During the first half of the twentieth century, the Botanical Gardens in Bogor was the centre of biological research and education in Java. But it also played a decisive role in preserving one of the biggest butterfly collections ever amassed by a single collector, by sheltering it during WWII. The collection was the most precious possession of Jan van Groenendael, a Dutch physician who lived and worked in Java and Flores, together with his wife, paediatrician Adriana Krijger, between 1931 and 1954. In this paper, we peek into the life of the Van Groenendaels, following them through the 1930s, WWII and the decolonisation period, to discover that, up to now, the collection has survived the humid tropical climate, two wars and several funding cuts, and has travelled more than 11,000 km. Towards the end of the doctor’s life, his collection had grown to include nearly half a million specimens from one of the most biodiverse areas of the world. The collection is therefore of great scientific relevance, and because of the archival material accompanying the butterflies, it may also prove to be of interest for historians. Altogether, the comprehensive Van Groenedael-Krijger archives can provide insight into very diverse themes, such as the experience of a Dutch physician in Indonesia during and right after WWII; the customs and health of the residents of Flores; the mind and motives of a natural history collector or the state of entomology during the 1950s.

Meet the Van Groenendaels

Joannes van Groenendael (1896–1980) and his wife Adriana Krijger (1901–1993) sailed as newlyweds to Java on the 12th of May of 1931, the very next morning after they got married.1 Jan, Catholic, was a general practitioner and Adri, Protestant, a paediatrician. As this interfaith marriage was frowned upon by their families, they decided to leave the Netherlands and settle down as far away as it was physically possible. They settled down in Sukabumi, about 110 km south of Jakarta, a small city of Western landowners dedicated to the cultivation of tea, coffee, rubber and quinine. In 1932 they were both licensed by the colonial government to practice general medicine and midwifery.2

Jan had been an avid butterfly collector since the age of 11. By the time he married Adri, his collection comprised around 10,000 specimens, mostly from Europe and Central Asia. Before sailing to Java, Jan left his collection in the care of the Zoological Museum of Amsterdam. As a return favour, he would collect butterflies for the museum. Once in Sukabumi, he resumed his collecting activities and trained local people to collect for him. In Jan’s own words: “During my long stay in Java I had a big bunch of natives collecting for me, which was a great success.”3 Dutch missionaries and expatriates proved to be a good source of specimens, too. On top of this, Van Groenendael employed a Dutch dealer living in Surabaya named Jorinus P. A. Kalis, an entomologist and professional collector active in areas like Sulawesi, Lombok and Bali.4

Thanks to such an extensive network of dedicated collectors, Van Groenendael received butterflies and moths from all corners of Southeast Asia, from the Philippines to Australia. He kept his specimens in envelopes made of newspapers, magazine pages or any other available type of paper. Van Groenendael scribbled relevant information on those envelopes – the species name, date and locality of capture. Van Groenendael collected eagerly and continuously, even though he did not have the time nor the material to prepare the specimens – that is, to pin, mount and preserve them in glass topped drawers for display and study. So he continued collecting and papering specimens, drying them again and again to prevent mould and decay.5

The Van Groenendaels spent nine happy years in Sukabumi. Their activities included alleviating patients and expanding collections, sprinkled with sporadic social activities. Judging by the doctor’s journals, they felt quite at home. Unfortunately, their peace – and that of half of the world – ended with WWII.

