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Spitfire sawfly

The spitfire sawfly refers to the larvae of several species of sawflies in the family Pergidae, subfamily Perginae, particularly Perga affinis, a native to south-eastern . These larvae, often mistaken for caterpillars, are gregarious, bristly grubs growing up to 5 cm long, with colors ranging from tan to dark brown or black, a black head, and an at the rear; they cluster in groups of 10 or more on branches during the day and feed nocturnally on leaves. The name "spitfire" stems from their defensive behavior of raising the and regurgitating a mustard-yellow, irritating fluid derived from compounds, which deters predators but is harmless to humans. Adult spitfire sawflies are short-lived, four-winged wasps lacking stingers, measuring 4–18 in length, and emerging after pupation to lay eggs without feeding. Females deposit eggs in rafts or slits within leaves or bark, where they hatch in 2–8 weeks; the larvae then undergo six instars over 3–4 months, using vibrational signals like twitching and tapping to coordinate group movement before burrowing into to form protective cocoons. Pupation can last from a few months to 4 years due to , with adults living only 7–9 days, mostly as parthenogenetic females producing fertile eggs without mating. These sawflies inhabit eucalypt woodlands, forests, and urban areas across temperate to subtropical eastern , from to , where they play a role in the ecosystem as herbivores and prey for , parasitic wasps, and tachinid flies. While generally harmless, heavy larval infestations can cause significant defoliation in young plantations, potentially reducing tree vigor or leading to mortality, though widespread damage is rare and natural predators often control populations.

Taxonomy and nomenclature

Classification

The spitfire sawfly is scientifically known by the binomial name Perga affinis Kirby, 1882. Its full taxonomic classification places it within the following hierarchy: Animalia, Arthropoda, Insecta, Hymenoptera, Suborder Symphyta, Superfamily Tenthredinoidea, Family Pergidae, Subfamily Perginae, Genus Perga, Species P. affinis. Sawflies like P. affinis belong to the Suborder Symphyta, which comprises primitive hymenopterans characterized by the absence of a constricted "" and lacking the advanced or social behaviors of true wasps in the Suborder . The Family Pergidae, endemic largely to the , includes over 450 species, with the Perginae representing a significant Australasian that includes the Perga. The species was first described by William Forsell Kirby in 1882, based on male specimens from the collection, in his monograph on and Siricidae.

Common names and etymology

The "spitfire sawfly" primarily refers to species in the genus within the family Pergidae, with Perga affinis being the most frequently associated taxon in contexts. The term "spitfire" is a colloquial broadly applied to the larvae of several Pergidae species, evoking their defensive behavior rather than any literal fire-spitting. The of "spitfire" originates from the larvae's remarkable defense mechanism: when threatened, they rear up in groups and regurgitate a yellowish, irritating fluid derived from oils ingested during feeding, which mimics the act of spitting. This fluid, often mustard-colored and acrid, can cause or eye in humans but serves primarily to deter predators, giving the appearance of a fiery expulsion. Alternative common names include "spitfire ," reflecting the larval stage's grub-like form, and " ," highlighting their association with host plants. In cultural lore, spitfire sawflies, often called "spitfire bugs," hold a place in childhood , where tales of their clustered defensive displays on gum trees were used to caution children against disturbing , blending wonder with mild warnings of irritation. These references underscore their role as an iconic, if sometimes mythologized, element of rural and suburban encounters with native .

Morphology

Adult morphology

The adult Spitfire sawfly (Perga affinis) measures up to 25 mm in body length and possesses a of up to 40 mm. These dimensions contribute to its wasp-like appearance, facilitating flight for mate location and oviposition, though adults are short-lived and rarely observed in the field. The body exhibits a predominantly black to brown coloration, accented by yellowish markings on the and , which may serve as aposematic signals or of more dangerous hymenopterans. Unlike true wasps, the connects broadly to the thorax without a constricted "," a characteristic feature of Symphyta sawflies. The wings are (transparent) with prominent dark veins and are typically held flat over the body at rest, aiding in identification from other . The antennae are geniculate (elbowed) with a filiform structure, comprising 6 segments that are shorter than the combined head and lengths; this configuration enhances sensory capabilities for detecting host plants and pheromones during the brief adult phase. Females possess a distinctive saw-like , formed by modified valvulae with serrated edges, enabling precise incision into eucalypt leaves for egg deposition. This structure underscores the species' phytophagous lifestyle, though adults themselves do not feed.

