Authorship：Lead author,　Corresponding author  

File： Takasuka 2021 Am. Arachnol.pdf

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

File： Takasuka 2019 Acta Arachnol.pdf

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

File： Takasuka 2019 J. Arachnol.pdf

DOI： 10.1636/JoA-S-18-082

Authorship：Last author,　Corresponding author   Language：English  

File： Discovery of a bagworm devouring an orb web.pdf

DOI： 10.13156/arac.2018.18.2.147

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/jzo.12668

Authorship：Lead author,　Corresponding author  

© 2018 British Arachnological Society.All Rights Reserved. Parasitism upon Cyclosa omonaga (Araneidae) by the ichneumonid ectoparasitoid Reclinervellus nielseni is reported for the first time, based on molecular identification, corroborating that R. nielseni is a specialist parasitoid of members of the genus Cyclosa, having previously been recorded from C. argenteoalba, C. conica and C. laticauda. The parasitoid larva at the time of discovery (11 December) was still tiny in spite of the beginning of winter, indicating it was in its overwintering phase, and this is the first case of the overwintering R. nielseni larva found in Japan. The host's cocoon web, with fibrous and fluffy thread decorations (FTD) resulting from the wasp's behavioural manipulation, produced by the parasitized C. omonaga is described and illustrated, and its potential role is discussed.

File： Takasuka 2018 Arachnol.pdf

DOI： 10.13156/arac.2017.17.8.406

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier GmbH  

Polysphinctine wasps are exclusive parasitoids of spiders and their host utilisation strategies are highly taxonomically specific. In this study, the host utilisation of two Australasian parasitoid wasps of the genus Eriostethus was studied for the first time. Our study revealed considerable differences in host-parasitoid interactions between Eriostethus minimus associated with 3D tangle web-building spiders from the family Theridiidae (new family record for Eriostethus) and E. perkinsi associated with 2D orb-web weaving spiders from the family Araneidae. A pupa of the former species was located in a spider retreat in the centre of an unmodified 3D tangle web and the pupal cocoon had a sparsely woven and partially transparent wall. In contrast, a cocoon of the latter species was suspended at the centre of a modified irregular sparse 3D cocoon web and the pupal cocoon had a strong, densely woven cocoon wall. This difference in host utilisation is not in agreement with the synonymisation of Millironia with Eriostethus.

DOI： 10.1016/j.jcz.2017.11.006

Scopus

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：EDP Sciences  

Accurate egg placement into or onto a living host is an essential ability for many parasitoids, and changes in associated phenotypes, such as ovipositor morphology and behaviour, correlate with significant host shifts. Here, we report that in the ichneumonid group of koinobiont spider-ectoparasitoids ("polysphinctines"), several putatively ancestral taxa (clade I here), parasitic on ground-dwelling RTA-spiders (a group characterised by retrolateral tibial apophysis on male palpal tibiae), lay their eggs in a specific way. They tightly bend their metasoma above the spider's cephalothorax, touching the carapace with the dorsal side of the ovipositor apically ("dorsal-press"). The egg slips out from the middle part of the ventral side of the ovipositor and moves towards its apex with the parted lower valves acting as rails. Deposition occurs as the parasitoid draws the ovipositor backwards from under the egg. Oviposition upon the tough carapace of the cephalothorax, presumably less palatable than the abdomen, is conserved in these taxa, and presumed adaptive through avoiding physical damage to the developing parasitoid. This specific way of oviposition is reversed in the putatively derived clade of polysphinctines (clade II here) parasitic on Araneoidea spiders with aerial webs, which is already known. They bend their metasoma along the spider's abdomen, grasping the abdomen with their fore/mid legs, pressing the ventral tip of the metasoma and the lower valves of the ovipositor against the abdomen ("ventral-press"). The egg is expelled through an expansion of the lower valves, which is developed only in this clade and evident in most species, onto the softer and presumably more nutritious abdomen.

