How to kill scarab beetles? Five effective control methods
The larvae of scarab beetles, commonly known as chicken-manure grubs, gnaw at the roots of seedlings. Besides biting through lateral roots and the main root, they can also strip and devour the root bark completely, causing missing seedlings and broken rows, and in severe cases even disastrous damage. Adult scarab beetles feed on both leaves and flowers, and they reproduce extremely quickly, so they can easily harm seedlings. They are a common major pest in forestry. The period when adults cause rampant damage is roughly from June to October, and this is the best time for control: it both controls the damage caused by adults and keeps the next generation's population density in check, yielding twice the result with half the effort.
I. Manual capture using their death-feigning behavior. Scarab beetles have the trait of feigning death: they often sit quietly on trees, and when touched they drop down and do not move at all, as if dead. Taking advantage of this trait of the adults, we can capture them by hand. Where pest density is high, weeds are abundant, or the trees are relatively tall, you can spread a layer of plastic sheeting under the tree, then shake the tree forcefully, and they will drop down on their own for capture. The captured adults can be crushed directly. This method is low in cost, fairly effective, and free of chemical pollution.
II. Light trapping using their phototaxis. Adult scarab beetles have phototactic behavior. In forest clearings, along roads, or on rooftops, set up a black light lamp, and pair it with a 3000 to 5000 V
high-voltage electric grid or a basin of water. Large numbers of adults will fly to the light at night and die by electric shock or drowning. With this method, the dead insects must be cleaned out every 1 to 2 days. Besides killing scarab beetles, it can also kill many other phototactic pests, achieving the effect of killing several birds with one stone.
III. Poison baiting using their feeding preference. Adult scarab beetles prefer to feed on poplar, willow, and elm plants. On a windless afternoon around 5 p.m., we can dip their branches and leaves in a 200-fold dilution of 80% trichlorfon, place a bundle every 10 to 15 m, and stick them in the nursery or forest land as poison bait. This can protect the target tree species well and keep the damage under control.
IV. Fumigation using their nocturnal habits. Scarab beetles all come out at night to move about and feed. On windless nights, we can release insecticidal smoke agents in forest land with appropriate canopy closure, which will also achieve fairly good results. When using this method, you must predict weather changes well to get better results.
V. Chemical spraying. Spray insecticidal agents: a 1:800 to 1:1000 dilution of trichlorfon, 1.5% dimethoate powder, 25% trichlorfon powder, or a 800-fold dilution of 40% dimethoate onto branches, trunks, and leaves; after scraping off the coarse bark of the trunk, apply 40% omethoate liquid at 1 to 2 times strength. All of these have very good insecticidal effects on adults.