Larval morphology

The larvae of the spitfire sawfly (Perga affinis) possess a segmented, cylindrical body that mimics the form of a , but differs in having three pairs of true thoracic legs and up to eight pairs of abdominal for locomotion. This proleg count serves as a key morphological distinction from true , which typically have five or fewer pairs. Mature larvae reach lengths of up to 80 mm, enabling them to consume substantial amounts of foliage during their development. Body coloration in P. affinis larvae varies between dark blue-black and yellow-brown forms, with shifts occurring across instars and influenced by geographic location. The is sparsely covered in short white bristles, which contribute to a textured surface and may aid in sensory perception or on foliage. The head capsule is small and sclerotized, featuring robust chewing mouthparts specialized for rasping and ingesting tough leaves. Reflecting their gregarious lifestyle, the larvae often adopt a clustered posture, aligning in compact groups or linear trains with heads and tails interlocked to facilitate coordinated movement and defense. This arrangement enhances group cohesion during foraging excursions on host plants.

Distribution and habitat

Geographic distribution

The spitfire sawfly (Perga affinis), a native hymenopteran of the Pergidae, is primarily distributed across southeastern . Its range encompasses the Australian Capital Territory, , , , , and extends marginally into southeast Queensland. Historical records date back to the , with the species first formally described by Kirby in 1882 based on specimens from southeastern Australian states. This distribution is closely associated with temperate to subtropical zones, particularly areas receiving 450–700 mm (18–28 inches) of average annual rainfall, where woodlands predominate. The species' presence is influenced by seasonal and patterns from October to March, which affect larval survival and host availability in these habitats. Populations remain confined to their native range, with no documented major invasive spread beyond ; fluctuations in abundance are linked to climatic variability and the health of host plants.

Host plants and ecology

The spitfire sawfly (Perga affinis), a member of the family Pergidae, primarily feeds on foliage and young shoots of various Eucalyptus species, including E. viminalis and E. globulus. Other preferred hosts include species from the genera Melaleuca and Callistemon, all within the Myrtaceae family, reflecting the insect's specialization on native Australian sclerophyll vegetation. Larvae typically aggregate on host branches during the day and disperse nocturnally to consume leaves, contributing to defoliation in affected stands. As a key in eucalypt-dominated ecosystems, the spitfire sawfly plays a role in nutrient cycling and plant regulation within these forests, where insect grazing influences tree growth and community dynamics. Its populations exhibit fluctuations driven by environmental factors, underscoring its integration into broader ecological processes such as herbivory-mediated energy transfer. The species interacts extensively with native parasitoids, including tachinid flies (Froggattimyia spp.) and the trigonalid wasp (Taeniogonalos venatoria), which regulate larval and pupal survival rates. These interactions, combined with predation by , help maintain population balance in settings. Pupation success is particularly influenced by levels and , with posing a major mortality risk in drier conditions. Spitfire sawflies inhabit open forests, woodlands, and plantations across temperate to subtropical regions of eastern , favoring mesic environments over arid interiors. This distribution aligns with the availability of suitable host plants and suitable pupation substrates in leaf litter or soil.

Egg stage

The egg stage initiates the of the spitfire sawfly (Perga affinis), a parthenogenetic process where unmated females deposit eggs on host plants. Using their saw-like , females abrade the leaf surface for several hours before cutting slits into the tissue and inserting eggs in closely spaced rows perpendicular to the midrib, typically forming a single long row known as an "egg raft" between the upper and lower leaf layers. This oviposition occurs during autumn in southeastern , from January to May, aligning with the availability of suitable foliage for subsequent larval feeding. Females exhibit variable , with each capable of laying between 34 and 86 eggs on average, though some sources indicate potential for up to 100 eggs per female depending on individual condition. The eggs are small, measuring approximately 3.5 mm in length on average, and pale yellowish in color, allowing them to blend effectively with the surrounding leaf tissue for against predators. Laid in rafts within the protected slits, the eggs remain immobile and dependent on ambient conditions for development. The embryonic development period lasts 2-8 weeks, after which the first-instar larvae hatch by chewing through the . This brief but critical phase sets the foundation for the gregarious larval colonies that follow.

