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Background Yersinia entomophaga is an entomopathogenic bacterium that is active against scarab beetles, among other insects. In New Zealand, the African black beetle, Heteronychus arator (Coleoptera: Scarabaeidae), is a major pest of pastures and arable crops but very few control options exist and no insecticides are registered for use in established pastures. Results In laboratory bioassays, H. arator adults were susceptible to a bait containing Y. entomophaga at low doses. This bait was more effective against H. arator adults during spring than autumn in small-scale field plots (320 mm diameter). A large-scale field trial (40 × 40 m plots) reduced adult numbers substantially: approximately twice as many beetles were captured in pitfall traps from untreated plots compared with plots treated with the Y. entomophaga bait at 70 kg ha-1 . This single bait application in spring also reduced subsequent larval populations in summer. Conclusions Heteronychus arator is a difficult pest to manage using chemical insecticides. This biopesticide with Y. entomophaga as the active ingredient offers a new solution for New Zealand pastures, with potential for application to other crops affected by H. arator and for control of other pests. © 2020 Society of Chemical Industry.

Beauveria pseudobassiana formed three-dimensional aggregates of cells (CAs) in liquid culture. CAs were formed mainly by blastospores and conidia, distinct from microsclerotia formed through adhesion of hyphae. The formation, germination and sporulation of CAs were studied, as well as the pathogenicity of conidia produced from them against adults of black beetle. After 4 days of culture, CAs were formed, becoming compact and melanised after 10 days of incubation. Electron microscopy showed three-dimensional CAs averaging 431.65 µm in length with irregular shapes and rough surfaces, where cells were trapped within an extracellular matrix. CAs germinated after 2 days of incubation on agar-plates producing hyphae and forming phialides and conidia after 4 days. Produced conidia caused 45% mortality of black beetle adults. CAs germination and sporulation on soil were directly correlated with soil moisture, reaching 80% and 100% germination on the surface of soil with 17% and 30% moisture, respectively. CAs maintained 100% germination after 2 years of storage under refrigeration. These CAs could have a similar function as microsclerotia in nature, acting as resistant structures able to protect internal cells and their ability to sporulate producing infective conidia, suggesting their potential to be used as bioinsecticides to control soil-dwelling insects.

Epichloë endophytes are filamentous fungi (family Clavicipitaceae) that live in symbiotic associations with grasses in the sub family Poöideae. In New Zealand, E. festucae var. lolii confers significant resistance to perennial ryegrass (Lolium perenne) against insect and animal herbivory and is an essential component of pastoral agriculture, where ryegrass is a major forage species. The fungus produces in planta a range of bioactive secondary metabolites, including ergovaline, which has demonstrated bioactivity against the important pasture pest black beetle, but can also cause mammalian toxicosis. We genetically modified E. festucae var. lolii strain AR5 to eliminate key enzymatic steps in the ergovaline pathway to determine if intermediate ergot alkaloid compounds can still provide insecticidal benefits in the absence of the toxic end product ergovaline. Four genes (dmaW, easG, cloA, and lpsB) spanning the pathway were deleted and each deletion mutant was inoculated into five different plant genotypes of perennial ryegrass, which were later harvested for a full chemical analysis of the ergot alkaloid compounds produced. These associations were also used in a black beetle feeding deterrence study. Deterrence was seen with just chanoclavine present, but was cumulative as more intermediate compounds in the pathway were made available. Ergovaline was not detected in any of the deletion associations, indicating that bioactivity towards black beetle can be obtained in the absence of this mammalian toxin.

