Carl Casselton, Richard Harris
Carl Casselton, Richard Harris
Includes locust wing flutters and birds.
NPR/NGS Radio Expeditions
20 Oct 2004
- The road between Saint-Louis and Richard Toll
- 16.2837577 -16.1240673
Decoded MS stereo
Show: Locust R. Harris
Engineer: Leo Del Aguila
Date: October 16-23, 2004
00:27: on the road between St. Luis and Richard Toll, it is the middle of a very hot open desert. it is 35 degrees centigrade and we have stopped along here to see what kind of locust damage we can scout
54RH what do you have?
56 CC looks like the results of the spraying program. Here we have a handful of actually uh dessert locust cadavers. Pretty recent, the ants haven't gotten at them, they are in pretty good shape here.
1:11 could you describe them
cc probably about two and half inches long, the gregarious form, more slender than the solitary desert locust. Trying to see if they have any smell of pesticide on them¿they don't
RH and they sort of have a pink cast, what does that mean?
1:37 CC yeah that means they are still, they are an adult locust. These were probably born here, some place in Senegal but they are pinkish which means that they have not yet have not yet reached sexual maturity. So these would have been emerged These are received from hopper bands here in Senegal, turn into adults, mill around a bit and form young swarms and these are the targets of the control efforts.
2:05 RH what were they eating here probably?
CC Probably some of the roadside grass, because this is actually a sugar cane plantation on the other side of this irrigation ditch. Hoping to get to the other side to see what type of vegetation was there to see if we had any residual locust, but it looks like they are all dead
I don't think it's been long but we don't have the complete records. But this looks like the results of the last days spray
RH they remind me of flying shrimp in a way, the pinkish cast.
2:56CC yes, and not with the ethnic groups that live here in Senegal they don't eat locust but elsewhere in Sahel, particularly up in northern Niger, you would have people who gather desert locust kill them put them in sacks and bring them to market. Like shrimp, like dried shrimp Good source of protein. But there are other groups because of religious belief would not eat insects or other arthropods.
(Color matches their shirt)
4:32 AMBI 9:42 out
RH: we are on the road approaching the town of Podor and a moment ago something whacked on the windshield and we looked up and the sky was¿ the air all around us was full of fluttering insects. Locusts! XXXXXXXXXXx
They're crunching under our feet. Many are dead but some are inside a thorn bush here. In the hot sun.
11:18 Castleton interview:
11:15 Q: so what do you make of this scene?
CC: I stopped the vehicle also.
Looking at this particular thorn bush and the piles of locust cadavers next to the road, this looks like it has been treated recently. There's still a lot of locusts flying around and I think we have two things here: one it may have been a v. large swarm and even aerial treatments are at best 80 to 85 pct effective. So what we're seeing¿ we are seeing quite a bit of apparently healthy locusts flying about 5-10 feet above the ground thru the driving pasture grasses here. I think these are basically what have escaped from this morning's aerial treatment. But it is impressive to see the numbers, which have ¿ but on the other hand, every place we look, in every direction, we have a light swarm that's still vv active and has escaped this morning treatment.
1225. This is the brightest of the pink we've seen. When they're still alive, they're a beautiful beast XXXXXXXXXXxxx with dark pink legs, spotted wings, oops that one just hopped away from me there ¿ they're very soft to to the touch, these are young adults. They are pink, a sign they have not yet reached sexual maturity they'll be turning yellows¿ wd be an indication they'd be able to lay eggs. XXXXXXXXXXx
1303 if they survive this treatment¿. They'll be heading north into Mauritania. Maybe some of the individuals we see here might make it as far north as morocco XXXXXXXXX and reach sexual maturity. If they're not controlled at that point wd be the source of the egg which wd give rise to hopper bands in the migrant countries.
1331 Q: so morocco is a long way from here. They can make it that distance/
1335 CC: morocco is a long ways but yr talking about an insect that's quite capable of moving 400-500 miles in a day. XXXXXXXXXXXxxx on its own speed¿ if it's taken by the wind might get more mileage out of that. XXXXXXXXXXXxx
1405 a complicated lifecycle¿ (Interrupted by car)
14:28 the desert locust is one of our most historic species, has one of the more complicated lifecycles. ¿ What has helped it survive so far. Normally in any given year you'd find a solitary form whose entire personality wd be such that it wd try to avoid close contact with others of its species. XXXXXX more green, heavy
It's like a big grasshopper.
At one time there were considered a dift species¿
1528 if the eggs which have been laid in the ground hatch out then you have many young nymphs close to each other. If the weather conditions are such that food is scarce, that helps bring those hoppers together in close contact with each other. As they make contact the whole nature of their body changes, they become gregarious in nature, they change in color, a brighter yellow with distinction¿ basically be yr gregarious forms of the nymphs.
