Biocontrol Trip Logs
The East African Diaries By R. Copeland
20 February - 5 March 2007
The daily reports below are taken from a scientist’s record of his trip to Burundi and Uganda in search of biological control insects to control the invasive aquatic weed, hydrilla.
The Hydrilla and Hygrophila Demonstration Project is supporting activities to identify potential biological control agents for hydrilla in Uganda and Burundi. Dr. Robert Copeland, an American who has spent the last 25 years of his life working on insect biodiversity in Africa, leads the effort. In Uganda. the team is composed of UF graduate, Dr. Fred Wanda, accompanied by a USAID supported UF MSc student, Brian Gidudu. In Burundi, Mr. Benoit leads the effort with the expert assistance of Evariste Nkubaye, a technician who worked with a USDA project to locate natural enemies of hydrilla in the 1980s. In both countries, hydrilla populations have been identifiedand a large number of small midges have been reared fromthe weed. It's interesting to note that everywhere hydrilla has been observed in Africa, it is completely submersed, often under two or more feet of water. The challenge now is to determine the trophic relationships of the insects with hydrilla, learn to rear them and then make shipments to the new UF/IFAS quarantine facility in Fort Pierce.
Introduction by Dr. William Overholt, UF-IFAS
20 Feb – Tuesday
Drove with Silas Ouko from Mbita to Jinja, met briefly with staff and a potential new Masters student, Mr. Gidudu Brian.
21 Feb – Wednesday
The entire group went out in a boat to collect at the Masese site. Masese is located near Jinja on the shore of Lake Victoria. Two full buckets of Hydrilla were collected. Lax and slightly larger leaves than normal led me to suspect that the plant we collected might actually be Egeria or Lagarosiphon. Need to examine the plant more closely under the microscope. The rearing room was switched to the upper level of the NAFIRRI main building. This area appears perfect, with multiple electrical outlets, a huge skylight, and space to easily hold all our rearing buckets, colony cages, etc. Plants were set up in buckets for rearing using air pumps, air stones and tubing to see if we can stop spoilage. The cage was modified so that the insects now exit directly into a Perspex cage, provided with honey drops and water-soaked cotton wool. Additionally, to allow us to drain old water from rearing buckets without disturbing the Hydrilla cultures inside, faucets were fitted at the base of two buckets and sealed with silicon. These were set to dry to be used with the samples expected to be collected later in the week from Lake Bisina. Also, a small hole was made on the side of each bucket near the top. This hole, blocked when not being used, is intended to allow us to add fresh water without having to remove the cover of the rearing bucket.
In the afternoon I examined the insects reared from Bunyonyi Hydrilla collected by us in November 2006. Unfortunately the insects had all been saved into formalin. However, a provisional list of insects was made. I also examined more closely the insect specimens from Burundi collections I picked up in January. The Ephydridae (a type of fly) appeared to be an accurate identification, but the poverty of optics in the Burundi and Uganda labs forced me to leave a more definite identification for my return to Mbita.
22 Feb – Thursday
Checked on the emerging insects from the two buckets. Many chironomids (flies) emerged overnight. Most of these thought to be species which as larvae cling to roots and stems and are detritivores. Flies were colleted into 70% EtOH. The rearing units appear to be working well, but a look inside the buckets shows that many flies are resting on the surface on emergent plant parts. Checks later in the afternoon reveal very few insects have migrated into the cages during the daylight hours. These species are probably night fliers.
I began dissections, concentrating on the apical growing portion of the stems. About 200 stems were selected from various parts of the “Hydrilla” culture in both buckets. No evidence was seen of the “cup-like” damage to Hydrilla growing tips reported by Markham to be caused by Polypedilum larvae. Egg masses were seen fairly commonly, attached to the “Hydrilla” stems. Several stem pieces were removed to a beaker in an attempt to observe any potential hatched invertebrates. Over several days many 1st instar heteroptera larva hatched out. These were identified as Notonectidae, predaceous bugs that would have no effect on the plant.
Towards the end of the day we planned the trip for 23 Feb to Lake Bisina. Fred, Brian, and the coxswain would go for 1.5-2.5 days. I trained Fred on how to adjust the Dissolved Oxygen meter to reflect atmospheric pressure based on altitude. Fred was to take the water chemistry kit with him to record readings at the sites they sample in Lake Bisina. Ganda and I were to continue collecting emerged insects and dissecting plants.
23 Feb – Friday
Fred, Brian, and coxswain off to Lake Bisina. Ganda and I made morning and evening collections from the rearing containers and viewed the specimens under the dissecting scope. We spent the rest of the day dissecting plants, with no success at finding internal phytophages (organisms that feed on living plants).
