Christine Bays joined the Six-Legged Aggie Lab in May of 2019. She is a Sophomore at the University of Texas at Tyler and is earning her bachelor’s degree in Biochemistry. Christine also works in an Ant Symbiosis Lab at UT Tyler, studying the relationship between fungus-gardening ants and their fungus. Christine is currently considering pursuing pharmacy school, assuming she doesn’t get bit by the ferocious entomology bug!
This summer, Christine will be helping with research on crapemyrtle bark scale, whitefly biological control, mealybug insecticide efficacy, and other small research trials. We are excited to have her as a part of the six legged aggie team this summer.
In her free time, Christine likes to take care of the vegetable and flower gardens her family grows. She also enjoys playing video games, swimming, going to the movies, and drinking coffee. She also loves animals and has two cats of her own.
From June 16th till the 30th, I was in Guyana as a part of a two-week volunteer project through US AID Farmer-to-Farmer program, administered through Partners of the Americas. The whole first week was spent visiting farmers to learn about their pest challenges and pest management materials that can be sourced locally. You can read more about those visits in the four separate posts below:
During the last week, I conducted a series of workshops/trainings to help identify some of the key pests the farmers were facing and how to manage them; whether preventatively, physically, or even with the responsible use of pesticides.
In the four posts I wrote after visiting the farms, I identify some of the key crop challenges. On some farms, we found: Fifty percent of young coconut trees lost to rhinoceros beetle, 60% loss of watermelons to rind necrosis, 100% of guava fruit lost to guava fruit fly, most of the soursop fruit containing soursop seed borer damage, tomato leaf curl virus vectored by whiteflies, bacterial leaf spot on peppers, and leafminers on shallots, just to name a few. I spent the better part of my first weekend in Guyana learning more about these particular pests, learning about locally available pesticides (and prices), and created some presentations on managing some of the identified challenges. If you’re interested, I have posted the presentations in PDF format and related resources for convenience: Farmer-to-Farmer: Guyana 2019 Resources
The setting of the trainings were, of course, rather different than what I am accustomed to in the US. In the US, we are indoors with air conditioning, have control of lighting & the environment in general, have reliable electricity, and breakfast consists of donuts and sweet tea. I was prepared to expect none of the above (I know… even the sweet tea!), since some of the locations we visited did not even have electricity. For our very first training, we used a gas-powered generator – and other than it being a bit loud (the generator) and a bit sweaty, it went rather smooth.
First workshop for “California Youth Group” Farmers.
Conducting the workshop for the California Youth Group
Using my fantastic miming stills to bring a “life-size” mole cricket in their presence
Demonstrating the use of a digital microscope to see some of the smaller insects
I feel inclined to mention that the generator ran out of gas about 3/4th of the way through, resulting in the projector spontaneously shutting off, but that didn’t slow us down too much. I talk a lot with my hands and can pretty convincing act like many of the insects that I’m describing.
*Be the aphid… be the aphid…*
Of course all of the farmer groups were incredibly attentive, but I certainly learned a lesson for next time. In my presentations, I was trying to provide as many resource and information as I could, relevant to their production. Sometimes that information would, for example, be a few different insecticides that they could rotate through, in order to minimize insecticide resistance. However, I noticed very quickly that no one was taking any notes. For some, it was because they were illiterate or very low level of literacy – of course they aren’t going to take notes! For others, I think a part of it is that they just never learned or thought to take notes. Only one group (The permaculture group) took notes throughout the presentation and asked for handouts/PDFs, likely due to the fact that they are all working professions in various fields that take up backyard farming as a hobby. Next time I do such a training program, I’ll have to consider methods of driving specific messages home, whether it be with physical gestures/actions, demonstrations, or repetition – all ways to help them remember the material, rather than relying on them taking notes.
I had a few other “firsts” – I have never had a situation in which my projector screen starts blowing away in the wind. Nor have I ever had to speak over goats or pigs right next to me while presenting. I would imagine that our livestock specialists have faced similar situations to that – but a bit unique for an entomologist.
Presenting for the Bath Settlement group, with focus on shallot, lettuce and cabbage
Group photos with the California Youth Group
A kind “thank you” from the Bath Settlement group
Leon providing opening remarks for the Permaculture group in Georgetown, Guyana
Animals heckling me during my presentation
Training focused on pepper, tomato, and some cabbage pests
One Last Farm Tour
After one of our trainings, one of the farmers (California Youth Group) was kind enough to show us more of their farm. This was the same farm we visited last week and ate all kinds of incredible fruit! Well, turns out, they have more and more plots of land, hidden behind creeks and more bush.
Crossing a bridge over a creek full of caimans. Ok fine… it ‘felt’ dangerous, despite the lack of caimans.