After hatching they go thru 5 larval instars¿ when they get too big from their skins then split¿
1636 they have limited mobility¿ they hoppers wd not¿ if they congregate in bands they can move hundreds of meters in any given day¿ from fields of grass into crops¿
1707 food preferences.
1716 from the fifth instar when they have their last molt you then have a fledgling¿ wd have wings¿. Reached its adolescence¿. They'd be going up into a perching area¿. Letting everything dry out¿ letting blood in ¿ much like butterflies, hardening off its exoskeleton and then trying out its new wings¿
1809 this is a very voracious phase when they first become young adults¿
(Pause for truck)
18:20-35 passing truck ****************
1840 gregarious form¿ as it reaches sexual maturity¿.
Truck and cell phone¿.
19:30 SFX Leo walking mostly¿
2050 walking with Carl and Leo¿ truck passes *************
23:19: Q: what triggers this docile green solitary grasshopper to turn into this locust form?
CC: there's something about the physiology of this pest¿ anytime that numbers of them get together, contact with one another triggers reversal of their normal behavior and ¿ they become gregarious. The closer they're come together, cd be caused by scarcity of food¿ to feed, pretty soon those small bands merge and you've got one big hopper band. The longer they stay in contact of course the stronger this instinct to become gregarious becomes. XXXXXXXXXXXxxx nymphal stage¿.. early adults¿
Q: and when these mature and lay eggs, will those automatically become gregarious?
CC: yes, it sometimes takes a generation or so ¿
Some individuals will start a transition¿ it's not like turning it off and on¿ within a generation they go thru this transitory phase, and then almost all of them you'd see¿
25:15 these will continue to propagate as gregarious until something happens¿we'd hope these control efforts will be one of those some-things¿ but probably will happen is weather conditions will be such that the popn's we see will be reduced due to natural causes and the biological need they have to be gregarious will stop and their natural state will kick in and they'll start to be solitary again.
2550: Q: this was a particularly good year for rain in this part of Africa. Does that play a role in what happened here?
I think that normally the absence of rain and the spottiness of vegetation is what makes them gregarious. But once they're gregarious rain produces an abundance of food and that helps with the multiplication of their numbers. So on one hand rain is detrimental of getting the whole phenomenon launched, but once you have rain it multiples their numbers.
2623: Q: so how predictable was this year's outbreak?
Cc: I think it was fairly predictable. We'll find gregarious breeding in the northern part of the Sahel, the mountainous parts of Mali and Niger, parts of Mauritania, almost any year. And those popns need to be controlled¿ last year those numbers built up to beyond the control capacities of the folks in Mauritanis¿ alerted to the international community.
Q: there were signs something was afoot
Cc: there were signs as late ¿ EARLY ¿ as October of last year the popn ran the risk of really exploding¿
Q: and the good rains came and I guess, that was it!
CC: yep, they had food to eat and areas with sufficient moisture to lay their eggs. And every time they lay their eggs, you've got a 400-fold multiplication in their numbers. That reinforces their gregariousness, and you've got swarms forming and moving on at 200-400km a day looking for other suitable habitats whey can breed, lay their eggs and multiply their numbers. XXXXXXXXXXXXXXXXXXXXx
27:47 Q: 20 or 30 yrs ago these were treated with v. strong persistent pesticides which have been phased out because they cause such envtl damage. ¿ the spray pgm now is using much shorter actinb pesticides which, as we've seen, requires a lot more logistical support to make it work. Is this the best we can do, or is there something we can (steps on end of !Q)
28: 13 I think we're doing the best with what we can .. not the best the technologies that can be depl9yed¿. A lot of research is under way to find adequate replacements for those products that had more residual activities. For a pest like this if we had some a product with more residual activity, as we mobilized the aircraft was we put down one swath of 50 m ¿ once every KM rather than trying to cover all the cropland
28:57 Q: so instead of having to hit the insects, you can put out a poison they can encounter as they move around.
Yeah, and this is particularly important to control the hopper bands. They've vv mobile and we have more time for them to find the strip, which wd be their demise than the winged form. XXXXXXXXXXx
The winged form often miss the areas that are treated.
These strip treatments cd be vv cost effective and is targeted toward the hopper bands and not the adults.
29:35 Q: so among other things, that means intervening earlier in the locusts cycle.
