Garden blogs

Farming and Wildlife in July



As described in May, the Botanic Garden covers about 568 acres of which 216 acres is farmland and 100 acres is woodland. There are 25 head of pedigree Welsh Black beef cattle and 30 non-pedigree Balwen sheep, with the permanent flower rich. grassland of the Waun Las National Nature Reserve being grazed and cut for hay.

There are about 31,000 agricultural holdings in Wales with an average farm size of 93 acres [38 ha] and about 58,000 people working on them. That’s not many people directly producing food for Wales’s population of 3 million is it?

Only 4.3% of Wales’s workforce does the actual producing of the food, whilst the other 95.7% of the population – and the farmers themselves of course – do the eating of it!


Is it when there is a hosepipe ban, or farm boreholes and wells dry up, that streams slow down and stop flowing, or just when the grass stops growing? In UK an absolute drought is currently defined by the Meteorological Office as:

a period of at least 15 consecutive days or more where there is less than 0.2 mm (0.008 inches) of rainfall’.

Compared to other countries, the UK definition of a drought is just a short period with no rain. In Libya in North Africa, a drought is usually only recognized after two years without any measurable rainfall. Can’t imagine Derek Brockway giving the BBC weather forecast and saying:

Sut mae. Well no rain is forecast for next month but as we’ve had only 14 months without rain, there’s still a long way to go before we can declare a drought’.

We are lucky really; not of course that we admit it very often…

Do you remember the Summer of 1976? Summer 1975 had been dry but there had been little winter rain and a Minister for Drought was appointed in May 1976 as reservoirs dried out. I know, it’s 42 years ago but it was our first year of milking on our dairy farm at 800 feet above sea level and 9 miles north of Carmarthen, and our well dried up in early May. With no mains water we had to take our Mini-Traveller 3 miles down the road and fill 6 x 10-gallon milk churns from a stream that carried on flowing throughout that summer and to do this 3 times each day – including Sundays! Now that really was a drought and what we are having now is just a long dry spell.

Every Sunday for months in 1976 we watched with bated breath the weather forecast on the Sunday lunchtime TV programme called Farming hoping the high pressure would move away!

Flowering plants continue to flower when weather conditions turn bad and when plant death seems inevitable they speed up their reproductive processes and set seed early; almost as if they are thinking ‘even if I die now then my seed will survive to carry on’.

Grass really is in short supply on some farms in South Wales and most dairy farms started several weeks ago to feed to their cows with the silage that they harvested in May this year for the coming Winter! Huw says that The Farm is managing OK for several reasons:

First is that there is more than 200 acre of grassland and only 30 cattle and 30 ewes plus calves and lambs of course.

“This is a very low Stocking Rate[1] of about 0.2 Livestock Units per acre compared with many other more intensive farms at 1 Livestock Unit per acre.”

Second is that with permanent grassland if there is good ground cover then the sun and the drying wind has little access to the soil which doesn’t dry out nearly as much when there is no groundcover – it’s a bit like mulching around plants in your garden isn’t it! But what will the future hold if the drought continues, eh?


After the F&W in May appeared in the Volunteer Weekly Newsletter a reader asked about my comments on the need for cattle and sheep to graze wildflower rich grassland to prevent it from reverting to scrub and then within 10 years or so to secondary woodland. “Do you not think” she asked, “that natural scrub has some wildlife importance of its own and should be kept?” Yes, scrub is a valuable habitat as it’s neither grassland nor woodland but in between and with its own, although sometimes overlapping range of birds, mammals, insects and all others that depend on it for food, security and breeding.

Just inside Trawscoed Meadow on the right-hand side there is a bank of Bramble/Blackberry on the edge of Trawscoed Wood. Here, Dormouse are believed to be active and the migratory Chiffchaff Warbler – with that most distinctive of calls during the breeding season, makes its dome-shaped nest almost at ground level in scrub. The Chiffchaff is named ‘onomatopoeically for the sound of its simple chiff-chaff song. I do like that word – onomatopoeically – don’t you?

So, in an ideal world some scrubland should be kept on any Nature Reserve or farm. But Huw always has to manage the need for grassland for the cattle and sheep and the need to manage scrub and prevent it getting out of control, encroaching into the grassland and to ensure a range of ages of scrub as well.

