rice fields in Hangzhou, Zhejiang in July 1957, as many as 97.1% of rice brown stink bug eggs were parasitized by scelionid wasps, of which the parasitism rate of this species was 94.2%, and that of the rice stink bug small black egg wasp was 2.9%. The sex ratio of this species was 81.54%. According to another investigation in Wangcheng, Hunan, of the 67.24% parasitism rate of rice brown stink bug eggs, this species accounted for 41.75% (Zhou Renlian, 1955). Parasitized eggs are black before emergence and light yellow after emergence. The emergence hole is on the top surface of the egg, irregularly round, with an uneven cut edge, and strip-shaped debris connected to the rim of the hole; creamy egg contents also remain on both sides inside the egg. Adult wasps mate immediately after emergence, for a very short time, only 3-5 seconds. When laying eggs, they constantly use their antennae to explore above and to the sides of the egg, and always lay eggs into it from the side; laying one egg takes about 30 seconds, and after laying they move slightly, then lay eggs on another host. When reared on fresh stink bug eggs, the period from egg laying to emergence was 7 days, with an average of 22 offspring wasps. Adult wasps live 4 days, and if dilute honey solution is provided, this can be extended to 20-22 days.