A citrus fruit, sweet like a tangerine, but the skin is green when ripe.
Passion fruit farm – the idea here is to tie up the passionfruit into a ‘canopy’, allowing you to walk underneath and harvest
Leon, finding his little piece of heaven
Reynard, the son of the farmer. He was an excellent resource, very kind soul, and is working very hard to improve these rural parts of Guyana
Reynard and Leon
We had a blast tasting different fruit right off the tree (passion fruit and some species of citrus), as well as learning more about native plants, irrigation/drainage, and the opportunities for future Ag Tourism in the area.
The Last Leg
On my last official ‘working’ day in Guyana, I provided a workshop for the permaculture group. My presentation for them was quite different from the others for two reasons; (1) they are more interested in creating habitats to naturally suppress pests and some yield loss is tolerated, and (2) insect/disease identification needed strengthening (at least, from my experience visiting them the previous week). What’s surprising was that, although farming is just a hobby for this group, they are incredibly enthusiastic and delighted to learn more. I hope that their passion for farming leads them to seek future opportunities to help local farmers.
One of the things I taught this group was how to identify beneficial insects from pests, using lacewing eggs as one example. We have lacewing insects in the USA as well – a small green “fly” that lays eggs on single threads. The young (larvae) emerge from those eggs and look for soft-bodied insects to feed on. To the unacquainted eye, lacewing eggs can look like some type of fungus or mold and treated as such, but in fact, should be left alone to emerge and eat all of the bad bugs. It was particularly rewarding when the local F2F coordinator shared with me the next day a message that a member of the permaculture group had sent in a WhatsApp message, containing a great image of some lacewing eggs and the message “I was able to identify the lacewing eggs in the pic… learning is taking over”. Moments like these are incredibly rewarding – to know that the information you were trying to relay was assimilated and already being used by those in attendance!
Lacewing eggs on papaya
Green lacewing larva consuming an aphid
Green lacewing adult. Frank Peairs, Colorado State University, Bugwood.org
The two weeks in Guyana were not only a great personal experience, but also a great opportunity professionally. I met many kind, generous, and hardworking souls, but also learned about some pests and diseases that are currently rare in Texas, but are important to recognize to prevent future outbreaks. They also have certain pests that we do not have yet – so being able to learn about them in Guyana will help any future research/work we need to do in Texas if they ever get here.
Today we visited an urban farmer group that pays special attention to permaculture. For those that aren’t familiar with permaculture, it’s a type of gardening or farming aimed at creating a self-sustaining ‘ecosystem’ that doesn’t require intervention to manage insect pests or weeds. This strategy, in theory anyway, relies on plants that do not interfere with each other and attract natural enemies (i.e. predators of pest insects). If plants are being attacked by an insect or disease, the typical ‘philosophy’ behind permaculture is that the plant doesn’t belong there anyway – so maximum crop or yield production is not the main or only goal.
I’m not certain whether it’s because these gardeners were using permaculture or because they are in an urban setting, but they had a lot of different kinds of insect pests. The variety of pests and diversity of plants made it a bit challenging to pin down just a few pests or diseases that were the most important – there was a lot of equally somewhat important pests.
One of the permaculture gardens
Second shot of one of the permaculture gardens
Cabbage damaged presumably by the diamondback moth, although it could be by another chewing insect as well
Using palm leaves to create ‘shade’ on some of the beds
Basil leaves curling and signs of blotch leafminer
Another permaculture garden we visited
Some of the insects I took particular note of were the blotch leafminer on basil, abundance of ant-sucking pest mutualisms, and the spiraling whitefly.
It was easy to mistake the blotch leafminer, at first glance, for some kind of downy mildew or other plant pathogen. The symptoms are circular and produce ‘wet spots’, as you’d expect in a bacterial infection. After doing some research online, I found out that it’s actually damage caused by a fly that lays an egg on the leaf. The larva then comes out and feeds within the tissue of the leaf, causing that blotching effect. Removing this pest in an organic permaculture setting is a bit challenging, but they can certainly reduce the populations by removing any leaves showing the symptoms – that will remove the larvae, and subsequently future adults from laying more eggs on the basil.
