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Local Bug Population Will Grow As Temperatures Rise


Could our wet winter lead to a big boom in the local insect population? We speak to San Diego County Entomologist David Kellum about how the winter rains and recent warm weather will affect the bug population. Plus, find out which insects you'll see flying around your porch light this spring and summer.

Could our wet winter lead to a big boom in the local insect population? We speak to San Diego County Entomologist David Kellum about how the winter rains and recent warm weather will affect the bug population. Plus, find out which insects you'll see flying around your porch light this spring and summer.


Dr. David Kellum, San Diego County Entomologist with the Department of Agricultural Weights and Measures

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This is a rush transcript created by a contractor for KPBS to improve accessibility for the deaf and hard-of-hearing. Please refer to the media file as the formal record of this interview. Opinions expressed by guests during interviews reflect the guest’s individual views and do not necessarily represent those of KPBS staff, members or its sponsors.

MAUREEN CAVANAUGH: I'm Maureen Cavanaugh and you're listening to These Days on KPBS. Our hint of really warm weather last week seems to have given even a case of spring fever, including San Diego's insect population. As the therm meter goes up, we start to notice the buzzing and the crawling and the marching ants. So what kind of insect season is San Diego in for this spring and summer in here to talk bugs with us is my guest, doctor David Kellum, he's San Diego County entomologist with the department of weights and measures. And doctor Kellum, welcome.

KELLUM: Thank you.

MAUREEN CAVANAUGH: Now, we're asking our listeners to chime in, if you've got a question about bugs in your neighborhood, you can give us a call at 1-888-895-5727. That's 1-888-895-KPBS. We had kind of a wet winter, and I'm wondering how that might impact our local insect population this spring and summer.

KELLUM: Well, this wet weather brings out our usual suspects, what we call the ABCs, the ants, the bees, and the caterpillars, and the snails. And most of these are not a big problem, but you're gonna see a lot of these, and the ants issue it's the time now to try to control the ants before they become a serious problem in the summer time, in late summer in August and September, when they're trying to get into your home. This is the time to try and control them now.

MAUREEN CAVANAUGH: When they're still outside.

KELLUM: When they're still outside. There are indicators of other things out there, because you're gonna see -- ants out there mean there's other things feeding on your plant, and other food out there, when that food is dried up and gone, that's when they come into your home and that's when they become a serious problem.

MAUREEN CAVANAUGH: Okay. So the ants begin their population boom. What other insect populations start about right now?

KELLUM: Well, it is biggest one everybody's seeing right now are honey bees. And it's the swarming season. A normal warming season, but we have Africanized honey bees here too, so bees swarm year-round in San Diego County. And we've heard a big thing about the shortage of honey bees, and this is a shortage of honey bees throughout the nation. But it's mostly with commercial bees of San Diego is doing very well with the honey bees right now because of our nice weather here. And people should be aware of there is a shortage of bees, but we don't need everyone trying to raise bees. It takes a skilled person to do that. And you have to consider your neighbors and everything else if you want to raise bees. You also have to be registered with the county and follow the different ordinances from different cities in San Diego County.

MAUREEN CAVANAUGH: I want to talk to you a little bit more about that. Because I think it's interesting. People trying to be sort of amateur bee raisers. But there's one thing that you said in the initial conversation that we had with you when you were coming on here, that the local insect population begins to explode when the temperature reaches about 80 degrees. Why is that?

KELLUM: Well, the life cycle of the insect is all based on environmental conditions of as temperature increases up to a limit, 75, 80 degrees, the population -- the life cycle speeds up, so they actually grow faster. If it's cool, it takes them twice as long sometimes to get it a certain age to where they can mature and lay eggs. Right now, the life cycle can move very fast 678 so they can turn over a lot of insects very quickly.

MAUREEN CAVANAUGH: Okay. So that makes sense now. So your warning for people just a minute ago, even though there is sort of a honey bee shortage nationally, that you perhaps sa to take into consideration a lot of things before you actually try to raise the bees issue the honey bees yourself. Do you find people are trying to do that now?

KELLUM: Yes, there is a lot of people who are trying to do that. And they're not doing it properly. You have to be trained and be able to do this. And some of those people get discouraged once they get stung a couple of times and just want to get rid of the bees at that point. Or they get the whole neighborhood stung up. But you really need to consider your neighbors, if there are a lot of kids and animals around, and maybe it's just not the best spot for you to be raising bees. And we're asking people to please consider that when they do that. But the main thing is, you're gonna see a lot of swarms, these are just wild, natural, swarming season right now. And they're not very -- they look very threatening but they're not very harmful at all. And most of the people, give them time to leave. Don't panic and throw water on them to try to get rid of them. You'll just make them angry at that point. They're very docile because they have no young, they have no honey, or anything to protect. So it takes with three-week enforce them to build up to that.

MAUREEN CAVANAUGH: So when they are actually swarming they're not very aggressive.

