Diversity and abundance of lepidopteran stem borers and their host plants in Ethiopia

Lepidopteran stem borers are among the most important insect pests of maize, sorghum and sugarcane in sub‐Saharan Africa. Except for Chilo partellus, the other stem borer pests in Ethiopia are indigenous to Africa and are assumed to have coevolved with some native grasses and sedges in the natural habitat. In addition to pest species, natural habitats harbour diverse non‐economic stem borer species, some of which are new to science. However, with the growing threats to natural habitats, some non‐economic stem borer species may switch or expand their host ranges to include cultivated crops and evolve as “new” pests. Besides host switch, some of the unknown species currently limited to natural habitats may disappear. We examined the diversity, abundance and interactions of lepidopteran stem borers and their wild host plants in five different vegetation mosaics in Ethiopia. The stem borer species diversity varied among vegetation mosaics and host plants. Forty‐four stem borer species belonging to 14 different genera in the families of Noctuidae, Crambidae, Pyralidae and Tortricidae were recorded from 34 wild host plants and through light trap. Among these families, Noctuidae was the highest in species richness in which 31 species were identified, out of which 15 species and two genera were new to science. This paper discusses the ecological interpretation of host plant–stem borer species interactions, particularly in relation to habitat disturbances.     

Diversity and distribution of lepidopteran stemborer species and their host plants in Botswana

Lepidopteran stemborers are amongst the most important insect pests of maize, sorghum and sugarcane in sub-Saharan Africa. With the exception of Chilo partellus (Swinhoe), which was accidentally introduced into Africa, the other stemborer pests are indigenous to the continent and have co-evolved with native grasses and sedges. In addition to pest species, wild habitats harbour diverse non-economic stemborer species, some of which are new to science. However, the diversity and distribution of both non-economic and pest species of stemborer are currently mostly unknown in Botswana. Accordingly, country-wide surveys were conducted during 2014/15 and 2015/16 austral summer to determine species diversity and distribution in cultivated and wild host plants of stemborers in Botswana. A total of 1597 stemborer larvae and 228 pupae were collected, constituting 63.1 and 36.9 larvae and 84.8 and 15.2% pupae from cultivated versus wild habitats, respectively. In addition to C. partellus, Sesamia calamistis Hampson and Eldana saccharina Walker which were previously reported, 12 more stemborer species were recorded for the first time in Botswana, including nine undescribed species. These species were from the Sciomesa, Sesamia and Conicofrontia genera and Tortricidae and Pyralidae families. Fourteen wild host and two cultivated host plant species of stemborers were recorded. Chilo partellus was most abundant (89.5%) in cultivated habitats whilst E. saccharina (33.6%) was most abundant in wild habitats. Stemborer species diversity was higher in wild habitats than cultivated. Current results highlight the significance of wild, especially wetland habitats for ecological functions and conservation of lepidopteran stemborer biodiversity.     

First report of Chilo partellus in Turkey,a new invasive maize pest for Europe

The spotted stem borer, Chilo partellus (Swinhoe, 1885) (Lepidoptera: Crambidae), an invasive pest of wild and cultivated grasses in Asia and Africa, was found for the first time during periodic surveys of maize fields in the East Mediterranean region of Turkey in September and October 2014. The pest was recorded in maize fields of three of four provinces surveyed (Adana, Hatay and Osmaniye; it was not detected in Icel province). The Mediterranean corn stalk borer, Sesamia nonagrioides Lefebvre (Lepidoptera: Noctuidae), is the dominant maize pest in the East Mediterranean region of Turkey, followed by the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae). The new invasive species comprised 4.9% of the total number of collected lepidopteran pests collected from maize stems and cobs in locations infested by C. partellus. No natural enemies of the new pest were recorded during our surveys. We discuss possible interactions among these three lepidopteran pests sharing the same habitat, prospects for control of C. partellus by the control methods currently used against S. nonagrioides and O. nubilalis, and also speculate on the path of invasion taken by C. partellus into Turkey.     