Black beetle attacks pasture grasses in the northern and coastal North Island and with a warming climate, the beetle has extended its range and damage has become more prevalent. On-farm investigations into prevention of damaging populations suggested that black beetle density was inversely related to soil pH. Two replicated block experiments, the first in 2013-2015 on two farms, and the second on four farms in 2015-2017 investigated the effects of late spring agricultural lime applications at the rate of 5 tonne/ha on summer black beetle populations. The results showed that lime can help suppress black beetle populations. Importantly, the effect of lime persisted into the second year in Trial 2, preventing larval populations reaching damaging levels of over 40/m2. This adds to the already well-known benefits of lime in improving soil health and pasture quality, vigour and persistence. Keywords: agricultural lime, soil pH

The insect pests of ginger and their control: Primary discussion is on shoot borer (Conogethes punctiferalis Guen.), infestation, and its control. Further discussion is on rhizome scale (Aspidiella hartii (Cockerell 1895)) and its control and white grubs (Holotrichia spp.) and its control. There is also a discussion on minor pests, such as African black beetle, and also a discussion on nematode infestation and its control.

Epichlo&euml, endophytes are filamentous fungi (family Clavicipitaceae) that live in symbiotic associations with grasses in the sub family Po&ouml, ideae. In New Zealand, E. festucae var. lolii confers significant resistance to perennial ryegrass (Lolium perenne) against insect and animal herbivory and is an essential component of pastoral agriculture, where ryegrass is a major forage species. The fungus produces in planta a range of bioactive secondary metabolites, including ergovaline, which has demonstrated bioactivity against the important pasture pest black beetle, but can also cause mammalian toxicosis. We genetically modified E. festucae var. lolii strain AR5 to eliminate key enzymatic steps in the ergovaline pathway to determine if intermediate ergot alkaloid compounds can still provide insecticidal benefits in the absence of the toxic end product ergovaline. Four genes (dmaW, easG, cloA, and lpsB) spanning the pathway were deleted and each deletion mutant was inoculated into five different plant genotypes of perennial ryegrass, which were later harvested for a full chemical analysis of the ergot alkaloid compounds produced. These associations were also used in a black beetle feeding deterrence study. Deterrence was seen with just chanoclavine present, but was cumulative as more intermediate compounds in the pathway were made available. Ergovaline was not detected in any of the deletion associations, indicating that bioactivity towards black beetle can be obtained in the absence of this mammalian toxin.

An outbreak of the sporadic pest black beetle caused major damage on farms throughout Waikato and Bay of Plenty regions from 2007 to 2010. Two projects were initiated in these regions to gain an understanding of the interaction of black beetle with endophyte/ cultivar combinations and pasture renewal strategies. Monitoring of black beetle populations on the project farms showed that overall, abundance steadily declined from 2009 to 2013, possibly due to cool temperatures, and in the case of Bay of Plenty, high rainfall in 2010. In Waikato, pasture renewal in 2012 had no significant effect on beetle abundance in the following year compared to the unrenewed paddocks. Greater population levels in the Waikato sites were associated with lower soil pH. El Niño and La Niña weather events appear to be associated with changes in black beetle population levels, which may assist prediction of future outbreaks and damage risk. Keywords: Heteronychus arator, pasture, La Niña

African black beetle, Heteronychus arator (Scarabaeidae), is an exotic pest of pastures in northern New Zealand. Both adults and larvae feed on pasture grasses. Adults disperse by walking (short range) or flying (long range). Dispersal flights are triggered by warm night temperatures in spring and autumn. Short range adult dispersal in search of mates, food or oviposition sites is poorly understood. This study investigated walking activity of H. arator adults over three seasons in New Zealand pastures. Adult walking activity was monitored using pitfall traps along fence lines and in pasture plots on a dairy farm in Waikato, New Zealand, in spring 2013, spring 2014, and autumn 2015. Beetle populations were reduced by application of a biopesticide bait to compare walking activity between treated and control plots for up to 26 days post-treatment. Marked beetles were released into the pasture plots to measure the distance traveled by recaptured individuals. Trap catches along the fence lines were correlated with air temperatures in 2013. Trap catches were male biased in spring 2014 compared with autumn 2015. Trap numbers in the control plots were nearly double that of treated plots in both seasons. More beetles were caught in the pitfall traps at the edges of the treated plots than in the center. Trap catches were consistent throughout the control plot in spring 2014, but in autumn 2015 more beetles were caught in the center of the control plot than at the edges. Few marked beetles were recaptured with dispersal rates estimated as