KELLUM: No, they're not very aggressive at all. Their stomachs are full of honey, so it's difficult to sting. This is why beekeepers smoke bees. The bees anticipate there's a fire or some catastrophe coming so they engorge themselves with honey because they can only last a few hours without honey. So this gives them a little more time to move out of the area. But as they move, they can live for several days with their stomach full, but if they don't find a place fairly quickly, then they normally will starve to death and die. So the best thing is to, you know, look at nature, and observe it, but stay away from it, don't Harris it or anything else. And it'll leave in a few days. If it doesn't, then it's time to call the pest control you should bees in the yellow pages.

MAUREEN CAVANAUGH: Just one more question about this before we take a call, when are these honey bees -- when do they become aggressive?

KELLUM: Only after having established nest. This takes 3 to 4 weeks, and once they're inside a cavity or something, they're not gonna stay out in the open. Once they go inside a cavity or something, and they have honey there, and they have young, then they have something to defend.


KELLUM: They're not really aggressive unless they're defending their air area. And if they just got there, it's not their area until they become established.

MAUREEN CAVANAUGH: Got it. I'm speaking with doctor David Kellum, he is San Diego County entomologist with the department of weights and measures and we're taking your calls and questions about bugs in your neighborhood. 1-888-895-5727. Marg is calling from the north county. Good morning, Marge. Welcome to These Days.

NEW SPEAKER: Good morning, thank you for taking my call.

MAUREEN CAVANAUGH: You're welcome.

NEW SPEAKER: The question I had, and thank you for addressing this, last summer we were inundated with an Asian beetle, the bagrata bug, who washed up on the beaches as well as ate all of our green leafy vegetables. And we had a heck of a time controlling it naturally, we're organic. And I'm wondering if you have any suggestions, and if you think we'll be seeing them reemerge with the heat this spring.

KELLUM: Yeah, you're talking about the bagrata bug, and it's a stink bug. [CHECK AUDIO] and it's very pretty, but it can do a lot of damage, mainly to suck on the plants. Of and the population, it's an exotic pest 67 it's new here, and when they first get here, they have large colonies, but will moderate, others will start feeding on these insects and also by controlling your weeds, especially in organic areas, if you control the weeds around there, then they won't establish themselves there. Once they get established, once it dries out, they move to your gardens and other places, they usually cause a lot of problems in the fall time.

MAUREEN CAVANAUGH: Let's take another call. Alicia is calling from El Cajon. Good morning, Alicia, and welcome to These Days.

NEW SPEAKER: Good morning, and thank you for taking my call. I had a question on fleas. I see in our house, I have sprayed, I've tried pellets, a friend of mine sent me something called a sauna that he said is organic and they use it up north, all the farmers, to kill bugs, nothing seems to be getting rid of these fleas of my poor dogs are suffering.

MAUREEN CAVANAUGH: What about fleas?

KELLUM: Well, fleas are something that we have very little to do with, because we're agricultural, but that's something that can be addressed by the environmental health department in San Diego County.

MAUREEN CAVANAUGH: When we have a big bug season, though, do we usually have a big flea season as well.

KELLUM: Right. Fleas like moister areas and sandy areas, the habitat they like more than anything else. So they're very difficult to get rid of. But there are some controls that I think -- that the veterinarian can give you to try to control inside and outside. But sometimes you may have a large population of fleas, you may just have to call a professional pest company to handle that. Because it's a little bit daunting to try to rid of all those fleas.

MAUREEN CAVANAUGH: Another thing that I don't think you actually handle too much is we've heard stories about infestations of bed bugs in homes as well. ; is that right?

KELLUM: Right. But that's another one that's handled by environmental health. And it's not an agricultural thing. And it's a serious problem. Not as bad in San Diego County as in other places. So it's because of the worldwide travel and people can move around very quickly, and it gets a lot of publicity, but it's no more greater than it was a few years ago of it's just that we have the publicity from it now.

MAUREEN CAVANAUGH: Okay of we've been talking about wet weather. We just had a storm last week. I saw -- still saw some puddles around a couple of days ago. What about mosquitoes.

KELLUM: Again that's going to something from environmental health. But they will be a serious problem. And basically, you can call the environmental health company, in the county, and have them check it out if you have mosquitoes there, pools of water or something, you can report that, and they will come out and take care of that in most cases or tell you how to take care of it.

MAUREEN CAVANAUGH: Steve is on the line from City Heights. Good morning, Steve, welcome to These Days.

NEW SPEAKER: Hi. I noticed that there are a kind of worm on the elm trees on Vedra boulevard near where I live. And thee kind of reminded me of a webbed worm, but there are no webs in the tree the.


KELLUM: Right. We're quite familiar with this. This is called the spiny elm caterpillar, and it's a nice black butterfly when it hatches out 67 it's called the morning cloak butterfly. And it attacks elms and a few other trees out there. And it's not a serious problem, but you have to avoid this caterpillar because it has stinging hairs, and that can be very irritating if you get the hairs on your body. And we're not recommend -- the trees they cover [CHECK AUDIO] by the time you see them, they're big and spiny and black like that, it's almost too late to try to control them at that point because they're gonna pupate and turn into butterflies.