The role of wild host plants in the abundance of lepidopteran stem borers along altitudinal gradient in Kenya

Presence of wild host plants of stem borers in cereal-growing areas has been considered as reservoirs of lepidopteran stem borers, responsible for attack of crops during the growing season. Surveys to catalogue hosts and borers as well as to assess the abundance of the hosts were carried out during the cropping and non-cropping seasons in different agro-ecological zones along varying altitude gradient in Kenya. A total of 61 stem borer species belonging to families Noctuidae (25), Crambidae (14), Pyralidae (9), Tortricidae (11) and Cossidae (2) were recovered from 42 wild plant species. Two noctuids, Busseola fusca (Fuller), Sesamia calamistis Hampson, and two crambids, Chilo partellus (Swinhoe) and Chilo orichalcociliellus (Strand) were the four main borer species found associated with maize plants. In the wild, B. fusca was recovered from a limited number of host plant species and among them were Sorghum arundinaceum (Desvaux) Stapf, Setaria megaphylla (Steudel) T. Durand & Schinz, Arundo donax L. and Pennisetum purpureum Schumacher. In contrast, the host range of C. partellus was considerably wider [13 for S. calamistis]. However, the number of larvae of these species was lower in the wild compared to cultivated fields, thus the role of natural habitat as a reservoir for cereal stem borers requires further studies. Importance of the wild host plants as well as borer diversity along the altitudinal gradient is discussed.     

Predicting the Impact of Temperature Change on the Future Distribution of Maize Stem Borers and Their Natural Enemies along East African Mountain Gradients Using Phenology Models

Lepidopteran stem borers are among the most important pests of maize in East Africa. The objective of the present study was to predict the impact of temperature change on the distribution and abundance of the crambid Chilo partellus, the noctuid Busseola fusca, and their larval parasitoids Cotesia flavipes and Cotesia sesamiae at local scale along Kilimanjaro and Taita Hills gradients in Tanzania and Kenya, respectively. Temperature-dependent phenology models of pests and parasitoids were used in a geographic information system for mapping. The three risk indices namely establishment, generation, and activity indices were computed using current temperature data record from local weather stations and future (i.e., 2055) climatic condition based on downscaled climate change data from the AFRICLIM database. The calculations were carried out using index interpolator, a sub-module of the Insect Life Cycle Modeling (ILCYM) software. Thin plate algorithm was used for interpolation of the indices. Our study confirmed that temperature was a key factor explaining the distribution of stem borers and their natural enemies but other climatic factors and factors related to the top-down regulation of pests by parasitoids (host-parasitoid synchrony) also played a role. Results based on temperature only indicated a worsening of stem borer impact on maize production along the two East African mountain gradients studied. This was attributed to three main changes occurring simultaneously: (1) range expansion of the lowland species C. partellus in areas above 1200 m.a.s.l.; (2) increase of the number of pest generations across all altitudes, thus by 2055 damage by both pests will increase in the most productive maize zones of both transects; (3) disruption of the geographical distribution of pests and their larval parasitoids will cause an improvement of biological control at altitude below 1200 m.a.s.l. and a deterioration above 1200 m.a.s.l. The predicted increase in pest activity will significantly increase maize yield losses in all agro-ecological zones across both transects but to a much greater extent in lower areas.     

Species diversity of lepidopteran stem borer parasitoids in cultivated and natural habitats in Kenya

Field surveys were conducted during 2005 to 2007 to assess the species diversity of stem borer parasitoids in cultivated and natural habitats in four agroecological zones in Kenya. In total, 33 parasitoid species were recovered, of which 18 parasitized six stem borer species feeding on cereal crops, while 27 parasitized 21 stem borer species feeding on 19 wild host plant species. The most common parasitoids in cultivated habitats were Cotesia flavipes Cameron, Cotesia sesamiae (Cameron), Pediobius furvus Gahan and the tachinid Siphona sp., whereas in natural habitats, Siphona sp. was the most common. The majority of parasitoids were stenophagous species; only five species –Cotesia sp., Enicospilus ruscus Gauld and Mitchell, Pristomerus nr. bullis, Sturmiopsis parasitica (Curran) and Syzeuctus ruberrimus Benoit – were monophagous. In both cultivated and natural habitats, parasitoid species diversity was highest on the most dominant stem borers Busseola spp. and Chilo spp. On cereal crops, parasitoid diversity was highest on maize and among wild host plants, it was highest on Setaria spp. The ingress‐and‐sting attack method was the most common strategy used by parasitoids in both habitats. In all agroecological zones, parasitoid species diversity was significantly higher in natural than in cultivated habitats. Furthermore, the majority of parasitoid species were common to both cultivated and natural habitats. It was concluded that natural habitats surrounding cereal crops serve as refugia for sustaining the diversity of stem borer parasitoids from adjacent cereal fields.     