Blotch leafminer on basil
Closer shot of blotch leafminer on basil
Sucking insect pests are often trying to get at the nitrogen in the plant sap, to make more proteins, and thus make more babies. All the insects just want to make more babies! To get said nitrogen, they need to go through a lot of plant sap – so they poop out the extra as a sugary solution, known as “honeydew”. This honeydew creates sticky surfaces on leaves and also acts as “food” for mixture of molds referring to as sooty mold. Well it turns out that ants really like this sugary solution, so they will actually provide protection for sucking insect pests in order to get more honeydew! This results in a positive-positive relationship between the sucking insect pest and the ants; the pest benefits by getting protection from predators by the ants, and the ants get alllll the poop juice they want! We call this type of relationship a ‘mutualistic’ relationship. A very common mutualism is between aphids and ants; so I always advise looking for aphids or other sucking insect pests if ants are seen running around on leaves and stems of plants. We didn’t see any shortage of such mutualisms in these gardens! This is also makes managing the aphids a bit trickier; killing the aphids will result in the ants just bringing them right back! A management strategy also needs to consider how to prevent the ants from beginning them back into the garden.
More aphid-ant mutualism
Mealybug, a sucking insect pest, on okra
Mealybug, a sucking insect pest, on okra
Scale insects on the underside of a leaf
Several lady beetle pupae/exuviae
Lady beetles that emerged from the exuviae
Mealybugs on underside of palm leaf
I also observed a reasonable amount of beneficial insects, mainly lady beetles (common referred to as “lady bugs”). Most people associate lady beetles with the large red beetles with black spots, and don’t always recognize different species or even the larvae. Above are some photos of some black lady beetles with black spots – resembling the twice stabbed lady beetle.
Any applied entomologists knows to look on the undersides of leaves for insects. As I was flipping some palm leaves, I was seeing these funny patterns – almost like crop circles made of white wax. I just neglected it for a while, thinking it was some kind of anomaly and not worth trying to figure out what it was, but kept seeing it more and more. I started finally seeing some at different stages of development and it blew my mind when I realized that they were whitefly eggs! The spiraling whitefly lays eggs in a spiraling/circular pattern and when they emerge, will start sucking on the plant (sucking insect pest!). After some time, they will eventually pupate and become winged adults. Kept unchecked, these whiteflies can apparently grow to some staggering numbers.
Spiraling whitefly eggs
Spiraling whitefly nymphs
Spiraling whitefly adults
Cassava leaf-gall midge
On the cassava leaves I also saw some ‘galls‘; growths formed by the plant in response to insect feeding or oviposition (laying of eggs). The culprit is often within the gall, sucking on the plant juices as the new plant growth provides protection for the insect. It’s a type of ‘manipulation’ of the plant by the insect, if you will, to make it protect itself from predators while feeding. Very few gall-forming insects are of concern in terms of crop yields, although they can be rather problematic for ornamental growers that are trying to sell the whole plant.
The permaculture group was quite different from the others; they weren’t ‘farmers’ per se, but rather gardener enthusiasts with full-time jobs. They reminded me, in a way, of master gardeners in Texas. They are passionate not just about growing food, but also learning about the insects, the plants, and having beautiful gardens. They interchange information on what to plant, share cuttings, and even share produce with each other. It was a great pleasure to walk around and learn about the gardening they are doing here.
Last Thursday, we visited a few farms in remote locations, referred to as “the bush” by the locals. Completely off the grid; using rain-water as their water supply, no need for electricity or using diesel generators when needed, fruits and vegetables everywhere, and the forest is your toilet. There are lots of mosquitoes in the forest… and monkeys… but let’s focus on the crops, not craps.
We went to a few farms all in close proximity. We were accompanied by someone from NAREI (National Agricultural Research & Extension Institute) which plays a similar role to Texas A&M AgriLife in Texas, and he acted as a bit of a guide to show some of the pests and diseases the growers were facing there. For starters, one of the farmers appeared to actually be quite an involved entrepreneur. Her business card states that she also owns a hotel, restaurant, and nightclub, and she has this parcel of land as a side-gig. Alas, her guava alone was 100% infested by a fruit fly species, most likely the guava fruit fly (Bactrocera correcta). The fruit fly lays its eggs in the fruit and the larvae consume the insides; not unlike the spotted wing drosophila problem we have been facing in the continental USA since 2008, which effects pretty much all soft-bodied fruit. Spinosad, a toxin created by the soil bacterium Saccharopolyspora spinosa, is considered an effective insecticide against this pest, however I couldn’t find any registered spinosad products available in Guyana. The next best thing is to go for sanitation; the larvae stay in the fruit and come out as new adults after the fruit has fallen off the tree. The fruit need to be collected regularly, bagged & solarized or buried deep in the ground. This will, over time, greatly reduce the fly populations in their area.