Black beetle (Heteronychus arator) is a sporadic but serious pest of North Island pastures Field trials were established to test the efficacy of insecticides currently registered for use against scarab pests in pasture Three life stages were targeted newly emerged black beetle adults in autumn egglaying adults in spring and newly hatched larvae in early summer Although the insecticides used caused significant beetle mortalities in spring no treatment reduced the subsequent larval populations in summer Similarly while the autumn application caused significant beetle mortality; the number of surviving black beetle adults remaining in the plots was not affected Soil factors and the high mobility of adult beetles are likely to have contributed to treatment failure

An outbreak of the pasture insect pest black beetle began in the Waikato and Bay of Plenty in 2007/8 and has persisted. The extent and severity of damage caused by black beetle during the current outbreak has focused farmer and researcher attention on methods to maintain persistent pasture now and in future outbreaks. This paper reviews previous research in combination with data from the current outbreak and relates these to current pasture management practice. The possibility of being able to predict the distribution, occurrence and duration of black beetle outbreaks is explored while actual and potential means of controlling black beetle are outlined. We conclude that there are methods available to successfully renew pastures in the presence of black beetle but that outbreak situations increase risks and may limit subsequent pasture persistence. There are fewer readily available options to maintain an existing pasture and more research is urgently needed to provide these options. Keywords: Heteronychus arator, paspalum, pasture, pasture renewal, pest resistance, pest tolerance, ryegrass

Black beetle, Oryctes rhinoceros L. larvae and adults were inoculated in thelaboratory with three isolates of the fungus, Metarhizium anisopliae (Metsch.) Sor, toscreen their virulence against black beetle. All the isolates caused 100% mortality oflarvae and adults when treated with suspensions of 107 conidia/ml. Comparatively thelocal isolate caused a slow death rate in larvae and adults than the other isolates. Fiftygrams of the maize inoculum per 0.008 m2 of breeding medium were sufficient to cause100% death rate in larvae. In the field, the fungus was capable of disseminating at least10 m and the impregnation boxes (infection foci) were attractive to black beetle. It issuggested that M. anisopliae could be used as an effective bio-control agent in theintegrated management of black beetle.

African black beetle is a major agricultural and forestry pest in south-western Australia. In this study, we examine the effectiveness of various surface-applied chlorpyrifos treatments for the control of beetle damage in commercial forestry crops. Of those treatments tested, none had a strong, consistent effect on the abundance of the subterranean adult beetles through to 9 weeks after application, nor did they consistently reduce beetle damage or improve crop productivity. When incorporated into soil at rates presently employed successfully in agriculture, chlorpyrifos caused no mortality of adult African black beetles that were added to the soil post-treatment. Chlorpyrifos decays at an exponential rate in soil with 75% of the active ingredient remaining at 1 h post-treatment, 40% at 50 days and 10% remaining after 110 up to 170 days. It appears that the capacity of chlorpyrifos to cause mortality to African black beetle is through vigorous soil incorporation bringing the chemical into direct contact with the insect. Chlorpyrifos applications are not recommended for the control of African black beetle in tree crops because the restrictions on timing and use of soil incorporation techniques will generally mean that the insecticide will not be brought into direct contact with a sufficient proportion of the beetle population.

