Sarah Arnold

@sejarnold.bsky.social

2888 Followers 4535 Following

Entomologist, likes pollination, insect behaviour, IPM, horticulture and agriculture, sustainability, nature and especially wild bees. Works at Niab (UK). Views my own. she/her Neurodivergent, quirky, sometimes wrong but usually teachable.

A screw-topped plastic pot in a human hand, containing a large number of quite large green shieldbugs of varying life stages, and also some bright red bryony berries to keep them hydrated.
A red-and-black true bug a bit under 1cm long; its abdomen has some sort of triangle and diamond shaped black bits, but also two circular black spots. It is sitting on a common mallow with shrivelled-up pink-purple flowers and held in a hand for focus.
A flat, small and mostly black true bug, perhaps 7mm long, that has a distinctive orange-coloured diamond-shaped splotch in the middle of its abdomen. It is walking across dry, cracking soil, with a few blades of grass visible.
A rainbow arcing across the cloudy sky, over a partly blossoming tree and (less prettily), a damp car park. There are trees and bushes in the background, and if you look really closely, the primary rainbow is a stacker with a baby rainbow underneath, and there is a faint secondary rainbow above it too. The grass between the car park and rainbow is lit by spring sunshine. It is a very April scene overall.
A bright yellow shaggy-petalled dandelion flower on which a medium sized golden-orange bee is sitting. She has impressive flowing orange hairs on her hind legs, a more tawny thorax and her abdomen has tawny-interspersed-with-more-blond hairs on. She looks dopey but tidy and fresh, and she is a real live bee on a flower in February!
A microscope image of a small but not tiny ladybird (3mm), black all over on the back, but covered in short pale hairs. And because it's a bit hairy, it's snagged a few bits of light detritus as well - fibres, bits of crud, that sort of thing. The centre of its elytra are less hairy and lightly punctured.
A cocoa tree in dappled light, with its trunk absolutely covered in pale creamy-white flowers, each about 1cm across and coming straight out of the trunk, not on twigs or anything.
The trunk of a cocoa tree that is very heavily covered in developing pods, close to maturity, but not quite there (pods green and have some growing to do). Credit: Michael Adjaloo
A Brazilian cabruca farm, with the cocoa trees almost an afterthought amongst towering shade trees and other plants everywhere. It is very lush and verdant, with many plant species present.
A rather odd looking midge under a microscope, about 3mm long perhaps, with very long gangly legs, quite long antennae, and wings with only 2 main veins really. The fly is pale, almost transparent in places, with prominent halteres and a head that is dominated by big dark compound eyes.
A clearing in a cocoa farm, with banana trees around the edge and a shade tree in the middle. At the base of the shade tree is a big pile of fresh, yellow cocoa pods. Around that is a ring of old, rotten, blackened cocoa pods.
A tiny parasitoid wasp under a microscope - probably barely over 1mm long in real life. But magnified, it has long, elbowed, clubbed antennae, and a cool abdomen that is yellow with dark brown stripes.
An image of a midge that is mostly dark brown, with more yellowy legs. It is pictured in a microscope-magnified image so the lighting is a bit odd. In real life it is about 2.5mm long. The wings have fine hairs along all the veins and around the edges.
A microscope image of a midge with a fairly robust body that in real life is about 3mm long. She has dark markings along the back of her abdomen, a few dark bristles along the sides, and a lighter brown thorax. Her legs are longish and yellow. Her antennae are longish and a bit hairy.
A graph showing annual cocoa production in Ghana from 2021 to present. the 2020/21 season peaked at over 1 million tonnes, but since then it's not even managed 700,000 tonnes annually with a real low in 2023/24 of less than 550,000 tonnes.
A yellow and black striped worker bumblebee visiting white Choisya flowers, amongst evergreen leaves. The image is lit by bright winter sunshine.
A montage of 9 flower images, in 3 x 3 grid. From top left: scentless mayweed, white skinny petals, yellow centres, floofy foliage; common daisy, white petals/yellow centre and neat green leaves; annual mercury, tiny green flowers in clustery strings; common mallow, a single rich pink flower, half-open, quite big; black nightshade, white flowers with pointed yellow middles, and black mini-tomato-like fruit; marigold, big bold orange flowers; red deadnettle, pink tubey flowers; shepherd's purse, tiny white flowers and heart-shaped seed pods; sowthistle, floppy long yellow petals in a skinny pom-pom, and long spear-shaped leaves.
A wooden box (c. 20 x 20 x 20cm) with a plastic funnel on the front, in a wooden alcove. On close inspection, the funnel has a wax chimney coming out, and all on the chimney and edge of the funnel are lots of tiny (c. 4mm long) slender bees.
A large (c. 12cm wingspan?) moth, mostly dark brown but with various silvery-gold iridescent patterns, a white stripe across its forewing, and a comma-shaped stigma on each forewing too. Lying dead on grass, with a human hand framing it - forewing length is nearly the same length as the human's forefinger.
