psychochemist

Chapter 97 The Immortal Cockroach
Uncle Guo proposed a test, and it was a test for Yu Fan and Guo Na. He didn't know what kind of medicine was sold in the gourd.

Guo Na coquettishly said to Uncle Guo: "Dad, don't embarrass your elder brother. What are you doing?"

Uncle Guo waved his hand and said to Guo Na: "It's not that I deliberately made things difficult for you, it's that we have encountered difficult things recently. I wanted to ask you about this when you came back to help, and it happens that Xiao Yu is here today, so then I just need you two masters to help me figure out a solution together."

Yu Fan smiled and said, "Uncle, it's okay to say, let's see if we can help."

Uncle Guo: "Hey, it's actually not a big deal. It's just our pet store. We didn't pay attention to the cockroaches recently, but now it's out of control."

Guo Na asked strangely: "What's so scary about cockroaches? If you spray them with insecticide, it's over."

Uncle Guo shook his head helplessly: "Yes, we sprayed it with insecticide at the beginning, and it really worked. Once sprayed, the cockroaches fell over. We went up and trampled them to death, and then disposed of them, and the cockroaches did disappear. For a while, but in a few days they came out again, and there were more. Not only more, they also ran into the dashboard of the rice cooker and the water dispenser, making us sick."

Guo Na was puzzled: "Then continue to spray with insecticide."

Uncle Guo sighed: "That's the problem. This time we sprayed them with insecticide again, and they seemed to be immune, and they didn't respond at all."

Guo Na then asked: "Then increase the dose?"

Uncle Guo: "We also tried the method of increasing the dose, but it didn't work. And there are so many dogs in our store, we were worried that the dogs would be poisoned if we sprayed too much insecticide. We dare not use strong drugs anymore."

Guo Na raised his chin: "Well, this is indeed a bit tricky." Guo Na looked up at Yu Fan who was also thinking, and asked, "Brother Yu, do you have any good ideas?"

Yu Fan pondered for a few seconds, pursed his lips, and said: "The characteristics of cockroaches in the north are actually very different from those in the south, and there are some differences in handling. The size of the southern cockroach is the size of a lighter. The northern cockroach It is only the size of a peanut. The southern cockroach belongs to the American cockroach, with a butterfly-shaped brown stripe in the middle of the pronotum. The northern cockroach belongs to the German cockroach, and the pronotum has two parallel dark brown longitudinal lines."

Guo Na added: "Yeah, I remember the first time I saw a southern cockroach it gave me a big jump."

Yu Fan continued: "When dealing with cockroaches in the north, you must be careful not to crush the cockroaches. After the cockroaches are crushed, their eggs will burst and disperse. You can think of it as stabbing a hornet's nest, and the little cockroaches won't be around for long." After hatching, it will be everywhere. The correct way is to flush the dead cockroaches directly into the sewer. So the cockroaches broke out after resting for a few days, in fact, it was the seeds you put in."

Yu Fan paused and continued: "The growth process of cockroaches is: egg→larva→adult in three stages. It can lay 4-17 eggs in its lifetime, and each egg contains 20-50 eggs. There is an unwritten It is said that when you see a cockroach, there are already 40 cockroaches around. What is even more frightening is that cockroaches, a species with strong vitality and adaptability, are highly resistant to pesticides. If your insecticide Spraying can't kill them all at once, they will develop antibodies to the drug, and spraying it will no longer work."

Guo Na summed it up: "So the group of 'Xiaoqiang' we are facing now are actually evolved super cockroaches?"

Yu Fan: "I'm afraid so."

Uncle Guo asked anxiously: "Then what should we do? Is there nothing we can do?"

Guo Na: "I remember that there seems to be a cockroach bait glue on the Internet. That can get rid of cockroaches. Do you want to try that?"

Yu Fan thought for a while: "Well, this should work, but the toxicity may be a bit strong. If it is eaten by a dog, it will definitely be poisoned."

Uncle Guo: "Then what should I do?"

Everyone was at a loss.At this time, Guo Na's mother, Aunt Cao, came back.

Uncle Guo immediately introduced Yu Fan to Guo Na's mother, and Aunt Cao also praised Fan greatly.

Before he could say hello, Yu Fan suddenly saw a bag of white sugar in the vegetable basket brought back by Aunt Cao.

Yu Fan asked, "Auntie, have you bought candy?"

Aunt Cao didn't know why Yu Fan asked this question, but she still answered: "That's right, Lao Guo said he was going to make dumplings for his daughter tonight, so I bought some white sugar for dipping dishes."

Yu Fan clapped his hands suddenly and shouted, "Yes!"

Yu Fan said: "Guo Na, please bring me some washing powder, auntie, please give me some sugar, I want to prepare a cockroach repellent!"

Guo Na brought the washing powder, and Yu Fan mixed the washing powder and sugar together, then put the mixture on a piece of white paper and placed it on the countertop of the bathroom.

Uncle Guo was very puzzled: "Can this thing kill cockroaches? Isn't it true that all pesticides are useless?"

Yu Fan smiled and explained: "The body surface of insects uses wax shells to keep moisture. Cockroaches are no exception, and almost all washing powder needs to add sodium tetraborate (borax) as a modifier. Borax can destroy the wax shells of insects." It leads to dehydration of insects. Cockroaches have cannibalism, and boron-killed cockroaches will be eaten by their companions, causing boron to gradually enter the entire cockroach community system. When boron is too high, cockroach egg sheaths will also dry out and inactivate, eventually leading to the death of the community. "

Guo Na also understood at once: "It turns out that this is the case. Pesticides are not effective, so we use boron as a carrier to let it enter the cockroach population, let the cockroaches lure wolves into the house, and then kill each other."

Yu Fan continued: "This method has relatively low toxicity and is more practical. Insecticides on the Internet often only consider the effect, and the toxicity is very high. Moreover, with the continuous improvement of cockroach resistance to insecticides, the effectiveness of insecticides The toxicity is also getting higher and higher, which poses a safety hazard. It is relatively safe to use our homemade ones. After all, there are so many cats and dogs in pet stores, and poisoning is a big problem.”

Aunt Cao patted Yu Fan on the shoulder and said approvingly: "Young man, you are not bad, you are very smart. You are Guo Na's master. You will teach my daughter more in the future."

Aunt Cao turned to Guo Na again and said, "Look at you, Xiaoyu is about the same age as you, but he is better than you in terms of professional knowledge and behavior. You have to learn more."

Guo Na stuck out her tongue, making a naive look.

Yu Fan repeatedly thanked his aunt for her approval. Although Guo Na's parents were not highly educated, they were still very sensible.

While chatting, Guo Na and Yu Fan's mobile WeChat suddenly rang, and they both took out their mobile phones at the same time.

It was Chen Zhenyang who sent the message, which said: "Chen Taizhou's case has progressed again. Police officer Ziyi from Jinbu Town has provided us with a new clue. Let's set off on Monday!"

It seems that I am busy again.

　In life, there will always be unexpected warmth and endless hope. ——Sodium Tetraborate

　　
　
(End of this chapter)