Stem borer infestation of cereal crops in Jere,the Sudan-Sahelian savanna region of Nigeria

Field data collected during the rainy season of two years, 2010 and 2011, were used to determine the per cent plant infestation and stem borer abundance on cultivated cereal crops grown by farmers' in Jere or the Sudan-Sahelian savanna ecological region of Nigeria. Stem borers were recovered using destructive sampling. Mean total per cent plant infestation and stem borer abundance per farmers' field were significantly higher on millet (40% and 25 individuals, respectively) and sorghum (30% and 21 individuals, respectively) than on maize (19% and 13 individuals, respectively). Of the five stem borer species found in this study, Coniesta ignefusalis (Lepidoptera: Pyralidae) (3.5)/Chilo sp. nr. aleniellus (Lepidoptera: Crambidae) (2), Busseola fusca (Lepidoptera: Noctuidae) (3.1)/Sesamia calamistis (Lepidoptera: Noctuidae) (2.4) and S. calamistis (2.9), with significantly higher number of individuals per plant, tended to be more important pests on millet, sorghum and maize crops, respectively. Although, mean total per cent plant infestation and abundance of stem borers in this study were generally moderate, further studies on the effects of different types of cereals intercropping (locally practiced) on stem borer infestation and abundance should ascertain the true importance of these pest species in the Sudan-Sahelian savanna ecological region of Nigeria.     

Species diversity and distribution of lepidopteran stem borers in South Africa and Mozambique

Country‐wide surveys of lepidopteran stem borers in wild host plants were undertaken between 2006 and 2009 in South Africa and 2005 and 2010 in Mozambique. A total of 4438 larvae were collected from 65 wild host plants in South Africa and 1920 larvae from 30 wild host plants in Mozambique. In South Africa and Mozambique, 50 and 39 stem borer species were recovered, respectively, with four new species and two new genera among noctuids. Less than 5% of the total number of species collected are considered to be economically important in Africa. These species were Busseola fusca (Fuller) (Noctuidae), Chilo partellus (Swinhoe) (Crambidae) and Sesamia calamistis Hampson (Noctuidae). Data from this study and others in East Africa on the very low abundance of stem borers in wild host plants question the putative role of wild host plants as reservoir for stem borer pests. One new host plant family (Prioniaceae), as well as 24 and 13 wild hosts from South Africa and Mozambique respectively, was added to the list of known hosts in Africa.     

Habitat functionality for the ecosystem service of pest control: reproduction and feeding sites of pests and natural enemies

• 1 Landscape management for enhanced natural pest control requires knowledge of the ecological function of the habitats present in the landscape mosaic. However, little is known about which habitat types in agricultural landscapes function as reproduction habitats for arthropod pests and predators during different times of the year.
• 2 We studied the arthropod assemblage on six crops and on the seven most abundant native plant species in two landscapes over 1 year in Australia. Densities of immature and adult stages of pests and their predators were assessed using beat sheet sampling.
• 3 The native plants supported a significantly different arthropod assemblage than crops. Native plants had higher predator densities than crops over the course of the year, whereas crops supported higher pest densities than the native plants in two out of four seasonal sampling periods. Crops had higher densities of immature stages of pests than native plants in three of four seasonal sampling periods, implying that crops are more strongly associated with pest reproduction than native plants. Densities of immature predators, excluding spiders, were not different between native plants and crops. Spiders were, however, generally abundant and densities were higher on native plants than on crops but, because some species disperse when immature, there is less certainty in identifying their reproduction habitat.
• 4 Because the predator to pest ratio on native plant species showed little variation, and spatial variation in arthropod assemblages was limited, the predator support function of native vegetation may be a general phenomenon. Incentives that maintain and restore native remnant vegetation can increase the predator to pest ratio at the landscape scale, which could enhance pest suppression in crops.