Puncture marks made by the guava fruit fly female, laying eggs in the fruit
One of the most hard-hit fruit here appears to be the Soursop, which I mentioned in one of my earliest posts. The farms we visited appeared to have consistent bore holes caused by the soursop seed borer; a wasp that uses a long ovipositor (organ used to lay eggs) to lay eggs inside the seeds of the soursop fruit when it’s small. The larvae stay within the fruit and eat the seeds, pupate (similar to a ‘cocoon’ in butterflies) and come out of the fruit as new wasps, creating those bore holes (seen below). The soursop fruit also have a few species of scale insects and mealybugs that also seem to attack it. The species that are on the fruit resemble a species of snow scale, pink hibiscus mealybug, and breadfruit mealybug. It also doesn’t help that there are ants that appear to be tending the scale and/or mealybugs – a common mutualistic relationship between ants and sucking insect pests, where ants where eat the sugary solution excreted from the sucking insect pest and in return, provide them with protection from predators. Since soursop is considered a relatively high-value crop, it may be feasible to bag with plastic or fine mesh around the fruit when small (less than 5 cm in diameter) to prevent the wasp from laying eggs. Once the fruit is larger than that diameter, the wasp’s ovipositor is not long enough to get to the seed – so larger fruit are at a greatly reduced risk. However, before bagging, the fruit need to be cleaned of any scales or mealybugs, with a brush and water/soap solution, otherwise the scale may do very very inside the bag (due to exclusion of predators).
Soursop breadfruit mealybug and species of snow scale
Closeup of snow scale on soursop
Pink hibiscus mealybug on soursop fruit
Closeup of breadfruit mealybug on soursop fruit
Soursop fruit seed damaged by the soursop seed borer
Lady beetle eating the scale on the soursop fruit
However, when you’re out and about on these farms, it’s not all work and no play. These farmers are incredibly generous and loved to feed us. Starting with some coconuts right off the tree to quench our thirst, we then started eating fruit that I had never heard of before. Sapodilla, rose apple, sugar apple, and ‘peach’ (which is not like our peach at all and I’m having difficulty finding the correct taxonomic name for it!), just to name a few. I also saw Pomelo larger than I have ever seen before! Pomelo is considered one of the original citrus species, which many other species are hybrids of. The textures, flavors, and aromas of these fruit are nothing like I have had before, so it’s hard to give them some context or explain them. All I can say is that they have a great abundance of it and they are incredibly delicious!
One of each fruit we ate that day
One of each fruit we ate that day
“Souree“, a fruit as sour and flavorful as sourpatch kids.
Pomelo, the largest citrus fruit – the size of a melon!
Red rose apple – apparently the whole tree is covered in red during peak season
Insides of the red rose apple – starchy texture but sweet and smells like rose
Sapodilla – I think my new favorite fruit. Texture of persimmon but really sweet, small and easy to eat.
An interesting conversation we had this day with NAREI employee was the meaning of “poverty” – whether its just a state of mind. These people in ‘the bush’ have nothing, but have everything! Their dwelling was incredibly simple, no tech or connectivity to the world, very few manufactured material possessions, but they had land rich in food and a beautiful landscape. In one way it made me appreciate the things I do have, but also makes me reflect on what we truly need to be ‘prosperous’.
Below are a few more relevant photos from this day of farm touring, without too much elaboration.
Cabbage grower – one of the ‘cleaner’ farms that we visited, in terms of weed management
Inspecting the cabbage for signs of diamondback moth, a devastating pest of cabbage in these regions
Cassava plants – the roots are commonly eaten in Guyana cuisine
First thing in the morning, we headed towards the interior of Guyana, where we visited a coconut, pineapple, and other smaller ‘cash crop’ farms. The most important pest brought to our attention was the devastation being caused by a rhinoceros beetle; a beetle that bores at the base of the coconut trees and into the main stem, resulting in total tree mortality. The growers said they have lost about 50% of their coconut trees to the rhinoceros beetle! The bore holes always appear to be right at the stem of the coconut tree. This problem made me think of the Diaprepes root weevil problem in Texas; a beetle that kills citrus plants by laying eggs on the leaves, and the larvae fall onto the soil below, burrow into the ground, and feed on the roots. Research at Texas A&M demonstrated that the weevil could be stopped by using a plastic mesh over the soil, which prevents the larvae from being able to burrow down below and the larvae subsequently die. In theory, this same solution should work to prevent the rhinoceros beetle from getting into the trees – I proposed this as a solution to the coconut growers and hopefully provides some promising results.
Bore hole created by the rhinoceros beetle
Hole made by the rhinoceros beetle
Hole created in the base of the coconut tree by the rhinoceros beetle
Coconut propagation trial
Next, we visited a region of Guyana that is known for producing chives and lettuce – most of the growers in that small area specialize on those two crops. Many of these growers are small acreage, growing mainly in their backyards in beds or shade-houses. We identified many different crop challenges, including leaf-miners, root-knot nematodes, and mealybugs. The leaf-miner appears to be a species within the genus Liriomyza– a fly that spends its larval stage between the upper and lower leaf tissue, making it really challenging to control with insecticides and tend to produce scars on leaves even if you do manage them. The mealybugs are difficult to notice until too late, as this particular group appears to feed on the roots. Root-feeding mealybugs will reduce the growth and uptake efficiency of the roots, resulting in above-ground effects but with no obvious culprits (until you take the plant out of the ground!).