Larval stage

The larval stage of the spitfire sawfly (Perga affinis) commences upon hatching and spans 3-4 months, with activity peaking from late winter to spring (July-November) in . During this period, larvae progress through six instars, feeding intensively on foliage to support rapid development. Environmental factors, such as temperature and group size, significantly influence growth rates, with larger aggregations often enhancing and accelerating development. Larvae exhibit substantial morphological changes across instars, growing from small hatchlings to lengths of up to 50 mm by maturity. Each molt accommodates this expansion, allowing the larvae to consume larger quantities of leaves and increase in overall robustness. The body develops a covering of short white bristles, which may contribute to defensive traits, though primary growth is driven by nutrient intake from host plants. Social behavior is a hallmark of this stage, with larvae forming sibling colonies that aggregate in clusters of 20-30 individuals during daylight hours for mutual protection against predators. At night, these groups coordinate via vibrational signals—such as tapping and contracting—to march in orderly lines toward feeding sites on higher branches, dispersing briefly to graze before regrouping. This collective movement optimizes foraging efficiency and minimizes individual risk. If environmental conditions prove unfavorable, such as during prolonged dry periods or low temperatures, mature larvae into the to form cocoons and enter a prepupal prior to pupation, delaying development to ensure survival. This facultative can extend for up to four years, allowing synchronization with more suitable seasonal cues for emergence, though most individuals complete the in about 1 year.

Pupal and adult stages

Following the larval stage, mature larvae of the spitfire sawfly (Perga affinis) burrow into the at the base of trees to pupate. They construct leathery cocoons, typically measuring 15-20 mm in length, often clustered several centimeters deep in the . The pupal stage is characterized by a facultative that typically lasts about 1 year, though it can extend up to 4 years, allowing the to endure unfavorable environmental conditions and synchronize development with availability. This prolonged contributes to the univoltine , with a single generation per year adapted to the seasonal of hosts. Adults eclose in autumn, with emergence timed to coincide with leaf flushing for optimal oviposition sites. The short-lived adults, surviving 7-9 days, focus primarily on and egg-laying, with females capable of parthenogenetic in the absence of males.

Behavior and interactions

Feeding behavior

The larvae of the spitfire sawfly, primarily species such as Perga affinis, exhibit exclusive folivory, consuming leaves and young shoots of eucalypt trees (Eucalyptus spp.) and related Myrtaceae like paperbarks (Melaleuca spp.) and tea trees (Leptospermum spp.). Unlike some other sawfly larvae that skeletonize leaves by feeding between veins, spitfire sawfly larvae typically devour entire leaves, often starting from the margins and progressing inward, which enables them to rapidly defoliate branches. Feeding activity is strictly nocturnal, with larvae dispersing from daytime resting clusters to forage under cover of darkness, thereby reducing risks of in the hot daytime climate and avoiding diurnal predators such as . During the day, the larvae aggregate tightly on stems or trunks, forming conspicuous groups that enhance and predator deterrence through collective behaviors. This temporal partitioning of activity allows efficient resource exploitation while minimizing environmental stresses. In group dynamics, the larvae display cooperative foraging patterns, often moving in processions led by experienced individuals to locate food sources, which benefits followers by improving efficiency and growth rates. These aggregations facilitate targeted defoliation, with a noted preference for tender new growth on host plants, as older foliage contains higher concentrations of deterrents like sideroxylonal-A that can reduce feeding rates. Such collective strategies amplify the impact on host trees while optimizing nutrient intake for the . To cope with the high levels of toxic essential oils in foliage, spitfire sawfly larvae have evolved specialized nutritional adaptations, including mechanical filtration via brush-like mandibular scopae that extract and divert oils into pouches before ingestion. Complementary chemical occurs in the , aided by that produce to emulsify and neutralize oil toxins, enabling safe consumption of otherwise unpalatable plant material. These mechanisms not only support survival on defended hosts but also allow the larvae to sequester oils for defensive purposes.