AR1 is a new fungal endophyte that is being released in perennial ryegrass to New Zealand farmers. This endophyte lacks the mammalian toxins, ergovaline and lolitrem B, but produces peramine which provides resistance to a major ryegrass pest, Argentine stem weevil (Listronotus bonariensis). Black beetle (Heteronychus arator) is another important pest of ryegrass in northern areas of New Zealand. Adults are selective feeders, and avoid feeding on ryegrass infected with wildtype endophyte. A limited supply of suitable food greatly reduces their reproductive capacity. Laboratory and field investigations were therefore carried out to evaluate the degree of resistance to black beetle provided by AR1. Assessments of adult black beetle feeding were made on two field trials planted in autumn 1999. In both trials, adult feeding was significantly higher on ryegrass infected with AR1 than on ryegrass with wild-type but also significantly lower on AR1 than on endophyte-free ryegrass. In a pot trial conducted in summer, black beetle adult damage to 4-week-old AR1-infected ryegrass was no different from damage to endophyte-free plants. However in 6-month-old plants, damage to AR1 plants was significantly less than to endophyte-free plants and was similar to damage levels on wild-type plants. A further pot trial showed that beetles overwintering on AR1 ryegrass had a higher reproductive capacity than those overwintering on wild-type infected ryegrass. In February 2001, two field trials planted the previous June were sampled for black beetle larvae. Black beetle presence was significantly higher on endophyte-free plots than on wild-type plots, with presence on AR1 intermediate between these treatments. Ryegrass infected with AR1, although showing a degree of resistance to black beetle compared with endophyte-free ryegrass, is more susceptible to damage than wild-type, particularly in its first year of planting. Limited data indicate that older AR1 swards may have similar resistance to that of the wild-type but further research is needed to clarify the effect of stand maturity on black beetle damage to ryegrass infected with this new endophyte. Keywords: AR1, black beetle, endophyte, Heteronychus, Listronotus, Neotyphodium, ryegrass

Black beetle (Heteronychus arator) attacks pasture grasses in the northern North Island and with warming temperatures the beetle has extended its range and damage has become more prevalent Onfarm investigations into prevention of damaging populations suggested that black beetle density was inversely related to soil pH Furthermore laboratory experiments indicated that first instar black beetle larval survival declined with increasing soil pH A replicated block experiment in 20132015 on two farms with two sites/farm investigated late spring agricultural lime applications at the rate of 5 tonne/ha on summer black beetle populations Over both summers there was an overall significant reduction in black beetle populations in the lime treatments compared to the untreated plots with peat soil but no overall impact on the farm with ash soil The effect appeared most pronounced in December when the early instars were present A larger trial with eight sites and using the same application rate commenced in 2015 Initial results confirmed previous findings and showed a 41 reduction in December populations and an inverse relationship between soil pH and black beetle abundance in dairy pastures in late summer/early autumn The results suggested that a soil pH of about 6 will both help mitigate black beetle and optimise pasture vigour to withstand the pest

Summary The plantation estate of Eucalyptus globulus in Western Australia, though small in relation to hardwood plantations elsewhere, has generally been free of insect problems. Ten insect species have, however, been recorded causing significant, but sporadic, damage. The four most important are Wingless grasshopper, African black beetle, Leafblister sawfly and Spring beetle. The first two have caused mortality though defoliation and bark chewing respectively and the other two height decrement. Preparation and dissemination of an Insect Manual in 1990 has helped co-ordinate the detection of damaging levels of insects and ensure the use of appropriate control measures. The major deficit in knowledge concerns the economic injury levels for insect species in plantations.

Populations of African black beetle, Heteronychus arator (Fabricius), a subterranean pasture-dwelling pest of potatoes, were examined in pastures in geographically separated potato-growing areas covering 3½° of latitude in southwestern Australia. Abundance of all life stages was estimated by taking soil cores and the reproductive state of females was assessed from the stage of their ovarian development. H. arator adults emerged in late summer-early autumn (January–March), ovaries matured slowly during winter and oviposition occurred in spring (September–November). The interval between equivalent population events was about six weeks from the northernmost to the southernmost regions. Fecundity was estimated to be around 12 eggs/female and greatest natural mortality occurred late in the pre-adult development phase.

