Two of Clairville Hydroporus

Two new species of Hydroporus Clairville (Coleoptera, Dytiscidae) from Siberia

ANDERS N. NILSSON

Nilsson, A. N.: Two new species of Hydroporus Clairville (Coleoptera, Dytiscidae) from Siberia. [Två nya Hydroporus-arter (Coleoptera, Dytiscidae) från Sibirien.] — Ent. Tidskr.

I 1 1: 33-37. Umeå, Sweden 1990. ISSN 0013-886x.

Hydroporus angusi n.sp. and H. ^yakutiae n.sp. are both described from Siberia. H. ^angusi was found in small taiga pools W of Lake Baikal. This species is very close to H. ^neglectus Schaum from which it differs in the simple male protarsal claws and the shape of the male genitalia. H. yakutiae was found in mossy pools in forest tundra about 400 km W of the Lena river. This species is most similar to H. elongatulus Sturm, from which it differs in the larger size and more elongated male protarsal claws.

A. N. Nilsson, Department of Animal Ecology, University of Umeå, S-901 87 Umeå, Sweden.

Introduction

There is at present only a very limited amount of aquatic Coleoptera from Siberia available for study, and this limitation is particularly striking when the vast area and high diversity of wetlands of Siberia are considered. Most probably the Sibe- rian fauna includes a large number of undescribed species, especially in the large dytiscid genera Agabus Leach and Hydroporus Clairville, which are particularly diverse at high latitudes, and have many species of very similar habitus.

During two visits to Siberia in 1970 and 1982 Dr Robert B. Angus, the well-known British spe- cialist on Helophorus, collected some dytiscids in various regions. One species, Agabus vereschagi- nae, has already been described from this material (Angus 1986). The study of a part of the material of Hydroporus has revealed two new species from Siberia, described below. Siberian Dytiscidae were revised most recently by Zaitsev (1953).

De scriptions

Hydroporus angusi n.sp.

Figs 1, 3, 5, 6, 11, 14.

Type locality: Siberia, Buryat ASSR, Irkut valley by Tunka.

Type material: Holotype d labelled "Siberia.

Buryat ASSR. Tunka Irkut valley. 90 km W of L.

Baikal R.B. Angus 12.vi.70" and my holotype la- bel. — Paratypes 2 9, one with same original label as holotype, the other one labelled "Siberia. Ir- kutsk obl. Tibelti Irkut valley 28 km W of L.

Baikal R.B. Angus 8-15.vi.70" and my paratype labels.

Type depository: Holotype and Tibelti paratype in the Zoological Institute of the Academy of Sciences of the USSR, Leningrad. Tunka paratype in the British Museum (Natural History), London.

Etymology: The species is named after its discov- erer Dr Robert B. Angus, London.

Diagnosis. A small, narrow species with dorsum rufous. The posteriorly narrowed pronotum gives the lateral outline an evident constriction. Meta- coxal processes with posterior margin conjointly bisinuate. Male protarsal claws simple; aedeagus laterally flanged; paramere with apex twisted and hooked towards subapical dorsal process.

Description

Size and shape. Total length of body 2.38-2.54 mm; maximum body width 1.17-1.23 mm. Body elongate oval, lateral outline with evident con- striction at level of base of pronotum (Fig. 1).

Two new species of Hydroporus Clairville (Coleoptera, Dytiscidae)frOm siberia

ANDERS N NILSSON

Nilsson, A. N.: Two new species of Hydroporus Clairville (Coleoptera, Dytiscidae) from Siberia. [Tvfl nya Hydroporus-arrer (Coleoptera, Dytiscidae) frAn Sibirien.]

-

Ent. Tidskr.

I I l: 33-37. UmeA, Sweden 1990. ISSN 0013-886x.

Hydroporus angnsi n.sp. and H. yakutiae n.sp. are both described from Siberia. H. angusi was found in small taiga pools W of Lake Baikal. This species is very close to H. neglectus Schaum from which it differs in the simple male protarsal claws and the shape of the male genitalia. H. yakutiae was found in mossy pools in forest tundra about 400 km W of the Lena river. This species is most similar to H. elongatulns Sturm, from which it differs in the larger size and more elongated male protarsal claws.

A. N. Nilsson, Department of Animal Ec'ology, University of Ume,i, S-901 87 Umed, Su'eden.

Type material: Holotype

d

^labelled "Siberia.