KELLUM: And we also have, if you're very concerned about that, you can call our department, and we can probably get someone who will come out and rescue those caterpillars. [CHECK AUDIO] we have a butterfly rescue program that's going on. And people will actually come out and try to recover those cater pillars if it's not too high up in the trees.

MAUREEN CAVANAUGH: That's wonderful. Jose is on the line from Chula Vista. Good morning, Jose, welcome to These Days.

NEW SPEAKER: Hi, I just moved into my place about two years ago, and last year, I noticed that I had a wasp's nest, and I have a newborn in the house, and I just want to know how aggressive wasps in this area really are, and if I need to take care of it soon.

KELLUM: Yes, we're talking -- most wasps, if you're talking about the ones under the eaves, they have the little umbrella shaped nest? Or are you talking about the yellow jackets --


KELLUM: Oh, those are not very aggressive at all. They're actually feeding on caterpillars right now. They's beneficial. You can either knock the nest down or you can spray the wasps with hornet spray, which goes up to about 25 feet, and just knock them down and take care of them at that point. If they're too close to you. But in most cases, if they're high and out of the way, they're really very beneficial, and you really want to avoid killing those.

CAVANAUGH: Now, our environment reporter, Ed Joyce, did a report last week on the golden spotted oak borer that's reeking havoc in the Cuyamaca Rancho state park. What is the county doing to get rid of this insect? The spotted oak borer?

KELLUM: Well, the county's working with other organizations, UC Riverside, university of California, and the forest service and trying to get more information. We're taking calls from areas that people are reporting this, and transferring those calls to the forest service, and people who are working with this. This is a serious problem. We don't know all the factors of why it's such a big problem. But it's mainly in San Diego County, and not anywhere else. And it's one of the exotic pests that we have to learn to live with, but we're trying to find ways to control it and protect the oak trees out there.

MAUREEN CAVANAUGH: Now, we still have quarantines in effect for the light brown apple moth. We talked about that last year, and the Asian citrus psyllid. What information do you want to give to the public about the danger of those insects and the purpose to really respect those quarantines?

KELLUM: Well, the main thing we're asking people not to move certain plants around and to double check [CHECK] because they can all be spread by moving plants around, and these are very damaging to citrus and to industry and to why your backyard products. The light brown apple moth, you have a spot infestation of those, but the Asian psyllid is basically throughout the county right now. And these quarantines are really to slow down the spread of this particular pest because once it gets into the agricultural areas where they're growing a lot of citrus, then they can't sell that produce, and can't sell the citrus to other countries.

MAUREEN CAVANAUGH: I remember that big problem last year or a couple years ago our growers had with that.

KELLUM: Yes, they just have to try a lot of pesticide and everything, treat them before they can sell them to other countries and move them around the area.

MAUREEN CAVANAUGH: Now, let's take another call, Matt's calling from Del Mar. Good morning, Matt, welcome to These Days.

NEW SPEAKER: Good morning. Thank you. I've been seeing more and more of these brownish spiders with an orange hour glass like a black widow. It looks like they may be brown widows.


NEW SPEAKER: I thought they may be dangerous but not all that aggressive. Can is you tell me about that?

KELLUM: Yes, this is a brown widow spider, and you're seeing more of those, because unlike the black widow, they're very secretive. They tend to be more open. They're gonna be around your garden and your cars, and around trash can lids. Now, the venom is more toxic than the black widow, but the fangs are very small and can barely penetrate the skin. So they're non aggressive, and the likelihood of being bitten by those are very slim. But you also want to make sure that you take care of those if they're around children and places like that. But in most cases, it is not a big deal. They're just part of the environment called the brown widow spider now. But it's very common, and you're gonna see a lot more of those than you do of the black widow spider. But there are very few reports of bites. A few people have been bitten without consequences so this is not a big deal.

MAUREEN CAVANAUGH: Interesting. Now you told us what to watch for right now. How you does the local insect population change as we get into the summer?

KELLUM: Well, it changes quite a bit. Right now, we have the cater pillars, the bees, but later on, we'll start getting a lot of the feed bugs, that you see in heavy populations, like the red bugs, different types of bugs that are out there. They're moving from the dry area in the fields that are not taken care of, they're moving away from those, and moving toward the lush green yards in the water areas. And as it dries up, those insects will follow the water, basically.

MAUREEN CAVANAUGH: I see. And you told us beforehand that a lot of people like to contact you about bugs. What's the best number to reach you at the department of entomology?

KELLUM: The best number is 1-800-200-BEES. That's 1-800-200-2337. That's the pest information line right now.


KELLUM: So you can leave your questions there, mainly we tell you to bring in the information, bring in the insect, send it in to us. Make sure we see something visually there because it's kind of difficult to go by your identification of it. Pictures of it, we prefer for you to bring the insect in, are and we can identify it that way.

MAUREEN CAVANAUGH: I want thank you so much for talking with us. Thanks, doctor David Kellum.

KELLUM: You're welcome.

MAUREEN CAVANAUGH: And I want to tell anybody, if they want to comment, please go on-line, Days. Coming up, the complex problem of teenaged depression, that's as These Days continues here on KPBS.

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