The butterflies and the Botanical Gardens in Bogor

After the Japanese occupation of the Indonesian Archipelago in March 1942, most of its Dutch residents were detained, imprisoned, executed or sent to Japanese prisoner-of-war (POW) camps. Adri stayed in several internment camps in Java. Her husband, then a reserve officer of health for the Royal Netherlands East Indies Army, was taken as a prisoner of war.6 Jan stayed in camps in Java, Malacca, Siam and Burma, where he worked on the infamous Burma-Siam railway. Both of them survived, according to Adri thanks to the fact that they were medical doctors.7 A particularly surprising detail is that Jan, as a POW, managed to collect some butterflies in and around the POW camp in Siam. However, given the precarious situation of the prisoners, these specimens were lost, but it seems the doctor never lost his interest or, for that matter, his will.8

During the war, the couple lost their house in Sukabumi along with their possessions – all but one. Amazingly, the butterfly collection survived. Van Groenendael wrote to a friend in 1952: “I succeeded in bringing a big part of my prewar collection through the war, thanks to the help of a native friend, a Menadonese veterinary surgeon.”9 According to Hans Duffels, entomologist and Van Groenendael’s friend, this local veterinary was “Frits Waworuntu, head of ’s Lands Plantentuin in Buitenzorg, who took the collection to Buitenzorg to watch over it.”10 On the other hand, Arnold de Boer – entomologist and Hans Duffels’ colleague at the Zoologisch Museum Amsterdam – affirmed in biography of Van Groenendael that Waworuntu “had been appointed head of the botanical gardens by the Japanese government”.11 However, the director of the Gardens under Japanese rule was actually Takenishin Nakai, a botanist from Kyoto University.

Van Groenendael explained to Jeanne Marie van Diejen-Roemen, a civil servant working in Ternate and friend of the Van Groenendaels, what had happened with his collection: “My collection was robbed by a Jap officer and taken to the museum in Bogor. There I found back most of it after the war.”12 Curiously, he made no mention of Waworuntu on this occasion. De Boer gives a different account, attributing the initiative of taking the collection to Bogor entirely to Waworuntu, who “tipped a Japanese officer about the fact that an important Lepidoptera collection stood deserted in Sukabumi. Waroroentoe [sic] made it clear that he would like to have this collection in the Bogor Museum.”13 The role Waworuntu played is unclear, but the butterflies did find shelter in the Zoological Museum of Bogor, within the relative safety of the Botanical Gardens. It is interesting to note that Takenishin Nakai put especial effort into protecting the scientists and the Gardens against any military action during the war, and with that, he helped protect the Van Groenendael butterfly collection as well – even if he was unaware of it.14

Fritz Karel Waworuntu was born in Sonder, Minahasa, south of Menado. He obtained his PhD degree from the Academy for Veterinary Medicine in Utrecht in 1924.15 Waworuntu travelled back to Indonesia to work as a government livestock veterinarian in Modjokerto, East Java.16 Although I have not been able to find other records of him in the Van Groenendael archives, F.K. Waworuntu was indeed a ‘veterinary surgeon from Manado’, who also had a close relation with Dutch expatriates: in 1925, he married a Dutch woman born in Groningen, Grietje Lubbers.17 Unfortunately, his exact relationship with the Botanical Gardens is not clear, but he somehow did have enough influence within the Zoological Museum to play a key role in the fate of the butterfly collection.

The butterflies of Flores

After WWII, the Van Groenendaels spent a few years recovering and trying to find a position that would satisfy them both professionally and personally. In their quest, the butterflies stood central when it came to decide where to live and whom to write. They worked briefly in Java, but in 1948 – when the situation worsened due to the Indonesian War of Independence – Jan and Adri returned to The Netherlands. Nevertheless, a few months later they were back and stationed in Padang, Western Sumatra, working for the Dutch colonial government. Judging from the couple’s love for Indonesia, it is not too far-fetched to assume that they had requested the appointment.18

When Indonesia proclaimed its independence, Jan and Adri remained in the country and by April 1950, they were both working for the new Indonesian government. At first, Jan worked for the Central Office of Malaria Control in Jakarta while Adri worked at the Children’s Department of the Carolus Barromeus Hospital.19 But they strongly disliked Jakarta. They had poor accommodation and no butterflies, and they longed to return to a rural environment. After four months, they were again on the move. In September of 1950, Jan and Adri arrived on the island of Flores.20