Buryat ASSR. Tunka Irkut valley. 90 km W of L.

Baikal R.B. Angus 12.vi.70" and my holotype la- bel.

-

^{Paratypes 2 9, one with same original label}

as holotype, the other one labelled "Siberia. Ir- kutsk obl. Tibelti Irkut valley 28 km W of L.

Baikal R.B. Angus 8-15.vi.70" and my paratype labels.

Type depository: Holotype and Tibelti paratype

in the Zoological Institute

of

the Academy of

Sciences of the USSR, Leningrad. Tunka paratype in the British Museum (Natural History), London.

Etymology: The species is named after its discov- erer Dr Robert B. Angus, London.

Diagnosis. A small, nalrow species with dorsum rufous. The posteriorly narrowed pronotum gives the lateral outline an evident constriction. Meta- coxal processes with posterior margin conjointly bisinuate. Male protarsal claws simple; aedeagus laterally flanged; paramere with apex twisted and hooked towards subapical dorsal process.

Description

Size and shape. Total length of body 2.38-2.54 mm; maximum body width l.l7-1.23 mm. Body elongate oval, lateral outline with evident con- striction at level of base of pronotum (Fig. l).

Introduction

There is at present only a very limited amount of aquatic Coleoptera from Siberia available for study, and this limitation is particularly striking when the vast area and high diversity of wetlands of Siberia are considered. Most probably the Sibe- rian fauna includes a large number of undescribed species, especially in the large dytiscid genera Agabus Leach and Hydroporus Clairville, which are particularly diverse at high latitudes, and have many species of very similar habitus.

During two visits to Siberia in ^{1970 and 1982} Dr Robert B. Angus, the well-known British spe- cialist on Helophorus, collected some dytiscids in various regions. One species, Agabus veresc'hag,i- nae,has already been described from this material (Angus 1986). The study of a part of the material of Hydroporus has revealed two new species from Siberia, described below. Siberian Dytiscidae were revised most recently by Zaitsev (1953).

Descriptions

Hydroporus angusi n.sp.

Figs l, 3. 5,6, I I, ^14.

Type locality: Siberia, Buryat ASSR, Irkut valley by Tunka.

34 Anders N. Nilsson

Figs 1-4. Hydroporus. — 1-2. Outline of body. — 1. H.

angusi n.sp., holotype. — 2. H. yakutiae n.sp., holotype.

— 3-4. Male protarsomere 5 with claws, lateral aspect.

— 3. H. angusi, holotype. — 4. H. yakutiae, holotype.

Vertical scale bar 1.0 mm (Figs 1-2); horizontal scale bar 0.1 mm (Figs 3-4).

Pronotum with maximum width anterior to poste- rior angles.

Colour. Head rufous. Antenna basally testaceous;

segments 4-11 gradually darker brown in distal 2/3. Palpi testaceous; apically pale brown. Prono- tum and elytron nifous; sutural margin subapically piceous. Ventral surface mainly black; proster- num, hypomeron, epipleuron, metacoxal proces- ses and posterior margin of each abdominal ster- num rufous. Legs rufous.

Sculpture. Dorsal surface with fine microreticula- tion and sparse punctation; disc of pronotum with few punctures, some of which are very small; ely- tron with punctures relatively large and sparse.

Prosternal process smooth. Metastemum, meta- coxal plate, and abdominal stema 1-2 with fine microreticulation and coarse punctures about 4 meshes apart. Abdominal stema 3-6 with very fine microreticulation and very sparse punctation.

Structural features. Antenna relatively short. Pro- notum with narrow but well-defined lateral bead;

disc convex. Prosternal process narrow, of low

even convexity, with lateral bead well-defined;

subbasally with low transverse ridge. Metacoxal lines only slightly diverging anteriad; posterior margin of processes conjointly bisinuate.

Sexual features. Male protarsal claws simple (Fig.

3); pro- and mesotarsi not dilated; aedeagus later- ally expanded in distal half (Fig. 5), apex pointed and ventrally deflected (Fig. 6); paramere with subapical dorsal process, apex twisted and hooked (Fig. 11). Female gonocoxostemum as in Fig. 14.

Habitat

The species was collected in small woodland pools, probably in wet spruce forest. At Tibelti the pools were in the taiga near the village, and the type locality is due N of Tunka in the taiga near Arshan, in the foothills of the mountain range Tunkinskiye Goltsy.