File： Takasuka et al. 2018 Parasite.pdf

DOI： 10.1051/parasite/2018011

Scopus

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER GMBH, URBAN & FISCHER VERLAG  

Most parasitoid wasps establish close interactions with their host taxa, and polysphinctines (ichneumonid koinobiont spider-ectoparasitoids) are no exception. Two polysphinctines, Zatypota picticollis and Reclinervellus nielseni, are, respectively, partial and exclusive parasitoids of Cyclosa spp. (Araneidae), which build an orb web with web decoration. The main aim was to investigate the host association of these wasps, including the behavioural alteration of spider hosts across two sides of the Palaearctic (Central Europe vs. Japan).
R. nielseni was associated with relatively common local species of Cyclosa both in Europe (C. conica), sharing these with Z. picticollis, and in Japan (C. argenteoalba). We also found a new alternative host spider, Cyclosa laticauda, in Japan.
Host web alterations were observed in all parasitoid-spider interrelationships. The alteration patterns of the two polysphinctines have a similar constructional plan that exploits pre-existing frame lines for the cocoon webs; however, they differ partially in their radii, which are either straight or zigzag shaped and in hub loops present or absent. This indicates that certain differences in the neurophysiologic changes in the spider host occur depending on the parasitoids. The fluffy decoration induced in C argenteoalba manipulated by R. nielseni was not found in C. conica or C. laticauda, probably because of its non-innateness.
The cocoons of R. nielseni had four conspicuous long ribs making the cocoon quadrate in cross-section regardless of the host spider species or region; such ribs do not appear in two co-generic species. (C) 2017 Elsevier GmbH. All rights reserved.

DOI： 10.1016/j.jcz.2017.01.001

Web of Science

Scopus

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：The Company of Biologists  

© 2015. Published by The Company of Biologists Ltd. Host manipulation by parasites and parasitoids is a fascinating phenomenon within evolutionary ecology, representing an example of extended phenotypes. To elucidate the mechanism of host manipulation, revealing the origin and function of the invoked actions is essential. Our study focused on the ichneumonid spider ectoparasitoid Reclinervellus nielseni, which turns its host spider (Cyclosa argenteoalba) into a drugged navvy, to modify the web structure into a more persistent cocoon web so that the wasp can pupate safely on this web after the spider's death. We focused on whether the cocoon web originated from the resting web that an unparasitized spider builds before moulting, by comparing web structures, building behaviour and silk spectral/tensile properties.We found that both resting and cocoon webs have reduced numbers of radii decorated by numerous fibrous threads and specific decorating behaviour was identical, suggesting that the cocoon web in this system has roots in the innate resting web and ecdysteroid-related components may be responsible for the manipulation. We also show that these decorations reflect UV light, possibly to prevent damage by flying web-destroyers such as birds or large insects. Furthermore, the tensile test revealed that the spider is induced to repeat certain behavioural steps in addition to resting web construction so that many more threads are laid down for web reinforcement.

File： Takasuka et al. 2015 J. Exp. Biol.pdf

DOI： 10.1242/jeb.122739

Scopus

PubMed

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：UNIV HAWAII PRESS  

The seasonal life cycle of Zatypota albicoxa, an ectoparasitoid of the house spider, Parasteatoda tepidariorum, was examined in Toon, in warm-temperate southwestern Japan. The larvae were found all year round, but eggs, pupal cocoons, and adults were found only from March to November. In winter, only the medium second-instar larvae were found, suggesting that they are in diapause state. Seasonal occurrence of each developmental stage in the field indicated that this parasitoid produces more than four generations per year. The life cycle in Toon is substantially similar to that in Hirosaki, in cool-temperate northern Japan, but some of the traits differed geographically. Occurrence of newly formed pupal cocoons was 2 months earlier and length of the season for growth and reproduction was 4 months longer in Toon than in Hirosaki. Appearance of the pupal cocoon is more or less coincident with the period when monthly mean temperatures reach around 10 degrees C. The observed geographical difference in the seasonal life cycle may be due to the difference in local climatic conditions, but not to a difference in seasonal host availability.

DOI： 10.2984/67.1.7

Web of Science

Scopus

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：PENSOFT PUBL  

Apechthis cantika sp. n. (Ichneumonidae: Pimplinae) is described from the island of Sulawesi, Indonesia. This is the first known representative of the genus in Indonesia and also the southernmost record of Apechthis in the Oriental region, extending the known distribution far southwards. Discovery of a second yellow Apechthis in the Oriental region, following A. taiwana Uchida, suggests that the genus suddenly changes its body colour entirely from black to yellow towards the equator, independently in both the Oriental and Neotropical regions. The holotype of A. taiwana, apparently closely related to A. cantika sp. n., is also redescribed for comparison.

