Pseudoscorpions to the rescue!

 
i got home one night and spontaneously thought I will go up on the hill a few weeks ago looking for more silver fish in a rotting log and i heard a buzz..na i thought can't bee that  this time of the night so i followed the buzz and found a large bee - that will be good in my collection. i placed the insects into the freezer and 24 hours later i pinned out the bee which got me thinking what's happening to our honey bees and the industry in New Zealand. As i have not seen any for a while, i wonder if have they succumbed to the varroa mite?  has research id any predators of the varroa mite, climate change?

a friend of mine was having a boys night out and told me later on that they had talked about pseudoscorpions as a biological control of varroa mite - that's what i want to know about so i began looking for information and finding research papers full text on line was an utter nightmare. Unable to find papers in the uni library i went direct to the source of some articles i wanted to use for this blog and they gave me electronic copies! what a huge relief of stress.

anyway i have read many articles and found them fascinating. the paper i will blog about today is New Zealand pseudoscorpions kill varroa, New Zealand Bee Keeper, October 2006.

but first of all a little background on how important the bees are to New Zealand sourced from http://nba.org.nz/   (national beekeeping association of New Zealand)

the good guys
 Bees are crucial to our horticulture and agriculture crops meaning  we are more dependent on pollination from the honey bee than any other nation on earth.

New Zealand honey bee products are sought after worldwide. Around approximately 9,000 to 12,000 tonnes of honey are produced annually, with almost one third to half exported. Exports of honey alone are valued at around $81 million, including $4 million of premium organic honey.
$5.1billion of NZ's economy is attributable to pollination by honey bees, domestic honey sales and exports, beeswax and exported honey bees.

as of 10 March 2011 there were 3,251 registered beekeepers, 23,395 apiaries and 388,369 beehives in New Zealand.The number of beekeepers has declined dramatically over the last 10 years, not helped by the Varroa incursion – a mite which feeds off live bee larvae and adults. Just over 3,000 New Zealanders keep bees, with the 287 biggest beekeepers managing 96% of registered hives.



The enemy
Varroa is an external parasite of honey bees. Adult female mites are fairly large about 1.1 x 1.6mm. They have a hard reddish to dark brown body that is flattened and oval in shape.
Varroa mites are transferred to new bee colonies on adult bees. The mite will then leave the bee and crawl into a brood cell. Once in the cell the mite submerges itself into the larval food at the bottom of the cell and start feeding on the pre-pupa. The mite will then lay its eggs. The eggs will hatch and go through two juvenile stages before becoming adults. The adult mites will leave the cell when the bee emerges.





Now on to the main story... the saviour of the honey bee!


pseudoscorpion picture taken down a microscope.
 (photo: Ian Harvey)

The pseudo scorpion is also called a chelifer and false scorpions. It is an arthropod in the order Arachnida and class Pseudoscorpionida. They are about 8mm long with 8 legs and a pair of massive pincers protruding out the front. They live in soil and leaf litter and under loose bark on trees. They like to eat caterpillars, small insect larvae and eggs, springtails and mites. Overseas a few pseudo scorpion  were noted to have lived in beehives and clinging to bees when they formed new hives.

In New Zealand in 2000, pseudoscorpions were found in a hive near Leeston and 6 years later in Katikati, some chelifers were observed. these pseudo scorpion were NZ natives - Maorichernes vigil (nationwide) and Nesochernes gracilis (Norfolk island, North island, Marlborough and Westland). pseudoscorpions had not co evolved  with the honey bees(introduced 1839) so it was a surprise to see them in high numbers in the beehives

A trial was carried out to observe if the pseudoscorpion would eat varroa mite. When a varroa was encounted by the pseudoscorpion, it seized the varroa in its pincers (poison that stun prey) and placed it with in its mouthparts (digesting fluid injected into varroa - internal organs turn to soup) and this took 10-15mins later varroa was dead!. it was also observed that they worked as a team - one holding the varroa while the other ate - together 3 varroa were consumed in an hour! view the eating at :

 www.youtube.com/watch?v=-qw3eVjQPXQ

any problems viewing the above video, Google chelifers eating varroa mite in lab conditions - you tube

it was also noted that the bees ignored the pseudoscorpions even when they were underneath their legs.