Hydroporus yakutiae n.sp.

Figs 2, 4, 9, 10, 13, 16.

Type locality: Siberia, Yakutskaja ASSR, Olen- jok.

Type material: Holotype d labelled "Siberia. Ya- kutia. Olen&. R.B. Angus. 18-19.vii.70", and my holotype label. — Paratype 9 with same original label as holotype and my paralectotype label.

Type depository: Holotype and paratype in the Zoological Institute of the Academy of Sciences of the USSR, Leningrad.

Etymology: The species is named after the type area Yakutia, put in the genitive case.

Diagnosis. A medium-sized species with dorsum dark rufous and pronotum broad with lateral mar- gin curved and only narrowly beaded. Male pro- tarsal claws long.

Description

Size and shape. Total body length 3.55-3.94 mm;

maximum body width 1.83-2.15 mm. Body elongate oval with pronotum broad and lateral out- line with evident constriction at level of elytral base (Fig. 2).

Colour. Head dark rufous. Antenna basally testa- ceous; segments 4-11 more or less brown in distal 2/3. Palpi testaceous. Pronotum rufopiceous; later- al margin broadly rufous. Elytron rufopiceous; ba- sally and laterally rufous. Gena and gula rufous.

34

ス″″′

€3

Figs l-4. Hydroporus.

-

^l-2. Outline of body.

-

^{l. H.}

angusi n.sp., holotype. - ^{2. H. yakutiae n.sp., holotype.}

-

3-4. Male protarsomere 5 with claws, lateral aspect.

-

^{3. H.} argasi, holotype.

-

^{4. H. yakutiae, holotype.}

Vertical scale bar 1.0 mm (Figs l-2); horizontal scale bar 0.1 mm (Figs 3-4).

Pronotum with maximum width anterior to poste- rior angles.

Colour. Head rufous. Antenna basally testaceous;

segments 4-l

I

gradually darker brown in distal 213. Palpi testaceous; apically pale brown. Prono- tum and elytron rufous; sutural margin subapically piceous. Ventral surface mainly black; proster- num, hypomeron, epipleuron, metacoxal proces- ses and posterior margin of each abdominal ster- num rufous. Legs rufous.

Sculpture. Dorsal surface with fine microreticula- tion and sparse punctation; disc of pronotum with few punctures, some of which are very small; ely- tron with punctures relatively large and sparse.

Prostemal process smooth. Metastemum, meta- coxal plate, and abdominal sterna

l-2

^with fine microreticulation and coarse punctures about 4 meshes apart. Abdominal stema 3-6 with very fine microreticulation and very sparse punctation.

Structural feafures. ^Antenna relatively short. Pro- notum with narrow but well-defined lateral bead;

disc convex. Prostemal process narrow, of low

even convexity, with lateral bead well-defined;

subbasally with low transverse ridge. Metacoxal lines only slightly diverging anteriad; posterior margin of processes conjointly bisinuate.

Sexual features. Male protarsal claws simple (Fig.

3); pro- and mesotarsi not dilated; aedeagus later- ally expanded in distal half (Fig. 5), apex pointed and ventrally deflected (Fig. 6); paramere with subapical dorsal process, apex twisted and hooked (Fig. I l). Female gonocoxostemum as in Fig. 14.

Habitat

The species was collected

in

small woodland pools, probably in wet spruce forest. At Tibelti the pools were in the taiga near the village, and the type locality is due N of Tunka in the taiga near Arshan, in the foothills of the mountain range Tunkinskiye Goltsy.

Hydroporus yakutiae n.sp.

Figs 2,4,9, 10, 13, 16.

Type locality: Siberia, Yakutskaja ASSR, Olen- jok.

Type material: Holotype d labelled "siberia. _Ya- kutia. Olen€k. R.B. Angus. 18-19.vii.70", and my holotype label.

-

^Paratype

I

^{with same original}

label as holotype and my paralectotype label.

Type depository: Holotype and paratype in the Zoological Institute of the Academy of Sciences of the USSR, Leningrad.

Etymology: The species is named after the type area Yakutia. put in the genitive case.

Diagnosis. A medium-sized species with dorsum dark rufous and pronotum broad with lateral mar- gin curved and only narrowly beaded. Male pro- tarsal claws long.

