Are global populations of insects in collapse?
While western Europe has experienced intense commercial agriculture with dramatic changes to its landscape, South Africa has a smaller agriculture industry that has been operating for a shorter span of time. It still has large areas of natural vegetation such as the Kruger National Park, the largest of its 19 national parks.
The major decreases in insect biomass observed at sites in the northern hemisphere over the past 30 years may be linked to intensification of agricultural activities and associated pesticide usage. But it is unclear whether the drastic decline in insect populations is also occurring in South Africa's national parks as data are lacking.
Widespread insect declines are a growing concern.
Simon van Noort, Curator of Entomology at Iziko South African Museum, says that "there is a dire shortage of data on African insect species richness." Of the 100,000 species described from sub-Saharan Africa, about 44% are recorded from South Africa.
However, total estimates of African insect species vary widely, "potentially 2- to 6-times higher than the known species richness," he says. "Based on my experience with the hyper-diverse Hymenoptera (bees, wasps, and ants), I am of the opinion that the 20,000 or so described African species represent, at most, 20% of the true richness for the region, and possibility as low as 5%."
The ACDB has already barcoded all the trees of the Kruger National Park, a project spanning from 2006 - 2011. "Barcoding insect species is the next logical step in monitoring biodiversity in the Kruger," van der Bank says.
This meeting, held in Kruger National Park in November 2017, was a great success, attracting nearly 500 delegates from 71 nations. Discussions during the conference led to a plan; Kruger National Park would serve as a model system to demonstrate how DNA barcoding can rapidly advance understanding of biodiversity in national parks in South Africa and other countries.
"Barcoding insect species is the next logical step in monitoring biodiversity in the Kruger"
- To show that DNA barcoding can enable rapid, low-cost evaluations of the species composition of arthropod communities in National Parks.
- To quantify seasonal and spatial patterns of variation in arthropod biomass in Kruger National Park.
- To provide baseline data on arthropod community structure and species diversity in Kruger National Park to evaluate future changes.
- To provide detailed information on species distributions to help South Africa meet its reporting obligations under the Convention on Biological Diversity.
"The marrying of high tech lab techniques and simple field techniques allows for co-creation of knowledge between conservation managers and scientists"
Danny Govender, general manager of the Savanna & Arid Research Unit of South African National Parks, is keen to support the program highlighting that, "with 100 years of biodiversity research, the Kruger will for the first time have access to a comprehensive, spatially and seasonally explicit dataset of insect life." She says, "the marrying of high tech lab techniques and simple field techniques allows for co-creation of knowledge between conservation managers and scientists, ensuring that research findings are meaningful and relevant.”
As it is ideal for the traps to be placed in an area with minimal artificial light, natural water regimes, and within a fenced area, the team set up each trap within a quiet corner of each section ranger's property.
A difficult task was made so much easier by the SAN Park staff. The deployment team met with incredible enthusiasm and support from the rangers and their families, staff, and students. Despite numerous other responsibilities, each person made an effort to meet with the team and assist with the selection of a suitable location for the trap.
The maintenance of traps and collection of weekly samples depends upon continued support from SAN Park staff. Without their help, this project would not be possible.
The ACDB team, consisting of Eugene Shongwe and Ross Stewart, returned to Kruger in August and November 2018 to meet with rangers, drop off progress reports, and collect samples.
Greg Bond, the section ranger at Lower Sabie, the site with the highest abundance and species diversity in the program thus far said: “My interest sparked when the first report came through. That’s when I really thought, ok, this is really interesting and that’s when I started reading more about it. It sparked questions, you know, as to why? I’ve become more aware [about insects] just sitting around at night.”
"It sparked questions, you know, as to why? I’ve become more aware [about insects] just sitting around at night.”
Being more aware of what insects are doing is the first step in noticing and recording observations, information that is incredibly important to scientists as it adds perspective to the data collected in Malaise traps within the park.
Philile Dlamini, the section ranger at Woodlands, hoping to do her Masters this year said we are some of the first scientists to actively engage Kruger staff: “No! They [other scientists doing research in Kruger] will just come and then they will tell us that they are going to the field and they will be with their guide, but we are never given more time to get involved like we are doing now, no. So, this is the first time for me.”
"We are never given more time to get involved like we are doing now, no. So, this is the first time for me.”
Experience collecting, and recording data is valuable for everyone, particularly people interested in pursuing higher education in science. While actively engaging with rangers, staff, and communities can often be quite challenging for scientists given the many constraints in research funding and time, addressing biodiversity loss requires all of us to make more of an effort to collaborate across scientific disciplines and social boundaries.
Marius Renke, the section ranger of Houtboshrand, appreciated the large scope but simplicity of the program, without which it would be a lot harder for rangers to get involved: "the intensity of the poaching operations makes it really difficult for us to get to our conservation tasks. Because that is what we are trained to be, conservationists, not so much soldiers. But that is what we currently do, protect only certain species, not biodiversity."
"I am specifically interested in what causes outbreaks of certain things like mopane worms, armoured ground crickets, and these small little stink bugs."
Marius sees tremendous value in better understanding insect dynamics: "I am specifically interested in what causes outbreaks of certain things like mopane worms, armoured ground crickets, and these small little stink bugs." These interests were shared among many others in the park.