     

Distribution,pest status and agro-climatic preferences of lepidopteran stem borers of maize in Kenya

Lepidopterous stem borers are the main field insect pests that attack maize, Zea mays L. in tropical Africa. A survey was carried during the long and short rain cropping seasons of 2002 / 2003 across six main agro-climatic zones (ACZs) to determine the spatial distribution of important stem borer species in Kenya. A total of 474 visits were made in the seventy-eight localities conveniently chosen to represent each of the six ACZs. 189,600 stems were checked for infestation, of which 27,799 infested stems were destructively cut and dissected for stem borer larvae identification. An average of 1.4 stem borer larvae were recovered per infested plant. 54.5% of the recovered larvae were identified as Chilo partellus (Swinhoe) (Crambidae), 39.7% as Busseola fusca (Fuller) (Noctuidae), 4.5% as Sesamia calamistis Hampson (Noctuidae) and 0.8% as Chilo orichalcociliellus (Strand) (Crambidae). Minor species present included Eldana saccharina Walker (Pyralidae), Sesamia nonagrioides (Lefebvre) (Noctuidae), Sesamia cretica Lederer (Noctuidae), Sesamia sp. (Noctuidae), Sciomesa piscator Fletcher (Noctuidae), Busseola sp near phaia (Noctuidae), Chilo sp, Ematheudes sp 1 (Pyralidae) and Ematheudes sp 2 (Pyralidae). Farms were grouped into respective ACZs for statistical analysis and subsequent comparison of dominant species. Results indicated that B. fusca was the dominant stem borer species in high potential zones (highland tropics, moist transitional zone and moist midaltitude) while the exotic C. partellus dominated smallholder farms in low potential zones (dry midaltitude, dry transional and lowland tropical zone). Within each ACZs, there was evidence of variation in species proportions between seasons. These spatio-temporal differences in community structure are discussed in terms of agro-climatic biological adaptations.     

Lepidopteran cereal stemborers and associated natural enemies on maize and wild grass hosts in Cameroon

Abstract:  In Cameroon, the noctuid Busseola fusca is the most important pest of maize. The braconid Cotesia sesamiae , which is the most common larval parasitoid of noctuid stemborers in eastern Africa, was absent on B. fusca attacking maize. Thus, it is planned to introduce several strains of the parasitoid from Kenya. Pre-release surveys were undertaken in major maize growing areas to catalogue stemborer species, and larval and pupal parasitoids on maize and four wild host plant species. On maize, B. fusca was the predominant borer in all ecozones except for the lowland coastal forest, usually accounting for 60–99%, followed by the pyralid Eldana saccharina in the forest zone and the crambid Chilo sp. in the mid-altitudes. Contrary to what was reported before, the noctuid Poeonoma serrata – and not B. fusca – was the predominant borer on elephant grass, constituting 70–96% of all borers. On wild sorghum in the forest zone, the noctuid Sesamia poephaga was the most abundant species, while on Panicum sp., Chilo sp. predominated. On Setaria megaphylla in the forest zone, Chilo sp. was the most abundant species followed by Busseola quadrata . Busseola fusca was scarce on all wild grass species, indicating that previous reports on the predominance of this pest species on wild host plants were the result of misidentifications. Three tachinid and 16 hymenopteran parasitoids were obtained, most of them from B. fusca and P. serrata , on maize and Pennisetum purpureum respectively. C. sesamiae was scarce and never recovered from B. fusca on maize. In view of the new findings, acceptability and suitability studies involving the different stemborer species identified from wild plant hosts are required to determine if they will form a reproductive sink or perennate C. sesamiae populations during the off-season when maize is scarce and B. fusca is diapausing.     

Distribution,relative importance,and agro-climatic preferences of cereal stem borers in Eastern Ethiopia

Abstract

The distribution and relative importance of lepidopteran stem borers attacking maize and sorghum were investigated in farmers’ fields during the main cropping seasons of 2015 and 2016 across three main agro-climatic zones (ACZs) of eastern Ethiopia. Three stem borer species, namely Busseola fusca Fuller, Chilo partellus Swinhoe and Sesamia calamistis Hampson were found attacking these crops with different levels of distribution and abundance among ACZs. Busseola fusca was the only borer species in the highlands and dominant (67%) in the midhighland zones, while C. partellus was predominant (75%) in the lowlands. The abundance of S. calamistis was low across its distribution range. Across both years, mean plant infestation by B. fusca ranged from 20.38 in lowlands to 42.97% in highlands. Chilo partellus resulted in a mean infestation of 27.38% in the midaltitude to 68.24% in lowlands. Mean density of larvae per plant was higher for C. partellus (2.85), followed by B. fusca (1.41) and S. calamistis (0.46). Moreover, within each ACZs, variation in plant damage variables was observed between the study periods. These spatio-temporal differences in community structures of stem borers are discussed particularly in relation to agro-climatic requirements.     

