These strange little objects in the trees on the side of the road are all pest killers

Source: Science and Technology Daily

These strange little objects in the trees on the side of the road are all pest killers

In the trees on the side of the road in the city, you can often see some strange things, such as plastic "belts" on tree trunks, triangular "small houses" hanging from branches, cocoons nailed to tree trunks, etc. What exactly are these things for?

"Belt": Prevent pests from going up the tree

On many large trees, you can see a variety of "belts".

"The plastic 'belt' on the trunk of the tree is to prevent grasshoppers or other pests such as the spotted wax cicada from climbing from the ground to the tree." Wang Xiaoyi, a researcher at the Institute of Forest Ecology Environment and Protection of the Chinese Academy of Forestry, told Science and Technology Daily.

Industry insiders say the most common is smooth, snuggly tape that sticks to the trunk of a tree, which effectively prevents flightless insects such as grasshoppers from climbing up from the bottom up onto the tree. Sometimes it can also be filled with straw or artificial fibers under smooth tape, allowing pests to hide in them and eventually die because they are difficult to drill out. In addition, it is also possible to change the smooth plastic "belt" to a viscose "belt", which can effectively kill the nymphs with strong jumping ability, just like the sticky board of the cockroach in the home, and eliminate the pests.

"Little House": Not a bird's nest but a trapper

On some trees we can often see triangular "small houses" hanging from the branches. This device is common in the north and is often misinterpreted as an artificial bird's nest.

"In fact, the triangular 'little house' hanging in the air is a trap made of chemical attractants that lure the pests by releasing odor information substances and glue them to the glue." Wang Xiaoyi said.

This triangle house has a sticky base plate with glue, and a hanging lure bait in the middle (mimicking the pheromone of female insects, trapping male insects), mainly targeting the locust ruler moth that harms the national locust. Locust inchworm moth, also known as locust inchworm, has been seriously harmful in many places in the north, when the incidence can eat the entire locust tree without a leaf left, their larvae are often called "hanging ghosts" - because they often hang from the tree and get their name.

This sex trap hut is simple and convenient, and has a certain degree of specificity, which has a significant effect on the control of locust ruler moth. But there are sticky plates at the bottom, and there is also the possibility of accidentally injuring birds.

Yellow Sticky Board: Use color to form a beautiful trap

In addition to the "little houses", in the park or on the green belt by the road, we often see some yellow boards waving in the wind on the branches.

Experts say that the yellow sticky board coated with glue is often called the yellow board. The reason why yellow is chosen is because many small flying insects such as aphids have a tendency to bright colors such as yellow. For green plants, aphids are one of the main pests, and yellow plates are a good choice when it is necessary to avoid spraying pesticides to kill them. Since peach trees are particularly prone to aphids, yellow plates are more often hung on peach trees.

Although the yellow plate is very effective in killing small flying insects such as aphids, it is a broad-spectrum insecticidal measure, so it can also accidentally injure a large number of beneficial insects, including rare species with small populations.

Cocoon: Contains a pest killer

In recent years, biological control has increasingly replaced traditional drug control, and people often see silkworm cocoons hanging from trees as a measure of biological control.

"Some of the cocoons nailed to the trunks parasitize the Chow chicks that control the American white moth." Wang Xiaoyi said.

These cocoons are the cocoons of the tulips of the family Macromothidae, and the pupae inside do not feather out of the moth because the pupae have been parasitized by parasitic wasps like the Chow chicks. In order to allow the parasitic wasps to fly out smoothly after feathering, a hole is artificially opened in the cocoon. Parasitic wasps will look for Lepidoptera pests such as the American white moth in the urban green space, and stab the egg laying device into the vermin pupa, so that its larvae will develop and grow in the pupa and eventually lead to the death of the pest, so as to achieve the purpose of control.

However, experts remind that at some levels, excessive control may also kill some "innocent" insects by mistake, and the reduction of butterflies in urban areas may be related to the excessive release of parasitic wasps, so the control of control is very critical.