Chives in raised beds in a ‘shade house’
Roots of the celery
Mealybugs on the celery roots
Small acreage fruit and vegetable farm
Leaf-miner on chives
Leaf-miner on lettuce
We saw the root-knot nematodes at some farms the day before too – so this problem is relatively widespread, it seems. One method of killing nematodes within a bed is to use the soil solarization technique – a method that involves using clear plastic to cover a bed and allow the sun to essentially ‘cook’ the bed completely of weed seeds, nematodes, insect eggs, and bacteria. They have access to clear plastic here at the local agricultural supply stores, making this a possible option for future nematode control.
Although I provide the growers with some solutions as we are making observations on their farm, the purpose of this week is really to make observations in order to develop the training programs for next week. I will be developing more specific diagnoses and multiple solutions to each challenge they are facing, with the hopes that they find at least one that is suitable and works reliably to reduce crop yield loss.
We drove to region 6, which is far down south along the coast for a total of about 3 hours commute time in each direction. Throughout the whole drive, Guyana felt like just a very large village. People are all outside, working together, talking to each other… everything seems very grass-roots. Rather than each farmer having a full set of their own equipment, individual houses along the road had different tractor equipment (tractors, harvesters, etc.), all of which would be needed to till, disk, sow, and/or harvest the different crops in the area. We saw some large rice paddy fields, rice processing plants, a couple sugar cane fields, and some pasture with livestock. Along the roads everywhere are cannals – cannals that feed a whole network of cannals and irrigation throughout the country. They also have dams that can open after heavy rains to let the excess water into the ocean, and close when rain levels are low, to prevent salt water from getting in… Can tell that the hands of the Dutch have been here!
Leon pointing out some rice paddies
Cultivated bees. There are lots of wild bees here, apparently Africanized, but they are starting to cultivate them here too for honey and wax.
One of the cannals leading to a dam that is opened during heavy rain to prevent flooding.
Cannal going under the bridge – irrigation is fed out of these cannals
One of the rice processing plants can been seen on the right in the distance
The only way across into parts of region 6 used to be a ferry, with high congestion and long wait times.
This bridge replaced the ferry and is only closed during specific hours to allow for ships to go through
The city signs (seen on the right) are sponsored by Pepsi
One of the backroads to get to our destination
Most of what we saw was rather familiar. The first couple farms were mostly peppers (i.e. bell peppers), with some tomatoes, cabbage, citrus, melons, and eggplant. There were also some tropical fruit, such as Soursop and starfruit, which I currently know very little about! Another very interesting nearby plant was the abundance of neem trees, Azadirachta indica.
What’s interesting about neem trees is that we actually have several insecticides in the USA that are based on Neem, specifically neem oil (which covers and suffocates the insects) and azadiracthin; a compound extracted from neem seeds that has some repellency and growth disruption (insect growth regulator) effects.
The Farmers themselves were all very kind, welcoming, and generous. A couple of them were rather young too and Leon confirmed that more young people are getting into farming. One of them may actually be a great resource, because he knew a lot about what was wrong with the plants and could quickly recognize symptoms.
Young pepper plants (up front) and older pepper plants (back)
Young farmer and a donkey
Pepper plants in shade house. This operation was a side hobby of a builder
Farmers and collaborators discussing next to the peppers
Without a doubt, the growers here face some serious yield loss. One of the growers estimated 20% of pepper yields to disease, another 60% loss of melons to a rot, and another 45% yield loss of cauliflower due to diamondback moth. Their rainy season sees very high humidity (currently 87% RH outside) and high moisture, making diseases difficult to prevent in the first place for disease-susceptible crops/cultivars. Some other crop challenges they face include some cultural practices (nutrient management), whiteflies (and subsequent diseases transmitted by them), “gandhi” (known as “stink bugs” in the US), leaf-footed bugs, thrips, spider mites (in the dry seasons), flea beetles, root-knot nematodes, and goats… yes, goats… just to name a few. The goats appear to be rather crafty – in one instance, they pushed a fence over and go to an entire plot of large pepper plants and chewed them up quite good! I guess that’ll just help fatten up the goats a bit…
I found it interesting that they call stink bugs “gandhi”, specifically because “gand” in the Persian language means “stinky”. Used in a sentence, my mother would say something like “Erfan, put on some deodorant, you smell like gand!” during my teenage years (FYI. I wear deodorant much more regularly now…). I wonder if gandhi in an Indian language (one of the main cultures in Guyana) means “stinky” (for stinkbug) and the Persian language shares the same root.