Bidirectional movement of aphid parasitoids (Braconidae: Aphidiinae) between crops and non-crop plants in agroecosystems of central Argentina

The movement of predators and parasitoids between natural and cultivated habitats is a common process in agroecosystems, which may be affected by different biotic and abiotic factors, mostly related to the availability of resources. Here, through a broad approach, we aimed to obtain an overview of factors affecting the bidirectional movement of aphid parasitoids (Braconidae: Aphidiinae) across cultivated habitats and their natural vegetated borders. Using bidirectional flight traps, we measured the number of parasitoids moving from borders to crops and vice versa, in fields of three common crop species (alfalfa, oat and wheat) in the Pampean region, Santa Fe, Argentina. The effects of the abundance of aphid prey, abundance and richness of flowers in both habitats, as well as temperature and wind speed on parasitoid movement, were assessed through generalized mixed models, considering sampling date and field as random factors. The relationship between parasitism percentages and parasitoid movement from the borders to the crops was explored separately for three pest aphid species: Aphis craccivora Koch, Rhopalosiphum padi (L.) and Schizaphis graminum (Rondani). Overall, we found a prevalence of parasitoids moving in the border-crop direction, mainly in wheat and alfalfa crops. Aphid abundance in the arrival habitat affected parasitoid movement in both directions. A link between parasitoid movement and parasitism percentages was observed for the aphid species S. graminum in wheat, suggesting a beneficial role of natural vegetation in pest control.     

A review of sugarcane stem borers and their natural enemies in Asia and Indian Ocean Islands: an Australian perspective

This paper provides a review on lepidopteran stem borer pests of graminaceous crops in Asia and Indian Ocean Islands which have the potential to invade Australia. Information on the geographical distribution, host plants and potential of invading Australia is provided for 36 stem borer species. A literature review of all natural enemies of 18 key pest species is provided. A knowledge of possible biological control options is essential to determine which natural enemies are to be considered for introduction following an incursion. The Braconid, Cotesia flavipes Cameron (Hymenoptera: Braconidae), stands out as a promising candidate for introduction into Australia following a borer incursion. Studies are currently being conducted on a native Cotesia species in Australia, which may be able to parasitize larvae of exotic borers, therefore minimizing the need for other parasitoids introductions.     

Effect of cropping systems on cereal stemborers in the cool‐wet and semi‐arid ecozones of the Amhara region of Ethiopia

1 Field experiments were conducted on maize and sorghum at three locations in the Amhara state of Ethiopia to determine the effects of mixed cropping on stemborer infestation, borer natural enemies and grain yields. In the cool‐wet ecozone of western Amhara, sole maize was compared with maize intercropped with faba bean, mustard, potatoes and cowpea. In the semi‐arid ecozone of eastern Amhara, the trial was conducted on both maize and sorghum with the companion crops haricot bean, sesame, cowpea and sweet potatoes. 2 The results showed that the predominant borer species in western and eastern Amhara were, respectively, Busseola fusca and Chilo partellus. In Addis Zemen, western Amhara, maize intercropped with mustard and potatoes had significantly lower pest numbers and percent tunnelling than other intercrops and the maize monocrop during the vegetative stage. In eastern Amhara, the cropping system did not significantly affect pest densities but damage to stem, ear or heads tended to be greatest when cereals were intercropped with sweet potatoes. 3 Parasitism of C. partellus by the braconid Cotesia flavipes was greater on maize than sorghum, and on maize it was greater with sweet potatoes than in other intercrops or sole maize. Cocoon mass number per plant did not vary significantly between treatments. 4 There were significant differences between treatments in yields of both sorghum and maize (per plant and per unit area) with the lowest yields observed when they were intercropped with a tuber crop. 5 The results suggest that simultaneous planting of the crop species selected has little advantage over monocropped maize.     

Characterization of eight microsatellite loci in the maize stalk borer Busseola fusca Fuller, 1901 (Lepidoptera: Noctuidae)

The noctuid stem borer Busseola fusca occurs throughout sub‐Saharan Africa, where it is considered as a major pest of corn and sorghum. To understand B. fusca phylogeography, we isolated and characterized eight microsatellite loci in this species. We investigated these loci for polymorphism on a subset sample of individuals from different geographic populations. All loci were polymorphic, showing between four and 10 alleles. Cross‐species amplification of four of these loci was tested on 11 other noctuid species.     