Defensive mechanisms

The larvae of the spitfire sawfly (Perga affinis) employ a combination of chemical, behavioral, and physical defenses to deter predators, primarily during their vulnerable larval stage. These mechanisms are particularly effective against predators but less so against specialized natural enemies. The primary involves the sequestration and regurgitation of eucalyptus-derived oils stored in a diverticular pouch of the . When disturbed, larvae eject a strong-smelling, yellow-green rich in these oils, which causes to the eyes, mouth, and skin of predators such as , , and small mammals. This defensive secretion, chromatographically identical to oils from their host eucalyptus leaves, is the origin of the common name "spitfire" due to its startling and deterrent effect. Behaviorally, larvae respond to threats by rearing up their anterior body in a synchronized display, often in groups, while projecting the fluid in arcs up to approximately 20 cm. This collective head-waving and regurgitation enhances the visual and olfactory warning, amplifying deterrence through and the dilution of individual risk in aggregations. Physically, the larvae's body is sparsely covered with short white bristles, which, combined with their gregarious aggregation into dense clusters, further discourages attacks from and by increasing handling difficulty and perceived threat. Additionally, the sequestered toxins render the larvae unpalatable and potentially toxic to predators, reinforcing avoidance behaviors in species like and mice. Despite these defenses, P. affinis larvae are avoided by most vertebrates but remain susceptible to specialist parasitoids, such as ichneumonid wasps, which can overcome chemical barriers to oviposit internally.

Economic and ecological impact

Damage to vegetation

The larvae of the spitfire sawfly (Perga affinis) cause defoliation by feeding gregariously on the foliage of young eucalypts and regrowth stems, often skeletonizing leaves or stripping entire branches during periods of abundance. This phytophagous activity targets host in the genus , particularly in eastern Australian woodlands, where clustered larvae can denude upper canopies of saplings. Damage is typically not lethal to mature trees, which exhibit through rapid leaf regrowth; however, it severely impacts establishing saplings and young trees up to six years old, potentially reducing vigor and form through repeated or extensive leaf loss. In such cases, whole individual trees may be defoliated, with rare instances of mortality under sustained pressure, while mature specimens are infested only during outbreaks indicating high population levels. Outbreaks follow cyclic patterns influenced by weather conditions, particularly October–March rainfall and temperatures that favor larval survival and host availability; these events are more prevalent in ecologically uniform areas with suitable soils for pupation, such as light-textured riverine sites. Historical observations note periodic surges in abundance affecting southeastern forests, though widespread defoliation remains uncommon outside localized hotspots. Ecologically, spitfire sawfly defoliation results in temporary canopy reduction, but affected eucalypts often recover via epicormic sprouting, preserving overall forest structure over time. Persistent low-level infestations on preferred hosts like Eucalyptus blakelyi, E. camaldulensis, and E. melliodora contribute to natural herbivory dynamics without long-term ecosystem disruption.

Management and control

Management of the spitfire sawfly (Perga affinis) primarily focuses on integrated approaches that minimize environmental impact while protecting host plants such as eucalypts in gardens, plantations, and natural settings. Control measures are often unnecessary for mature , as a single defoliation event typically causes little long-term harm, but intervention may be required for young saplings or high-value plantings where larval feeding leads to significant of leaves. Cultural controls emphasize non-chemical methods suitable for home gardens and small-scale plantings. Manual removal involves knocking or washing larval clusters from branches using a strong water spray or by hand-picking and destroying them, particularly effective on smaller trees during the larval stage. infested branches and disposing of them by or deep prevents further spread and reduces population buildup. These practices are recommended for early intervention when infestations are localized. Biological controls leverage natural enemies to regulate populations without human intervention. Predatory birds, such as small insectivorous species, consume eggs, while larger birds target larvae; parasitoid wasps and tachinid flies attack larval stages, laying eggs inside hosts that develop into parasites. Encouraging these beneficial organisms through habitat diversity, such as maintaining native vegetation, enhances natural suppression in affected areas. Diseases, including fungal pathogens, also contribute to larval mortality under favorable conditions. Chemical options are used judiciously to avoid disrupting beneficial and are targeted at young larvae for best . Insecticidal soaps and provide contact control on small larvae, while registered synthetic insecticides, such as pyrethroids, can be applied to saplings when populations exceed tolerable levels. Broad-spectrum insecticides are discouraged to preserve predators and parasitoids, aligning with sustainable practices. Applications should follow label instructions and be timed for active larval feeding periods. Monitoring is essential for timely management, particularly in eucalypt plantations where (IPM) principles are used to balance economic and ecological needs. Regular scouting for egg clusters on foliage during adult emergence (typically in eastern ) and early larval signs, such as grouped feeding on leaves, allows for proactive measures.

