This study examined a multitude of potential substrates across horticultural and livestock industries that supported the development of the stable fly, Stomoxys calcitrans (Linneaus) (1081 samples from over 100 properties (2010–2016)). Stable fly developed in high numbers from vegetable crop residues left after harvest, notably celery and leeks as well as several brassica crops, lettuce and silverbeet. Unmarketable vegetables (reject produce) and processing waste provided another source of stable fly development, in particular from carrot production (green tops and processing washings) as well as beetroot and daikon leaves, reject zucchinis, rockmelons, eggplants, turnips and squashes. Reject produce from mostly solanaceous plants either did not support any or rarely supported the development of adult stable fly. Reject vegetable produce fed to livestock presented a source for stable fly to develop in the vegetable/manure mix, especially from carrots and corn cobs. Large accumulations of cattle dung in feedlot situations, hay feeding out sites, wet grain feed and exposed silage produced the highest numbers of stable fly from livestock industries. Cattle dung from rangeland pastures, pig manure and horse manure rarely if ever supported the development of stable fly. Only cattle dung that had aged or pig manure that had been mixed with straw and left to age allowed for any stable fly development. Miscellaneous sources of stable fly development include rotting lawn clippings, rotting weeds, ageing olive pressing residue, and to a lesser extent, rotting wild melons and seaweed.

Southern highbush blueberry plants (Vaccinium corymbosum hybrid) from a commercial blueberry farm were placed in quarantine glasshouses and either exposed to adults of the western golden-haired blowfly Calliphora albifrontalis (Malloch) or no insects at all over a 21-week period. Laboratory reared C. albifrontalis were regularly released into one house to maintain a population of 1000-1500 flies. Flies could only obtain sugar from the plant flowers, and there was sufficient water from the leachate fraction draining out of each bagged plant. Berries were harvested at least twice weekly from the bushes over 21 weeks (46 harvest dates), and yield (both total berry weight and numbers) recorded. Temperature and humidity were very similar between the glasshouses, and plants were irrigated daily with 2.5-4 L/plant as per the producer's recommendations. Adult C. albifrontalis required at least 1.5 flowers/fly to survive. Both more berries (17.14 kg from 9108 berries vs. 10.43 kg from 6379 berries) and larger berries (1.88 vs. 1.63 g/berry) were produced by the bushes with adult C. albifrontalis present. Mature berries are ready to pick ≈10 weeks after flower opening. This study showed that yield between the two treatments began to differ 11 weeks after the flies were first released. Berry yield remained higher in the house with flies (11.29 kg from 6177 berries at 1.83 g/berry) compared with those plants without flies (4.98 kg from 3427 berries at 1.45 g/berry. Berry size was positively correlated with seed numbers. This is the first demonstration under controlled conditions of the ability of an Australian calliphorid blowfly to pollinate and increase yield of commercial blueberry bushes.

Stable fly (Stomoxys calcitrans L.) remain a significant pest affecting livestock and rural communities on the Swan Coastal Plain around Perth, Western Australia. Vegetable crop residues remaining after harvest enable stable fly development. Left untreated they can produce from several hundred to >1,000 stable fly/m2 of post-harvest residues. We studied the effect of burial and compaction of sandy soils on adult emergence of stable fly and house fly (Musca domestica L.) (Diptera: Muscidae). Adults of both fly species can move up through 50 cm of loose, dry sand, however at depths greater than 60 cm, emergence rapidly declines with <5% of adults surviving under 100 cm of soil. Burial of stable fly larvae and pupae under 15 cm of soil followed by compaction using a static weight dramatically reduced adult emergence. Moist soil compacted at ≥3 t/m2 completely prevented stable fly emergence whereas house fly emergence was not affected. One t/m2 of compaction resulted in <5% emergence of stable fly buried as pupae. Soil that was easily compactible (i.e., high silt, fine sand and clay content) reduced stable fly emergence more than soil with more coarse sand and low clay content. This study demonstrates the potential for a novel and chemical-free option for controlling stable fly development from vegetable crop post-harvest residue. Field trials are needed to confirm that burial and compaction of vegetable post-harvest residues using agricultural machinery can dramatically reduce the subsequent emergence of adult stable fly on a large scale.

Spent poultry litter use as a fertilizer in horticulture supports stable fly Stomoxys calcitrans (L.) (Diptera: Muscidae) development. Stable fly continues to have an economic impact on livestock production and rural lifestyle in south-western Australia. The use of raw poultry manure is banned in 12 Shires surrounding Perth. The loss of market options for West Australian broiler growers has caused economic hardship. Hence, this study examined a range of chemical and biological amendments to spent poultry broiler litter in preventing stable fly and nuisance fly development. These included alkalizers (i.e., lime sand, quicklime, soda ash, and shell grit), acidifiers (aluminum sulfate, sodium bisulfate), gypsum, zeolite, spongolite, calcium cyanamide, and two fungal agents. The treated litters were placed under irrigation in horticulture with amendments added prior to them being exposed in the field as replicate 1-liter pads. In total, 19,559 stable flies developed from the spent litters exposed over five field experiments (88.7% of all flies recovered). House flies (Musca domestica L. (Diptera: Muscidae); 2,067 or 9.4%), false stable flies (Muscina stabulans Fallén (Diptera: Muscidae); 414 or 1.9%), and two sarcophagids (flesh fly) also developed from the litter. Borax completely prevented any fly development from the litter. Calcium cyanamide (1-2.5% v/v) and sodium bisulfate (10%) reduced stable fly numbers by as much as 99-100% when added to litter. Alkalizers, zeolite, spongolite, and entomopathogenic fungi had no significant impact on stable fly development. The addition of either calcium cyanamide or sodium bisulfate to raw litter can boost the fertilizer value of the litter while preventing stable fly development.