Euetheola humilis (Burmeister) é um escarabeídeo praga das culturas do arroz, cana-de-açucar e milho, que ataca as cultura na fase larval e na adulta. A ocorrência de E. humilis foi observada em área florestada com Eucalyptus saligna Smith, pertencente a Votorantim Celulose & Papel (Fazenda Aroeira), no município de Candiota, RS. Plantas de aproximadamente 1m de altura foram danificadas por insetos adultos de E. humilis na região próxima ao colo, desfiando seu córtex, levando algumas à morte. Verificou-se ataque em torno de 10% das plantas de eucalipto, em uma área de aproximadamente 30 ha. Euetheola humilis (Burmeister) is a scarabaeid pest of rice, sugarcane and corn cultures, that attacks the crops during both larval and adult phase. The occurrence of E. humilis was observed in a forest area with Eucalyptus saligna Smith, from Votorantim Celulose & Papel (Fazenda Aroeira), in the Municipality of Candiota, Rio Grande do Sul State. Plants approximately 1m high were damaged by E. humilis adult insects near the stem base, what unraveled its cortex and led some of them to death. The attack was verified in about 10% of the eucalypts plants, in an area of approximately 30 ha.

The Australian black beetle Adoryphorus couloni (also known as the redheaded cockchafer) was found in large numbers in Barrington Park in Christchurch in May 2008 Severely damaged areas comprised 1020 of the park with populations reaching over 300 larvae/m2 The thatch layer produced on sports fields appears ideal for this insect which favours grasslands with high organic matter levels and could explain the very high grub numbers To reach a population of this size A couloni had probably colonised and remained undetected in the park for several years In Australia the insect is a serious pest of pastures Severe damage occurred in Tasmania in the 1980s and 1990s when the insect spread through the central Midlands stripping bare thousands of hectares of pasture The beetle was accidentally introduced to Canterbury through Lyttelton harbour in the 1960s and has slowly spread around the Port Hills in lowquality hill pastures The outbreak in Christchurch marks the first move of this pest into habitat favourable for development of populations large enough to pose a serious risk of further westward expansion onto the Canterbury plains AgResearch is assisting the Christchurch City Council with identification and control recommendations for the pest and is evaluating potential biocontrol measures

(1976). Ovarian Development in Black Beetle, Heteronychus arator (Coleoptera : Scarabaeidae) New Zealand Entomologist: Vol. 6, No. 2, pp. 165-170.

The consumption, utilization and growth of third-instar larvae of black beetle, Heteronychus arator (F.) feeding on roots of ryegrass (Lolium perenne), paspalum (Paspalum ***dilatatum) and white clover (Trifolium repens) were studied. Consumption was greater on the grasses than on white clover when assessed by gravimetric methods, Larvae had a higher growth rate on the grasses. Utilization of the roots of the three species was similar indicating that poor growth on white clover is the result of low consumption probably induced by the presence of feeding deterrents in the roots. ZUSAMMENFASSUNG DIE OEKOLOGIE VON HETERONYCHUS ARATOR (COLEOPTERA, SCARABAEIDAE) EINFLUSS DER PFLANZENART AUF FUTTERAUFNAHME, FUTTER VER WERTUNG UND WACHSTUM DER LARVEN Die Futteraufnahme, die Futterverwertung und das Wachstum von Drittstadiumlarven von H. arator beim Fressen von Wurzeln von Paspalum dilatatum, Raygras (Lolium perenne) und Weissklee (Trifolium repens) wurden gravimetrisch gemessen. Der durchschnittliche Futterverzehrindex auf Grasern war 0.65 mg/mg Larve/Woche verglichen mit 0.18 auf Weissklee. Die relative Wachstumsrate auf Paspalum und Raygras war 0.158 und 0.124 mg/mg Larve/Woche verglichen mit 0.043 auf Weissklee, was den geringen Verzehr an Weisskleewurzel widerspiegelt. Die Verwertung der gefressenen Wurzel war 22%, 18% und 24% fur Paspalum, Raygras und Weissklee. Das Fehlen gesicherter Unterschiede in der Futterverwertung der drei Pflanzenarten deutet darauf hin, dass die geringe Wachstumsrate auf Weissklee bloss durch geringe Futteraufnahme verursacht ist. Es wurde gezeigt, dass in Weisskleewurzel Frasinhibitoren fur H. arator vorhanden sind. Die erhaltenen Schatzungen fur Futteraufnahme durch Scarabaeiden sind die besten Daten fur wurzelfressende Arten und liefern eine Basis, um den Einfluss der Weidepflanzen auf H. arator Populationen zu verstehen.

