Bijdragen tot de Dierkunde, 55 (1): 177-180 — 1985

Stadial distributions of Moreleti at different

altitudes in Madeira with reference to life history

phenomena(Diplopoda; )

by

Helen J. Read

Zoology Department, University of Manchester, Manchester, England*

of Abstract some method controlling the spread of the

pest. is a julid native of Spain and the several of Portugal. It has been introduced into , where it During present study, aspects

the of O. moreleti with has become a considerable pest, and also into Madeira, ecology were investigated,

where it is be the now reported to commonest of features. species special emphasis on life cycle millipede.

In April and August 1981 an expediton from the

METHODS University of Manchester Zoology Department visited

Madeira and collections of the made in species were a In 1981, Madeira was visited by expeditions from the of locations and habitats. The instar variety sex, and University of Manchester Zoology Department. Collec- dimensions of each individual were later determined. tions made in from were April and July to September, in The stadial distributions at different altitudes are given 21 locations on Madeira (mostly towards the east side of for April and August. the island), 5 on Deserta Grande and 5 on Porto Santo. A pattern is found with difference in altitude which made Collections were by pitfall trapping, hand and litter varies between the times ofthe studied. This variation year and of habitats and sampling encompassed a range is discussed with the climate ofdifferent reference to parts altitudes. of the island.

The sex, instar and dimensions of each individual were

determined (the instar in this species can be identified us-

ing the ocular field method described by Vachon (1947)

INTRODUCTION and Saudray 1953)).

moreleti Ommatoiulus (Lucas) is a julid millipede, STADIAL DISTRIBUTIONS indigenous to Spain and Portugal where it is

considered In 1953 comparatively rare. it was Effect ofaltitude in April discovered in at Port Lincoln. Fig. 1 illustrates the stadial distributions in Since then it has spread at an estimated rate of Two evident in this April. patterns are set of 200 m per year (Baker, 1978a), and has become

troublesome histograms. very in south-eastern Australia, by each altitude there be food Firstly, at appear to infesting and destroying crops. The species the first stadia two peaks, at V, VI or VII and has also been introduced at an earlier date into the second at stadia VIII, IX or X. These South Africa, the Azores and Madeira. On the prob-

latter ably correspond to two generations of . O.archipelago, Enghoff (1982) reported

O. moreleti is to in autumn moreleti to be by far the commonest species of thought oviposit (Baker, 1978b, and Metchnikoff, cited millipede. by Halkka, 1958), thus by April 1981, the 1980 The post-embryonic development, life cycle will have reached young stadia V-VIII and the and habits of this species in Australia have been 1979 stadia VIII-X. At the studied Baker young highest by (1978b) with a view to finding altitude there is a further peak at stadia XIII-

XIV which may be a third generation.

* at low altitudes the first Present address: Departments of Botany and Zoology, Secondly, (<200 m)

University of Bristol, Woodland Road, Bristol, England. generation has succeeded in reaching stadia VI 178 PROCEEDINGS 6th INTERNATIONAL CONGRESS OF MYRIAPODOLOGY

Fig. 1. Stadial distributions ofOmmatoiulus moreleti collected Fig. 2. Stadial distributions of Ommatoiulus moreleti collected

at different altitudes in April 1981. at different altitudes in August 1981.

whereas 600-900 it has to VIII, at m only Effect of altitude in August reached V to VI. Thus as altitude increases the

is earlier 2 shows stadial distributions in younger generation represented by Fig. August.

At the stadia; this is also true for the second genera- Two generations are again present.

correlation of altitudeand lowest the has tion. Statistically this height range youngest generation

is when tested stadia significantly negative us- only advanced one stadium from April to

correlation coefficient As altitude stadia have ing a Spearman rank August. increases, more

= been between these at (r, = -0.4266, df 272, p = <0.001). passed through dates, so

the lower 600-900 three stadia have covered. The older the generation the m been

due Animals altitudes catch with those numbers, perhaps to mortality or to a at higher up sampling bias, as only a representative sample lower down and may even surpass them. Thus of older animals was taken. This is unlikely to in August there is a significant shift to later affect of the reliability the histograms greatly, as stadia with rising altitude (Spearman rank cor-

it to stadia above those where the relation coefficient r = = = applies only s 0.3722, df 467, p peaks occur. <0.001). - 1985 179 BIJDRAGEN TOT DE DIERKUNDE, 55 (1)

lections were taken. Locations of weather sta-

tions and collecting sites are not identical,

for each however weather data are present

used in the height range analysis.