Description

Size and shape.Total body length 3.55-3.94 mm;

maximum body width 1.83-2.15 mm. Body elongate oval with pronotum broad and lateral out- line with evident constriction at level of elytral base (Fig. 2).

Colour. Head dark rufous. Antenna basally testa- ceous; segments 4-l I more or less brown in distal 213. Palpi testaceous. Pronotum rufopiceous; later- al margin broadly rufous. Elytron rufopiceous; ba- sally and laterally rufous. Gena and gula rufous.

Figs 5-10. Hydroporus, aedeagus in dorsal (5,7,9) _and lateral (6, 8, 10) aspect. -54. H. angusi n.sp., holotype.

-

^{7-8. H.} neglectus Schaum, Sweden, VB: Vindeln.

-

9-10. H. yakutiae n.sp., holotype. Scale bar 0.1 mm.

Ventral surface mainly dark rufous; metastemum and -coxa dark rufopiceous. Legs rufous.

S<'ulpture. Dorsal surface microreticulate, lines of

meshes relatively deeply impressed, slightly more so in female. Head with punctation fine. Pronotum with punctation coarse and dense along anterior and posterior margin; on disc fine and punctures about 4-5 ^meshes apa(. Elytron with ^punctures relatively large and not deeply impressed, about 2-3 meshes apart; each puncture with long whitish seta. Prostemal process subrugose. Ventral surface

with microreticulation. Metastemal wing, meta- coxal plate and abdominal stema

l-2

with large, not very deeply impressed punctures; punctation fine on stema 3-6.

Ａ Ｗ 鵬

9

New Hydroporus from Siberia ³⁵

Figs ll-13. Hydroporus, paramere, extemal aspect.

- ll.

H. angusi n.sp., holotype.

-

^{12. H. neglectus}

Schaum, Sweden, VB: Vindeln.

-

^13. H. yakutiae n.sp., holotype. Scale bar 0.1 mm.

Structural features. ^Antenna relatively long. Pro- notum with very narrow lateral bead; lateral mar- gin curved with maximum width slightly anterior to posteriorly slightly deflexed obtuse hind angles;

disc convex. Elytral margin slightly ascending to humeral angle. Prostemal process basally with transverse grooves, neck with transverse ridge;

distal portion of relatively low even convexity, lateral bead well-defined, apex blunt. Metacoxal lines very slightly diverging anteriad, subparallel.

Metacoxal processes conjointly with posterior margin truncate.

Sexual features. Male pro- and mesotarsomeres

l-

3 dilated; basal tarsomeres each bearing two pairs

of oval scales beneath, and second tarsomeres each with one pair; protarsomere 3 about 0.8

x

as broad as long, slightly narrower than tarsomere 2; protarsal claws long, about 0.8 X as long as the claw-bearing segment, with basal ventral expan- sions and subapically subarcuate (Fig. 4); ^aedea- gus broad with slightly curved sides suddenly contracting to an obtuse apical point (Figs 9, l0);

paramere as in Fig. 13. Fernale gonocoxostemum as in Fig. 16.

Habitat

The species was collected in mossy and swampy pools on flatland by the Olen6k river near the village of OlenEk. This site is in the forest tundra region with Larix dahurica.

／

／

︲

36

Anders N. Nilsson

Discussion

The new species H. angusi is very similar to the Palaearctic

H.

neglectus Schaum. Synapomor- phies that unite these two species are the laterally flanged, bulbous aedeagus (Figs 5-8) and the cal-

liper-like apex

of

the paramere (Figs 11, 12).

However, both structures have a species-specific shape in spite of their general similarity. Besides male genitalia, H. angusi differs from H. neglectus chiefly in the following characters:

(l)

male pro- tarsal claws simple; (2) head, pronotum and elyt- ron of about same colour; (3) antenna shorter and more robust; (4) elytron with microreticulation less deeply impressed and punctation sparser; (5) metastemum, -coxae and abdominal stema l-2

with punctation coarser; (6) female gonocoxoster- num basally rounded, not truncate (Figs 14, l5).

The posterior margin of the metacoxal proces- ses are conjointly bisinuate in both ^species (Foster

&

^{Angus 1985:5} for drawing of H. neglectus).

This character together with the relatively short metacoxal lines made Guignot (1945) erect the subgenus Hydroporinus with H. neglectus as type.