File： Watanabe & Takasuka 2013 J Hym Res.pdf

DOI： 10.3897/JHR.31.3813

Web of Science

Scopus

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

File： K. Takasuka et al. 2012 JJSysEnt.pdf

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Pensoft Publishers  

Cryptopimpla sulawesiensis sp. n. (Ichneumonidae: Banchinae: Atrophini) is described from the island of Sulawesi, Indonesia (Sundaland). This is the first known representative of the genus in Indonesia and is also the southernmost record of Cryptopimpla in the Oriental region. The presence of Cryptopimpla in Sulawesi, which belongs to Wallacea, indicates the potential distribution of Cryptopimpla in the Indochina Peninsula, Sundaland (other than Sulawesi Is.) and possibly Australia, where there have been no records of the genus.

File： Takasuka et al. 2011 J Hym Res.pdf

DOI： 10.3897/jhr.23.1595

Web of Science

Scopus

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MAGNOLIA PRESS  

Zatypota albicoxa (Walker) is newly recorded from Mt. Merapi, Java Is., Indonesia. This is the first record of Z. albicoxa from this part of the Oriental region and from the Southern Hemisphere, and the first record of the genus Zatypota from Southeast Asia. The Indonesian population of Z. albicoxa attacks a theridiid spider of the genus Parasteatoda, as do populations of Z. albicoxa in other regions. The spider is a new species, and is described under the name of Parasteatoda merapiensis.

Web of Science

Scopus

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

When encountering an already parasitized host, a parasitoid's optimal choices (superparasitism, host rejection, host feeding or infanticide) seem to depend on the individual species' life history, because the same choice may have different fitness consequences. We demonstrate infanticide under laboratory conditions by a polysphinctine, Zatypota albicoxa, which is a solitary koinobiont ectoparasitoid of spiders. The female always removed any previously attached egg or larva from the body of the host spider, Parasteatoda tepidariorum, with a rubbing behaviour. She rubbed her ovipositor back and forth toward the undersurface of the attached egg or of the saddle under the attached larva to pry it off and laid an egg after removal. When removing a larva, the infanticidal female engaged exclusively in unfastening the 'saddle' which fastens the larva to the body of the spider. All larvae were removed with the 'saddle' attached to the ventral surface of the body. The female invested more time to remove the medium second and the large penultimate instar larvae than to remove eggs and first instar larvae because of the labour involved in unfastening the saddle. Oviposition with infanticide of the medium second and the penultimate instar larvae imposed more time upon the female than that on an unparasitized host. Removal of any previous occupant in spite of the associated labour costs suggests that infanticide will always be adaptive, no matter the time costs to Z. albicoxa, because so much is invested in attacking the host and because the parasitoid cannot detect whether the spider is already parasitized until she achieves subjugation.

DOI： 10.1007/s00114-011-0797-9

Web of Science

Scopus

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER JAPAN KK  

Unique host enticing behaviour has been observed for the first time in Zatypota albicoxa (Walker), which parasitizes the house spider, Parasteatoda tepidariorum (Koch), which weaves irregular, three-dimensional webs. One female wasp lay on her dorsum on the floor and grasped one of the vertical gumfoot threads with her legs (reclining-style). The wasp picked the thread with her legs, feigning a captured and struggling prey. Although this behaviour seems to be a variety of the ambush style, it is quite similar to that of a wandering and captured wingless insect, and it seems an adaptation to the host being hidden in a complex web. As the wasp touched the gumfoot directly, this suggests the possession of behavioural or morphological mechanisms for avoiding entrapment by the sticky masses on the web. Diversity in mode of attack correlates with the fact that the spider constructs webs of various forms in a variety of situations. Digital video images relating to the article are available at http://www.momo-p.com/showdetail-e.php?movieid=momo100416za03a, http://www.momo-p.com/showdetail-e.php?movieid=momo100415za01a, http://www.momo-p.com/showdetail-e.php?movieid=momo100416za01a, and http://www.momo-p.com/showdetail-e.php?movieid=momo100416za02a.