A pinkish purple thistle flower with a bright yellow crab spider sitting underneath looking quite obvious and not at all cryptic!
A black beetle with distinctive orange shoulders, on a brick wall that has holes in the mortar. (Sitaris muralis.)
A very cute small bee with big green eyes sitting on the tip of a person's finger (Anthophora quadrimaculata)
The white frothy "platform" of flowers from an Apiaceae plant, on which a medium-sized wasp is sitting. The wasp is black and yellow striped, but a bit more gracile and leggy than a "normal" Vespula. This individual has a partly-crushed abdomen, with T1 and T2 both distorted badly.
A pale purple-pink pompom of a thistle on which a large bee with absolutely splendid fluffy bright orange pantaloons perches. She is otherwise quite chunky, with a black and white striped abdomen and golden hairs on the thorax and she contrasts quite nicely against the flower.
A fairly plump green caterpillar with a white stripe all down its side, and a tail-horn (what is it called?) that is blue with an orangey-yellow tip. Sitting on hedge bedstraw (tiny white flowers).
A long, dark green and hairy leaf on which a small, slightly shiny, oval-shaped beetle is sitting. The beetle is kind of golden-brown colour and has large black femora (just visible). There is minor feeding damage on the leaf surface.
A green, hairy and long leaf, pinched between fingers, on which a small 3mm long beetle is perched precariously. The beetle is black and shiny, has large femora for jumping, and four orange splotches on its elytra. The leaf has many brown-edged, irregular holes from herbivore (beetle!) feeding damage.
Close up of a tiny beetle (3mm long?) inside a glass tube being held in a human hand. The beetle has large hind femora for jumping, and otherwise is black and shiny, with long antennae, and four orange-red spots on its elytra.
A highly magnified microscope image of a yellow-white pupating wasp. The wasp's body is fairly slender and still pale as it develops. It has long antennae, and its eyes are brown. It is probably 2mm long and lying on tissue paper.
A "capped blossom" from an apple tree where the brown leaves have been eased back to reveal a pale larva inside the damaged blossom. The blossom has had the anthers, etc. of the developing flower all eaten away.
A close-up image of an unopened apple bud that has turned brown and crispy from ABW damage.
A weevil about 5mm long, with ridged elytra and a paler v-shaped band across the abdomen (otherwise dark grey-brown). It is crawling across an apple blossom cluster on a tabletop, which is green and downy.
A QR code leading to a form: https://forms.office.com/e/N3zFGvcMnr (it asks questions about orchards with apple blossom weevil)
A fairly close-up view of the tip of an apple branch, with green leaves and a flower bud that is shrivelled and brown because it contains a weevil that has damaged it.
Human hand holds a leaf (about 4-5cm long?) on which a smallish caterpillar (1-2cm long) feeds. Caterpillar is black with an orange-brown dorsal stripe and white dots along the side, with various clumps of hairs sprouting. Leaf is comfrey, so a bit hairy and quite soft.
Cocoa solutions: sustainable pest management Synthetic pesticides (crossed out) - reduce and replace these! Use: (in order of preference on an IPM pyramid, from bottom (better) to top (less preferred) Habitat management - usually healthy, biodiverse habitats resist pests and disease better (image of a plant-rich agroforestry cocoa farm) Trapping and monitoring - detecting pests early means controls will be more effective than leaving it too late (image of a yellow sticky trap in the field) Biocontrols, biopesticides - some nematodes and fungi control pest insects. Some plant extracts kill pests (image of a nematode and a fungal growth under microscope) Larger stylised image of a cocoa tree, with an inset image of white, fluffy insects (mealybugs) feeding on a branch
Infographic shows two options: manual and natural pollination Manual pollination (with a pair of human hands holding forceps to demonstrate this on a flower): gives high yields but trees need to be kept healthy, and it takes takes skill. Image to the left shows a tree very heavily laden with pods, that has been hand-pollinated Natural pollination: is it possible to breed pollinators on the farm? Research is working on this. Protecting natural pollinators: reduce pesticide use, provide habitat and breeding materials that stay moist in the dry season (images of a plastic insect tent on the farm with materials for pollinators to breed in, a pile of cocoa pods on a farm, and a close-up of a midge pollinator).
Cocoa solutions: caring for soil. Fertilisers - synthetic or organic - based on evidence of the crop's needs Other soil amendments include beneficial fungi and plant extracts that support crop health Biochar may improve water retention and reduce erosion Increasing shade trees and plant diversity reduces runoff and erosion
Cocoa solutions: Smarter water management The right irrigation for the farm: - drip - solar-powered - river or borehole? Cycle showing cocoa flowers, pods developing in dry season and harvest, then rains arriving before it flowers again. An arrow leads to the question: Can suitable irrigation here (dry season) support sustainable yields and reduce crop loss? Additional benefits for moisture loving pollinators? Images show cocoa trees, irrigation lines and solar panels.
