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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 small 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 feels the venom work- ing its way all over the system. These symp- toms generally last for two or three days, when, it the patient is of good constitution, a profuse cold perspiration, often necessitat- ing many changes of garments or bed clothes, ensues, together with great irrita- tion of the skin, especially about the bitten spot. The virus or venom of this spider,

which only exists in very minute quantities, is proportionately more powerful than snake poison." Dr. Tidswell, Microbiologist 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 he remarks:-"From the few accounts available the poison appears to be capable of causing pretty severe suffering. The most striking feature seems to be the

rapid development of acute pains, especially  

in the lower limbs, but also in the abdomen and precardial region. These are accom- panied or followed by tremors, paresis, or paralysis of the limbs. The patients are restless, delirious, or depressed and lethargic. Clammy perspiration, pallor, and syncopal symptoms indicate a tendency to collapse.   The occurrence of jaundice is recorded. The acute illness is said to last three or four days, but it is noted that complete recovery may not occur till weeks after the bite. Various skin lesions, such as erythromatous rashes, papulae, vesicles, pustules, etc, may occur during the protracted convalescence."

During the course of preliminary investiga- tions a number of experiments were made   by Dr. Tidswell, and witnessed by me. These included injecting extracts of the crushed (spiders') heads, and allowing living spiders to bite a mouse and several rabbits. The "in- jecting" experiments proved unsatisfactory, but the animals bitten suffered more or less acutely. Of the "biting" experiments Dr. Tidswell concludes:

"The crude method of observation is ob-   viously inadequate to elucidate the physio-

logical action of the spider venom, and failed   even to secure reproduction of the leading   symptoms observed in human beings. The mouse was certainly sick, but the rabbits appeared to have suffered only from local effects of the venom. The results may, how-

ever, be taken as indicating the improbability    

of a fatal issue from poisoning by Latro-   dectus hassellti."  

There is one feature almost invariably over-   looked in connection with the bites of alleged noxious animals, where human beings are concerned, namely, the element of fear. Doubt- less this fact may account for much differ-   ence in symptoms displayed by man and the  

lower animals. The evil effects of injury sustained by the former may be greatly in- fluenced by mental agony and suspicion—from fright in fact, produced byimagination, or    

the remembrance of weird tales. With the     lower animals this is obviously not the case.     jThe red-striped spider is common about old    

lumber and rubbish, neglected outhouses, old   fences, hollows in old trees, empty boxes and    

tins; in fact, anywhere dark and noisome.   During the day it generally lies in conceal-   ment, but at night it fabricates its snare, which is set for the capture of prey. The latter consists of various kinds of insects,   some of which are often much larger than   itself. Like all spiders, it is a cannibal; it will give battle to any of its own species

venturing within the precincts of its domi- cile, and if victorious, devour it. On the   other hand, if it falls to maintain its own, it   will fall as prey to the intruder. The fe-  

male is much larger than the male, and the latter has to be very careful, see-

ing that if the lady disapproves she     will eat him. In web-building the   male takes no part, but if successful in   winning the lady's favour, will condescend to live upon the proceeds resulting from the "fair" architect's industry. The cocoons, usually about half a dozen, are strung upon the web. They are tough, round, yellowish, and full of eggs. When the young have hatched out they are at first grey, with dark spots about the body and legs. During im- maturity each spiderling moults several times. With each moult it gradually assumes a darker colour, until the 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 of spiderlings hatch out from the eggs contained in each cocoon, comparatively few arrive at maturity. Some die naturally, others fall a prey to other spiders, or natural enemies, and many die as a result of their inherent cannibalism, for not only do they fight and eat one another, but many are devoured by the males when prowling.  

In furtherance of experiments still neces- sary the writer will be glad to receive living   specimens of this spider.

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

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