How to control the lychee stink bug? Anastatus wasps lend a hand
The lychee stink bug is now found all across Taiwan, and it directly reduces the yields of lychee and longan fruit and of nectar At present, Taiwan hopes to solve the lychee stink bug problem with a native parasitic wasp called the flat-bellied wasp, but because the lychee stink bug has a fixed egg-laying period, the flat-bellied wasp can only be reproduced through artificial rearing between August and February of the following year, so its production is limited; however, the Miaoli District Agricultural Research and Extension Station recently found through trials that eri silkworm eggs can also serve as hosts for the flat-bellied wasp, and because they are easy to obtain, this is expected to bring a new breakthrough in the mass production of the flat-bellied wasp. The lychee stink bug originally lived in India, Southeast Asia, China and other places, and after it appeared in Kinmen County in 1999, it began to spread across Taiwan. Because it pierces and sucks the tender shoots and flower clusters of longan and lychee, causing flowers to drop, fruit to drop, withering, blackening and other adverse reactions, it not only directly hits yields and causes losses for fruit farmers, but the reduced flower clusters also leave beekeepers with no nectar to collect, so it can be called a kind of insect pest and a double blow. For example, Hsieh Mei-li, who runs an organic guava orchard in Shigang, Taichung, has had no longan harvest for 2 consecutive years; what is even more troublesome is that when she wants to remove the lychee stink bugs in the field, she is also attacked by the stink bug's foul liquid, which not only causes skin redness, swelling and burns, but if it accidentally sprays into the eyes, it may also cause blindness, leaving farmers quite helpless and troubled. Also because of the foul liquid, even rural downtown areas and urban zones now have to raise their alertness. Besides lychee and longan, other Sapindaceae plants such as soapberry and Taiwan goldenrain tree are also among its favorites, and if these plants are not common street trees, they are campus plants, very close to people's living circles, with the foul liquid lurking all around. At present, the most effective control method for the lychee stink bug is chemical control, that is, spraying pesticides such as carbofuran, permethrin, carbaryl and fenitrothion. But on the one hand, if the lychee stink bug hides behind leaves, the effect is reduced; at the same time, for organic farmers who are unwilling to spray pesticides, apart from manually removing egg masses and adults At present, the only thing the organic sector can pin its hopes on is a native parasitic wasp called the flat-bellied wasp. They can lay the next generation's eggs in other insects, and when the larvae hatch they feed on the parasitized insect eggs. The lychee stink bug has now been confirmed to be parasitized by the flat-bellied wasp, so if a certain number of flat-bellied wasps are released into the field, they should be able to achieve control by parasitizing the eggs of the lychee stink bug. At present, the researcher with the most results is Chang Tsui-ying, assistant professor in the Department of Plant Medicine at National Pingtung University of Science and Technology. Last year she and the Kaohsiung City Government already released them near Qiaotou, Tianliao and NPUST, and this year, besides hoping to track follow-up results, they also hope to obtain data on release density, to find a solution for organic farmers and urban areas where pesticides cannot be sprayed. But also because of the parasitic nature of the flat-bellied wasp, when the lychee stink bug is not laying eggs, roughly from September each year to February of the following year, the flat-bellied wasp has no host to parasitize, so its population also declines, and at present it can only be bred through artificial rearing, so mass production is still limited.Fruit drop and foul liquid: from farmers to urban residents, everyone is affected
Native parasitic wasp controls the lychee stink bug, but production is insufficient