Because of The Farm’s organic status, no herbicide can be used and the scrub must be ‘managed’ by that less than enjoyable job of cutting it back by hand during the Autumn and Winter and trying to avoid the Bramble’s seemingly deliberate attempts to become twisted up in your shirt and make deep scratches along your hands and forearms!

In Winter it’s always a battle to pull out ewes that have got tangled up in Bramble with the ewe having become more securely ensnared as she twisted around trying to get herself free. Often the shepherd must carry a pair of secateurs to clear the Bramble from the wool, even a reasonable size of pocket knife isn’t enough to cut through 3 or 4 Bramble stems twisted together like rope!


It will be St James’s Day on 25th July and almost all Ragwort will be flowering then, which is why one of its other names is St James’s Wort in honour of the saint! We talked a bit about Ragwort in June, about how it has always been thought to cause substantial fatalities of UK livestock from its poisons, especially horses.

Inside the growing plant the poisons are in non-poisonous form[2], and after the plant has been eaten it first has to be changed by the intestines and then broken down by the liver. Both these processes are necessary for toxicity. The poisonous alkaloids do not accumulate inside the body of an animal as they are excreted in about 24 to 48 hours. It is the damage that is caused to liver cells that can, if sufficient ragwort is consumed at each dose, be cumulative to the point of death.

We often hear about the laws that we think prevent us from having Ragwort growing on our land, don’t we? Rubbish!  Ready for a quick legal lesson? The laws on Ragwort do not require ragwort to be automatically removed or killed off. The Weeds Act 1959 and the Ragwort Control Act 2003 are routinely misquoted.  Under the 1959 Act a landowner or occupier may be ordered by the Local Authority to control the spread of Ragwort and the 2003 Act goes a little further. But neither makes Ragwort control compulsory in the absence of an order.

So, is there’s no compulsion on landowners to remove Ragwort? Only if, for example, your neighbour in those downwind fields complains to the Local Authority about your plantation of Ragwort and the seed blowing into his wildflower-rich meadows, will the LA approach you and tell you to control your Ragwort – or else!  Otherwise, grow all the Ragwort you want! Mind you, it probably makes sense to try and manage Ragwort on your land.  Why risk any liver damage to your livestock?  But perhaps try to manage it to a reasonable population of Ragwort rather than to try and eradicate it.

After all, it would be a shame if we were never again to see those yellow and black banded caterpillars of the often day-flying Cinnabar moth wouldn’t it! But why you ask, when so many other caterpillars have a colour pattern intended to camouflage them from all those lurking predators, are these ‘Tiger caterpillars’, as I used to call them as a kid, so obvious and noticeable to those potential predators?  Well, apparently the Tigers absorb the alkaloid poisons in Ragwort that we talked about in June and become toxic or at least very inedible themselves and so their garish ‘warning colouration’ or ‘aposematism’ warns potential predators to ‘keep away’.  So, the poisons in the Ragwort plant pass to the Tiger caterpillar, then to the pupa and finally to the Cinnabar moth itself.

It’s perhaps better not eat any Ragwort and, although some of us are becoming aware that insects can be a very good food source for humans, best not to eat the caterpillars or adults of the Cinnabar Moth either!

“These Tigers are voracious eaters of Ragwort and were introduced to New Zealand[3] and Australia to control Ragwort populations there.  This is yet another example of ‘Biological Control’ and of using one organism to control another!”

But here’s another important legal bit! Did you know that it is illegal for anyone other than the landowner, tenant, someone authorised by them, or by a specified official to uproot any wildflower, including Ragwort? Ragwort is usually a biennial plant and although pulling it out of the ground by hand will leave you with stems and leaves in your hands, even in the wet when the roots pull out more easily than if the soil is dry, pieces of root will still be left behind. And these bits are very likely to sprout shoots and roots and for the Ragwort plant to grow again next year as a perennial – and this despite your back-breaking efforts this year!

Common Ragwort was also known in the past as Stagger-wort perhaps because of the reputed effect on those horses that ate too much. Ragwort, Stagger-wort, Figwort, Sneezewort, titchwort, Soapwort and Bladderwort? Why do they all have Wort[4] in their name do you think?


The Farm’s Welsh Black cows appear to be enjoying the attentions of Gwilym the bull who is equally enjoying his harem. He’ll run with them for 6 weeks or so, Huw says, and they will ‘cycle’ every 21 days and so Gwilym can cover them 3-4 times if necessary during that time and hopefully ‘get them in calf’.

