MUIRHEAD'S MYSTERIES: Interesting Invertebrates Part Three

Hello again,

Today I am going to look at some cases involving insects and spiders from various parts of the world, mainly clustered around the late 1980s and early 1990s. There is no particular reason for this; it is just that I happen to have quite a large collection of cuttings from this time period.

This extract is from BBC Wildlife Magazine July 1984.:

'BUZZ: The world`s biggest bee has been rediscovered in the rainforests of Indonesia. The species, Chalicodoma pluto, was presumed extinct, having not been seen since it was discovered in 1859 by Alfred Russel Wallace. He collected the only specimens known to science (two females) on the North Molluccan island of Bucan, and that was the extent of our knowledge until an American biologist, working on the neighbouring island of Halmahera in 1981, heard an ominous buzzing….” The bees built communal nests, which 'were always built inside those of tree-dwelling termites, though the resin and wood-fibre galleries constructed by the female bees were tough enough to resist termite invasions. The huge mandibles of the female, reminiscent of a male stag beetle, were found to be tools for scraping resin, which was then bulldozed by the central labrum into a 10mm diameter ball….' The article then goes on to describe how the male of the species are much smaller. (1)

'Locust retribution for Washington`s sins Guardian May 5th 1987: After biding their time for 17 years buried deep below ground in the luxuriant spring gardens of Washington, a plague of locusts is preparing to descend upon the capital. The curious creatures, which have sent Washingtonians to the hardware stores to block up their windows and doors with defensive screens, have been quietly awaiting their moment to attack…Many millions of creatures have already tunnelled their way to the surface and are waiting the right moment to take part in one of nature`s most unusual dramas. Those people who have lived through it before – in 1902, 1919, 1953 and most recently, in 1970 – say it is an experience they will never forget. Local garden stores warn there is nothing you can do. (2)

So if this number 17 was consistent, then 2004 should have been another significant year. But I have no records from 2004. The next plague year is 2021. Michael Oliver wrote to The Guardian on May 9th 1987:

'A plague on their houses: Sir,- The article by Alex Brummer (May 5th) is quite intriguing. It seems that this plague of locusts in Sodom recurs in 17 year cycles – 1902, 1919…1953, 1970, 1987. The interval between 1919 and 1953 is 34 years, i.e. 2 x 17, and it seems therefore that 1936 was for some reason 'spared.' However, this multiple factor of 17 would appear to be too much of a coincidence, and I am wondering if there is a scientific explanation for it.' (3)

A letter dated May 13th 1987 from L. E. Mack stated that [Richard] 'Dawkins claims that the only suggested explanation of this so far offered is that the numbers 13 and 17 are prime numbers. The advantage of regular 'plague' eruptions is that the insects can alternately “swamp” their predators: if these eruptions are timed so that they occur at intervals a prime number of years apart, predators do not get the chance to 'syncronise' their own cycles. So when the food is there, they are not. (4)

Now, the strange case of the spiders webs in the Croatia-Serbia war of 1991. On November 8th 1991 'Zagreb radio claimed “large quantities” of live, yellow-backed spiders were dropped on the east Croatian town of Daruvar. “The spiders are being used by the aggressor army as a biological agent. On television, an unnamed doctor said there was no trace of poison among the samples he had seen. “But the next generation could be the killer strain,” he cheerily confided. In fact, the tale of Serb-trained killer arachnids ranks as one of the sillier fabrications in an alarmist propaganda war, fit to stand alongside earlier claims that Croats in the town of Osijek had freed tigers from the local zoo which then roamed the countryside lunching on Chetnik guerrillas.' (5)

Finally, a headline from the Cork Examiner September 26th 1994: `Extinct` insects discovered near Thurles: “Very rare insects thought to have been extinct in Britain and Ireland have been discovered near Thurles. Now zoologists and entomologists from both sides of the Irish Sea are putting the insects under the microscope. “The discovery is very exciting and a big breakthrough said Tom Grace, Chairman of Cabragh Wetlands Trust near where the insects were found. The rarest insect is called Limnephilus pati, a caddisfly resembling a moth. Two males and two females of the species were found.' (6)

1. Anon. Buzz. BBC Wildlife Magazine. July 1984.
2. A.Brummer. Locust retribution for Washington`s sins. The Guardian May 5th 1987.
3. M.Oliver. A plague on their houses. Letter in The Guardian. May 9th 1987
4. L.E. Mack `Nymphs and shepherds of Sodom-on-Potomac` Letter in The Guardian. May 13th 1987
5. I.Traynor. Croatian media at battle stations for attack by eight-legged yellow peril. The Guardian November 12th 1991.
6. Anon. `Extinct` insects discovered near Thurles`. Cork Examiner September 26th 1994

Sorry, I forgot to look up a song lyric again. But try listening to Batchelor`s Hall by Steeleye Span.