there is enough evidence to suggest restoring pseudoscorpions to the beehives would provide the bees with a natural predator/protector against the bees enemies.

suggestions for further investigation include modified bee hives to suit both the bee and pseudoscorpion and creating pseudoscorpion farms but the biggest problem then was funding. Up until this paper was written there had been 7 attempts at funding, all failing

but now the varroa are in both islands....so currently

Plant and Food are doing ongoing research on the potential commercial propagation of pseudoscorpion for varroa control in honeybee hives. outcome unknown

the papers were unavailable on the internet therefor I sourced them from the author and have pdf files, if anyone wants to read them, let me know and I will email to you.

 information available at

http://nba.org.nz/ - for the bees

 

http://soilbugs.massey.ac.nz/pseudoscorpions.php -  the predator

 

http://www.biosecurity.govt.nz/pests/varroa - the enemy

 

 

 

 

 

 

What's a 'Flat bug'?

If it wasn't for this insect collection I would never have come across this strange insect!  Hiding under the bark of a eucalyptus tree was a collection of flat-looking bugs that I thought had been squashed!  but upon inspection under a microscope I discovered that this was it's natural state.

To find out what this insect could be, my friend photographed it through the microscope and sent it to a colleague who is a forest entomologist by the name of John Bain.  This insect was identified as an aradid bug from the order Hemiptera, from the family Aradidae.  This one is a species in the sub-family Isoderminae. probably Isodermus crassicornis.   Here's the picture:

I wanted to find out some more information on this bug so, as I was given a reference by the forest entomologist, I then began the l..o..n..g process of finding this reference!  The reference was by Prendergast who gave as a source a book published in 1959 by two Americans. This was entitled "Classification of the Arididae (Hemiptera-Heteroptera)".  The librarian at the Lincoln Uni Library eventually found this book hidden in an obscure corner!  Here are some fascinating facts about aradid bugs or 'flat' bugs:

• Key features of the I. crassicornis include rostrum free at base and the wings deciduous, antennae thick with the second segment strongly thickened, forth antennae segment is longer than the third and finally their abdomen is wider than the thorax (see above picture).
• their flattened form and sombre colours are well-adapted for a life on or under the bark of dead trees
• flat bug measures 6.4mm in length and has a depth of 0.10mm!
• their coiled setae are a remarkable adaptation for sucking the juices out of fungi and is more than 6 times as long as the insects body and when not in use is coiled up like a watch spring inside the flat bugs head, as can be seen in the picture below.

• the first of these species was described as early as 1746 by Linnaeus
• the genus Aradus was proposed by Fabricus in 1803
• Aradus is most likely derived from Arados - Greek name of an ancient Syrian city.
• there are about 30 species of aradid bugs found in NZ
• I. crassicornis is a native species and the most commonly found in NZ
• NZ is a natural storehouse of aradid types unequalled by any other continent as they evolved over time from a Carventus-like ancestor

Mating occurs around fungi and or bark, their natural habitat. the male is beneath and to the right of the female. Copulation  can take  between 3 - 8 hours and has been known to go for 24hours! Eggs
(0.45mm-0.86mm) are then laid in frass underneath bark, rotten logs or stumps and could be glued to the surface of the bark or fungi.
The are 5 nymphal instars and nymphs do overwinter with the adults under bark.

if this insect is most commonly found in NZ why have i and others i have spoken not ever seen it before!
if copulation takes that long it must be a mans dream!!
hope you have found this as fascinating as I have!! go forth inspect and explore
amazing insect for its size!

extra information can be read in the following papers.

1. 1965a. The Aradidae of New Zealand (hemiptera, heteroptera) I. Introduction; The Aneurinae. Transactions of the Royal Society of New Zealand, Zoology 6 (5): 53-63.

2. 1965b. The Aradidae of New Zealand (hemiptera, heteroptera) II. The Isoderminae. Transactions of the Royal Society of New Zealand, Zoology 6 (23): 235-243.

3.1968. The Aradidae of New Zealand (hemiptera, heteroptera) III. The Aradidinae and Calisiinae.
Transactions of the Royal Society of New Zealand, Zoology 10 (10): 81-88.