The calves born earlier this year are still suckling their mothers although they have been eating grass for some months now and are already ruminating well[5]. The bulling heifers – aged about 18 months but still without a calf on board – are lively and nosy.  If you turn up in a field they’ll come and find out what you are up to.  And sit down and just like any cow, they’ll come over and check you out.  It’s like they can’t work out how you suddenly got to be the shape that you are and with the smell that you have and besides what are you doing in their field anyway!


We talked a bit about these in June and about how when grass is cut it has 75-80% moisture, which must be dried down to 14-18% moisture content for hay. This often takes 4 or even 5 days in dry weather unless there’s both sun and a strong breeze. It doesn’t matter too much if the drying hay gets rained on providing that the drying weather continues afterwards. Hay used to be baled up in those small oblong bales [±1 x 0.6 metre] and about 40 bales to the ton. Then in mid-1970s the big baler was introduced making round bales weighing about 200 kg each and these could be moved from the field on a trailer but lifted onto the trailer by a tractor with a front-end loader fitted with a spike and pushed through the centre of the bale; then unloaded into the hay barn at the farm for Winter feed.

Traditional hay-making and feeding was OK in the 1970s when milking a 20-30 cow dairy herd. But the labour required for manhandling hay was too much when herd size increased to 60 cows and even less so at the 2018 average size dairy herd of 75 cows for the 3,712 herds in Wales. But with increase in machinery, moving heavy bales was not a major problem.

About 60 years ago both dairy and beef farmers started realised that silage making was a less weather dependent method of conserving grass for the Winter than making hay, and that storing silage in a silage pit was easier as well. In the old days, a silage pit or silage clamp was often just a hole scraped in the ground into which chopped grass could be put and then rolled with a tractor to get rid of the air, so it didn’t heat up and lose the valuable energy, and then covered over with plastic sheeting often weighed down with old car tyres to prevent the sheet blowing off in the wind! Nowadays, most silage is made inside buildings with reinforced concrete walls to allow the larger tractors that farmers have now, to roll the silage before sheeting over with the black plastic as before.

So, for silage, grass is always cut younger than it would be for hay, when it has less stem and more leaf. After mowing it is turned on the ground for 1-2 days so that at least some of the moisture in the grass is lost – ideally silage is 25-40% dry matter. If it’s too wet when put into the clamp or pit, then the moisture drains out of the clamp as silage effluent that if it reaches a stream, river or pond will remove oxygen from the water and prevent water creatures from breathing and so they’ll die. This effluent can kill the fish downstream of the leakage for miles, and Natural Resources Wales can trace back and find who’s the culprit and there’s hell to pay!

Then with the big baler arriving, farmers realised that silage could be ‘big baled’ as well, providing that the bales were put into big black plastic bags to reduce the risk of air getting into the cut grass and forming ‘secondary fermented’ silage that cattle would not eat. Then some farmer somewhere was making hay and after 2 or 3 days when the hay was still wet, the weather changed and an unexpected ‘low pressure system’ came in and ruined his prospect for drying his hay and it was already too dry for silage. But he baled it anyway, bagged it up and – lo and behold – this was Haylage! Then a different and better way was introduced with bales being tightly wrapped in thin black or nowadays almost any colour of plastic – usually in 2 layers.

Haylage can be thought of as a highly nutritional hay but without the dust and spores of hay, and usually with 50-70% dry matter, compared with 80-90 % in Hay and 25-40% in silage. You know, the ‘only constant in life in change’, and farming is no exception is it!  There’s a lot of Haylage made now and often it is double wrapped when baled for horses, as mould from air getting through a hole in the wrap can kill a horse. Ideally Haylage should be just moist enough not to be dusty, that’s what both horsey folk and horses like!

Silage is now the system that most commercial farmers use to conserve grass in the Spring & Summer and then keep for feeding in the coming Winter. This year most lowland farmers made their first crop of silage in early May and then 6-7 weeks later at end June their second crop. But it has been so dry hasn’t it and the second crop will not be nearly ‘as heavy yielding’ as the first crop was. Many farmers take a third crop sometime in August and some even a fourth! All farmers are different you know!