Crude extracts of root of the resistant pasture plants lucerne (Medicago sativa) and Lotus pedunculatus contain strong feeding deterrents for third instar Costelytra zealandica and Heteronychus arutor larvae. Purified saponins isolated from active crude lucerne root extract markedly reduce grass grub feeding and have an ED of 0.019%. Black beetle larvae are even more sensitive to the material. Separate and chemically distinct feeding deterrent fractions, active against the two insects, have been isolated from Lotus pedunculatus root. The role of feeding deterrents in mediating the non-preference of these insect pests for lucerne and Lotus is discussed.

The influence of pasture plant species oli the aggregation and oviposition behaviour of black beetle adults was examined. Adults tended to aggregate under grass species rather than white clover or bare ground. A preference for grasses, and in particular for Paspolum dilatatum, as oviposition sites was noted. The significance of this to larval development and population sampling is discussed.

Black beetle (Heteronychus arator) and black field cricket (Teleogryllus commodus) may attack pastures in Northland, particularly in dry years. No appreciable pasture production responses to controlling black beetle with insecticides have been measured. In contrast, significant production increases have been obtained from controlling crickets. Crickets can be readily assessed using a simple flushing technique. Effective and economx control can be achieved using maldison grain baits. Drought or black beetle have been wrongly blamed for cricket damage. It is therefore important to correctly identify pest problems so that control measures can be successfully carried out. Keywords: black beetle, black field cricket, damage, control.

The influence Of temperature on the growth and survival of first-instar larvae of black beetle feeding in soil was examined. Similarly the consumption, utilisation, growth, and survival of second- and third-instar larvae feeding on carrot were investigated using gravimetric methods. Soil temperatures in the range 20–25° c were found to be necessary for optimum growth of all instars. First-instar larval growth increased exponentially over the temperature range 10–20°c. Third-instar larvae were tolerant of higher temperatures than second-instar larvae. The temperatures for optimum levels of consumption and utilisation of carrot varied between the instars.

Field monitoring of black beetle, Heteronychus arutor (F.), populations in Waikato pasture showed a strong association between black beetle numbers and the presence of Paspalum dilatatum Poir. Increasing paspalum gave higher adult numbers in spring resulting from increased overwintering survival, and in some seasons, reduced autumn dispersal. Numbers of larvae damaging pasture in February were directly related to adult numbers in September. Black beetle preferentially select paspalum plants in mixed pasture. This can place paspalum at a competitive disadvantage relative to other pasture species, but also permits the retention of higher adult black beetle numbers, even at low paspalum levels.

Pasture production was measured on plots infested with black beetle, Heteronychus arator (F.) (Scarabaeidae: Coleoptera), and insecticide-treated plots from 1983 to 1986 on sandy soils near Kaitaia in Northland. Black beetle densities ranged from 11 to 27/m2 on ryegrass (Lolium perenne L.)—dominant and from 16 to 112/m2 on kikuyu grass (Pennisetum clandestinum Hochst.) —dominant pastures. Livestock pulling plants from the soil caused pasture damage on plots infested with black beetle. Insecticidal control of black beetle, however, resulted in relatively small transient increases in pasture production. In contrast, nitrogen (N) applications significantly boosted production, ranging from 35 and 25 kg dry matter (DM)/kg N in spring to 25 and 17 kg DM/kg in winter for ryegrass- and kikuyu grass-dommant pastures, respectively. Spelling kikuyu grass p~sture from grazing over the summer and autumn III 1985 and 1986 resulted in an increase in pasture production of from 470 to 960 kg DM/ha. The role of bl...

Black beetle, Heteronychus arator (F.), causes sporadic outbreaks of pasture and crop damage. Rational control depends largely upon the accurate prediction of pest numbers. Progress in the development of methods of predicting black beetle populations and damage on a regional basis using spring temperature data, and on a farm or paddock basis using a simple sampling technique and damage thresholds, is reviewed.