Being able to predict outbreaks of mopane worms, for example, will be particularly valuable for community projects involving communal harvesting. Mopane worms are a highly nutritious food source but also quite expensive as they are not as readily available as they once were. Both Marius and Philile mentioned that they would like to be able to use information on the factors that trigger outbreaks to provide opportunities for neighbouring communities to benefit from the park. This, Marius says, is the future of conservation - community involvement.
Vackia Mei, the environmental monitor working alongside Marius in Houtboshrand, told us how much he has enjoyed working with the Malaise trap. As a zoology graduate from the University of Venda, Vackia said: "It is quite an impressive trap you have there. I have worked with various traps for insects, but this one has proven quite effective."
"I have worked with various traps for insects, but this one has proven quite effective."
Despite many interesting stories of trap destruction and ingenious repairs, it is incredible to see that the majority of Malaise traps have been able to stay standing and sampling in sections for a full year.
Vusi, general staff working with section ranger Rob Thompson at Tshokwane, told us how disappointed he was when the trap in his section was destroyed by strong winds. He was very keen to get another trap in order to continue sampling: "I was so disappointed with the wind. But I need to continue with this job. This program is like a school for me. With this trap I am able to learn more and more."
"This program is like a school for me. With this trap I am able to learn more and more."
Many people were involved with helping replace traps when they went down. Overall, there are only a few instances where sample collection had to stop for a significant span of time.
Verah Masilane, the environmental monitor at Phalaborwa, told us about the unique way field rangers in the area patrol the bush. Led by section ranger Karien Keet, horses have been deployed for mounted anti-poaching patrols allowing field rangers to cover larger distances and get closer to wildlife. Species of flies that carry diseases known to affect horses has been detected, a fact Verah learned through the program: "We were not aware that we have those insects that can influence our horses. But know at least we have that knowledge. From there we might be able to better care for our horses."
"We were not aware that we have those insects that can influence our horses. But know at least we have that knowledge."
The further we explore the data collected through the KMP, the more we will understand the insect species present in Kruger National Park. And the more we understand, the better we will be able to access the state of insect biodiversity.
When Robin Petersen, the freshwater ecologist for Scientific Services in Kruger responsible for aquatic biomonitoring on most rivers in the park, realized how much data the program has been able to generate and that the data would be accessible online, he says: “That’s fantastic! That’s unheard of! We wouldn’t be able to do it. In my life time probably. That’s very impressive. We are very fortunate that you are willing to collaborate with us.”
"Insects are telling us something, for sure."
He also shared his concerns with global insect declines: “We have been seeing it in Kruger Park, through casual observations. You can definitely see that something is going on. Insects are telling us something, for sure. There is a global decline, and locally we are observing it. And it goes beyond just aquatic ecosystems, for food production, agriculture, you name it. Without insects, ecosystem would basically collapse.”
Section ranger Albert Smith (not pictured) & his daughter - Malelane - Trap D
Section ranger Neels van Wyk (not pictured) & Lufund Chantal Muthelu - Crocodile Bridge - Trap U
Section ranger Marius Snyders & his wife Ronel - Stolznek - Trap X
Section ranger Craig Williams & Zodwa Sibuyi (left to right) -Pretoriuskop - Trap C
Section ranger Greg Bond (not pictured) & Constance Mathoho - Lower Sabie - Trap A
Donovan Tye & Laurence Kruger (left to right) - Skukuza SSLI Camp - Trap B
Conservation students Nomndeni Nkosi & Lindokuhle Gumede (left to right) - Skukuza Research camp - Trap W
Meurel Baloyi - Skukuza Nursery - Trap Y
Section ranger Kally Ubisi & his son - Skukuza - Trap V
Section ranger Rob Thompson (not pictured) & Vusi - Tshokwane - Trap F
Section ranger Robert Bryden (not pictured), Rodger Masango & Piet Mokgothu (left to right) - Nwanetsi - Trap E
Section ranger Richard Sowry (not pictured) & Sergeant Lucky - Kingfisherspruit - Trap F
Section ranger Agnes Tibane (not pictured) & Sergeant Wilson Siwela - Satara - Trap H
James Belebes & Section ranger Marius Renke - Houtboshrand - Trap G
Section ranger Rangani Tsanwani & Nkateko Rikhotso (left to right) - Olifants - Trap J
Section ranger Karien Keet & Verah Masilane (left to right) - Phalaborwa - Trap K
Section ranger Andrew Desmet, Sbonelo Mathebula & Windy Maleto (left to right) - Letaba - Trap L
Section ranger Thomas Mbokota (not pictured) & Sergeant Jimmy - Mahlangeni - Trap T
Section ranger Joe Nkuna - Mooiplaas - Trap M
Morries Chauke, Section ranger Philile Dlamini & Succeed Mathebula (left to right) - Woodlands - Trap N
Section ranger Ndwakhulu Mutobvu & Sameer (left to right) - Shangoni - Trap O
Section ranger Rendani Nethengwe - Shingwedzi - Trap S
Section ranger Thomas Ramabulana - Vlakteplass - Trap R
Section ranger Dalton Mabasa, Oupa Maluleke, Ndima Ramashidzha, Badji Mashamba, Agelaite T and Joy Mabasca (left to right) - Punda Maria - Trap P
Section ranger Sandra Visage (not pictured) & Gilbert Chauke - Pafuri - Trap Q
Godfrey Baloyi - Return Africa - Pafuri camp - Trap Z