Cocoa solutions: (Dynamic) Agroforestry Cocoa trees alongside: - fruit trees (e.g. mango, papaya), - banana or plantain, - shading timber trees Provides different forestry products More complex environment = fewwer pests and diseases, more resistance to drought, flooding, heatwaves Image shows a stylised cluster of cocoa trees interspersed with other non-cocoa trees, including banana, shaded by a large tree that projects above the main canopy
Cocoa challenges: Deforestation Many cocoa dfarms have low/declining yields - same land, less income Sketch of cocoa farm adjacent to forest Cocoa farm expands into forest Sketch of the same cocoa farm and forest, but chunks taken out of the forest and converted to farm Areas of forest gradually lost Solution bubble: Sustainable improvement of yield from the same land area means less need to expand. Better data collection allows us to map farms' boundary changes
Cocoa challenges: Pollination Image showing cocoa flower cluster Many cocoa varieties need pollination or they will not produce pods Option 1: Natural pollination. Midges, other insects. Threats: Climate change, pesticide use, farm management Images show two small insects highly magnified, a midge and a parasitoid wasp. Option 2: Hand (manual) pollination Image of a human carrying out hand pollination of cocoa with forceps. Drawback: costly, difficult, time-consuming. Pollination is a problem for all cocoa-growing regions. Solution bubble: Better understanding of the most important/effective pollinators, creation of habitat, reduce toxins in environment
Cocoa challenges: Drought Late rains can delay or prevent the cocoa trees flowering, and also there may be fewer pollinators. A cycle shows rains arriving, cocoa flowering, pods developing, then during the dry season, harvest occurs. Annotations explain that yields will be lower in drought years, and in extreme drought, trees can drop leaves and forest fires become more likely. The solutions bubble explains that better harnessing of nature, via agroforestry and soil protection, can help. Affordable and sustainable irrigation, and breeding drought-tolerant varieties also helps.
Cocoa challenges: Black pod Infographic showing cocoa pods that are over half dark-brown/black with disease, explaining "Caused by Phytophthera (an oomycete, a fungus-like infection". Can cause total crop loss. Old pods on farms can be a source of spores. A photo of rotting cocoa pods asks "But is there a tradeoff? Old pods are important for pollinators!" Solutions bubble: Research – better understanding of how the disease moves on farms Safe/biological pesticides Managing humidity on farms – can be harder with climate change
Cocoa challenges: CSSVD Infographic shows white fluffy mealybugs on woody plant material, with virus icons coming out and into a tree image. Icons indicate felling as the only real control option, with associated income loss to farmers. Solution bubble says: New methods to control mealybug – biological methods, trap crops? Early detection = fewer trees need felling Breeding virus-resistant trees
An infographic showing the exchange of money for cocoa farmland by symbols representing gold-mining, resulting in tree loss. A collection of symbols indicates that this has bad impacts in terms of contamination of land and water. Another collection of symbols and brief text explain this trades of short-term cash for long-term income. A bubble "solutions" explains: Sustainable cocoa yields and good prices means more motivation to keep farming Community coordination means communities can resist galamsey better than individuals
Two bright yellow flowers among darker green leaves and grass.
A young green cocoa pod about 15cm long showing signs of severe surface pest damage, as it has dark/black blemishes across the surface.
A clearing in a cocoa farm with a central non-cocoa shade tree surrounded by fresh yellow pods, then a larger ring of old rotten black pods. The clearing is ringed by cocoa trees and banana/plantain trees.
Yarrow - some delicate white flowers in clusters, with small floofy ferny leaves below. Background is grass and a kerbstone.
Images showing samples of white mouldy cocoa beans without a protective culture, and healthier looking dark beans with it added, projected on to a screen in front of a conference audience.
A crowded conference room with a screen, and logos of many industry organisations on the wall around.
A young, green cocoa pod hanging from a horizontal branch. It has squiggly brown lines from a boring/mining pest across the surface, and a brightly coloured true bug nymph is walking down the pod. Near the pod there is a creamy-white cocoa flower about 1cm across. The background has dappled sunlight.
A plant growing at the kerbside in a grass verge, with slightly ferny, pinnate leaves and a pair of ~2cm across pink flowers with rather narrow, slightly tatty looking petals.
A lush strawberry plant with bright white flowers, in a commercial polytunnel.
A parasitoid wasp shown under a microscope. It is mostly dark-coloured, with long black antennae, long dark brown legs, and wings that have a dark brown stigma.
A view down a commercial strawberry polytunnel, with a long row of lush flowering strawberry plants, with some fruits. The plants grow in long, narrow coir bags (not visible) on a sort of bar at human shoulder-height. The ground underneath and between the rows is a mixture of bare soil and "weeds", i.e. non-intentional wild plants of different species.
A smiling man posed, bending down a bit, next to a cocoa tree with a moderate-high yield of developing pods, green to yellow in colour. Credit: Dr MK Adjaloo and field assistant Ebenezer
A man (Dr Michael Adjaloo), in a bright, colourful shirt, standing by a cocoa tree which has a heavy crop of developing green pods, sizes ranging from about 12cm to about 20cm long. Credit: Dr MK Adjaloo and field assistant Ebenzer.