The Soursop also had an interesting insect pest – a borer that goes straight for the seeds! After some quick research and based on the description of the damage, the culprit appears to be a wasp (commonly referred to as the Soursop wasp) that lays eggs into the seeds with a long ovipositor (organ used to lay eggs) when the fruit is small. When the fruit is larger, the larvae emerge from the seeds and exit out of the fruit, causing these large holes on the outside of the fruit. This provides an opportunity for other insects and diseases to also infiltrate the fruit, increasing the problem, and ruins the seeds for future plantings.
Soursop with exit holes from the fruit
Cutting the fruit open, we can see the seeds are eaten/ruined
In this case, it appears to be a scale or mealybug on the fruit
The peppers faced a range of issues. They appear to be affected by a bacterial leaf spot, possibly anthracnose, feeding damage from stink bugs, and root-knot nematodes. Root-knot nematodes can be a challenge to manage, even in the US. They resort to some of the harsh (Danger-level) nematicides, such as Vydate, and even then, appear to have lots of nematodes. With the way the water constantly moves around the land here, nematode management may prove challenging. With all of the pesticides they spray, people may be concerned how it affects the surrounding environment – but the abundance of frogs, dragonflies, and ludicrous quantity of mosquitoes suggests that the ‘environment’ may be doing reasonably well. Below are several images of some of the types of plants disease and insect damage that we saw today. If you see anything that you definitely recognize, please feel free to provide your insight!
What appears to be “cat-facing” of some of the Soursop, which can be caused by stink bugs
Some light green between leaf veins, may be a sign of lack of nutrients (i.e. nitrogen)
Common problem afflicting peppers, may be Anthracnose
Disease afflicting the melons. May be bacterial fruit blotch or bacterial rind necrosis.
Disease afflicting the melons. May be bacterial fruit blotch or bacterial rind necrosis.
Root-knot nematodes choking up the pepper plants
Pepper plants that were dying prematurely
A small brown stink bug, or “Gandhi”, as they referred to them here.
A small green stink bug, or “Gandhi”, as they referred to them here.
Spots on the citrus
Leaf-footed bugs – a common insect pest in North American gardens too
Lastly, I wanted to mention the melons. Seen above is a melon that has a spot starting to form on it that eventually expands and takes over the whole fruit; in my quick search, I found either bacterial fruit blotch or bacterial rind necrosis as the possible culprits. The farmer here described this disease as a “terrible tragedy” with the melons right now, with around 60% of yields lost to this problem. What makes it worse – it only appears after the fruit is just about to ripen, meaning that the plant and fruit has taken the space, water, and nutrients before it completely rots.
In the next few days I will be visiting some more farmers to see whether they face any additional unique challenges. Once I have consolidated all of the photos and information on their crop challenges, I can break it down by region and start forming workshop materials to hopefully provide practical solutions to at least some of their crop yield losses. I have also been taking notes and photographing their pesticides application practices and will consolidate that in a separate post later in the week – information that will be vital to understand current management practices and how they can be improved. Spoiler: farms here may benefit from chemical rotation to prevent promotion of pesticide-resistant pests.
Our flight arrived early this morning, from Miami to Guyana. Our driver recognized us using our F2F hats we were provided in our orientation packages and started the one-hour driver to Georgetown. Like the couple other countries I have visited in South and Central America, ‘highways’ are two or maybe four lanes (maximum), with houses, businesses and all kinds of vendors along the roadside – in other words, it doesn’t quite feel like a ‘highway’. I was a bit surprised to learn that there’s another F2F volunteer here this week at the same time as me, Patrick, who focuses on solar panels and sustainable energy sources for farms.
We arrived at the F2F headquarters, where were given telecommunications devices from a large brown envelope – ok fine, it’s a cell phone for our use during our time here, but it took me a while to remember how to even add a phone number and/or text on this thing! In a way, it’s a bit nostalgic. At the headquarters, we were briefed on the ten administrative regions of Guyana, with the fruit and vegetable production focused along the coast in regions 1-6. F2F has been operational in Guyana for about 30 years with new volunteers coming in every two weeks with different specializations! It’s rather impressive how the small local F2F team is able to quickly address the needs of the local farmers by recruiting foreign specialists and coordinating grower visits/programs for every week.
F2F Local team (Jermaine Joseph, Kelvin Craig, and Leon Peters from left-to-right) and volunteers (Patrick and myself)
F2F briefing room
The F2F local headquarters
It’s also quite impressive to see how much Partners of America is able to accomplish, with activity in 30 countries, 5,870+ volunteers worth $1.8M USD in 2017 alone.