References

  1. [1]
    Steel-blue sawflies
    ### Summary of Steel-blue Sawfly
  2. [2]
    Perga affinis
    Perga affinis is also known as the Australian spitfire sawfly. The adult female sawfly lays her eggs underneath the surface of leavesl.
  3. [3]
    Eucalypt sawflies | Business Queensland
    Mar 7, 2024 · Eucalypt sawflies are also known as clustering sawflies or spitfires. The larvae are often seen in clumps on stems.
  4. [4]
    Everything you didn't need to know about spitfire bugs
    Jul 22, 2021 · The term spitfire is slang for sawfly babies, technically larvae. They are bristly black grubs that look like strange caterpillars and grow into wasps.
  5. [5]
    Great balls of spitfires - CSIRO
    Nov 16, 2018 · The term spitfire is most commonly a slang term for several species of sawfly larvae from the family Pergidae. Despite the name, the larvae ...
  6. [6]
    Species Perga affinis Kirby, 1882 - Australian Faunal Directory
    Perga affinis atrata Riek, E.F. 1961. The distribution and inter-relationships of Perga affinis Kirby and Perga dorsalis Leach (Hymenoptera, Symphyta).
  7. [7]
    Pergidae | Sawfly GenUS - IDtools
    Tenthrediniodea Family: Pergidae Family common name: pergid sawflies. Subfamilies: Acordulecerinae, Conocoxinae, Euryinae, Loboceratinae, Parasyzygoniinae, ...
  8. [8]
    Wood Wasps and Sawflies - Insects - Amateur Entomologists' Society
    The suborder Symphyta (Wood Wasps and Sawflies) includes those Hymenoptera which are structurally most primitive. There are approximately 500 species present ...
  9. [9]
    Chemical and visual ecology of the Symphyta - Guignard - 2022
    May 12, 2022 · The Symphyta is an older paraphyletic group that contains the primitive Hymenoptera (woodwasps, horntails and sawflies). The younger suborder, ...<|control11|><|separator|>
  10. [10]
    Family PERGIDAE - Australian Faunal Directory
    The Pergidae are divided into a number of subfamiles, including the Perginae (58 spp.) and Phylacteophagainae (5 spp.). The former subfamily includes Perga spp.
  11. [11]
    Sawflies - The Australian Museum
    Their name comes from the female's saw-like egg-laying tube, which she uses to make a slit in a plant leaf or stem, into which she lays her eggs.
  12. [12]
    Spitfire sawfly - Facts, Diet, Habitat & Pictures on Animalia.bio
    The spitfire sawfly (Perga affinis, family Pergidae) is a hymenopteran insect found in Australia. It is up to 22 mm long, has two pairs of wings, ...
  13. [13]
    Biology:Spitfire sawfly - HandWiki
    The spitfire sawfly (Perga affinis, family Pergidae) is a hymenopteran insect found in Australia . It is up to 22 mm long, has two pairs of wings, ...Missing: taxonomy | Show results with:taxonomy
  14. [14]
    SAWFLIES AND SPITFIRES - Professional Pest Manager
    May 30, 2022 · These caterpillar-like pests gather in groups and threaten predators with poisonous spit, giving them their common name – spitfires.
  15. [15]
    Morphology | Sawfly GenUS - IDtools
    Morphology. Like all insects, sawflies have three body segments and three pairs of legs. The head includes a pair of compound eyes, a trio of simple eyes ...
  16. [16]
    the anatomy of the sawfly perga affinis affinis kirby - ConnectSci
    Summary. This paper is an account of the anatomy of the larval and adult stages of the sawfly Perga afinis afinis Kirby. Particular attention has been paid ...Missing: original | Show results with:original
  17. [17]
    Perga species identification - Life in a Southern Forest
    Jun 26, 2024 · Antennae 5 or 6-segmented with club. Antennae shorter than ... (Species without a link have no RG observations at this time). Perga affinis ...
  18. [18]
    Saw Fly Larvae: Spitfires - Australian Lepidoptera
    Sawfly larvae are not true Caterpillars, but are the larvae of various species of wasps, or more accurately Symphyta. They have 3 pairs of true legs, and up to ...
  19. [19]
    The characteristics and bhaviour of the Saw-Fly Perga affinis affinis ...
    The characteristics and bhaviour of the Saw-Fly Perga affinis affinis (Hymenoptera). PB Carne. Australian Journal of Zoology 10(1) 1 - 34. Published: 1962 ...
  20. [20]
    Sawflies: Suborder Symphyta - The Australian Museum
    Larvae are caterpillar-like and feed on plant material. The egg-laying apparatus (ovipositor) of most species looks like a saw, which gives them their name.
  21. [21]
  22. [22]