Yr right about that, Richard, but it also means we have to finish some of these field trials. Even though we have some biopesticides, fungal products and other very much more environmentally friendly way to try to control these populations¿ look very promising in the lab and small scale field trials, but we haven't' been able to set up large scale field trials so those could be used in times of crisis as decision makers come together to figure out how to apply millions of dollars of resources. XXXXXXXXXXXXXx
That moment of decision you want a technical dossier showing this will work and under what conditions. Unfortunately since it's a mobile pest, these are tough field trials to set up. XXXXXXXXXXXXXXXXXxxx have a field team right now in southern Mauritania looking for¿
30:50 there will be very few additional hopper bands in Senegal¿ so if they were to find those hopper bands now that wd give us ¿ wd prob be in northern Mauritania and southern morocco¿ wd mean having workers set up an
3128: Q: so how much good does this kind of spraying do? Obviously yr killing individuals but are you making a dent in the overall outbreak?
Good question. I think that much of the spraying will have at best minimal impact on the desert locust populations¿as you can see a lot have escaped this morning's treatment. It's a good goal to reduce the risk that desert populations from the Sahel move northward, but the way it's already underway and I really don't think this current treatment will impact whether desert locusts can reach potential breeding areas in the countries of the Magreb. Some are already there, more are on their way. What this treatment could do, however, is insure a swarm like this is killed, and therefore wont be coming back to the farmer's fields, we're here in the ¿ and it wd really be a real shame if, as we've seen in the village yesterday, to have successfully fought during a couple of times during the cropping season, only to find that a ¿ a swarm like this cd come, find yr crop and destroy it. XXXXXXXXXXXXXXX so I think this is mainly to protect the crops that have not been harvested here in the Sahel.
Q: so it wd help individual farmers, but might not make a difference¿
CC in the overall dynamics of the movement of this pest from the Sahel to up north and back. XXXXXXXXX
3325: Q: and what about overall food production for Senegal¿ ?
we're not quite sure what the situation is in terms of food security. Our initial impression is localized damage, some quite severe, both in food crops such as millet and cash crops such as peanuts. But much of the rest of the country looks like it had a great harvest yr¿ so a team trying to figure out how much does this balance out¿an abundant harvest in part of the country, versus the losses on the part of some villages, particularly here in the northern part of Senegal. XXXXXXXXXXXXXXXXx
3428: Q: these are creepy insects because they come in, they're silent, and as we've heard, can be devastating under a very short period of time. But in the big pic how important is this ¿ as a threat to the farmers out here in west Africa?
That's a good question. We were in fields together and ¿. There are a lot of other pest problems that have to be addressed in addition to the desert locust. Desert locusts are a very spectacular pest. They get people's attention they cause a lot of alarm and certainly can cause a lot of damage in localized areas. But many of the farmers of the Sahel lose up to half their crops due to various insect pests, as well as weeds, nematodes and other pest problems. So we can't look at this as the end-all of what we need to do insure food security in the Sahel. XXXXXXXXXXXxxWe need to address those other problems as well, which means many many yrs of research¿.
36:05 Q: I guess the difc is a weed is an every year thing, and even if it's very destructive and time consuming it is in some ways factored into what a farmer expects ¿ to cope with, whereas having the locust descend and eat everything is a catastrophic kind of pest.
Catastrophic and I think ¿ as we meet with the villagers, they even forget to mention nematodes and plant disease, organisms in the long run that may cause them more loss than the more spectacular loss as the desert locust. ¿ it's not one pest v another¿ they need the results of the research¿.
37:05 it's not a question of do we do desert locusts or the multitude of other pests, it's really a matter of doing both at the same time.
37:25 Q: slow response¿ it's there a way to break that cycle
37:45: we all know the story about crying wolf ¿ how when you do that year after year¿ the response team questions whether they ought to send the ¿. I think that's happened a bit in places like the Sahel¿ donors have experienced a bit of fatigue. It seems it has experienced one crisis after another required major funds.
It's quite understandable that when the situation became serious in Mauritania some of the donors may have said, Mauritania, that's not a major food producing country. What's the problem. Without really understanding that a problem that was basically in pasture areas of Mauritania could grow to such magnitudes it wd be affecting many of the cropping areas of the Sahel in future years. XXXXXXXXXXXXXXXXXXXXxx
3846 one of the ways we can overcome this is to strengthen some of the organizations¿ eg setting up a prevention control program throughout west Africa¿
3930: my role with FAO¿ is to figure out at what point does control of Sahel need to come to a close for this year and resources focused more on west Africa¿ also what went well, what didn't go well and what wd work better next round since it's highly probably locusts will be back here as early as June or July of next year.
4003 q: is it possible to tell how extensive this swarm is?