The 7 acres of mixed Peas and Oats for arable silage and 4 acres of Spring Barley both sown in mid-May[6] in Cae Circus and Cae Gors have germinated and can easily be seen looking from the Observation Lookout point in front of Principality House towards the Tower. Walking over to look at them at end-June after 3 weeks of no rain, I was surprised to see them looking quite strong with good ground cover – especially the Peas and Oats. Less well established was the Ryegrass and White Clover sown into Cae Pysgwydda next door that needs rain; the cracks in the ground are an inch wide! You can only look at these from a distance as these fields are all part of a restricted area whilst heavy machinery is working for the Regency Restoration Project that is clearing the silted-up lakes – so keep clear!

Before being given a ‘slapped wrist’ by the Project Manager, Helen John, for trespassing in this restricted area, I looked for any rare ‘arable weeds’ as these fields have not been ploughed for some years and I thought that there might be some germination from the old seed bank in the soil. Few really: some of the bright yellow-flowered Charlock in Cae Gors and Cae Circus, Fat Hen in Cae Pysgwyddfa and in Cae Circus what looked like Amphibious Bistort between the rows of Peas and Oats.


Most people think that sheep are pretty daft animals; always bleating about this and that problem! Even the farmers’ definition of a sheep would tend to confirm this:

A sheep is a small woolly creature that limps and that suffers from a number of diseases, the first symptom of which is sudden death.”

And yet sheep always show a keen interest in survival, coming together as a ‘flock’ for example when danger comes into the field and threatens. Mind you, some breeds such as the Soay from Scotland don’t flock, perhaps to confuse a potential predator, which makes it awkward to move them with a sheepdog! About 15 years ago, the National Trust introduced a Soay flock onto Cheddar Gorge in Somerset; small sheep, very sure-footed, no shearing needed, easy lambing and ideal for making sure that scrub invasion didn’t take over the rocky cliffs and pathways that tourists wanted to see. All fine that is until there was a case of Sheep Scab[6] and the whole 100 ewe flock had to be treated. No good putting a dog to collect them, so they had to be rounded up with scores of volunteers and then bribed into an enclosure with the promise of food in troughs. This was not an easy job!

But our flock at home was put into the yard for shearing in early June, and they all immediately moved over to some plant pots on the side, in which were growing some plants of wheat in which the ears of grain were just beginning to emerge from the leaf stem. The ewes all lined up to eat these wheat ears that were ‘cheesy’ and not hard and ripe as they would have been at harvest in July, and they also nibbled on the seed heads of Cocksfoot grass that was flowering nearby – both full of energy. Sheep can be very annoying sometimes yes, but they are definitely not stupid!


Hedges are growing fast, aren’t they? They never fail to amaze as to how much life there is in hedges considering they are just an ‘accidental habitat’ created by humans merely for the demarcation of field boundaries. But at this time of year they are flowering busily or at least the ones that weren’t ‘scalped’ last Winter are. Flowering of most woody hedge plants such as Hawthorn and Blackthorn usually only occurs on branches in their second year or more of growth.

A Botanic Garden staff member who shall remain nameless but has the initials JD and is always an impeccable information source, told me at the beginning of June that when rain is about to fall, the scent of Honeysuckle flowering in hedges becomes even stronger than normal. I have tried to test the veracity of this information but since being told, there has been no rain – anyway I have no sense of smell. But Honeysuckle certainly is a superb component of any hedge or field boundary and shredded Honeysuckle bark seems to be the Dormouse’s bedding of choice for its nest.

Mind you, when checking our Dormouse nest boxes at home last week, slid the door down on Box number 19 and was warned by the intense buzzing sound to push the door back up fast and then back off. Yes, it was those Tree Bumblebees again, streaming out of the entrance hole behind the box in an attempt to see off and sting the intruder – me. Lucky it was Box 19 on a tree with Honeysuckle but on level land and no Bramble; just as well it wasn’t Box 23 on a slope amidst Bramble and Blackthorn scrub. Otherwise might still be getting over the stings from a score or more of aggrieved bees – all females of course!


We tend to think that it is only human and livestock diseases that spread from one continent to another and which we have measures to try and minimise. But no, its plants as well and there have been several invasions of tree diseases in recent years. There has been: Acute Oak Decline [1980s]; Sweet Chestnut Blight [2011]; Horse Chestnut Bleeding Canker [2008]; Dutch Elm Disease [1920s & 1960s]; and Phytopthera spp on Alder [1993], Juniper [2011], Beech [2014] and Oak [2015]; all these are now living and spreading in UK.