Later, Guignot ⁽¹⁹ 49) synonymized Hy dr o p or i nus

with Sternoporas Falkenstr6m. Based on larval characters, Nilsson (1989) characterized H. neg- lectus as one of the most plesiomorphic species of Palaearctic Hydroporus, and synonymized both Hydroporinus and Sternoporas with Hydroporus (s.str. ).

The distribution of H. neglectus is northern and central European. The only Siberian record known to me is that given by Zaitsev (1953:176) from the westem part. This record should be checked as it may be based on a misidentification of H. an- gusi.

H. yakutiae is in its habitus rather similar to the Palaearctic H. elongatulu.s Sturm. In both species, the pronotum is slightly broader than the elytral base, with a very narrow or obsolete lateral bead, a convex disc, and posterior angles slightly pro- jecting posteriad. The elytral pubescense is also strong in both species, and the male genitalia are of the same general shape. However, the following characters separate H. yakutiae from H. elong,atu- /as:

(l)

male protarsal claws equal, and 0.8

x

as long as the distal protarsomere; (2) aedeagus with apex narrower in lateral view; (3) body larger; (4) dorsal surface dark rufous without evident differ- ence between pronotum and elytron; (5) dorsal surface with microreticulation more deeply engra-

Figs 14-16. Hydroporus, female gonocoxostemum, dor- sal aspect,

-

^{14. H. angusi n.sp., paratype from Tunka.}

-

^{15. H.} neglectus Schaum, Sweden, VB: Vindeln.

-

16. H. yakutiae n.sp., paratype. Scale bar 0.1 mm.

ved. Detailed descriptions of H. elongatulus were

provided

by

Falkenstr<rm (1930) and Foster (r976).

H. elongatulus is a very rare species in North and Central Europe. The only Siberian record is a unique specimen from Nikolskaja by the Lena river described by Poppius (1905) as Hydroporus lenensis. The male holotype of H. lenensis (in University Zool. Mus., Helsinki) is of the same size as H. elongatulus. The specimen is teneral, but the shape of the male protarsal claws and the aedeagus must be considered bery similar to that of H. elongatulus. As the head of H. lenensis ^is markedly smaller than in H. elongatulus, I am still not sure

if it

is the same species or not. More material of H. lenensis is needed to settle this question.

Acknowledgements. I thank Dr Robert B. Angus, Lon- don, for the opportunity to describe the two species and for valuable help with the preparation of the manuscript.

Dr O. Bistr<im, Helsinki, is thanked for the loan of the holotype of Hydroporus lenensis.

References

Angus, R. B. 1986. A new Siberian Agabus Leach, with notes on the other species with clubbed male antennae (Coleoptera: Dytiscidae).

-

^{Ent. scand. 15:193J02.}

Falkenstrcim, G. 1930. Stockholmstraktens Vatten-Co- leoptera. Fjiirde tilliigget.

-

Ent. Tidskr. 51: 143-

159.

Foster, G. N. 1977. Hydroporus elongatulus Sturm (Col., Dytiscidae) new to Britain.

-

Entomologist's mon. Mag. ll2(1976): l3-18.

Foster, G. N. & ^{Angus, R. B.}

species of Hydroporus.

Newsletter 33: 1-19.

-

1985. Key to British Balfour-Browne Club

Guignot, F. 1945. Dix-huitdme note sur les Hydrocant- hares.

-

^{Bull. Soc. ent. Fr. 50: 18-23.}

Guignot, F. 1949. Note sur les Hydrocanthares (Vingt- neuviEme note).

-

^{Bull. Inst. R. Sci. Nat. Belg.}

25(26): l-18.

Nilsson, A. N. 1989. Larvae of northem European Hyd- roporus (Coleoptera: Dytiscidae).

-

^{Syst. Ent. 14:}

99-r r 5.

New Hydroporus from Siberia ³⁷

Poppius, B. 1905. Beitriige zur Kenntniss der Coleopte- ren-Fauna des Lena-Thales in Ost-Sibirien. I. Halipli dae und Dytiscidae.

-

Ofv. Finska Vet.-Soc. frir- handl. 47: l-24.

Zaitsev, F. A. ^{1953. Nasekomye} zhestkokrylye. Pla- vuntsovye i vertyachki.

-

Fauna SSSR, New ser. 58:

1-376.

Insekters

sasonganpassningar

Tauber, M. J., Tauber, C. A. & Masaki, S. 1986.