24 Feb – Saturday
Silas and I made collections from rearing buckets in morning and afternoon. More dissections with no positive results.
25 Feb – Sunday
Checked on the cultures from Jinja. These were still fresh-smelling (in fact, less foul than when first set). I decided not to change the water as the aeration appeared to be keeping down decomposition and bacterial growth. We made collections in the morning and evening, with cultures still producing large numbers of chironomids.
26 Feb – Monday
Fred’s group returned from Lake Bisina with large collections of Hydrilla from 3 Lake Bisina sites. Much of the Hydrilla is red-stemmed. Most of the day is spent setting up these samples and entering the physical and chemical data from the sites. Collections continue from the Jinja rearing buckets. Silas and I plan our sampling trip to western Uganda.
27 Feb – Tuesday
Silas and I leave for western Uganda. We decided to sample three new lakes (Lakes Kyugi, Nabugabo, and Kachera) as we proceeded in the general direction of Lake Bunyonyi, and later to also tried sampling at Lake Mutanda about 2.5 hrs west of Lake Bunyonyi. We arrived at Lake Nabugabo where there was a NAFIRRI boat that we were allowed to use. We contacted Mr. Mutebi Jackson who has been working at and around the lake for about 15 years. He agreed to arrange for 4 paddlers to take us on Wednesday to those regions of the lake where he knows that water weeds are present. He and I and Silas proceeded to Lake Kyugi. This is a small sacred lake near Nabugabo on which modern boats are not allowed to move. We found a guide who took Mutebi and I through a narrow channel hacked out of a thick border of papyrus. At the end of the channel we found a recently constructed boat fashioned out of lengthwise portions of banana tree-trunks. He and I decided to try to use it to push out onto the lake. However, the boat was not lake-worthy and sank before I could get on it, necessitating a “rescue” of the guide using a rake handle. I sampled at the edge but found nothing except rotting papyrus stems. Walking back I caught the rake tines on a papyrus plant, lost my balance and fell into the channel. Not nice.
28 Feb – Wednesday
We spent most of the day on Lake Nabugabo. The lake turned out to be unproductive for Hydrilla. We sampled other aquatic plants. Silas and I set off in late afternoon for Masaka where we spent the night.
1 Mar – Thursday
We drove to Lake Kachera where we hired two crude boats and paddlers at Nyanga Beach. Lots of hippos here and the paddlers said they are occasionally killed for meat, so we stayed as far from them as possible. Kachera is a big lake and we sampled a large area within Nyanga bay. No aquatic plants of any kind were collected. The entire lake is surrounded by papyrus. In the afternoon we drove to a larger fishing village, Rukukuru. There we sampled the beach shoreline and as far past it as foot access allows. Like Nyanga, we found no plants here. We left at about 3 and decided that we could make it to Kabale before dark, and so we continued past Mbarara. About 65 km before Kabale we lost the drive train. I flagged down a matatu and threw my things inside it. Silas remained with the vehicle. I arrived in Kabale about 1930 hr and found a breakdown service willing to get the vehicle and Silas. They returned with the vehicle at about 2300 hr.
2 Mar – Friday
Spares are found for repairing the drive train and, if nothing else, this allowed us to identify a first class shop and mechanic at Anguzu’s Garage. Hopefully we won’t need his services again. The vehicle was ready by the afternoon.
3 Mar – Saturday
Silas and I set out for Kisoro and Lake Mutanda, a short distance from Kabale on the map, but a poor road with plenty of hill driving. Took us 2.5 hrs to get to the lake. We found no evidence of fishing boats except one small boat far in the distance. We found a young student on school holiday who’s English was excellent and he guided us to a bay with 3-4 fisherman. One of these was called and he agreed to take us out in a dugout canoe. We spent 3 hours sampling in this bay and were rewarded with finding Hydrilla at three places, though not common in any of them. Hydrilla appeared fed on, with considerable leaf damage (by fish?). We drove back towards Kabale and sampled the northernmost tip of Lake Bunyonyi, collecting two buckets of Hydrilla, which is the dominant plant, as it was at the more southern sites of Bunyonyi that we sampled in Nov 2006. This new site is at the lake outlet where the Kamyora River begins. The area is referred to as Isesoro. We returned to Kabale.
4 Mar – Sunday
Silas and I traveled to Jinja arriving at 1830 hr and we set up the Hydrilla cultures.
5 Mar – Monday
We met with Ganda, collected the plant specimens for DNA analysis, and all the reared insects from current and previous collections. We then set off for Mbita, and arrived on the 1900 hr ferry.
Survey Sites in Africa, Uganda