    On the population dynamics of the Eucalypt-defoliating sawfly Perga ...
    A variable proportion of the prepupae entered a diapause which persisted for 2 or more years. Although extended diapause ensured the survival of the subspecies ...Missing: pupal | Show results with:pupal
  23. [23]
    On the ecological role of insects in Australian eucalypt forests
    A slow nutrient cycle is maintained by the trees while a smaller pool of nutrients is rapidly recycled in the litter and understorey. Insects skim off nutrients ...Missing: parasitoids | Show results with:parasitoids
  24. [24]
    [PDF] Insect Treatments for Eucalypts - Elm Leaf Beetle Control | Elmsavers
    egg laying occurs from January to May, females die after egg laying. •. The ... The whole life cycle takes approximately 1-2 months but may be longer ...
  25. [25]
    Six things about sawflies - Life in a Southern Forest
    Oct 28, 2022 · The feeding biology of the familiar Steelblue or Spitfire Sawfly (Perga affinis) is well understood (ref. 3). The larvae are gregarious ...
  26. [26]
    Examining potential benefits of group living in a sawfly larva, Perga ...
    Although P. affinis lives gregariously for its entire larval stage, group size changes dramatically over time (Carne 1962), increasing to vast numbers in the ...
  27. [27]
    Susceptibility of Eucalyptus globulus ssp. globulus to sawfly (Perga ...
    On the population dynamics of the sawfly Perga affinis affinis Kirby (Hymenoptera) ... based on growth characteristics in Tasmania and geographic distribution.
  28. [28]
    Leaders benefit followers in the collective movement of a social sawfly
    Larval aggregations of the steel-blue sawfly Perga affinis forage ... In rare instances, when an aggregation splits into multiple directions, the first larva in ...<|control11|><|separator|>
  29. [29]
    On the population dynamics of the Eucalypt-defoliating sawfly Perga ...
    a. affinis were recorded during eight successive years in a study region extending from the Southern Tablelands of New South Wales to north-eastern Victoria.
  30. [30]
    Host plant adaptations in myrtaceous-feeding Pergid sawflies ...
    We describe a novel morphological adaptation of the inner mandibular surface of larval stage Pergagrapta species, which feed on leaves of Melaleuca ...
  31. [31]
    Leadership Behaviour in Sawfly Larvae Perga dorsalis (Hymenoptera
    Australian sawflies in the genus Perga have gregarious larvae which disperse to feed upon Eucalyptus foliage at night. To investigate possible polyethism in ...Missing: fluctuations | Show results with:fluctuations
  32. [32]
    The effect of sideroxylonal-A on feeding of steelblue sawfly, Perga ...
    Insect herbivory on Eucalyptus. Annual Review of Entomology 36, 637–657 ... Pergagrapta polita Leach (Hymenoptera: Pergidae) feeding on two Eucalyptus species.
  33. [33]
    Chemical detoxification vs mechanical removal of host plant toxins ...
    ▷ Australian sawflies deal with toxic components in their host plants differently. ▷ Pergine larvae have brush-like structures on their mandibles for separating ...
  34. [34]
    Chemical Detoxification vs Mechanical Removal of Host Plant ...
    Some of the eight Australian subfamilies in the sawfly family Pergidae are associated exclusively with Eucalyptus and Melaleuca species that often have high ...Missing: Perga | Show results with:Perga
  35. [35]
    Chemical detoxification vs mechanical removal of host plant toxins ...
    Australian spitfire sawfly larvae sequester oils from eucalyptus plants and store them in oesophageal pouches which when regurgitated helps in defence ...
  36. [36]
  37. [37]
  38. [38]
    Distribution of the eucalypt-defoliating sawfly Perga affinis affinis ...
    The distribution of the insect is influenced strongly by climatic factors, the rainfall and temperature statistics for the critical period October-March for ...
  39. [39]
    Spitfires — Bug Busters-R-Us Pest Control, Melbourne
    On saplings and smaller trees, clusters of larvae can be knocked or washed off or removed by hand and killed. Otherwise, a registered sawfly insecticide (with ...
  40. [40]
    Sawfly Larvae Control in Your Garden - Yates Australia
    The larvae regurgitate these stored oils just before feeding or during feeding, as well as when provoked by predators. The oils are toxic to the Sawfly larvae ...Missing: nocturnal reason