The Van Groenendaels had been allowed to choose their destination. Java would have seemed a logical choice in terms of accommodation, facilities and social life, but the promise of new butterflies and a quiet location was much more alluring. Their choice was certainly determined by the butterflies: Jan wanted to be in Flores because he hoped to find there the boundary between the Indo-Malaysian and Australian faunas.21 Under the supervision of Dr. Pirngadi from the Dinas Resehatan (Public Health Office), Jan became a government health inspector, touring the island on horseback and giving medical aid to the rural population – 400,000 patients for one doctor.22 Adri worked at the hospital in Ruteng and sometimes, accompanied her husband on his patrols to remote villages to offer medical treatment and vaccinate the children. At the same time, the butterfly collection kept on growing, while Adri avidly collected shells and ethnographical artefacts.23

While in Flores, Jan tried to re-establish his relationships with old friends and fellow entomologists. Many of them had died or retired and the doctor put a lot of time and effort in finding new collectors with whom he could exchange specimens.24 He found a few Catholic missionaries interested in helping him, who received very specific instructions on how to catch, rear, prepare or store butterflies.25 He even asked Sister Tarsicius from the Kepala leper colony in Tual-Langur, on the island of Kei Besar, to put her leper patients to work, as that “stupid fear of contagion” meant nothing to professionals like him.26 Van Groenendael also wrote to Australian dealers, Malay and Japanese entomologists, and German suppliers. Besides chasing new specimens, Jan kept as well-informed as possible by writing assiduously to Dutch entomologists. His correspondents included those working in Bogor and the staffs of the Zoological Museum in Amsterdam and of the Agricultural College of Wageningen.27

Fig. 1: 

Adri and Jan van Groenendael by their house in Ruteng, Flores, 1950s. Archives Naturalis Biodiversity Center, Leiden.

Van Groenendael discovered that he could not get the local people of Flores to collect for him as he had done in Java. To his exasperation, the Florinese seemed utterly uninterested in any incentive, including money, Van Groenendael could offer them.28 He relied on missionaries, fellow collectors, himself, and on the widow of Jorinus Kalis, the professional dealer, who died of cancer shortly after WWII ended. Mrs. Th. Kalis-Heerfirt lived with Jan and Adri in Ruteng as their housekeeper and collector. And so the Flores collection kept on growing for four years into one of great scientific interest, as the island had never been explored before – entomologically speaking.

Fig. 2: 

Touring the island of Flores on horseback, 1950s. Archives Naturalis Biodiversity Center, Leiden.

The enormous Javan collection was still in Bogor in 1951.29 It is not clear whether Van Groenendael managed to bring the collection to Flores after that or whether it remained in Bogor. If so, it was probably under the care of the staff at the Zoological Museum until 1954. How exactly did Van Groenendael manage to retrieve his butterfly collection remains a mystery as well. It is possible that he still had friends at the Museum, perhaps Waworuntu himself, or that he claimed ownership of the collection to the Dutch officials returning to his posts, like L.G.M. Baas Becking, who became director of the Botanical Gardens in 1946. In any case, Van Groenendael succeeded in reclaiming most of his collection and, undeterred, resumed his collecting activities until circumstances forced them to return to The Netherlands – this time, for good.

Back to The Netherlands, butterflies and all

In June of 1954, the Van Groenendaels returned to the Netherlands. The decision was made partly because Jan and Adri were getting older and the patrols on horseback were becoming increasingly uncomfortable. The roads and bridges deteriorated, payment was delayed and medical supplies were difficult to obtain. By 1953, the Ministry of Health could not guarantee that their contract would be renewed and so it was that they decided to leave Indonesia.30

Fig. 3: 

Left: polyclinic in Bivak Ranggu (Flores). Right: Adri and Jan van Groenendael visiting patients in a village, Flores. Archives Naturalis Biodiversity Center, Leiden.