Energy in Guyana is expensive and they periodically experience power loss for 3 – 12 hrs. That’s where Patrick’s work with solar power comes in, especially for some of the growers in the region that are producing hydroponically. The local F2F personnel also emphasized that the growers use ‘shade houses’ (rather than greenhouses), with basic frames, plastic (to reduce direct rain) and netting (to reduce sunlight). Apparently water is not an issue in Guyana, which literally means “Land of Many Waters”. Tomorrow I’ll have my first grower visit and look forward to learning more about specific crops and pest management challenges.
The vegetation here is quite different than Texas (of course!). I have seen an abundance of palms, cacti, and lotus. The lotus, Nelumbo nucifera, is actually not native to Guyana and covers the small creeks between the roads and private properties. One of the spindly plants at our hotel was rather peculiar, but felt familiar after touching it due to the white waxy residue that stuck to my fingers. The Pencil Cactus, Euphorbia enterophora (or other related species), is in the same genus as poinsettias (which I do an abundance of work with) and looks like a bunch of green ‘stems’ with disproportionately small leaves.
Related to poinsettias
Pereskia, a unique genus of cacti
Lotus plants occupying the streams, often found flanking the roads.
That’s all for now! Look forward to taking more photos and sharing with y’all more as the week goes on.
This week, one of our Texas growers held an internal full-day training program and were kind enough to allow me to take notes and share them with the rest of you growers! One of the many things I continue to really appreciate and like about the green industry in Texas: they are collaborative and help each other out. See below for speakers and notes related to their presentations.
Please note that I do not personally endorse the products mentioned by the presenters below – the notes provided below are “as-is”, as written as accurately I could based on the information provided by the presenters. Any lack of information or misinformation is not intentional.
The current population of the whole country of Guyana is under 780,000 people in about 83,000 sq. miles of land mass. For a bit of context, the Dallas-Fort Worth metroplex is about 9,286 sq. miles with a population of about 7,500,000!
Agriculture is of great economic importance in Guyana, accounting for about 1/3 of its Gross Domestic Product and about 30% of its work force (export.gov). Two of the major commodities grown in Guyana include rice and sugar. At the end of 2015, the Ministry of Agriculture had reported an increased production of rice from 635,238 tonnes of rice (2014) to 683,516 tonnes (2015). The Ministry of Agriculture is working on trials to introduce several new cultivars of rice into the market to increase yields, which is rather crucial, seeing as how the 7.6% increase in rice yields was met by a 15% decrease in rice value in the global market.
As with any major commodity, there’s bound to be a pest or pests of great economic importance. In this case, it’s the “Paddy Bug“, what appears to be a sucking insect pest in the same family as stink bugs (Pentatomidae). This wouldn’t be the first Pentatomidae that causes major economic damage and we are no strangers of major Pentatomidae pests in the USA; an example in the USA is the brown marmorated stink bug – a generalist sucking insect pest that causes damage on several different fruits and vegetables in the northeast. Some of the current best management practices for the paddy bug include removing alternative plant hosts, where they can continue to breed or survive when the rice crop is not yet planted.
Sugar also saw great increases in crop yields, but also saw a decrease in global market prices. No major pests of economic importance were mentioned in the Ministry of Agriculture report.
I do not anticipate working much with growers producing rice or sugar, but rather speciality crop producers, such as vegetables, fruits, and perhaps even ornamentals. Another devastating pest mentioned in the report is the Red palm mite, particularly on coconuts, with $49M approved to help farmers affected by the red palm mite in Guyana back in 2015.
The red palm mite is considered an invasive pest (i.e. not native to Guyana), originally found near the Middle East. In 2004, this mite started to show in several regions in Central and South America, and in 2007, was even found in Florida (Ent Department, UFL). Give it some time, and this mite could become a pest in Texas as well – so I guess it will help to get a close look at first hand it in Guyana.
Note to self: wash clothes thoroughly before bringing back to Texas.
Guyana’s Ag has seen more recent increases in specialty crops, such as spices, new vegetables (cauliflower, broccoli, red cabbage, and sweet pepper), and revitalization of crops such as coconut and cassava, according to Guyana’s National Agricultural Research & Extension Institute (similar to Texas A&Ms AgriLife Extension in Texas). Interesting note about Cassava, the dried leaves can contain about 30% protein by mass (Awoyinka et al. 1995), although the same study seems to imply that dried leaves are not super palatable. I hope to find out for myself when I’m in Guyana.