DOI： 10.1007/s10164-010-0263-8

Web of Science

Scopus

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MAGNOLIA PRESS  

Japanese species of the genus Zatypota are revised and a total of twelve species are recognized. Nine of them, Z. baragi sp. nov., Z. brachycera sp. nov., Z. chryssophaga sp. nov., Z. dendrobia sp. nov., Z. elegans sp. nov., Z. maculata sp. nov., Z. sulcata sp. nov., Z. takayu sp. nov. and Z. yambar sp. nov., are new to science and one, Z. percontatoria, is newly recorded from Japan. Host records are given for ten species including seven new and one newly recorded species based on reared materials. Each species utilizes different spider species as hosts. All host spiders belong to Theridiidae (nine species) and Linyphiidae (Z. sulcata). A key to Japanese species is provided and notes on their biology are given.

Web of Science

Scopus

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Oviposition behavior of Zatypota albicoxa (Walker) is described. This wasp parasitizes the house spider Achaearanea tepidariorum (Koch), which weaves irregular, three-dimensional webs. Based on field observations, two modes of oviposition behavior were recognized. In one, the wasp hung on the web, pulling the thread with its fore leg, until the spider lifted it up (ambush-style). In the other mode, the wasp climbed the web (climbing-style). Under laboratory conditions in an aquarium, the wasp hung on the web in mid height of the gumfoot thread as in the former style, then flew toward unaware spider and paralyzed it. After paralyzing, the wasp usually rubbed the spider's abdomen with its ovipositor and tip of metasoma repeatedly at short intervals for several minutes. In all cases they adopted the same posture in which they grasped the spider abdomen with fore and mid legs during oviposition. As female wasps emerged from larger hosts and male wasps emerged from smaller ones, the ovipositing wasp apparently assesses the size of the spider and chooses whether to lay a fertilized or an unfertilized egg. In addition, it was confirmed that Z. albicoxa expelled the eggs not from the tip of the ovipositor but from the tip of its abdomen, as in other species of the Polysphincta group (e.g. Hymenoepimecis argyraphaga, Reclinervellus tuberculatus and Schizopyga circulator).

DOI： 10.1111/j.1479-8298.2009.00338.x

Web of Science

Scopus

Language：Japanese   Publisher：日本生物科学者協会 ; 1949-  

File： 髙須賀 網操作総説 生物科学2015 Vol.66(2) 89-100.pdf

CiNii Books

CiNii Research

File： Kachofugetsu 160 14-18.pdf

CiNii Research

CiNii Research

Language：Japanese  

File： 松山市産真正クモ類目録（第2版）.pdf

CiNii Research

Language：Japanese   Publisher：ニューサイエンス社  

File： 産卵にまつわる諸戦略（２）.PDF

CiNii Books

File： クモに寄生するハチ.PDF

Language：Japanese   Publisher：ニューサイエンス社  

File： 産卵にまつわる諸戦略（１）.PDF

CiNii Books

File： スラウェシ.PDF

Publisher：愛媛大学農学部附属演習林  

アメリカ合衆国アラスカ州の北緯66〜70°において、2006年8月2日から8月6日にかけて空中と地表部の昆虫を採集し、目単位の昆虫総数、その組成および1m2あたりの個体密度をそれぞれ求め、緯度の違いに伴う変化を考察した。空中の採集にはトラックトラップを、地表部の採集にはスイーピングを用いた。各緯度の空中で採集した昆虫の捕獲数は、北緯68°の森林限界を境に大きく減少し、さらに今回調査をした中で最も高緯度であった北緯70°では皆無であり、緯度と昆虫捕獲数との間に有意な負の相関が認められた。空中では常に双翅目の占める割合が著しく大きかったことに比べ、地表部では南部においてその割合が小さかった。つまり、地表部では昆虫相が多様でも空中へ飛翔する昆虫の多くは双翅目であると言える。しかし、地表部でも緯度の上昇に伴って、双翅目の占める割合が大きくなり、緯度の上昇に伴い昆虫相が単純化した。
identifier:772111
identifier:ZZ00007949

File： アラスカにおける緯度の違いに伴う地表と空中の昆虫相の遷移.pdf

CiNii Books

CiNii Research