In the Netherlands, finding a house that suited them and the gigantic collection was quite a challenge, so they built their own bungalow in Doorwerth, with an extra floor just for the butterflies. They stayed with relatives until they finally moved into their new home in July 1958. Although the couple had plans to return to Indonesia, they never did. Jan became a physician on hadji pilgrimage ships, transporting pilgrims from Indonesia to Mecca and back, and from 1959 to 1961, as a physician on cruise ships, until he retired at age sixty-five. Time, at last, for his butterflies.

Jan van Groenendael had amassed a prodigious collection of nearly half a million butterflies.31 The specimens were still folded in their original paper envelopes, packed in 108 tin boxes – made especially for him – and in a variety of other containers like cigar, biscuit and cocoa tins. There was no system to it whatsoever. Having now the time, he started to mount them, with assistance from the staff of the Zoological Museum of Amsterdam. He intended to carry out entomological research or publish about his findings after retirement. Unfortunately, just mounting part of his collection took him years and he never published any of his findings or observations. By 1980, he had mounted around 300,000 specimens.

The collection was officially donated to the Zoological Museum of Amsterdam in 1979. That same year Jan and Adri founded the Van Groenendael-Krijger Foundation with the goal to use their legacy to curate the collection and promote research on Indo-Australian butterflies. Jan died in 1980, at age eighty-five, and his beloved collection was shortly afterwards moved to Amsterdam. Adri survived him for thirteen years and passed away in 1993.

Biology and history: the double value of the collection

Since 1990, the Van Groenendael-Krijger Foundation has funded several projects at the Amsterdam museum, now part of Naturalis Biodiversity Center. The scientific value of the Van Groenendael collection becomes more evident as we re-curate it. It includes specimens from localities not yet represented in the Naturalis collection, mostly from Flores, Bali, Sulawesi and Taiwan. A significant 30% of the Nymphalid butterflies (the largest family of butterflies, containing around 1,800 Indo-Australian species) in Naturalis are from Jan’s collection. For some of these species, as much as half of the specimens are labelled as “collection Van Groenendael”. Furthermore, the doctor’s butterflies are of great scientific interest because of the period when they were collected. His pre-war collection provides a snap-shot of the fauna of Western Java, a region that has been deforested for centuries to make space for agriculture. The butterflies from Flores, on the other hand, are unique because no one had collected there before Van Groenendael did, and almost no one has done it after him. These butterflies are extremely valuable for biological research, especially now in the midst of the biodiversity crisis.32

Fig. 4: 

The Van Groenendael collection of papered butterflies and moths, before and after re-curation at Naturalis Biodiversity Center.

Similarly, as the collection is proving to be a new source of information for biologists, the related documentation can be of interest for historians. Family and colleagues of Jan and Adri van Groenendael were aware of the scientific importance of the collection and they made an effort to preserve all surviving documentation related to it. The resulting archive, comprising fifty-two of Jan’s journals, photographs and correspondence, is preserved in the Nederlandse Entomologische Vereniging archives (now at Naturalis Biodiversity Center). The diaries and ethnographical collections of Adri van Groenendael-Krijger are kept at the Royal Tropical Institute in Amsterdam. Jan’s journals offer a unique insight into the daily lives of the Florinese in the 1950s, provide accurate descriptions of their customs, clothing, housing and diet, and list the villages or kampongs he visited in his routes. He made numerous sketches of buildings, tombs and other constructions, and wrote glossaries of words useful for his work, including diseases and remedies. In addition to the journals, the Van Groenendael family has donated photographs and letters to Naturalis Biodiversity Center to help document the butterfly collection, the doctors’ life and network, and their life on Flores. This material is not yet categorized and further research is needed before it can be digitized and catalogued. In addition to this archival work, links between the archives preserved in separate institutes would further enhance the value of the Van Groenendael-Krijger legacy.

Fig. 5: 

Fragment of a letter from Van Groenendael to J.M. van Diejen-Roemen, dd. 9 Augustus 1954. Naturalis Biodiversity Center, Leiden, NEV archives, 58295.