Seasonal adaptations of insects. Oxford Univer- sity Press, New York, Oxford. 4l

I

sid. ISBN 0-

19-503635-2. Pris 65 USD.

Danks, H. V. 1987. Insect dormanc'y: An ec'ologi- c'al perspec'tile. Biological Survey

of

Canada (Terrestrial Arthropods), Ottawa 439 sid. ISBN 0- 9692121-0-7. Pris 50 CAD.

PA vAra breddgrader ar stdrre delen av Aret oglist- viinligt fijr insekter. Kyla och fcidobrist gtir att de flesta arter inte klarar av ett aktivt liv under vinter- halvAret. I andra delar av viirlden kan insekters liv hdmmas av t ex torrtider. Ibland kan levnadsbe- tingelserna ocksA variera mycket starkt mellan ^er.

SA t ex har vissa vflxter mycket stor variation i frrimiingd frfln Ar

till

^Ar, vilket gcir att insekten maste dverleva flera 6r utan frida.

Principiellt sett finns det tvA metoder att 6ver- leva sv6ra fdrhflllanden. Fdr det fdrsta kan insek- ten migrera till en annan, b?ittre miljci. Tack vare sina vingar har insekter goda mtijligheter till detta.

Det sker vanligen i lokal eller regional skala, men i vissa fall migrerar insekter 6ver hela kontinenter precis som flyttfAglar.

Den andra mcijligheten att klara perioder med dAliga fiirhAllanden dr att ^ga

i

^vila

-

^dormans.

Vanligen dr denna vila av ett slag som kallas dia- paus, vilket innebiir att vilstadiet ^utlOses av nigon omviirldssignal en tid innan miljtin fcirsiimras. I minga fall kombineras diapaus och migration, t ^ex genom att insekten migrerar till och frAn tjvervint- ringslokaler.

Hos mlnga fjiirilar som 6vervintrar i..puppsta- diet s[ iir larven kiinslig fdr dagsliingd. Ar ljuspe- rioden kortare en ett visst kritiskt viirde sfl bildas diapauspuppor vilka tivervintrar, iir dagen ^l2ingre sA utvecklas puppan snabbt och ger upphov till ^en ny generation. Det finns alltsA en signal (dags- liingd) som under ett kiinsligt stadium (hiir _larven)

inducerar ett diapausstadium (hiir puppan) vilket intrliffar senare

i

utvecklingen (Fig. I ). Det ^sker en utveckling under diapausen, kallad diapausut- veckling, och efter nAgra minader blir puppan okiinslig fcir dagsliingd. Under resten av vintem utvecklas puppan lAngsamt

till

fdljd av den lAga temperaturen. Men i och med stigande temperatur

pA vAren tjkar utvecklingshastigheten snabbt.

Denna fas under vinter och vAr kallas postdia- pausutveckling (Fig. 1).

КANSL10 PER100

DlAPAuS― POsTDlAPAUS―

UTVECKL UTVECКLINC

Fig. 1. Insekten utnyttjar under sitt liv mAnga omviirlds- signaler frir att reglera sin utvecklingstakt och gdra av- viigningar mellan perioder av tillviixt, vila och fortplant- ning. Bilden visar livscykeln hos en diapauserande insekt och illustrerar nAgra grundl?iggande begrepp.

Jag har skisserat ett enkelt typfall fdr att illust- rera nflgra begrepp.

I

sjillva verket ar variationen stor mellan arter. Frirutom dagsliingd anviinds ofta temperatur, och ibland fdda eller fuktighet, som signaler. Alla utvecklingsstadier kan vara kiinsliga fdr diapausinduktion. Ibland kan den kiinsliga pe- rioden t o m intriiffa en generation

i

fdrviig ^(dvs hos modern). Insekter kan diapausera

i

alla ut- vecklingstadier frfln iigg till imago. Vidare piver- kas fcirloppet av stviil diapaus som postdiapaus

ofta av olika direkt verkande omviirldsfaktorer (Fig. 1).

Ovan nAmnda generaliseringar baseras pfl en i dag mycket omfattande litteratur. Gliidjande nog har flera sammanfattande bdcker producerats un- der flrens lopp. Av tidigare bbcker utgdr A. S.

Danilevskiis bok "Photoperiodism and seasonal development

of

insects", som utkom

i

^engelsk

SICNALER