An imported disease confirmed in 2012 was Chalara Ash Die-back whose effects will not be known fully for some time yet. Apparently, some idiot person imported Ash saplings from a tree nursery in Holland that were infected with the Chalara fungus and the disease is well away here now. Look around and you will see it almost everywhere and it’s especially easy to see when the trees are in leaf both in younger saplings and branches of older trees as well. You know that Ash saplings and smaller trees always seem to have branches pointing directly upwards just like a multi-stemmed candlestick? It’s these Ash ‘candles’ that seem to show the dieback first, sticking out leafless amongst the leaves above them rather like a multi-branched Menorah candelabra. Have a look at Ash in the Corporation Car Park up against Trawscoed Wood and perhaps you can see what I mean? Some older and fully mature Ash trees have some – but not all – leafless and apparently dead branches that make them look a bit like those trees in a post-Apocalyptic film; not a particularly wonderful sight.

But just like those school kids that never seem to get infected when there’s a health hazard at school, some ash trees appear to be able to tolerate or resist infection. So, we don’t yet know what the full impact of Chalara will be in Britain. It can kill young Ash trees quickly but evidence from Europe suggests that older, mature ash trees can survive infection and continue to provide their landscape and wildlife benefits for some time. But who knows for how long? Mind you it could be that if Ash does start to disappear from the landscape like Elm did 40 years ago, then some other tree species may take over and fill in the gaps in hedges and woodland – the even faster growing and more aggressive invader called Sycamore perhaps?

But Ash is such a marvellous tree isn’t it: fast growing; marvellous firewood even when ‘green’ and freshly cut; superb strong and straight grained timber; and is perhaps only rivalled by Sycamore for the ability to grow anywhere at all! Apparently, it’s the 3rd most common tree in Britain and is rather complicated sexually – just like the media would like us to think about ourselves. Separate male and female flowers can occur on the same tree, but it is more common to find either an all male or all female trees. But a tree that is all male one year may produce only female flowers the next year, and similarly a female tree can become male, but perhaps only on a few branches. It’s confusing for us, perhaps less so for the Ash trees themselves?


It’s better now with the Meadow and Hedge Brown butterflies coming back, but from where I don’t know. The caterpillars of the most frequently seen Browns feed on common grasses including Cocksfoot and Yorkshire Fog! Still few of the Stinging Nettle feeding caterpillars to be seen although Comma and Red Admiral occasionally, but no Small Tortoiseshell or Peacocks yet. Bruce Langridge says that he saw a Scarlet Tiger early in June. This day-flying moth often seems to fly in a swarm of moths, just like the old TV films of a ‘squadron of Spitfires’. Caterpillars feed on Dead Nettle and Comfrey although I have seen a very large colony on Green Alkanet. Often thought that this plant, introduced in the 1600s to the UK to be grown as an alternative to importing the expensive Henna needed for its red dye – was misnamed. Have a look in your plant identification book; it has a blue flower, and a red dye from its roots, but is called Green Alkanet! As it keeps its leaves over Winter, perhaps it might be better called Evergreen Alkanet?

In early July this year, the White butterflies seemed to suddenly explode in numbers with Large Whites – also known as Cabbage Whites as that is what they often feed on – at the forefront mainly migrating to UK from southern Europe. You know that without that annual immigration there wouldn’t be many Large White butterflies in UK and we would have few of the Summer Snowflakes as they used to be called! They told us at college that Large White caterpillars – like so many others – are parasitized by a wasp that lays its eggs into the growing caterpillar inside which the eggs hatch and the wasp larvae eats away at the caterpillar whilst it is still alive! It’s often touch and go as to which happens first – the caterpillar dying after being eaten alive or the wasp larva being ready to leave the caterpillar and pupate!

It’s the Fly Season – not only around the kitchen and coming in through the open back door onto the food before being served up for dinner – but also for the many different types of biting flies in the countryside and on farms. These Horse Flies, Gad Flies, Stouts and Clegs tend to land on cattle, horses, deer and sheep and suck blood – often without the host even knowing that they are there! Only the female flies suck blood of course[7], the males being unobtrusive and mainly feeders on nectar! At least we no longer have the problem of the Warble Fly in this country after a nationwide eradication programme in the 1980s and 1990s using Organo-Phosphate[8] insecticides to treat cattle.