Guyana also has a Livestock Development Authority, with one objective aimed at increasing apiculture (honeybee cultivation) production to a nation-wide scale, increase yields and meet international standards. Guyana’s Pesticide and Toxic Chemical Control Board (PTCCB) is responsible for all things related to pesticide registration and application. An interesting initiative included in the PTCCB 2017 report is a pilot project aimed to educate secondary school students on pesticides nation-wide! Covering such topics at an early age may go a long way in increasing science literacy and decreasing misinformation about pesticides, which are incredibly valuable to food security, human safety, and the environment.
Some of the most imported (quantity, in kg) insecticides belong to the pyrethroid, organophosphate and neonicotinoid insecticide classes. Some specific examples include Alpha-Cypermethrin, Carbaryl, Chlorpyrifos & Cypermethrin, imidacloprid, and Triazophos. Most of these insecticides are “hammers” – they work really well, but will typically knock out beneficial insects as well. In the case of the chemical class containing imidacloprid, studies have demonstrated an outbreak of spidermites (a small plant-damaging mite) after pesticide applications (Szczepaniec et al. 2011); a phenomena that has since been attributed to the pesticide interfering with the natural defenses in the plant (Szczepaniec et al. 2013). In the case of carbaryl, it is thought that it devastates the natural predators of the herbivorous spidermites, resulting in a herbivore population that’s left unchecked. This also applies to people applying Sevin dust in their own garden; if you notice spidermite damage shortly after application, you may want to consider applying something different.
A short post can’t do the full scale and complexities of Guyana’s agriculture justice, but hopefully this post provided a sprench of context – I know it helped me become a bit more familiar with the agencies, crops, and pests that they may be dealing with.
In 2006, I took a course in Ecology instructed by Dr. Jeremy McNeil and subsequently chemical ecology instructed by him the next year. In this course, we learned about the interactions between plants and plants, plants and insects, and insects and insects using chemicals in the air. For example, we learned a plant could respond to an insect feeding on it by releasing chemicals that attract the herbivores predators, ultimately helping protect the plant. He provided examples of how such natural interactions between plants and insects had been used for very economic and sustainable pest management practices in regions where insecticidal or monetary resources were limited. His courses inspired me to pursue a career in entomology, specifically in the area of crop protection, and the ability to travel internationally to aid in crop protection is a wish come true.
In two days I fly to Guyana for the Farmer-to-Farmer volunteer program. I will be spending two weeks there: most of the first week will be spent visiting the farms, getting to know them and plant protection challenges. Week two I will be on a workshop/training spree, providing programs every morning and afternoon on topics ranging from scouting/monitoring, recognizing pests, recognizing beneficial insects, how to prevent pest outbreaks, physical and mechanical controls, biological control, and chemical control.
Before traveling overseas, you always need to check what kinds of vaccines or shots you need to take. Our local “travel” nurse practitioner in Tyler TX followed the CDC guidelines for travel to Guyana. I must admit, the Typhoid pills were a bit unpleasant, especially since I did not anticipate the side-effects of twisting/turning stomach and subsequent increased frequency to the porcelain throne for a few days. Interesting fact: apparently the vaccine for yellow fever is in limited is temporarily depleted, apparently due to manufacturing delays from the only supplier. An alternate is available (Stamaril) if I had time to book an appointment in Dallas. So… I’ll be rolling the dice on that one! I started taking my Malaria pills yesterday (two days before travel) – hopefully that are no unpleasant surprises with that one.
Malaria actually describes a protozoan parasite that invades the red blood cells and transmitted by mosquitoes. Interestingly, the parasite alters the feeding behavior of mosquitoes in two distinct ways: larger blood meals and more blood meal hosts (Koella et al. 1998). More specifically, they found that the mosquito takes larger blood meals when the parasite is in a stage in which the parasite can infect humans. When malaria infects humans, it can occupy both the blood (human blood cell stage) and the liver (human liver stage) (Medicines for Malaria Venture), sometimes remaining dormant in the liver for months or years before coming back in the blood and resurfacing symptoms. Speaking of symptoms, malaria infection can cause fever, chills, headache, nausea & vomiting, and muscle pain and fatigue (Mayo Clinic). In 2016 alone, it was estimated that 445,000 people died from malaria, most young children in sub-Sahara Africa (CDC: Malaria). One potential mechanism to reduce malaria is the use of transgenic mosquitoes – that is, mosquitoes that are genetically engineered to be unable to harbor the parasite, and thus, unable to vector it to humans. Marrelli and colleagues (2007) demonstrated that not only was their transgenic mosquito no longer able to vector malaria, but it actually had a fitness advantage compared to the wild mosquitoes – an important requirement if you’re going to replace all the wild mosquitoes with ones that don’t vector the virus (i.e. Gene Drive).
I finished packing and look forward to learning a lot on this trip, and hope to share what I learn, my experiences at the farms, and a bit about Guyana itself here – so stay tuned!