我国稻螟灾害的现状及损失估计

我国稻螟为害的确切记载始于 1 0 2 2年。 2 0世纪 5 0年代中期以前 ,以二化螟Chilosuppressalis(Walker)为害为主。此后十几年中 ,三化螟Tryporyzaincertulas(Walker)普遍大发生。 70年代 ,我国螟害轻微。 1 993年 ,二化螟急剧回升 ,三化螟也随之回升。 1 996年 2种稻螟大发生 ,此后连年暴发成灾。目前我国螟灾的主要特点是虫口密度高、受害范围广、受害程度重、持续时间长、经济损失大。首要螟灾区是沿江稻区 ,二化螟和三化螟分别约占 2 3和 1 3。全国年发面积约 1 5 0 0万hm2 ,防治约 3 80 0万hm2 次。该文首次估计年防治代价约 45 7～ 60亿元 ,残虫造成作物损失近 65亿元 ,总经济损失约 1 1 5亿元。由此可见 ,当前稻螟已取代稻飞虱、棉铃虫成为影响我国国计民生的头号害虫。     

Species richness and parasitism in an assemblage of parasitoids attacking maize stem borers in coastal Kenya

Abstract. 1. Parasitoids were reared from four species of lepidopteran stem borer collected in maize in southern coastal Kenya from 1992 to 1999. The stem borers included three native species, Sesamia calamistis Hampson, Busseola fusca Fuller, and Chilo orichalcociliellus (Strand), and one exotic borer, Chilo partellus (Swinhoe). A total of 174 663 caterpillars was collected, of which 12 645 were parasitised.
2. Twenty-six primary parasitoid species were reared from the exotic borer, C. partellus , indicating a rapid accumulation of native parasitoids on the alien borer.
3. The three most abundant parasitoids were the larval parasitoids Cotesia sesamiae Cameron, Cotesia flavipes (Cameron), and the pupal parasitoid Pediobius furvus Gahan. The pupal parasitoid Dentichasmias busseolae Heinrich and the larval parasitoid Goniozus indicus Ashmead were also common. All used an ingress-and-sting method of attack.
4. Cotesia flavipes , introduced into Kenya in 1993, was found in all seasons from 1997 onwards, and has become the most abundant stem borer larval parasitoid in the area. A native congener, Cotesia sesamiae , appeared in all seasons from 1992 to 1999. Together, these two parasitoids accounted for 83.3% of the parasitised borers.
5. Thirty parasitoid species were recovered in Kilifi district, 27 in Kwale, and 15 in Taita Taveta. Parasitism was much greater in Taita Taveta district than in Kilifi or Kwale districts.     

Landscape-scale forest cover increases the abundance of Drosophila suzukii and parasitoid wasps

Agricultural landscapes rich in natural and semi-natural habitats promote biodiversity and important ecosystem services for crops such as pest control. However, semi-natural habitats may fail to deliver these services if agricultural pests are disconnected from the available pool of natural enemies, as may be the case with invasive species. This study aimed to provide insights into the relationship between landscape complexity and the abundance of the recently established invasive pest species Drosophila suzukii and a group of natural enemies (parasitoid wasps), which contain species that parasitize D. suzukii in native and invaded ecosystems. The importance of landscape complexity was examined at two spatial scales. At the field scale, the response to introduction of wildflower strips was analysed, while the relationship with forest cover was assessed at the landscape scale. Half of the surveys were done next to blueberry crops (Vaccinium corymbosum), the other half was done in landscapes without fruit crops to examine effects of D. suzukii host presence. As expected, the number of observed parasitoid wasps increased with amount of forest surrounding the blueberry fields, but the number of D. suzukii individuals likewise increased with forest cover. Establishment of wildflower strips did not significantly affect the abundance of D. suzukii or parasitoid wasps and insect phenology was similar in landscapes with and without blueberry crops. This suggests that D. suzukii is enhanced by landscape complexity and is largely unlinked from the species group that, in its native range, hosts key natural enemies. Although management practices that rely on enhancing natural enemies through habitat manipulations can contribute to the long-term stability of agroecosystems and to control agricultural pests, other control measures may still be necessary in the short term to counteract the benefits obtained by D. suzukii from natural habitats.