TABLE I

of climatic for and 1981 Summary data April August ac-

cording to altitude.

April August

Height Temp. Rainfall Temp. Rainfall

m °C mm °C mm

<200 16.1 76.2 21.5 3.1

300-500 12.9 121.6 17.9 22.6

600-900 11.4 196.8 18.4 6.1

>1400 312.9

>1700 13.4 16.2

that the thrive in Assuming warm

moist conditions (as seems to be the case in

culture experiments, unpubl. obs.) it could be

presumed that during the winter and early

the animals best in the lower spring grow

altitudes as these are with Fig. 3. Climate graphs for five places of differing altitude warm, temperatures

total rainfall month and around 16°C and have the (metres), showing per (mm) mean some rainfall, higher

from the Observatorio altitudes cold for much monthly temperature (°C) (data are probably too Meteriologico do Funchal). the late and growth. During spring summer,

the low altitudes have an increased temperature

and decreased rainfall so animals slow their THE ALTITUDE EFFECT AND CLIMATE and growth to a negligible rate probably

Madeira is 58 km 23 km loss. The island of long by aestivate to stop excessive water A more

maximum of 1862 m. climate with wide, reaching a height equable occurs higher up a

The coastal than the similar that low areas are usually warmer temperature to found at

inland For Funchal has the there is also regions. example altitudes during the winter; an

hottest of abundance time. mean monthly temperature 22°C, of water during this Growth and there is reduction in of 1°C and a temperature proceeds more rapidly here "catches up"

the middle altitudes of per 155 m. At a layer with that of the aestivating animals lower down.

cloud exists, above this, in summer, there is The differences in rates and periods of often whereas between observed altitudes be bright sunlight, growth at varying may

is November and May the mean temperature one of the factors enabling successful coloniza-

less than 10°C and below 0°C. The tion. This can drop species can respond to advantageous

climate graphs (fig. 3) show data from 1981 for conditions with increased growth and to

altitude. places of different adverse conditions by reduction in rate of

Table I summarises the climatic features of exist in wide growth; and may therefore a range

the for the months when col- of and altitudinal ranges areas habitats. 180 PROCEEDINGS 6th INTERNATIONAL CONGRESS OF MYRIAPODOLOGY

introduced in south-eastern ACKNOWLEDGEMENTS (Diplopoda: Iulidae),

Australia. J. Zool., Lond., 186: 209-228.

I should like to thank Mr. G. Blower for his and en- J. help 1982. The ENGHOFF, H., millipede this I also throughout study. am grateful couragement — very on Madeira an insular species swarm (Diplopoda, to Dr. L. M. Cook, L. A. Lace, M. J. Jones, and all the : Julidae). Entomologica scand. Suppl., 18: other members of the 1981 Madeira for expeditions to 1-142. their help in collecting specimens, to C. P. Wheater and HALKKA, R., 1958. Life history of sabu- also to Dr. Biscoito for making the meteorological data losum (L.) (Diplopoda, Iulidae). Annls. zool. Soc. available to me. zool. bot. fenn. "Vanamo", 19 (4): 1-72.

SAUDRAY, Y., 1953. Developpement post-embryonnaire

d'un Iulide indigene Cylindroiulus (Aneuloboiulus) REFERENCES silvarum Meinert. Archs. Zool. 89 exp. gen., (Not.

BAKER, G. H., 1978a. The distribution and dispersal of Revue): 1-14.

1947. Contribution l'etude the introduced millipede, Ommatoiulus moreletii VACHON, M., a du developpe-

(Diplopoda: Iulidae), in Australia. J. Zool., Lond., ment post-embryonnaire de Pachybolus ligulatus

185: 1-11. Voges (Myriapodes, Diplopodes, Spirobolides). Les

de la croissance. Annls. Sci. , 1978b. The post-embryonic development and life etapes nat., (Zool., 11)

history of the millipede, Ommatoiulus moreletii 9: 109-121.