Hop in our 4wd vehicle and head out until we stop seeing locusts being flushed out¿ also transect to other side to understand width.
40:40 q: if this was one of the swarms they were talking about last night, this wd be 1000 to 4000 acres of insects.
CC: that's maybe 2km long and a km wide. That's not a very large distance to do the survey work¿ I'm not seeing the numbers of locusts ¿ were talking bout 120 locusts per square meter.
Even at roost
41:53 I'm very pleased to be here actually seeing some live locust and then the dead ones that are the result of the treatment pgrm. XXXXXXXX
4200 Q: so you're an entomologist. Do you have a special place in your heart for locusts or are they just like any insect pest. Do you like them, do you hate them? What is your feeling about them?
4210 I think locusts are one of the most fascinating of the locust species, it's one people recognize. There are lots of entomologists working on the pink hibiscus mealy bug or very important yet less known organisms.. this is one where you say, I'm working with desert locusts, people know what it is¿ because of its historic implications and also for its changing from solitary to gregarious nature and complete change in behavior¿ one of the more interesting organisms on which you can work. XXXXXXXXX
on the other hand, I'm at the end of my career,
if I were a young entomologist¿ I certainly wd not want my grad d
one of the unfortunate things is we don't' have a lot of young entomologist to work on this organism¿ many are still needing to finish grad degrees¿
this is one of the most hx one of the more interesting, but one of the more difficult organisms to do the research in order to do it better.
45:16CC and what is happening during the heat of day
Leo they are roosting
45:16 CC they come back to roast.
AMBI 46:10 wings fluttering
46:29 some fluttering of locust, with car traffic in the background 46:48---52 kicks them up?
47:06 can hear voices a bit, plane overhead, walking 47:59
48 walking with locust flying away?, 48:23 again
48:43 good flutter by with seconds of no footsteps
49:20 some flutter with less often footsteps, bird
50:19 shake tree
50:50 wind gusting
51:57 moment of good fly by
52:14 tree shake (nothing follows, truck passing)
52:45 tree shake 52:50 good take?
53:14, 53:18 flutter
you've got a poppy right on your shoulder
RH lets press on north
CC yes I think we need to make the military base in Podoor within the next hour or so.
If you see anything along the way just stop and give me a call and we'll stop the other car.
RH okay thanks
54:51 walk to cars
CC there are easier to get off than the cram cram
55:07 car door and start the car (55:30 out) car number 2 starts 56:05 out rough
56:30 AMBI car starts and pulls away
57:10 ¿ 58:35 AMBI
58:45 FX car arrives 59:16 out
59:40 truck whizzes past
1:00:45 windshield scenes, some wind
1:01:46 mostly car noise and not much splattering
1:02:05 sounds more like car rattle than locust
1:05:45 turn around
1:06:31 more splats
1:06:46 best (like popcorn) out 1:06:53
1:07:10RH we just drove through a cloud of locust that was flying across the road, coming out of the rice paddies to our left. They are littering the pavement and it was almost like driving through a short cloudburst of these pink and silver bugs
1:07:55 RH Lets ask Carl about this
we just drove through a fairly intense cloud of locust. They were coming out of the rice paddies to our left and uh, it was like a short intense cloudburst of these pink and silver bugs. Lets catch up with Carl and see what he has to say about this.
locust at paddy (locust eating or moving sounds like static) no footsteps
out 1:09:53 with some other bug too
1:10:13 good wave of locust movement
1:10:26 traffic with locust
1:11:33 good locust movement (little traffic)- 1:12 car sounds more
1:11:52 AMBI car driving, locust
we've stopped here by the side of the road. And there are thousands and thousands and thousands of locusts. They've descended on a rice paddy here and they are just covering it, as thick as, it's a carpet of these pink and black bugs. Its eerie because they are making essentially no sound except the sound eating, its eerie because they only sounds they are making is the chewing sound and the sound they make as they hop from place to place. Its so business like and so
vicious the way they are attacking these plants (bus drives by 13:55)
1:14:04 when we pulled over there was a man waving a cloth at this huge swarm of locust trying to get them to go away but he's now given up and he's sitting in the shade. It's a hopeless task to try and get rid of these insects
fx birds and crunching, bus 14:40 but you can hear the locusts over it! 1:15:07
1:16:35 AMBI to 1:19
could you please tell me your name
When did these bugs arrive
A week ago
RH have they eaten a lot of the fodder here?
Did they bother you?
Yes they bother us
RH how do they bother you? (truck)
They are eating up everything, they are even eating the trees
RH Is there anything you can do about them
1:21:42 did you try to kills them
1:21:52 we don't kill them we leave them as such