“The adult Warble Fly is about ¾ inch long with a faint hissing sound that induced terror and panic in cattle and caused their wild ‘gadding about’ often through hedges and fences. One female fly might lay up to 100 eggs on one animal!”

After about four days the eggs hatch and the larvae penetrate the skin of the legs into the connective tissue between the skin and muscle from where they begin their journey, slowly eating their way upwards through the legs of the animal, growing bigger as they go. Eventually reaching the oesophagus or the spinal canal, they would stay dormant for the Winter, but in early spring the larvae migrate to the back of the animal where they form a swelling under the skin. After a while, the swelling develops a small hole through which the larva breathes. Here they lie and eat for about a month growing bigger until they measure over an inch long and half an inch thick. Eventually, the mature larva crawls out through the breathing hole and falls to the ground where it buries itself and pupates. After around 35 days the pupae hatch into flies and the cycle begins over again. They reckon that 40 years ago there was a staggering 4 million cases of warble fly infestation each year in the UK – that was a huge loss of good quality hides, animal welfare issues, reduced milk and meat yields and downgrading of carcass quality due to discolouration of the meat where the larvae had burrowed and eaten their way through the animal. So maybe this is a success story for the much-maligned pesticide industry, eh?


to some rain! We’ve had the longest day of the year already and probably the pessimist would say that we’re heading towards Winter now – even if we are in the middle of a period of drought. True I suppose, but a realist would say that every season and every month in each season has its ups and downs and often there are more ups than downs, aren’t there? Anyway, Huw is getting ready to get the contractor in to mow the hay meadows perhaps some time in August? And there’s always those warm Summer days and cool Summer evenings to cheer us up anyway!


10 July 2018



[1] Stocking density is the relationship between livestock and the grassland and forage resource and measured in Livestock Units [LSU] per acre usually on the entire grazing area of the farm for the entire grazing season. Although the Livestock Unit attributed to each animal can vary a bit, most have the following: 1 cow plus suckling calf = 1.0 LSU; 1 x 6-24 month old cattle = 0.6 LSU: 1 ewe plus suckling lamb = 0.15 LSU, and; 1 > 6 month old pony or horse = 1.0 LSU.

[2] Which is why it’s not dangerous for humans to handle Ragwort.

[3] Ragwort was accidentally introduced to New Zealand in the late 1800s and, like so many invading foreign species, quickly became a pest and was rampant by the 1920s.

[4] From Old English ‘wyrt’, a Germanic word with the meaning of ‘root’.  –wort’ is frequent in compound plant names and often with plants that have had some medicinal use. 

[5] Cows, sheep, goats, lamas, alpacas and deer are ruminants that cannot digest plant material directly, because they lack enzymes to break down cellulose in the cell walls of grass and other vegetation. Instead they have a digestive tract that starts with the Mouth, and then an Oesophagus, and then a complex four-compartment stomach, small intestine and large intestine. The stomach includes the Rumen, Reticulum, Omasum and the Abomasum or “true stomach.” Grass is taken into the Mouth, chewed a little bit and swallowed down the Oesophagus into the Rumen where it is stirred around and is fermented by the resident microorganisms that live there and which can break down cellulose.  The Reticulum allows the animal to regurgitate to the Mouth and for the animal to “chew its cud“. More finely-divided food is then passed to the Omasum, for further mechanical processing. The whole lot is finally passed to the true stomach, the Abomasum, where the digestive enzyme lysozyme breaks down the bacteria so they also release nutrients. Horses have a less efficient form of digestion with bacterial fermentation mainly in the intestine and with the extraction of nutrients from plant material being less complete. If you compare horse droppings with ‘cow pats’ you will see that horse droppings contain intact plant material that may be scavenged by birds, whereas the cow pats are already broken down.

[6] Sheep Scab is caused by the mite Phoropters ovis and is characterised by intense itching, with repeated rubbing of the shoulders and flanks along the ground or against fences, foot stamping, clawing at the flanks, and biting the shoulders.  Sheep dipping was traditional cure, nowadays injection is more likely.

[7] Being incredibly protein-rich, mammalian blood is often the critical requirement for successful egg development. Red blood cells in mammals are 96% of the protein haemoglobin.

[8] These OP insecticides were much used at the time and although they were not as persistent as the Organo Chlorine insecticides such as DDT and BHC, they were more toxic to humans, acting as an anti-choline esterase.