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THE RED-STRIPED SPIDER

(BY W. J. RAINBOW, F.L.S., F.E.S.)

The red-striped spider of Australia is not only one of our commonest endemic Arach- nids, but one possessing an evil reputation owing to the potency and activity of its venom. It is a ubiquitous beast, seeing that it occurs not only in every State of our Commonwealth, but also throughout India, Malaysia, the Philippines, New Guinea, New Zealand, the South Sea Islands generally, and even Egypt. In New Zealand it is known as the Katipo, or "night-stinger." Naturalists all the world over know it as Latrodectus hassellti.

The genus Latrodectus is represented In all   tropical, sub-tropical, and temperate regions; the species are few, but the individuals are many, and all have a more or less notorious reputation. All the species are satiny black, with bright red markings. The form peculiar to Central Europe has 13 red spots; the Chi- lian example several short transverse median bars; and the Australian species a broad longitudinal bar running nearly the entire length of the abdomen, with frequently 3mall lateral spots or patches. Ludwig Koch, the great German arachnologist, described what he regarded as two distinct species from Aus- tralia-one of which he named "hassellti," and the other "scelio." The lastnamed, how over, is only a variety of the former, and not

a constant one at that.

Owing to their venomous nature, the spiders included in the genus Latrodectus have at- tracted attention, wherever they occur; but none have been more systematically studied than Lactrodeetus formidabills, of Chili, and L. 13-guttatus, of S. Europe. In respect of the latter species, Totti recorded two fatal cases from bites-one in 23 hours, and the other in 42. In 1891 a man died at Welling- ton, New Zealand, from an alleged katipo bite, but the inquest disclosed the fact that "erysipelas" had supervened. As far back as 1842 Dr. Shortland, of New Zealand, recorded several cases, some of which "came perilous- ly near death."

Although one hears, from time to time, of numerous eases of suffering, and even occas- ionally death as resulting from the bite of the red-striped spider, few official or au- thenticated records of illness are known, and certainly none of fatal results. Mr. J. W. Fawcett, of Townsville, N. Queensland, In writing of the effects in human beings of the bite of this spider, says:-"Its bite is fol- lowed by pricking sensations about the bitten spot, and violent pain, paralysis or numbness and loss of power in limbs and body succeed, followed ofton by utter prostration. The bit- ten person frequently fools tho venom work- ing Its way nil over the system. These symp- toms generally last for two or three days, when, it the patient is of good constitution, a profuso cold porsplratlou, often necessitat- ing many changes of garments or bod clothes, ensues, together with great Irrita- tion of tho skin, especially about the bitten spot. Tho virus or venom of thia Bpider,

which only exists it-very minute quantltlcs, 1s proportionately moro powerful than snake poison." Dr. Tidswell, Mlcroblologlst to the Board of Health of New South Wales, who kindly undertook at my request an Investi- gation Into the venom of our L. hassellti, has recently published a preliminary note, in the course of which ho remarks:-"From the fow accounts available tho poison appears to bo capable of causing pretty severe suffering. Tho most striking feature seoma to be tho

I rapid development of ncute pains, especially

in the lower limbs, but also in tho a'bdomen and proeardial region. These are accom- panied or followed by tremors, paresis, or paralysis of the limbs. The patients aro restless, delirious, or depressed and lethargic. Clammy perspiration, pallor, and syncopal 1 symptoms Indícalo a tendency to collapse. The occurrence of jaundice Is recorded. The ncute Illness is said to last throe or four days, but it is noted that complete recovery may not occur till weeks after tho bite. Various skin lesions, such as erythromatous raahes, papulae, veslel.s, pustules, otc, may occur during the protracted convalescence."

DurlLg the course of preliminary investiga [ lions a number of experiments were made by Dr. Tidswell, and witnessed by me. These included injecting extracts of the crushed (spiders') hoads, and allowing living spiders to blto a mouso and soveral rabbits. The "In- jecting" experiments proved unsatisfactory, but the animals bltton suffered more or less acutely. Of tno "biting" experiments Dr. (Tidswell concludes:

I "Tho crude _aethod of observation Is ob- viously Inadequate to elucidato the physio-

logical action uf tho spider venom, and failed | oven to secure reproduction of tho leading j symptoms observoj in human beings. The mouso was certainly oick, but tho rabbits appeared to have suffered only from local effects of the venom. The roaults may, how

, over, be taken as Indicating the improbability ¡

of a fatal lssuo from poisoning by Latro- : , doctus hassellti."

Tbero is one feature almost Invariably over- I 'looked in connection with the bites of alleged noxious animals, whore human beings are concerned, namely, the clement of fear. Doubt I loss this fact may account for much differ | once In symptoms displayed by man and tho

lower animals. Tho ovil effocts of injury sustained by the former may bo greatly in- fluenced by mental agony and suspicion-from I fright in fact, produced by Imagination, or

! the rcmembraneo of weird tales. With the | ! lower animals this is obviously not the case. | j The red-striped spider is common about old j

lumbor and rubbl-h. neglected outhouses," old . i fences, hollowB ii. old trees, empty boxes and ]

tins; in fact, anywhoro dark and noisome. | During tho day it generally lies In conceal- ' mont, but at night it fabricates its snare, which is set for the capturo of prey. Tho lattor et na!sts of various kinds of Insects, j somo of which aro often much larger than 'itself. Iil'.o all spiders, it Is a cannibal; it ?will glvo buttle to any of Its own specKs

¡venturing within the precincts ot Its domi-, ! olio, and if victorious, devour It. On tho i othor hand, if it falls to maintain Its own, It I will fall as proy to the intruder. The fe-

male Is much larger than the male, and tho latter has to bo vory careful, soo

i lng that If Iho lady disapproves ßho j i will oat him. In wob-buiidlng the I mulo taken no part, hut if successful in winning the lady's favour, will condescend to llvo upon tho proceeds resulting from the "fair" architect's Industry. The cocoons, usunlly about half a dozen, aro strung upon tho wob. They nro tough, round, yellowin, and full it eggs. When the young have hatchod out they aro at first groy, with dark spots about tho body and logs. During Im- maturity each spiderling moults soveral times. With each moult It gradually assumes a darker colour, until tho natural adult hues are obtained. The red marking at first ap- pears as a small spot, then, as the spider becomes older it assumes a series of dots, and these eventually merge into the charac- teristic broad red stripe. Although hun-   dreds ot spidcrllngs hatch out from the eggs contained in each cocoon, comparatively few nrrlve at maturity. Somo die n.-urnlly, others fall a proy to othor spiders, or natural enemies, and many die a_ n result of thoir inheront cannibalism, for not only do thoy fight and oat ono another, but many aro I devoured by the males when prowling.

In furtherance of experiments still nocos 1 aiiry tho writer will bo glad to receive living |Bpeclmens ot thlB spider._

Digitisation generously supported by
Vincent Fairfax Family Foundation
Digitisation generously supported by

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